I subscribe to many Substack accounts. I have found many outstanding writers, too many to mention here, who contribute excellent and important work on key events of the day. So, this past week, when two seemingly unrelated events dominated the headlines, two of my favorite writers, Bill McKibben and Paul Krugman, addressed each of them in ways that resonate very strongly with me.

One event is the horrific flash flood created by a collapsing glacier in the Himalayan mountains, resulting in a100-km long deadly catastrophic rush of ice, water and mud down a river along the Nepal-Tibet border. As of this writing over one thousand one hundred souls are known to have lost their lives, and thousands more are still missing. Although it is much too early to establish whether, or to what extent, climate change contributed to the glacier’s collapse, scientists have, for years, warned of climate change accelerating glacial melting, which can have complex and potentially devastating impacts on the downstream rivers fed by these glaciers.

These floods could be just the start of further disasters in the region in the coming days. Additional glaciers and artificial dams appear to be on the verge of collapse.

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Even as rescue efforts were initiated, another event, with potentially major climate as well as economic and geopolitical consequences, occurred halfway around the world. This was the signing of a deal, announced by Trump on his social media platform, that gives the US “majority control” over 65 billion barrels of Venezuela’s oil reserves. Venezuela is believed to have the largest reserves in the world, although the quality of the crude may make much of it unsuitable, or, in any case, very costly, to refine. And this is only if the refining capacity were available anyway...the world’s existing refineries are already at or near capacity. The deal means that now the U.S. has control of over 1/5 of Venezuela’s sticky stuff, although the details of the deal remain murky, and so far, willing investors appear to be non-existent.

So, what is the connection between these two headline stories? Bill McKibben, in his August 30 Substack post, described the connection very succinctly. Given the evidence that the Nepal-Tibet floods could possibly be attributed, at least in part, to global warming, one would expect the more developed and high carbon emitting countries to respond by addressing the dangers of global warming much more aggressively. But instead, and with some sick irony, the U.S., currently the world’s second biggest carbon emitter, signed a deal that could for sure result in substantial worsening of human-caused global warming impacts, even if only parts of the deal came to fruition. As McKibben notes, a Nepali’s carbon footprint is a mere fraction of an American’s, and Nepal’s power system is 99% comprised of hydroelectricity, free of virtually any carbon emissions. In other words, the region is suffering a devastating calamity that was possibly human-caused and not of their doing.

Also, importantly, McKibben highlights the U.S./Venezuela oil deal as a new example of a long-term criticism of America’s historic imperialistic behavior, especially to gain access to natural resources in foreign countries that go to support America’s lifestyle and its own corporate interests. In McKibben’s words:

In short: in a world beginning to turn away from oil, the United States has become the biggest force trying to insure we keep pouring carbon into the atmosphere. If the rest of that ice is going to fall off that Nepali glacier, this will be why.

Enter Nobel prize-winning Paul Krugman, who addresses America’s imperialistic past, and now, perhaps, its renewal, in his September 1 post. He writes about the legacy of an ugly reputation the U.S. has had in Latin America with respect to support of dictators, often with the aid of our military, for purposes of securing the country’s natural resources for the benefit of U.S corporations. In recent years this reputation has been replaced by somewhat more enlightened governance and behavior on the part of the U.S.

Until Trump 2, that is.

Here is Paul Krugman’s take on Trump’s latest imperialist actions:

The fact is that old-fashioned, extractive imperialism doesn’t pay. In fact, it hasn’t paid for well over a century. In the modern world nations grow rich through innovation and productivity, not conquest. In 1909 Norman Angell’s book The Great Illusion argued that even victorious wars cost far more than they can possibly yield in tribute, documenting his case with what was already extensive historical evidence. His argument has even more force now.

Back in January I had written about Trump ordering his military to kidnap Venezuela’s dictator Nicolás Maduro and his wife and escort them to the U.S. so Maduro could face criminal charges related to narco-terrorism. I suspect that many Venezuelan’s now feel disillusioned over Trump’s earlier motivations for this action. Because of Maduro’s ineptitude and atrocious human rights violations, the country has been experiencing a severe economic crisis, personal hardships, and massive out-migration. Maduro’s unpopularity has grown substantially during his presidencies. It is widely believed he lost his third re-election bid, perhaps by a landslide, to Edmundo González back in July 2024, but found ways to rig the voting system and remain in power. Upon his capture this past January most Venezuelans perhaps hoped and believed the Trump administration would then make arrangements to reinstate González, or to elevate another popular candidate, Mario Corina Machado, who had been disqualified to run against Maduro in the 2024 election, to the Venezuelan presidency. Instead, he allowed Darcy Rodriguez, Maduro’s Vice President, to remain as “Interim President” a title which she holds to this day. And she has apparently signed off on Trump’s oil deal. So, the governmental reforms for which the Venezuelans held out so much hope have not come to fruition. The extremely unpopular government remains in power, and the country is beholden to the U.S. for managing their oil reserves. Old fashioned imperialism is back in play.

Of course, it is much too early to determine if the Venezuelan oil deal is indeed “THE BIGGEST OIL DEAL IN WORLD HISTORY!”, as Trump proclaimed on his social media platform. And, as cautioned by climate scientist Dr. Zeke Hausfather in his Climate Brink substack, the tragic floods in Nepal have yet to be clearly attributed to climate change. There is plenty of circumstantial evidence, including summertime warming of 0.29 ⁰C/decade since 1940 in the region, and four out of five of the most recent summers ranking among the warmest on record. But clearly establishing whether climate change can be attributed to the ice-rock avalanche could take months, and even years, of dedicated research. Even then, uncertainties will likely remain.

We do know that burning oil does contribute to global warming, and global warming does cause glaciers to melt, which releases a lot of water in a short period of time with potentially fatal consequences.

In this case, for sure, oil and water do not mix.

I had intended to write more about how our off-grid solar cabin is performing this summer, but I felt it was urgent and important to focus on these events as well.

August continued the trend for this being the warmest summer since we purchased the land six years ago, although 2021 and 2024 are not far behind. September begins a new meteorological “season”; the summer meteorological season, June through August, is now behind us. Here is a profile of “summer season” average temperatures at our property:

But the weather patterns shifted recently, perhaps in part to the strengthening El Niño. Moisture moving up from the Pacific and Gulf of California has given us some relief in the ongoing drought.

Meanwhile fall is beckoning. There are still a few hummingbirds visiting our feeder as they build up energy supplies for their long migration southwards, although there are no longer five birds competing for the four feeding holes in the feeder. Moose have been around recently grazing on whatever they can find, drinking from a water puddle that formed on our patio after a rain (see below), and preparing for the winter to come. Late summer wildflowers, such as mountain asters and Shasta daisies, are in full bloom. The days remain warm, although with frequent showers, but the nights are definitely cooler. We will be seeing more signs of fall in the coming weeks, regardless of what influence El Niño may have.

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This past Sunday, August 23, Charlotte Howard, the U.S. editor of The Economist magazine, wrote in the “Checks and Balances” column about President Donald Trump’s losing bet on oil (I apologize if this article is only available behind a paywall). She notes how one of Trump’s early policy initiatives in the campaign for his second term was “energy dominance”. In his mind, energy dominance is achieved by an all-out assault on the earth’s fragile mantle to extract every last ounce of fossil energy.

Ms. Howard eloquently writes:

Mr Trump’s worldview was shaped by the oil shocks of the 1970s; his choice of the word “dominance” was always revealing, suggesting that he wanted America to wield power in the manner of a petrostate. But the main problem with Mr Trump’s energy strategy was not his desire to dominate, but that his vision of energy power was so narrow. He bet then, as he does now, that dominance comes exclusively from drilling oil and gas. It is a gamble grounded in a 20th-century view of geopolitics. And it is a gamble that the war in Iran has proved wrong.

She goes on to note, quite accurately, that while Trump is pushing the U.S. into the direction of a “petrostate”, China is seeking to become an “electrostate”. Trump’s narrow view of energy excludes any role for renewable energy, especially wind and solar technologies, while China is firmly embracing these technologies as it strives to electrify all aspects of its end use energy needs while simultaneously mitigating global climate change.

I wrote about this a few months back. Trump’s intentions have not deviated; all evidence points to his doubling down on a backwards transition to a 20^th-century type fossil driven economy, while China and much of the rest of the world are embracing a new, 21^st century energy transformation.

I put transition and transformation in italics for a simple reason: a renewables-based economy is more than just a transition. A transition merely takes us to a different level of a state in which we already exist which, in Trump’s case, is a continued and more aggressive expansion of fossil energy use. An energy transformation, however, gives a dramatically new paradigm for how we produce and consume energy. This paradigm includes features on the supply side such as a more distributed electricity supply system where consumers can also be prosumers, with freedom of choice in choosing where the electricity we use comes from, and with energy access for all. A transformed energy supply system is dominated by renewables, including variable renewable energy sources such as wind and solar, and with battery and long duration energy storage systems to secure firm twenty four hours a day, seven days a week (24/7) power. Large-scale baseload power stations, feeding high-voltage electricity into long-distance transmission lines to serve large numbers of distant customers are replaced by numerous distributed sources of clean, renewable energy where rooftop solar allows consumers to also become producers. The solar and wind energy resource that feeds this system is free, locally sourced, and accessible to all. No need to rely on imported fossil fuel sources. This transformed energy supply is much cleaner than one relying on fossil fuels, providing the added benefits of improved air and water quality, and lower greenhouse gas emissions.

On the demand side the energy transformation sees electricity as the predominant end use source, displacing the dependence on fossils in our transport and our building heating requirements. A new infrastructure emerges to support electric vehicles and heat pump heating and cooling systems.

The transformation is not without its challenges. Significant grid enhancements are required to manage a more distributed system and to match loads with variable energy sources when baseload plants are no longer dominant. To address climate change, some “hard-to-abate” manufacturing processes such as steel and cement are not readily amenable to a rapid switch to renewable energy supply.

Nevertheless, an energy transformation consistent with this paradigm is underway around most of the world. One of the primary challenges has been to convert variable renewable energy sources to reliable, firm, 24/7 dispatchable sources. And here substantial progress is being made, thanks, at least in large part, to advances in storage battery technology.

In a study released two weeks ago Ember, a global energy think tank, reported that in the first half of 2026 solar has provided roughly 10% of the world’s electricity requirements. Until recently, however most of this energy was injected into the grid only in midday, due to the lack of energy storage on the grid that could store excess daytime solar. Furthermore, since certain plants, such as coal-fired plants, cannot totally “shut down” during daytime, they must continue to operate even if at reduced levels. This means that as more and more solar comes on to the grid, its daytime contribution to the load can actually exceed what is already available from coal-fired facilities. As solar penetrations grow, the danger of having to curtail some of their output grows, which is a big cost to investors.

While solar can displace a number of fossil plants during daylight hours, without storage systems these fossil plants must ramp back up rapidly in the evening.

But this limitation is rapidly changing, thanks to the emergence of large-scale lithium-ion-phosphate battery storage technologies, adding significant value to the solar plants even during nighttime hours. Battery storage costs have dropped by 95% over the last fifteen years, from $2634/kWh in 2010 to $140/kWh in 2025. As Ember shows, enough battery storage is being installed in 2026 to allow for as much as 34% of the generation from new solar capacity to be shifted to the early evening hours. Not only does this stored energy delay the need to ramp up fossil facilities during evening hours it reduces the amount of solar curtailment during daytime, since excess solar can now be diverted to battery storage.

Unfortunately, our own U.S. Secretary of Energy sees his role as one supporting the old-fashioned backward looking “petrostate” paradigm of energy dominance (see the post I wrote two weeks ago, the same day Ember published its article). He often feels he must remind the country that the sun sets at night, and therefore solar has no use on the grid. Of course he should know better. The Ember study is just one of many showing that he may be correct about sunsets but is wrong about solar energy being available only in the daytime. And in most cases solar plus storage on the grid is less expensive, and can be deployed far more quickly, than new fossil (and for sure nuclear) energy systems.

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In our own off-grid solar powered cabin in the Colorado Rockies I have been tracking how much of the 24-hour household loads are met directly by the solar photovoltaic (PV) system (capacity = 7.3 kW) and how much is met by battery storage (capacity = 32 kW) when PV output is insufficient or non-existent for meeting loads. The way our Sol-Ark™ inverter functions, PV is given priority to meet loads. If PV exceeds loads, the excess is diverted to battery storage. When PV is insufficient to meet loads the batteries make up the difference. When battery storage is at 100%, excess PV (beyond that required to meet loads) is simply “curtailed”, or, unfortunately, wasted.

Below are the results for the most recent twelve months, as well as a chart showing the monthly total loads.

As one would expect, batteries supply more than 50% of the household power on those months when there are fewer daylight hours. What is noteworthy is that, even for those months that have longer daylight hours batteries still supply 40% or more of the household demand, especially when loads are high.

These charts do not show the amount of PV that is curtailed on sunny days, when the batteries are already full and there is nowhere to consume the PV output. I am still searching ways to calculate curtailment values. But given our current load profile, it is possible I have significantly oversized the PV system size, although loads are currently lower than what would be the case if we occupied the house full time.

The key message here is that the batteries ensure we have reliable power every hour of the day, virtually every day of the year. Only once since January 2025 did we have a weather-induced power outage; for 32 hours on April 20-21, 2026. This outage was caused by prolonged snow cover on the panels, which resulted in the batteries draining down to the point where they automatically shut off power to the house.

For us, the solar plus battery storage system has been a transformation. We have a fully functional modern home that we could never have built if we had to undertake a costly and disruptive process of connecting to the electrical grid.

I close here with an image of a bull moose exploring our property this past Sunday.

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For all my life I have had a passion for following, and tracking, the weather. Since junior high school I would record the daily weather, including daily high and low temperatures, provided I was able to find a good place to install the equipment where I lived.

This habit is still with me. After moving to Boulder in 1991 I installed a Davis™ weather station at home. Within weeks of purchasing the mountain property on which we have built our off-grid solar powered home I installed another Davis™ weather station at the site. As of this past weekend I now have six continuous years of measurements from our mountain property.

For sure six years does not make a climatological record. But my passion these days is on tracking the results of human-caused global warming and evaluating how natural climatic variability influences the well-documented warming trends. One of the goals of the SunBurst Almanac is to offer my personal thoughts and reflections on how these trends and variability impact the ability to maintain an off-grid solar powered home in a high mountain environment in the Colorado Rockies. Another goal is to reflect on how these trends and variability impact human life everywhere. A third goal is to demonstrate how transforming our energy system to renewable energy is the most effective way to mitigate climate change.

The latest reporting from Berkeley Earth shows July 2026 to be the warmest July (or for that matter of any month) on record for the contiguous (lower 48) United States, surpassing the previous warmest July which occurred in 2016.

This was certainly the case for the limited six years of measurements I have been collecting at our mountain property:

A prominent cause of natural climate variability, and one that we are hearing much about in the news these days, are El Niño events, which occur every two to seven years. An El Niño is a rather rapid warming of the eastern tropical Pacific Ocean surface temperatures. A “super El Niño” occurs when the warming exceeds 2.5 ⁰C above normal.

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Thanks to coupled air-sea interactions, the ocean temperature anomalies in this region result in changes in weather patterns around the world. The weather shifts can be much more noticeable in some regions than others and, importantly, are not always the same for every event. An El Niño can last roughly a year and typically peaks in intensity in the November-January time frame. In between El Niño events La Niña events can occur, where the eastern tropical Pacific ocean water temperatures drop below their normal values.

The previous El Niño event started in July 2023 and ended in April 2024. This event was followed by a La Niña, which ended early this year. The world is now experiencing a growing El Niño which has already achieved super El Niño status, and could well be on track to be the most severe on record (reliable records extend back to the mid-1800s), as documented in the Washington Post’s “El Niño Tracker”. This El Niño is not expected to peak until another 3 – 5 months.

As scientists track global warming caused by human activities, they find that El Niño events clearly impact global average temperatures due to the additional heat added to the atmosphere by the extra warm ocean waters. Climate scientist Zeke Hausfather, who, along with others, regularly tracks global warming through the Berkeley Earth site as well The Climate Brink and his own substack, has been writing how the current El Niño is on track to be, by far, the strongest ever recorded, and how the warming caused by this natural event can very possibly result in 2026, and very likely 2027, to be the warmest years on record, exceeding the 1.5 ⁰C target that the 2015 Paris Climate Agreement had intended to avoid.

This then raises the question: In the next year or so, will the earth experience the climate anomalies scientists predicted would occur if annual global warming exceeds 1.5 ⁰C above preindustrial levels?

The answer is actually very complicated. Hausfather and his colleagues, and many other scientists, are looking for answers now, particularly with a super El Niño upon us, and with global warming already approaching the 1.5 ⁰C target even without the impact of a super El Niño.

For sure, maintaining a steady power supply in an off-grid solar home requires a combined effort of closely monitoring the weather as well as the household electricity load. Available electricity is dependent on sufficient solar insolation reaching our rooftop panels and charging our storage batteries. Long periods of low insolation, or events such as heavy snowfall, will prevent the solar panels from charging the batteries sufficiently, eventually resulting in an unwanted power failure. So yes, I am very interested in how global warming will influence future weather in Colorado, and how a super El Niño will influence the weather this coming winter.

Hausfather and his colleague Andrew Dessler examine the question of whether the weather patterns resulting from the upcoming super El Niño will mirror the weather patterns predicted once the world has permanently exceeded the 1.5 ⁰C target. Based on estimates derived from the growing strength of the current El Niño they project that global temperatures will reach 1.76 ⁰C above preindustrial levels in 2027. If one were to extrapolate the long term trend line (which removes the year-to-year variability) provided in the latest Berkeley Earth July 2026 update, this level of warming, in the absence of El Niño events, would not be expected to be reached until 2037, as shown in a reproduction of Hausfather’s data provided by the Washington Post:

The authors then developed a spatial pattern of global warming attributed to human-caused climate change:

This figure demonstrates how global warming is occurring virtually everywhere on earth, and especially in the polar regions, but not uniformly. For example, I estimate that global warming in my part of the U.S. is only reached about 1 ⁰C; warming is much higher in the northeast U.S., but lower in Mexico.

The authors then analyzed the impact on spatial temperature distributions during El Niño events, factoring out the influence of human-caused global warming. The results are a bit more complicated. Two analyses are provided: one with no lag associated with the warming ocean, and the other with a six-month lag (there is approximately a five-month lag between when ocean water temperatures peak and when the warmest anomalous air temperatures occur):

Here we see that the influence of El Niños on mean temperatures in the region of the U.S. where Colorado is located are actually quite small. Colorado appears to lie in a region where El Niños generally result in warmer temperatures to the north and cooler temperatures to the south, with only small changes in Colorado itself. Although the weather patterns associated with each El Niño can vary substantially, the figure implies that we will not have unusual temperature changes in the coming year other than what is occurring through human-caused climate change, or other climate variability not necessarily associated with the El Niño.

Precipitation impacts due to global warming and to El Niño events are much more difficult to analyze, and the reader is encouraged to go to the authors’ actual article to untangle the details. Their results do offer some hints.

Here is their analysis of the geospatial change in precipitation associated with global warming:

Generally, there is an increase in global precipitation levels under global warming, although with strong and significant geospatial variations. This is expected since warmer atmospheres are able to hold more water vapor than cooler atmospheres. In the eastern and southeastern U.S precipitation levels are generally on the increase; however, the picture is less clear in the Rocky Mountain region, with a few areas showing essentially no change.

Pattern shifts in precipitation during El Niño events are shown here:

In some regions, particularly in the mid-latitudes and subtropics, precipitation pattern responses to El Niños are similar to the responses associated with global warming. But there are significant differences in other areas, especially in the tropics and polar regions. Colorado appears to be situated in a region where changes in precipitation associated with El Niños are positive, but small. However, precipitation events can be very sensitive to even the slightest changes in weather patterns, so the results here can vary substantially from one El Niño to the next.

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Based on this analysis alone, I do not expect significant temperature anomalies this coming year, although I do expect temperatures to remain somewhat above normal. More critically, the opportunity for higher precipitation levels this coming winter is significant, since precipitating systems in Colorado are often enhanced by increased atmospheric moisture to the south. This could be good news for the ski areas and for the severe western drought we have been experiencing. It also means that the possibility for higher snow cover will require me to be more vigilant against power failures in our mountain home than I needed to be this past year.

But will next year’s weather be a proxy for a future planet that has exceeded the 1.5 ⁰C warming target? In their latest Climate Brink study the authors conclude that while the El Niño-induced 2027 global warming will likely put us at levels that we might expect by 2037 under “El Niño neutral” conditions, this does not mean that 2027 will give us a sense of a future climate associated with global warming, although it will likely be a glimpse of that future. In their own words:

So while the 2027 El Niño may well help us gain some insight into what a hotter planet looks like, we should avoid thinking this is the climate of the future.

I will just have to adapt my load management strategies to the year-to-year trends and variations of our local weather.

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No sooner do I write about having lost our common sense in energy policy decisions, as I did last week, than more non-sensical news feeds clutter my inbox.

It came as no surprise that President Donald J. Trump, as he entered his second term last year, would surround himself with loyal and inexperienced sycophants to do all the bidding he was unable to do in his first term. Every day we are flooded with news of the latest missteps of his Secretary of Defense in executing Trump’s war of choice on Iran, of the fear and cruelty instilled into our immigrant population, some of whom are actual U.S. citizens, under his (two) Secretaries of Homeland Security, of growing national health insecurity under his Secretary of Health and Human Services, and of the all-out efforts to fulfill his retribution vendetta and gut the agency under his (now two) Directors of the Department of Justice. I could continue down the list of all in his orbit who have removed any remaining guardrails that had previously prevented many of Trump’s worst instincts and impulses to materialize during his first term.

But one important topic that sometimes evades the news radar is Trump’s efforts to dismantle the clean energy transformation that was moving so successfully before his second term, a dismantling that is destined to send the country backwards in its energy technology and which is being dutifully enabled by his Secretary of the Interior Doug Burghum and, more important, Secretary of Energy Christopher Wright. Given that fossil fuel use requires substantial environmental protection measures which often get in the way of their expanded use, Lou Zelkin’s shredding of the Environmental Protection Agency further enables the dismantling.

Let’s take a closer look at the Department of Energy (DOE). Chris Wright is the former CEO of Liberty Energy, a hydraulic fracking company, based in Denver, Colorado. His own Wikipedia column states that, as Secretary of Energy, he has overseen “...rollbacks of climate change mitigation policies and promoted fossil fuel use”.

I spent 37 years of my career at two national laboratories...Pacific Northwest National Laboratory (Richland, WA) and then the National Renewable Energy Laboratory (Golden, CO), recently renamed the National Laboratory of the Rockies, where I retired in early 2012. Both labs are funded primarily by DOE and are run by consortia of private companies and university research organizations on behalf of DOE. For sure, DOE policies set by whoever is in charge of the current Administration can influence the work of the labs and their priorities.

For all my years working at these two national laboratories I respected and admired the program managers and office directors at DOE who, regardless of shifting policies across administrations, devoted their careers to overseeing successful programs that would benefit the lives of Americans and everyone around the world with reliable and low cost energy technologies. This oversight came with ensuring that the health and well-being of all citizens would not be compromised by our energy use. And national lab researchers were dedicated to carrying out these programs, motivated by a continuous improvement of the way we produce and use energy. Traditionally the Department avoids the appearance of picking winners and losers but rather focuses on energy innovation, allocating R&D resources where they are most needed. But depending on where one lies on the political spectrum it can be fair game to complain how priorities are set and how resources are allocated based on personal prejudices and interests.

Enter the Trump Administration, where the belief is that fossil fuels, along with nuclear, always have been and always will be the clear and only winner for meeting our growing energy requirements. In this Administration’s view renewables are “fringe” technologies that are expensive and unreliable due to their “intermittency” and can never be successfully incorporated into the grid at scale. Furthermore, since climate change is a “hoax”, there is no need for emission-free energy supplies in the first place, unless, of course, it is nuclear energy.

In reality, although fears of impending budget cuts are always nearby not too much has changed in terms of how financial resources are allocated at the national laboratories so far. My former lab, which had “Renewable” ripped from its name late last year, still continues with its mission of advanced and innovative research on wind, solar, and other renewable technologies, explorations on clean transportation and building technologies, and top-rate analysis of state and local policies and actions.

All too often the rhetoric and policies coming out of DOE’s senior leadership is intended to sway public sentiment away from renewables and towards growing our domestic fossil-fueled energy resources. Chris Wright is in lockstep with the Administration’s frequent criticism of “intermittent” and “costly” renewable energy (especially wind and solar) and an incessant champion of fossil energy as the only reliable way we can meet rapidly rising electricity demand. Furthermore, their arguments against renewables are a way to justify cancelling important grid-hardening programs that make high penetration of renewable energy more feasible.

It is easy to presume that a major driver of this policy shift is the substantial financial support Trump received from the fossil industry in his election campaign. He has cancelled literally hundreds of DOE-funded clean energy projects since coming into office. Typically, the rationale his administration offers for these cancellations is to protect the taxpayer from waste, fraud, and abuse, or that the projects support a radical left wing agenda, or the “Green New Scam”. When it comes to killing solar projects Wright often offers the helpful explanation that the “sun does not shine at night”, apparently unaware that battery storage enables both excess wind and solar to be stored, then to be used during those times when wind and solar resources are unavailable, at costs much lower than new gas turbine generator systems.

These arguments do not hold up to technical scrutiny. The Administration must surely be aware of this. Recently the New York Times reported that the majority of cancelled grants, including those that would serve to strengthen the electricity grid, are, in fact, political retribution against states that voted against him in 2024.

It is, of course, distressing that agency heads feel they need to remind the public (or is it just reminding themselves?) that solar panels can no longer produce power once the sun sets. But Wright does not even stop there; his public statements indicate he knows very little about how grids operate, and as a result dispels dangerous disinformation about solar and wind energy’s imagined flaws. Such disinformation can negatively impact grid security and readiness for years to come, as already shown through examples where solar energy helps to keep grids operational even when they are under extreme stress.

Here is a person in charge of our national energy supply who fails to understand simple renewables plus battery storage logic, forcing the country to revert back to a fossil-dominated energy system from which we have been successfully moving away for the past quarter century. Welcome back to the twentieth century!

The One Big Beautiful Bill (OBBB), the partisan budget bill passed last year that removed most of the clean energy incentives enacted in President Biden’s Inflation Reduction Act (IRA), along with Trumps’s numerous executive actions, have led many to believe that Biden’s clean energy legacy is now dead. And for sure many key provisions are no longer in place, creating strong headwinds for many of the clean energy programs that were started before Trump ascended to office.

But the news is not all bad. Substacker Leah Stokes recently wrote in the Atlantic that many of the IRA programs, some of which went beyond climate mitigation, are still alive and, in a few cases, even well today. As she notes, the centerpiece of the IRA is a massive tax credit to stimulate domestic manufacturing, with an emphasis on clean energy products such as solar panels, batteries, and electric vehicles (EVs). Biden was able to get about $185 Billion in manufacturing investments out the door before his term ended, resulting in hundreds of clean energy investments throughout the country. Many efforts by Trump to claw back money that had been appropriated before the end of Biden’s term have been stopped by the courts, and in a few cases stopped by Republican Senators where the cuts would impact manufacturing facilities stimulated by the IRA in their districts. Ms. Stokes’ research shows that Kamela Harris likely received more votes from districts benefitting from IRA investments than has been assumed up to now. Chris Wright would be wise to keep this in mind when he tries to explain to the masses about what actually does not happen to the grid when the sun sets.

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As I write this at our off-grid solar cabin, the sun set several hours ago. Yet we have abundant and reliable electricity thanks to our solar panels filling up our batteries, providing high quality electricity to our household appliances. Our mountain home is a microcosm of a grid that operates on renewables pus battery storage, providing reliable, firm 24/7 power without the need for large-scale fossil fueled “baseload” plants that Wright so incorrectly assumes are essential for a functional grid.

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Here at our mountain cabin, concerns of losing power due to snow-covered solar panels and high electricity demand due to cold temperatures feel far, far away these mid-summer days. Our biggest challenge is to keep the place cool during yet another “heat dome” event. And smoke from regional wildfires continues to create unusually hazy conditions and daily air quality warnings.

July was our warmest month at the cabin since I started weather measurements six years ago. Both daytime highs and nighttime lows were well above average.

Then on August 2 we had the warmest temperature here since these measurements started…96.3 ⁰F (35.7 ⁰C); far higher than the previous warmest temperature, 92.0 ⁰C (33.3 ⁰C) recorded back on July 12, 2024. And the temperature once again climbed to 92.7 ⁰F (33.7 ⁰C) on August 3.

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Climate Central reports that July temperatures in Denver, about 35 miles (56 km) to the southeast, are 3.9 ⁰F warmer now than they were in 1970. Climate Central has developed a Climate Shift Index which indicates how climate change has influenced daily temperature anomalies for any location around the world. On 25 days in July, Denver had a climate shift index (CSI) of 2 or more, meaning that climate change had a dominant effect on Denver’s temperature anomalies.

Heat dome events are dominating the news this year. In meteorological terms, a heat dome is a strong high pressure system characterized by clear, dry, subsiding air. These high pressure systems can remain virtually motionless for multiple days. When plotted on a weather map these systems are shaped like the Greek letter omega, and are known as “omega blocks”, blocking new weather systems moving in from the west for days at a time.

A possible reason why these omega blocks are occurring more frequently and with stronger impacts is that climate change is slowing down the jet stream. A slower jet stream creates deep undulating long wave weather patterns. The normal eastward drift of weather systems in mid-latitudes slows down, creating conditions more conducive for the formation of omega blocks. Record-breaking and more frequent heat waves, such as what have made the news in western Europe, the western and eastern U.S., and in south Asia and the Middle East, are the result. Furthermore, heavy rainfall patterns often form to the west of these domes, which is why severe flooding is happening in some regions (such as the southern U.S.), while other regions suffer record heat and drought.

Already in 2026 the world is facing its worst wildfire crisis ever, creating untold ecological damage and human tragedy and contributing to ever worsening and dangerous air quality episodes. So far this year the U.S. has seen more acres destroyed by wildfire than all of 2025. The European wildfires are among the worst on record. And the wildfire season is far from being over.

Berkeley Earth released its June temperature report a few weeks ago. Globally it was the second warmest June on record since reliable measurements began back in 1850; second only to June 2024, and slightly warmer than June 2023. No other June prior to 2023 has been as warm as the Junes of these past three years.

This is also the case even if only terrestrial temperatures are considered. And June ocean surface temperatures were the warmest on record.

Although this year still remains cooler than the record warm years of 2023 and 2024, a very strong El Niño event, characterized by abnormal ocean surface temperature warming in the tropical eastern Pacific, has been developing since its counterpart, a La Niña cooling event, ended about six months ago. According to numerous modeling studies summarized by Berkeley Earth this El Niño could become one of the strongest on record, and very possibly strongest. The warmest ocean temperature anomalies associated with an El Niño event occur in the December-January time frame, so we will not know definitively for at least another six months how the current El Niño will rank against historical events. However, this El Niño has already reached “super El Niño” status, based on a +2.1 ⁰C temperature anomaly in the “Niño 3.4 Box” region of the tropical Pacific, and is currently on track to be stronger than either the 2015 or 1997 super El Niños of the recent past.

Since global temperatures have a ~5-month delayed response to El Niño events, the current El Niño could very well cause 2027 to be the warmest year on record globally. Even 2026 could still set the record for warmest global temperatures.

No matter how the rest of this year plays out, it is clear the steady rise in global temperatures since the 1970s is continuing unabated. This trend can be seen in the red line (locally estimated scatterplot smoothing, or LOESS) of the most recent global warming graphic from Berkeley Earth:

The Paris Agreement, signed by 194 parties, was a major outcome of the United Nations Framework Convention for Climate Change (UNFCCC) 21st Conference of the Parties in Paris in 2015. The Agreement calls for limiting global warming to well below 2.0 ⁰C above preindustrial levels (typically assumed to be global temperatures averaged between 1850 – 1900) and to pursue efforts to limit warming to no more than 1.5 ⁰C.

The Berkely Earth graphic, above, provides evidence that global temperatures are on track to exceed the “Paris commitment” of 1.5 ⁰C within the next few years.

The Paris Agreement required all countries to develop “Nationally Determined Contributions” (NDCs) which represent their pledges for reducing greenhouse gas emissions. These pledges are to be updated every ten years, based on current economic and policy developments. According to Climate Action Tracker, the pledged NDCs so far are insufficient to achieve the 1.5 ⁰C target by the end of this century. Even their most optimistic scenarios just a few years ago showed that global warming will most likely reach 1.9 ⁰C. But now, based on current global policies, they are projecting that global warming could likely reach 2.6 ⁰C.

The Trump Administration’s energy and climate policies strongly contribute to this more pessimistic outcome, not only by withdrawing from the Paris Agreement entirely (twice), but also for aggressive pro-fossil policy actions, especially in his second term. As I have been documenting in previous SunBursts, Trump is actively dismantling clean energy and energy efficiency programs, including electric vehicle incentives, to favor the fossil industry in every possible way.

Trump had the full support of the fossil industry to get him elected in his second term, and he is making every effort to reward them for his succession to the highest office in the country. He and his cabinet have no concerns over the climate change and environmental impacts that we are already seeing from global warming, not to mention rising energy costs.

His policies certainly do not make any sense for an Administration that promised to reduce the country’s inflation rates and to lower energy costs, making our lives more “affordable”. The non-profit, non-partisan policy and technology think tank “Energy Innovation” just published a report showing that to meet the extraordinary electricity demand growth in the U.S. through 2030, a fossil-heavy approach will actually cost customers nearly $30 billion more than if the country took full advantage of clean energy to meet growing electricity use. They use Texas as an example, where the demand for new electricity supply is higher than any other state in the country. Texas, a deeply Republican state, has nevertheless added 28 GW of solar, 15 GW of utility-scale batteries, and 15 GW of wind, compared to only 4 GW of natural gas turbines to their grid. Texas shows that when energy markets operate freely with limited regulations, clean energy is the clear winner over fossil energy.

Heat pumps produce the same output as traditional heating systems using 3-5 times less energy input as those traditional systems. The heat pump we installed heats our 1350 ft² two-story cabin adequately, even on very cold days, using no more than 2800 watts of input power, and cools the cabin with little more than 1000 watts of input power. Our electric vehicle converts 85% of its stored electricity into motion, compared to only 20 – 30% conversion to motion from vehicles running on gasoline or diesel. These efficiencies save consumers money, and improve the environment we all live in.

It makes no sense, then, for government policies to deny these savings opportunities and contribute further to our environmental destruction and negative health impacts. It is way past time to restore our government to one that supports the health and well-being of the population it is serving, rather than the energy industries that keep us stuck in the last century.

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In the process of moving some old books from our Boulder home to our mountain cabin I uncovered my paperback copy of James E. Lovelock’s groundbreaking work: “GAIA: A New Look at Life on Earth”. Published by Oxford University Press in 1979, the book is a mere 150 pages, but can be a dense, if not intriguing, read that introduces his Gaia Hypothesis.

Originally the book had piqued my own curiosity about the natural sciences and the way humans impact nature’s natural order. I decided to have another look at the hypothesis he presented and see how I would react to his arguments now.

In Lovelock’s own words, the Gaia Hypothesis represents a

...model, in which the Earth’s living matter, air, oceans, and land surface form a complex system which can be seen as a single organism [emphasis mine] and which has the capacity to keep our planet a fit place for life.

The idea had come to him in the early 1960s, when he visited NASA’s Jet Propulsion Laboratory as part of a team to detect life on Mars and other planets. NASA had just begun the Voyager Mars Program. Based on knowledge regarding Mars’ tenuous atmosphere following the Mariner 4 mission in 1965, NASA made plans to eventually launch both an orbiter and a lander to Mars on the same Saturn 5 rocket. However, the high costs of the program forced its funding to be terminated in 1968, and the entire program was cancelled in 1971.

Lovelock had a significant opportunity to formulate his hypothesis during the early days of the program. His idea was based on his cynicism as to how NASA planned to explore life on Mars...using essentially the same approach as to how one would explore life anywhere: probing the air and soil for signs of micro-organisms and chemical evidence of life at work. But Lovelock was not satisfied with this approach, in part because the experimental design was not at all equipped to answer the more fundamental question, “what is life?”. Struggling with an alternative approach, he suggested at one point that, if he was in charge, he would

...look for an entropy reduction [emphasis mine], since this must be a general characteristic of all forms of life.

What exactly does he mean here? Entropy, a thermodynamic state variable, represents the unusable (or perhaps “waste”) heat in a system, and cannot decrease over time. Entropy is central to the Second Law of Thermodynamics which, in Lovelock’s words, states that

...all energy will eventually dissipate into heat universally distributed and will no longer be available for the performance of useful work.

The argument is that life, in a sense, creates energy (or reduces entropy). Therefore, a “reduction or reversal of entropy” would indicate “a sign of life”. In other words, life shapes or forms itself at the same time it consumes energy, reducing the amount of entropy in life-giving processes.

In exploring his hypothesis, Lovelock examined the constituents of the atmosphere and concluded that the composition of the earth’s atmosphere is “improbable” unless the role of life processes on its composition is considered. For example, just by looking at the natural amounts of methane and oxygen in the atmosphere, he concludes that these levels are not possible under an “abiological” system. Instead, the atmosphere is an extension of the biosphere; the biosphere is able to manipulate the atmosphere to meet its survivalist needs.

He noted that the composition of the atmosphere, not to mention the earth’s climate, has remained surprisingly constant since life on earth first formed about 3.5 billion years ago, despite dramatic increases in solar intensity and drastic changes in the earth’s surface over that same time period. He concludes that a form of homeostasis, or equilibrium, exists between the earth’s atmosphere and its biological structure.

Lovelock was close friends with the author William Golding. He discussed with Golding his reflections on the symbiosis between the living earth and the atmosphere. Golding immediately thought of the Greek Earth goddess Gaia, or Ge. Lovelock embraced the name, and around 1969 began referring to his hypothesis as the Gaia Hypothesis.

As Lovelock states in his 1979 book, Gaia represents a

...complex entity involving the earth’s biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet. The maintenance of relatively constant conditions by active control may be conveniently described by the term ‘homeostasis’.

Although the Gaia Hypothesis remains unproven, Lovelock provides evidence of her existence by comparing the earth’s average temperature over the 3.5 billion years that life has existed on the planet with the temperature that would have resulted based on the 30% warming that the sun experienced during that same time frame. The earth’s climatic temperature increase is far lower than would have been the case if the temperature was dependent solely on the increasing temperature of the sun, as shown in Line B in this image taken directly from his book:

One way to understand our climate is to examine the earth’s heat budget over time. For the global earth-atmospheric temperature to remain constant (here, “earth” includes both land and oceans), thermal heating caused by the absorption of incoming energy from the sun must, over time, be equally dissipated to outer space through reflection of sunlight and re-emission of thermal energy. Short term natural events can upset this balance: volcanic eruptions, for example, or variations in solar output, or natural climate cycles can all contribute to changes in the earth’s heat budget that must ultimately be balanced out in some way in order to for the earth’s temperature to remain constant over time.

Gaia highlights the risks that result when some life forms, such as humans, introduce changes to the heat budget on their own. For example, for millions of years human activities related to agricultural practices have impacted the earth’s albedo (the ratio of sunlight reflected back to space to the amount of sunlight reaching the earth’s surface) to some extent. A change in albedo introduces an energy “forcing” that can result in heating or cooling of the earth-atmosphere system.

For the past two centuries, more or less since the start of industrial times, we have seen the benefits, and costs, that fossil fuels offer society. Fossil fuel use created vast wealth and well being for the human race. Life expectancy as well as quality increased. Rapid population growth followed, locking in an ever-increasing need for even more energy.

But demand for fossil energy resulted in massive disruptions to the natural environment over a relatively short time frame. Extracting and burning fossil energy stored under the earth’s surface for millions of years, which has unlocked vast reservoirs of sequestered carbon and turned them into greenhouse gas emissions to the atmosphere, causing rapid (compared to long term natural trends) warming of the atmosphere and oceans, with no compensating heat-dissipation mechanisms in place, has created a carbon footprint of immense portions; a source of “positive forcing” to the heat balance. Although some excess heat can be dissipated through increased thermal emissivity, the global warming trend observed in the oceans and atmosphere is strong evidence that the burning of fossil fuels has thrown the earth’s energy budget out of balance, with constant human-caused positive forcing now occurring.

This human carbon footprint has caused he homeostatic nature of Gaia to be significantly challenged. Gaia warns us that that changes to the single organism as defined above, must evolve in order to exist under new climate norms. This implies a planet with life forms different from those existing prior to the fossil fuel era.

Lovelock took the threats of climate change to earth’s life forms to heart. He was a strong opponent to further use of fossil fuels to meet our energy needs. The Gaia Hypothesis was a warning to the world that human-induced global warming will result in new atmospheric and oceanic states that could directly impact life on earth in ways that a new life structure would result; a structure potentially detrimental to the long-term well-being, and even existence, for human life as we know it today.

But the complexity of the science behind all this makes predicting the future state of life on earth and its relationship to the earth-atmosphere system that exists at that future state extremely difficult. How will humans react and respond to the rapid changes in their environment? Will they finally choose to mitigate the problem at its source, or hope to adapt to whatever future our ongoing industrial revolution will take us?

These are certainly complex, if not existential questions. So, on Sunday (July 26) this past week, I settled into a comfortable chair in our mountain cabin, where we have tried to limit our own carbon footprint by using only solar power, and took another look at this thought-provoking book. For sure, for me anyway, it made for an inspiring afternoon of reading in the cool, high mountains of Colorado, during an unprecedented heat wave.

Later I learned that July 26 was Lovelock’s birthday. He had passed away on this date exactly four years ago, the day he turned 103.

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Tomorrow morning, early (6 AM Mountain Daylight Time!) I will be participating in a webinar presented by the Global 100% Renewable Energy Platform and hosted by the World Wind Energy Association (WWEA). You can still register here; the event will be recorded.

In April 2013 Anna Leidreiter, a Policy Officer for Climate Energy at the World Future Council, based in Hamburg, Germany, spearheaded the formation of a global campaign advocating for 100% renewable energy. I was President of the International Solar Energy (ISES) at the time, and met Anna at a conference in Vancouver, British Columbia that year. ISES had already established 100% renewable energy into its vision statement, so joining Anna’s campaign, which ISES did along with 9 other founding organizations, was a logical move. The campaign slogan was shortened to “GO100% Renewable Energy”, and soon created its logo, which has had wide distribution over the years:

By 2017 members of the campaign felt it had accomplished many of its early goals, such as raising awareness of the technical feasibility and benefits of a 100% renewable energy world, and identifying the steps required to obtain policy support from decision makers to achieve such a vision. By then the informal network had 30 collaborators. It was decided to formalize the campaign into a robust multi-stakeholder platform providing the coordination and cooperation needed to accelerate the transformation to 100% RE using an inclusive, bottom-up approach.

In 2018 Stefan Gsaenger, the Executive Director of the WWEA, another original founder, was able to secure funding from the city of Bonn, Germany (WWEA’s home base) to establish the Platform as a legal entity. By this time Anna needed to leave the World Future Council, as well as her work on the Platform, due to other commitments. For a while the Platform had an interim Executive Director, Rian van Staden, who sadly passed away a few years ago. Today the Platform continues to function under the leadership of its Executive Committee which includes a representative from each the following organizations: the WWEA, ISES, the Climate Action Network (CAN), ICLEI-Local Governments for Sustainability, and the Institute for Sustainable Energy Policies (ISEP), Japan.

In 2019 the Platform launched WorldREnewDay, which takes place annually on or close to the June Solstice. With Stefan’s leadership, the Platform organized a special event on June 22 on the margins of the June Climate meetings, held every June at the headquarters of the United Nations Framework Convention for Climate Change (UNFCCC) in Bonn. These meetings are preparatory meetings for the annual Conference of the Parties (COP) climate meetings; the June 2019 meeting in Bonn was the 55th annual meeting of the Subsidiary Bodies of the UNFCCC, or SB 55.

The WorldREnewDay event featured music by “ambassadors” of the Platform (the Ukrainian rock star Ruslana and the Pakistani folk rock musician Arieb Azhar), and speakers representing the Platform from around the world. The event was well attended, especially during Ruslana’s closing performance.

Every year since 2019 the WWEA and other partners of the Platform issue a press release on WorldREnewDay reminding the world of the benefits to people and communities that come with a 100% renewable energy system.

This year the Platform designated June 27 as WorldREnewDay 2026. The belated webinar being held on July 23 represents the Platform’s first WorldREnewDay event since the 2019 event in Bonn. The webinar will renew the idea of 100% renewables as the most logical and cost-effective target for the clean energy transformation taking place around the world.

When I started this SunBurst Almanac at the beginning of this year, my first posting was about the possibility of 100% renewables. The basis for this discussion was the off-grid solar-powered home we have built in the Colorado Rockies, which represents a near- 100% renewable powered “microgrid”. With the exception of a wood stove the house is all electric (the main heat source is an air-source heat pump, supplemented by passive solar heating). We even use the household solar system to charge our electric vehicle which we use to get to the house from our main home in Boulder.

Admittedly we have not yet achieved a full 100% renewable system...we still rely, very occasionally, on a gasoline-powered generator to provide backup power to the house when the state of charge of the storage batteries drops below 20%. Each year we get a bit closer to our goal, as we learn how to better manage household loads and the solar plus battery storage system during extreme weather events.

But the main purpose of that SunBurst post was to articulate the benefits of a fully 100% renewable energy system globally, and to describe some work I was doing with the International Renewable Energy Agency’s (IRENA’s) Coalition for Action. For a number of years I was a co-Chair, along with Rainer Hinrichs-Rahlwes, of the Towards 100% Renewable Energy Systems Working Group within the Coalition. One year the Working Group undertook an evaluation of several energy transformation scenarios that achieve either 100% renewables, or “net zero” carbon emissions, in order for the world to meet the global warming target of no more than 1.5 ⁰C above preindustrial levels. The results were published by the Coalition in 2024.

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Clearly, achieving a 100% renewable energy future does not necessarily follow the same pathways as achieving a net zero energy future. Net zero implies that some fossil energy sources are still in operation even when the 1.5 ⁰C target has been achieved. The emissions from these fossil sources are offset by carbon capture, storage and utilization schemes, or, in some pathways, intensive carbon sequestration strategies, making total emissions net zero. For 100% renewables, there can be no fossil fuel generation facilities remaining in place; a complete phase out of all fossil energy generation, whether for electricity or transport or any other end use energy requirement, must occur.

This distinction provided some interesting contrasts among the scenarios that were studied. Perhaps most notably, the investment costs required to achieve a truly 100% renewable energy system actually tend to come out lower than costs for a net zero system. I suspect this is due in part to the high costs of carbon capture and storage systems, which continue to experience technical feasibility and scaling-up issues. Another major factor though, is the low costs of solar and wind technologies themselves compared with nuclear and fossil systems; a 100% renewable energy system has a much higher share of solar and wind resources than a net zero system.

One issue raised by skeptics of any clean energy system dominated by renewables (particularly solar and wind) is the variability of these energy sources. How can the utility be sure of having firm (dispatchable) power when its predominant sources are subject to the vagaries of the weather? This is where battery storage, or perhaps other types of storage, comes to play. In our “microgrid” house in the Rockies the battery energy storage system (BESS) is continuously charging and discharging depending on how much solar energy is delivered by the rooftop solar panels and on the electric load demands. The combination of the batteries and the inverter serves to convert variable power from the solar panels to firm power that reliably meets household loads 24 hours a day, 7 days a week. This same principle applies to large scale grid systems.

A recent IRENA report shows that the costs of firming the electricity supply form variable sources by combining them with BESS has dropped substantially in the past five years. In the U.S., for example, solar PV plus battery storage LCOEs have dropped 31% between 2020 and 2025 and are projected to drop another 32% by 2030, and 48% by 2035. Although the LCOEs in the U.S. are generally much higher than in other countries blessed with favorable solar and wind resources, the 2025 LCOE of around $115/MWh is well within the benchmark range of new gas turbine power plants (>$100/MWh). And LCOEs for gas-powered systems are rising rapidly due to a shortage of supply and higher gas prices.

A key pathway for achieving a 100% renewable energy scenario, then, is to electrify all end use energy requirements as much as possible. Globally the current share of electricity in total final energy consumption (TFEC) is about 22%, although this figure is higher in developed countries. The global share of renewables meeting this figure is now at 49.4%. The 100% renewable energy scenarios show electricity as a share of TFEC to be anywhere from 60% to almost 100%. And the vast majority of the renewables meeting these shares will come from low-cost solar PV and wind. In the U.S. that share is currently only 17%.

Any investments being made today that require a fossil fuel energy supply means that demand for fossils will continue for at least another generation. Purchasing a gasoline-powered car today signals the fossil companies to continue digging and extracting oil from the ground for years to come. Opting for a gas furnace rather than a heat pump for home heating signals that fracking must continue for decades to ensure that natural gas supplies for that furnace are always available.

Despite favorable trends in renewable energy development, much work is needed to achieve a fully 100% renewable energy system. The Global 100% Renewables Platform is a powerful means for stimulating grassroots action and decision making to achieve this aspirational clean energy goal.

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A few weeks ago, I reported on the 2025 results of Levelized Cost of Energy (LCOE) analyses in the U.S. power sector, as published by Lazard. This week Lazard released their 2026 LCOE+ report. Let’s take a look.

First,here are LCOE comparisons between 2025 and 2026. As Lazard reports, LCOEs rose in 2026 for all technologies, and especially for solar PV, due to factors such as supply chain pressures, taxes, and tariffs. The comparisons include the percentage change of the mid-points of the ranges:

2026 2025 % Change

Utility scale solar PV $40 - $98 $38 - $78 +19%

Utility scale PV + Storage $61 - $156 $50 - $131 +21%

Onshore wind $37 - $99 $37 - $86 +10%

Coal $72 - $177 $71 - $173 +10%

Gas combined cycle (GCGT) $51 - $129 $48 - $109 +15%

Nuclear $175 - $255 $141 - $220 +19%

Despite the 2026 cost increases new solar and wind technologies are still competitive with new conventional coal, gas and nuclear facilities, especially under conditions where fuel costs are high or energy demand is low.

Now let’s take a look at how new build renewable LCOEs compare with the marginal costs of conventional generation technologies that are already installed and operating:

Conventional Generation

New-build renewable LCOEs New LCOE Marginal Cost

Utility scale solar PV = $69 Coal = $124 Coal = $52

Utility scale PV + storage = $81 GCGT = $90 GCGT = $42

On-shore wind = $68 Nuclear = $215 Nuclear = $31

What are the implications of these results? They contain a couple of key messages.

First, as noted in my comments following the first chart, despite their increasing costs, (which have impacted all technologies at one level or another), renewables are still among the most cost-competitive technologies for adding new electricity generation capacity here in the U.S. Similar results are being found throughout much of the world. They also offer the fastest means by which new capacity can be added to the grid.

One might argue, however, that renewables are intermittent and therefore cannot be counted upon for firm, dispatchable power generation in the grid. This issue is also addressed by Lazard. They have developed a “Cost of Firming Intermittency” analysis. This analysis calculates the cost of converting intermittent resources such as solar and wind into firm power resources. Their analysis is based on information about grid operations and the adequacy of resources on the grid for various system operators. Their analysis shows that managing intermittency in ways that allows for renewable resources to be treated as firm power can add 31% to 55% to the LCOEs for utility scale solar, depending on the system in which they are installed. The percentage increases are lower when battery storage is factored in, since storage adds to grid flexibility by firming up the intermittency associated with solar PV. The cost increases for firming the intermittency of wind tends to be less than for solar. In any case, the LCOEs of all renewable technologies are still broadly competitive with gas combined cycle power plants even when firming costs are added in, and even when subsidy incentives are absent for renewables.

And it should be noted that conventional plants (gas, coal, nuclear) can also suffer intermittency issues due to fuel availability and system outages. The Lazard analysis does not add in these possible firming costs to gas combined cycle plants in their comparisons.

A second key message, based on the second chart above, has significant ramifications on the current situation of the U.S. power system, and on similar systems throughout the world. The electricity sector is growing rapidly, due to electrification of end use energy demand, new electricity demand from Artificial Intelligence data centers, and the general growth of populations and the economy. Rapid growth in electricity demand places utilities under significant pressure to add new sources of power at the lowest cost. One solution some utilities are taking is to keep conventional plants operational even well beyond their current life expectancy, and even if climate mitigation strategies are compromised. In the U.S. we have already seen the life of coal plants being extended, despite the risk of higher cost of power imposed on consumers than what renewables would offer. The second table confirms the possible cost advantage of keeping existing sources operating well past their time. However, if these plants continue to operate, rather than being replaced by new low-cost capacity, not only will this put upward pressure on future utility bills for consumers, their continued operation spells serious trouble for climate mitigation goals.

Another solution for utilities (and data center operators) is to restart long-shuttered nuclear power plants. This is not specifically addressed in the charts above, but such a strategy will very likely come at a significant cost to electricity consumers. And even restarting old nuclear plants can result in substantial delays in the availability of new electricity supply.

Unfortunately, the Trump administration is enacting policies that encourage, and even require, utilities to forego any climate mitigation goals by ordering aged, high-emitting coal plants to remain operational for many years beyond their current life expectancy. And the administration is doing this by discouraging any new installments of renewable technologies (especially wind) to existing grid capacity, even though renewables are the lowest cost and fastest-to-deploy of any new electricity source. These policies mean that we remain vulnerable to future energy supply, cost disruptions, and very likely much higher energy prices to consumers than a renewables-based economy.

Trump’s policies will end up adding substantially more CO₂ to the atmosphere than would have been the case if we continued with the climate mitigation strategies enacted by the previous Biden and Obama administrations. Trump’s policy U-turn also comes at a time when there is well-established scientific evidence that climate change is already impacting the U.S. and the rest of the world with longer, more severe heat waves, droughts and wildfire risks, stronger flooding events, and expanded airborne disease vectors, among many other risks. We also know that natural climate events, such as the El Niño Southern Oscillation (ENSO) on which I have reported earlier are enhanced due to human-caused climate change.

Another nail in the U.S. climate action coffin came last week when the New York Times recently reported that Trump has selected Dr. Mathew Wielicki, a well-known climate skeptic (and NOT a climate scientist) to head up the U.S. Global Change Research Program (USGCRP).

The law creating USGCRP was enacted by Congress in 1990. The role of the USGCRP is to coordinate and integrate research and observations for purposes of guiding the U.S. on its response to natural and human-induced global change. Since its inception the USGCRP has produced five National Climate Assessments (NCAs), the last one released in November 2023 just before the end of the Biden Administration. However, near the start of Trump’s second term, the Program was suspended and much information removed from the USGCRP website. With the appointment of Wielicki the USGCRP has been restarted under leadership that supports Trump’s misguided and dangerous world view of climate change being a “hoax” and an “alarmist” plot by left wing radicals to stifle the extraction and production of fossil fuels. Wielicki’s home page states that he is an earth science “professor in exile”, According to his CV he has a master’s and PhD degree in geochemistry. No background in climate or atmospheric sciences is indicated. Until recently he was an assistant professor at the University of Alabama but apparently left his position due in part to the University’s “obsession for equity in science and the rise of illiberalism”. His anti-DEI (Diversity, Equity, and Inclusion) views quickly won him over to right wing media, and his frequent appearances and wacky statements against climate science on Fox News eventually endeared him to the Trump administration (frequent appearances on Fox News are a clear prerequisite for a position in this administration).

Time will tell what, if any, kind of NCA will be produced under this new boss at the USGCRP.

In the meantime, the impacts of climate change remain all too real. Climate Central just reported the first half of 2026 to be the second warmest on record for the U.S.

To the extent possible, Paulette and I escape the latest “heat dome” over Colorado by spending as much time at our mountain cabin as possible.

Here is a photo from earlier this year:

As a postscript, you are welcome to join a webinar presented by the Global 100% Renewable Energy Platform and hosted by the World Wind Energy Association (located in Bonn, Germany) in which I will be participating on July 23, 6:00 AM MDT. Registration information can be found here.

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When a relationship comes to an end, either through design or from sudden, unexpected circumstances, one must contemplate what value that such a relationship had brought to their life, and what that value means for the rest of their life.

This is true whether we are talking about relationships among humans, or relationships between humans and the institutions for which they have chosen to align their lives.

On July 1, after twenty two and one half years, I completed my twelfth and final term as a member of the Board of Directors of the International Solar Energy Society (ISES). This was by design; it was time for me to step aside, and make room for a younger, more energetic individual with absolute passion for the idea of a world powered by solar energy and with the skills and motivation to actively advocate for its use around the world.

I previously wrote about ISES, and its U.S. Section, the American Solar Energy Society (ASES) in my Earth Day posting on April 22. When I first joined the ISES Board, in 2004, Board Directors were selected by the ISES Sections. I was already on the Board of ASES at that time and was appointed by ASES to serve on the ISES Board. A few years later the ISES Board elected me to be the Vice President for Science and Technology. Then in 2010 the ISES Board elected me as President, a position I held for 10 years.

ISES has a rich tradition of promoting research in all renewable technologies, although its main focus has always been on solar technologies. The history of ISES[1] begins in 1954 when, at the urging of Prof. Farrington Daniels, the Association for Applied Solar Energy (AFASE) was incorporated in Arizona. At that time the solar technologies being studied were often technologies designed for space and water heating, or process heating. That same year Bell Telephone Laboratories patented the modern photovoltaic (PV) solar cell. But still, at that time solar energy was primarily a topic for the research community, with virtually no commercial offerings available.

The first conferences of the AFASE were held in Tucson and Phoenix, Arizona in late 1955. These conference attracted international participation, which continued to grow within AFASE. In 1964 the name of AFASE was changed to the Solar Energy Society (SES), and Farrington Daniels became its first President. Following a joint conference in Melbourne, Australia with its Australia-New Zealand branch in 1970, SES changed its name to ISES to be recognized as an international society. ASES was then formed to become a Section of ISES. Since the Melbourne Conference ISES has held Solar World Congresses every two years.

The journal Solar Energy was started by the AFASE in 1957, along with a more popular publication called “Sun at Work” (in 1976 the name changed to SunWorld). SunWorld continued until 2000, when it was replaced by Elsevier’s publication Renewable Energy Focus (ReFocus). By 2010 ReFocus became an independent publication of Elsevier, no longer connected to ISES. Recently ISES began publishing a second journal, “Solar Energy Applications”. These two journals and the Congresses are among the most visible activities of ISES. For many years ISES also published “ISES News”, and continues to produce a periodic newsletter.

When ISES was formed in Australia in 1970 the headquarters also moved to Australia, although the laws of the Society remain incorporated in Arizona to this day. In the 1970s ISES thrived in part due to a key geopolitical event, the OPEC oil embargo. ISES membership grew more than tenfold by the end of the decade, and had 10 active Sections by 1977, with more to follow. But by the mid-1980s membership numbers fell significantly, due in part to R&D cutbacks in the U.S. and elsewhere. Maintaining the HQ in Melbourne soon became impractical since the majority of ISES members were in North and South America and Europe. In 1993, during a period of serious financial decline, ISES moved from Australia and established its legal entity in Germany. ISES HQ moved into Villa Tanheim in Freiburg.

A few key factors helped the Society turn around its financial misfortunes in the 1990s. One was its participation in the Rio Conference in 1992 and its ability to eventually become a United Nations (UN)-accredited organization, allowing ISES to have a seat at the table at UN meetings addressing sustainability and climate change. Another was the recognition that renewables, and especially wind technologies, were rapidly becoming commercially viable enterprises. The Society began adjusting its publications and Congresses to reflect this. Although it was still viewed as a primarily academic organization, it modified its membership structure to allow for non-academics to join the Society. Many of the Board discussions during that time focused on how ISES should be positioning itself in the rapidly changing renewable energy landscape. These discussions continue to this day.

Ever since my engagement with the Society, which started in the early 1990s, I experienced the constant debate over how to preserve ISES’ academic identity, for which it was highly respected throughout the world, and still appeal to broader audiences such as decision makers, industry, and end users. These were, in fact, the primary issues I took on during my Presidency, which began in 2010.

For sure I saw our UN accreditation as a unique asset and worked to build on it through our participation in the United Nations Framework Convention on Climate Change (UNFCCC) annual Conferences of the Parties (COPs). Working with a unique partnership called the REN Alliance, representing not only ISES but also the World Wind Energy Association, the International Hydropower Association, the International Bioenergy Association, and the International Geothermal Association we organized side events and press conferences at the COPs. Especially in the earlier years of the climate negotiations, renewables did not seem to play a significant role as a pathway to climate change mitigation, but the side events were often well attended and demonstrated the idea of how “renewables working together” can lead to a 100% renewable energy world.

During that same decade of my Presidency the Society also formed new or built on existing partnerships with other key organization dedicated to promoting a renewable energy world, such as the Renewable Energy Network for the 21^st Century (known more commonly as REN21) and their International Renewable Energy Conferences, the International Energy Agency’s Solar Heating and Cooling Technology Collaboration Programme, the International Renewable Energy Agency (IRENA) and its Coalition for Action, Intersolar GmbH (especially Intersolar Europe), the International Solar Alliance, the Global Solar Council (in which ISES was a founding member in 2015), and others. These partners all place high value on the science and technology expertise ISES brings to their programs.

For any organization, or organism for that matter, to thrive, it must remain flexible to diversify when the time is appropriate. ISES is no exception. ISES at its core is an academic organization, and it has performed its mission in this regard exceedingly well throughout its history. And for sure many R&D successes reported by ISES in its publications and Congresses have led to commercial successes. ISES should be proud of its legacy. Going forward, ISES has the opportunity to expand this legacy by continuously connecting the innovative outcomes of the research community it supports with the business community that marshals these innovations into successful enterprises. It is also more critical than ever for ISES to get the vast wealth of information garnered within the ISES community out into the mainstream to offset misinformation generated by politicians and companies who oppose the clean energy revolution.

I have full confidence in the new President of ISES, Dr. Francisco Beltran, to provide the necessary leadership for building on ISES’ value and its legacy. I am very impressed with his energy, his enthusiasm, and his intellect. The new Board of Directors, many serving on the Board for the first time, is also impressive. Working with Francisco they are fully capable of implementing programs that further advance this legacy.

I am also deeply grateful to ISES HQ for their unwavering dedication to the ISES mission they have shown for all the years I have known them. They provide the critical support and direction of ISES’ ongoing activities that make ISES the unique organization it is today, an organization with over 70 years of continuous service to the renewable energy community.

ISES, and ASES, represent communities of individuals and institutions passionate about advancing renewable energy technologies. Many of the ideas and motivations for building our off-grid solar home in Colorado come from the many friends and acquaintances I have made in my 35 years of involvement with these two organizations. Check them out...and consider becoming a member, if you are not already!

[1] The Fifty-Year History of the International Solar Energy Society and its National Sections, Vol 1 and 2. edited by Karl W. Boer, U of Delaware, 2005. Published by the American Solar Energy Society, Boulder, CO.

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On July 2, two hundred and fifty years ago, under a sweltering heat wave in Philadelphia, the U.S. Continental Congress, consisting of representatives from each of the thirteen original colonies, voted in favor of the Declaration of Independence from Great Britain. The event took place in the midst of the American Revolution. Twelve of the thirteen congressional representatives voted in favor; there was one abstention. Two days later, on July 4^th, the Congress ratified the document.

Every year, the U.S. celebrates July 4^th as Independence Day; the founding of the United States.

The American Revolution started as a rebellion against Great Britain in 1765, but became a full-fledged revolutionary war on April 19, 1775, with the Battle of Lexington and Concorde, in Massachusetts. Despite the ratification of the Declaration of Independence nearly 15 months later, the war raged on with highly uncertain outcomes until 1783, when the Treaty of Paris declaring America’s victory over Great Britain was signed on September 3. The Treaty was later ratified by the Congress of the Confederation on January 14, 1784; the British ratified the Treaty on April 9, and the ratified versions were exchanged in Paris on May 12 of that year, cementing the formation of the United States of America.

This Saturday we celebrate our semiquincentennial (250^th) anniversary of our independence.

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At the last major celebration, the 200^th, or Bicentennial in 1976, our president was Gerald Ford, the first “unelected” president in the history of our country. Ford was appointed by Richard Nixon two years earlier upon the resignation of Nixon’s elected Vice President, Spiro Agnew, who resigned on October 1,1973 under alleged bribery charges. Nixon himself resigned on August 8,1974 as a result of the Watergate scandal, and Ford then became President. Ford appointed Nelson Rockefeller as his Vice President. For the Bicentennial, nether the President nor Vice President presiding over this grand occasion was elected to their offices by the people.

In 1976 the country was dealing with the aftermath of a geopolitical energy crises, the “Arab Oil Embargo”. A somewhat similar crisis exists today, thanks to Trump’s war on Iran. However, in 1976 there was little in the way of an alternative to fossil energy for meeting our end use energy needs, other than nuclear and hydropower in the electricity sector. Virtually all transport, a large portion of space and water heating, and industrial process heat required fossil energy sources of one kind or another.

But there is a significant energy source available today that was not commercially available in 1976…renewable energy in the form of solar and wind technologies along with battery storage. In the absence of these technologies in 1976 the embargo of oil and natural gas imports to the U.S. created a full-blown energy crisis. Today, the blocking of oil and natural gas flows through the Strait of Hormuz creates a fossil energy crisis for those countries highly dependent on energy flows from the Middle East, and worldwide due to higher prices, but not a full-blown energy crisis. But the pathway out of this crisis, besides political negotiations which can be time consuming and fraught with uncertain outcomes, is a pathway towards a renewable energy future.

Since 1976 electricity demand and consumption has grown substantially in the U.S and much of the rest of the world. The way electricity is produced and distributed is changing substantially as well; I prefer to call the evolution of the new energy system we are entering as a transformation.

The advent of electric vehicles for transport and heat pumps for home heating has disproportionately added to global electricity demands. Additional new sources of demand, such as Artificial Intelligence Data Centers in some countries and expansion of electricity grids to previously unserved areas in others, is resulting in a rapid shift to electricity as the energy of choice for more and more of our end use energy needs. And as I have been recently reporting, the vast majority (>90%) of new electricity supply to meet this burgeoning growth is being provided by the lowest cost and quickest-to-deploy technologies: solar and wind combined with battery storage.

Yet to this day, just as they did in 1976, politicians address geopolitical energy crises with pleas for more oil and gas extraction, production and use to address the supply shortages. Why aren’t renewables playing a bigger role in response to these “crises”?

Renewable technologies also cut emissions of fossil byproducts nearly completely, cleaning up the air and water and serving to mitigate our growing crisis of global warming.

In 1976 concerns about increasing atmospheric CO₂ concentrations and their potential impact on global warming was a topic primarily for a few scientists around the world to investigate and discuss. At that time these rising concentrations and prospects of climate change were generally not newsworthy. Already by 1976, atmospheric CO₂ emissions were over three times higher than at the end of World War II, and atmospheric CO₂ concentrations were around 330 ppm, up from a preindustrial “baseline” of about 280 ppm. Still, in 1976 global warming had only reached about 0.3 ⁰C above preindustrial levels, and the future of climate change was still in debate, with some scientists even arguing that global cooling and a new ice age could actually be in the offing.

Today, accounts of global warming and its impact on our lives are in the news virtually every day.

As we approach our semiquincentennial we know that global warming is settled science. The atmosphere has now warmed to nearly 1.5 ⁰C above preindustrial levels, and atmospheric CO₂ concentrations have jumped to nearly 432 ppm, raising alarms throughout much of the scientific community. Yet our current government chooses to take no action to mitigate these trends and has reverted to a full-throated fossil- friendly set of energy policies; even going so far as to terminating wind farm projects already in the pipeline.

I recently met with a good colleague, Chuck Kutscher, a strong advocate for renewables and climate change mitigation (Chuck and I both worked together at the National Renewable Energy Laboratory, or the National Laboratory of the Rockies as it is now called). Chuck reminded me of an Economist op-ed written nearly a year ago, July 18, 2025, by Trump’s Secretary of Energy, Christopher Wright. I looked it up and confirmed that his article was an effort to justify the new Trump Administration’s attack on renewables and support for an all-out expansion of fossil energy exploration and use. The article contains much misinformation, and some disinformation, to support the Administration’s agenda. One of his main premises was that at least in some parts of the world, and for sure during the Biden administration, there are energy policies of “exclusion and scarcity that shackles humanity and limits economic potential”. In other words, Biden’s policies promoted energy subtraction, not energy addition, all for a singular effort to fight climate change. But the Trump Administration does not see climate change as an existential threat to humanity. Furthermore, they do not recognize renewables as a legitimate addition, since they make the system “…more uncertain, more expensive, and less reliable”.

Although Wright is very careful to avoid mentioning solar and wind technologies by name, his statements could not be further from the truth. As I have argued in previous postings renewables are legitimate and robust additions to our energy supply. Renewables benefit from an unending “feedstock” of solar and wind energy resources which are not subject to tariffs, supply chains, strait closures, and geopolitical tensions. As my previous articles noted, solar and wind are already the lowest cost additions to the electricity grid, and despite statements in Wright’s article, more and more of our end use energy is coming from electricity services.

Chuck very wisely wrote a rebuttal (scroll down to see his letter), published in the Economist two weeks later (August 1, 2025).

For sure I will be celebrating the ratification of the Declaration of Independence on this special day of the nation’s semiquincentennial. As Americans we have much to celebrate. But our celebration must come with honest and thoughtful recognition of the systemic problems that still exist in our country, including the ways we produce, deliver, and use energy. There are deep political divisions in our country and disturbing politically motivated setbacks in how we address energy. Going backwards to the way things once were will cost us dearly; it is like trying to put toothpaste back into the tube. Quite honestly this is not what most of us yearn for.

We all have much to be thankful for in this country, and for what the Declaration means to us. We must continue to remain vigilant that special interests do not undermine, for their own personal gain, the freedoms and privileges, and the “…life, liberty, and pursuit of happiness…” we are all entitled to enjoy.

The Declaration makes it very clear that its words apply to everyone living in this beautiful country.

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Although the calendar says midsummer is still weeks away, it feels as if summer, and the solstice, arrive faster and faster every year. This year the mild and dry winter and spring has made it feel especially this way.

With summer upon us there is much work to be done around our mountain property. There are a multitude of fallen trees (mostly trees that were already dead before they fell), to be cleared, thanks to the numerous high wind days we had this past winter and spring, including one just last week. The heavy, wet May snowfall took its toll on some trees as well. The work involved in clearing them provides a seemingly endless supply of firewood, but also a fair amount of forest slash that at some point will need to be hauled away...all part of our ongoing fire mitigation efforts.

And the fires are starting up. There is a big one to the west, in central Utah; another in Arizona. The air is hazy throughout the day, providing reddish-orange sunsets. This evening it is impossible to see the nearby Continental Divide, with so much smoke in the air.

We have set ourselves a quota of dealing with no more than one fallen tree on any given day. The quota does leave us with much time to reflect on the current political situation here in the U.S and elsewhere; on the precarious state of our climate; and on the ongoing transformation of our energy system to renewables, despite the recent headwinds. This past week was no exception.

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Let’s cover these in reverse order. On the renewables side, Solar Power Europe (SPE) just released its Global Solar Market Outlook 2026 – 2030, showing that 664 GW of global solar capacity was added around the world in 2025. This new capacity is 12% more than 2024. Solar markets are still robust, but they have slowed down in the past 2-3 years. China dominates the market with 57% of these additions. The U.S. (and India) each had 7% of this market.

Sometime early in 2026 total global solar capacity surpassed 3 TW. The world is on track to have 6.6 TW, more than double the current level, by 2030, even though the market is likely to shrink to 612 GW in the current year.

Perhaps even more significant, solar power generation increased by 636 TWh in 2025, 30% more than in 2024. This new generation supply dominated all other technologies, including wind (which was in second place with a 10% increase over 2024). Since 2020 solar power generation has increased by over a factor of 3.

Similarly, the U.S. Solar Energy Industries Association has announced solid gains in solar and battery storage installations in the U.S. In their most recent Solar Markets Insight report they announce that over 90% of all new power generation capacity added to the U.S. grid in the first quarter of 2026 comes from solar PV and battery storage technologies. During this first quarter 7.8 GW of solar capacity was added, bringing the national total to 287.7 GW. There are now over 6 million solar installations in the U.S.

Then on Monday Michael Bloomberg announced that Bloomberg Philanthropies will commit $285 Million towards scaling up clean energy “…fast enough to help power the world’s energy systems.” The commitment is an important next step in Bloomberg Philanthropies global energy work to accelerate “…clean energy’s ability to deliver reliable, affordable, and secure power worldwide”.

Bloomberg himself recognizes that clean energy technologies are lower cost than fossil fuels virtually everywhere around the world. The fund will build institutional and political support for the energy sector to help accelerate its transformation to fully clean and renewable technologies, a key step needed at a time when the transformation is hitting some bumps in the road due to current geopolitical forces.

In a related article the New York Times highlights how Bloomberg Philanthropies’ investments in clean energy and climate change mitigation, which total $590 Million overall, are flowing against the tide of funding being pulled back by other philanthropic organizations, including those philanthropies started by Bill and Melinda Gates, Jeff Bezos, and Mark Zuckerberg. By all appearances those philanthropies have succumbed to the right wing fervor and misinformation campaigns designed to prop up the legacy fossil industry.

In other renewables news, last week REN21 (Renewable Energy Policy Network for the 21^st Century) launched the Renewables-Based Economy (RBE) Tracker for 2026. During my time as President of the International Solar Energy Society (ISES) the Society became a member of REN21 and I served as the ISES representative on their Steering Committee for many years. I also attended many of their International Renewable Energy Conferences (IRECs) and contributed to their well-received annual Global Status Reports.

But now these reports are no longer being developed as static annual publications to be placed on bookshelves. Instead the valuable information they contained will be incorporated into a more dynamic platform, the RBE Tracker, to keep us regularly informed and updated on the status and trends of global renewable energy development.

A “renewables based economy” (RBE) takes a more holistic view of the role of renewables in society and its economic progress. Rather than just representing a niche part of an energy system, renewable energy is treated as an integral component of and serves as an organizing principle around social prosperity. In an RBE economy renewable technologies enable expanded energy security by mitigating impacts of global market shocks, creating local jobs, and lowering costs through improved energy efficiencies. The RBE Tracker essentially tracks the status of a renewables based economy in four ways: 1) energy systems and security; 2) economy; 3) society and governance; and 4) environment and climate. The tracker will take advantage of crowdsourcing information provided through the REN21 network to offer a platform that will help guide policymaking and accelerate the clean energy transformation.

On the climate front, the U.S. National Weather Service Climate Prediction Center predicts there is up to a 63% chance we will have a very strong El Niño later this year and into early 2027. A very strong El Niño occurs when the ocean temperatures in the “Niño 3.4” region of the eastern equatorial Pacific warm to more than 2 ⁰C above normal. Keep in mind that the current El Niño is in its early stages, so there is still considerable uncertainty around these predictions. Probabilities could change in the coming months. It is also too early to predict the exact ramifications of a very strong El Niño on local weather patterns, the economy, and society. However, one thing is certain: climate change will already act to strengthen the impacts of the El Niño.

How could a very strong El Niño impact our weather? As summarized in BBC Earth, we could likely see increased hurricane activity in the mid-Pacific Ocean region (and reduced activity in the tropical Atlantic), increased storminess and possible flooding across the southern U.S. and portions of South America, widespread drought in Australia, northern Africa, and parts of Asia, heatwaves spreading from the U.S. Pacific Northwest to Europe, and a mild winter with less snow in Canada.

A very strong El Niño in North America can lead to severe economic consequences. Increased flooding in some regions and droughts in others can negatively affect crop yields, food prices and supply chains throughout portions of the south and Midwest. But there is also a possibility of improved crop yields in the southern Great Plains.

Also on the climate front, a new digital platform called Project Cosmos was announced by Carbon Brief on Monday. Cosmos will help inform the scientific community as well as journalists and the general public by serving as the world’s largest database of human knowledge on climate change. Cosmos contains roughly 1.8 million scientific climate related publications linked by 40 million citation relationships. The interactive database “…reveals how different fields of climate research relate to, and build upon, one another.” The project developers have initially tested the database to produce “Cosmos 500”, which identifies the 500 most cited publications, authors, and institutions involved in climate research.

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And finally, a bit of good news on politics that impact climate research. The U.S. National Science Foundation, facing pressure from U.S. lawmakers and scientists, has suspended its dismantling of the ocean research buoy system known as the Ocean Observatories Initiative (OOI). As I reported recently, the OOI is a critically important program for monitoring possible changes in deep ocean currents, such as the Atlantic Meridional Oscillation Current. Changes in this ocean “conveyor belt” can have profound impacts on regional weather patterns and the potential reoccurrence of a Little Ice Age in parts the Northern Hemisphere.

At the moment such an occurrence might actually be welcome news, at least temporarily, to the millions of people currently suffering through Europe’s second major heat wave of 2026.

This week the news was dominated by a Memorandum of Understanding, sometimes called the Islamabad Memorandum, designed to end the Iran war, at least for 60 days. There are, of course, many other “important” topics competing for the news space this week: Trump’s vanity projects around Washington DC, Trump’s birthday celebration featuring ultimate fighters clobbering each other in a gladiator-esque arena on the White House lawn; Trump’s takeover of revered government institutions (remember the Kennedy Center?); Trump’s hijacking of the 250 Bicentennial celebration to make it into a traditional Trump rally; Trump’s performance at the G7; and so much more.

Paulette and I are currently spending much of our time at our off-grid solar powered cabin, trying to tune-out as much of this as possible. But the important issue of the Iran war, and what the supposed end to this war means for the future of the energy transformation, definitely deserves our attention. The details of the Islamabad Memorandum stipulates that Iran will immediately open up the Strait of Hormuz, the U.S. will end its naval blockade, and hostilities will cease for at least 60 days, during which time the more nuanced issues between the two countries will be hammered out (the most important of which is a resolution of Iran’s nuclear program).

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Based on what I am seeing, the memorandum represents a clear win for Iran and a humiliating loss for Trump. Iran will end up in a much more favorable geopolitical situation than any time under either Trump 1.0 or 2.0, and perhaps even more so than with the 2015 “Iran Nuclear Deal” (formerly, the Joint Comprehensive Plan of Action, or JCPOA). The JCPOA was hammered out by the Obama administration, and signed by multiple countries, including Iran. Under the JCPOA Iran was required to forego any plans for developing nuclear weapons. Although this is purportedly the reason Trump went to war with Iran on February 28 (after already claiming back in June 2025 that their nuclear program was “obliterated”), the Islamabad Memorandum implies that Iran is no longer held to this commitment. Instead, that discussion is being deferred to a 60-day negotiating period once the MoU is signed in Switzerland this coming Friday.

What have been the consequences of the war and its aftermath on the global clean energy transformation? The Strait of Hormuz will soon reopen. This will free up a many months-long backlog of millions of barrels of oil, liquified natural gas, and key petroleum products such as fertilizer, waiting to be shipped primarily to Asian countries. This backlog, as we all know, has had impacts on the global economy. But reopening the Strait simply puts us back to where we were on February 27, the day before Trump, at the urging of Prime Minister Netanyahu, started his devastating war of choice against Iran.

So now we are back to the world that existed on February 27. Only much worse off. The global economy is suffering. The civilian population in Iran (not to mention Lebanon) has suffered death and devastation. Iran’s leadership is perhaps even more hostile to the west, and especially the U.S. Iran’s nuclear program remains at least somewhat intact. Yet the global energy transformation to a clean renewables based system has been derailed, for sure in the short term.

Many countries felt obligated to rebuild or revitalize fossil fuel facilities in their own countries to make up for the supply shortages caused by the closing of the Strait. Some countries have decided to extend the life of existing coal plants to cover the shortfall of oil and natural gas needed for their electricity production. (Sadly, the U.S. already made this decision as soon as Trump rose to power for the second time in early 2025). One could surmise that Trump believed a shortage of fossil energy supplies will encourage other countries to build up their own fossil-powered energy systems such as what he has already been doing in the U.S., thereby reinforcing his own ambitious fossil agenda.

He has even mentioned the possibility of great new wealth for the U.S. once Iran’s vast oil reserves flow freely to global markets, including those under control by the U.S., enriching the oil giants that helped put Trump into power in the first place.

But there is also good news for renewables. The fuel shortages and high prices suffered by many countries have generated new interest in long term strategies towards oil independence, just as what we saw during the 1973 Arab oil embargo. The key to a clean energy transformation is the growth in the use of electricity to meet our final energy needs. A surge of electric vehicles (EVs) is rapidly electrifying the transport sector. Massive adoption of electric heat pumps is electrifying the heating and cooling sector. The emergence of large data centers to meet the growing needs of the artificial intelligence (AI) industry is contributing to growing pains in our total electricity supply.

Prices of renewable energy technologies continue to drop as deployments soar worldwide, even though growth levels are a bit slower in recent years. Recent data from the American investment bank Lazard shows how the levelized costs of energy (LCOE) of renewable technologies in the U.S. are competitive with, and even lower than, the LCOE of traditional fossil-based systems (LCOE takes into account the complete life cycle of an energy-producing technology from initial capital investment and installation through operations and ultimate decommissioning and dismantling). Here are some examples.

LCOE ranges for major electricity-generating technologies, 2025:

Utility scale solar PV $38 - $78

Utility scale PV + Storage $50 - $131

Onshore wind $37 - $86

Coal $71 - $173

Gas combined cycle $48 - $109

Nuclear $141 - $220

From the perspective of LCOE renewables (solar and wind) are clearly competitive with common fossil generating technologies (coal and gas combined cycle), and clearly ahead of nuclear. When taking into consideration variations in fuel prices, Lazard shows renewables can be even more competitive when prices go up:

Coal $67 - $179

Gas combined cycle $41 - $116

Nuclear $138 - $222

The Lazard report also shows how competitive new solar and wind technologies can be with existing coal and gas facilities, especially under conditions where fuel costs are high or energy demand is low. Here are the ranges of marginal costs of conventional generation:

Coal $31 - $114

Gas combined cycle $24 - $39

Nuclear $30 - $38

Nuclear LCOE is much lower as a marginalized cost rather than a new build cost since Lazard data are based on long-term operational data for calculating marginal costs. Overall new build nuclear costs are especially high in their latest data base, since costs from the expensive and yet-to-be completed Vogtle electric generating plant near Waynesboro, Georgia, the newest reactor to be built in the U.S., are primarily used in their latest LCOE iterations.

LCOEs for renewables have dropped significantly since 2009, while LCOEs for conventional technologies have remained relatively stable. Wind LCOEs dropped below the LCOE for gas combined cycle systems in 2011, and solar in 2016. Here are some examples of changes in LCOEs between 2009 and 2025:

Utility scale solar PV $359 (2009) to $58 (2025)

Onshore wind $135 (2009) to $61 (2025)

Coal $111 (2009) to $122 (2025)

Gas combined cycle $83 (2009) to $78 (2025)

Nuclear $123 (2009) to $180 (2025)

For all technologies, renewable and conventional, LCOEs have been increasing since 2021. Nevertheless, the Lazard figures reinforce the notion that solar and wind technologies are now price competitive for adding electricity supply to the grid. When combined with battery storage these technologies provide firm dispatchable power and add considerably to grid flexibility. What’s more, solar and wind technologies typically can be deployed in a fraction of the time required by new coal, nuclear, and even gas generation facilities.

The Iran war created a fossil energy crisis, but not a renewable energy crisis. The IEA reported today that although the Iran war has created supply constraints and higher prices, as well as decreased demand, conditions that could stay with us for much of the remainder of 2026, the end of the war could very well lead to an oil supply gut in 2027. Such supply and demand fluctuations are not an issue with wind and solar, which is clearly reflected in the significant drop in their LCOEs in recent decades. The Iran war has demonstrated how much more sensible a fossil-free energy supply can be for all the world, even for Iran itself.

If Iran is being truly straightforward about having a nuclear program only for peaceful energy use, abandoning that program altogether and focusing on an energy future dominated by renewables could very well be a geopolitical win for the country and the world.

Back here at our high-mountain home, the Colorado state flower, the Blue Columbine, is now blooming. Here is a photo of one I found on our property today.

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In the Colorado mountains, the transition from spring to summer can occur quickly.

Despite an unusually warm winter, we had two significant snowfalls at our off-grid solar home: one on May 5 and a second on May 18. Both brought heavy, wet snow that, at least temporally, eased the severe drought we have been having this year. This is good news.

But the heavy snow was very slow in melting off of our solar panels, persisting for up to three days or more. This is despite the much longer days and higher sun angles than what we experience in mid-winter. So, the (sort of) bad news is that we lost power on two occasions during the month, and for the first time in over a year; one outage required us to run our gasoline-powered backup generator for an hour to help recharge the batteries and get the power back on.

Regarding the drought, though, the heavy snow was truly good news. The precipitation provided much-needed runoff to our increasingly parched river basins. Total May precipitation at our mountain home was 4.01 inches (10.2 cm). May is typically the wettest month of the year, so this is what one would expect in a normal year.

The total for the previous six months was just 2.78 inches (7.1 cm); far below normal.

Even though one wet month does not end a long-term drought, a distinct shift in the weather patterns for the region seems imminent. A potentially strong El Niño (the warm water cycle that occurs in the tropical eastern Pacific, formally called the El Niño Southern Oscillation, or ENSO) is replacing the cooler La Niña cycle that has persisted for the past year.

These natural cyclical weather events do not necessarily show a clear impact on Colorado’s weather patterns. However, there is a good chance that El Niño will bring with it more rainfall in parts of the western U.S. this summer, including, in particular, southern Colorado. This is good news for the hydrologically challenged Colorado River basin. Its two largest reservoirs, Lake Powell and Lake Mead, both of which are in the southern basin region, are at historically low levels: just 24% and 31% of normal, respectively.

Warm summer weather is settling into the high country. Broad-tailed hummingbirds continuously buzz over our heads around the property; their distinctive high-pitched voices alerting us to their high-speed fly-bys. A variety of yellow and white wildflowers have emerged from the newly dampened soils. Yet we still await the blooming of Colorado’s state flower, the Blue Columbine. When they arrive (soon, I believe), summer will truly be upon us.

We have had a number of sightings near the house of a female moose and her nearly fully-grown offspring. The other day they blocked our entry way as they stood on the dirt access road. We have learned to keep a respectful distance, and especially to avoid positioning ourselves between the mother and her highly protected child.

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One becomes very attuned to the weather in the high country. The sun can be warm and intense. But when it passes behind a cloud, and especially if the wind picks up, the air can feel suddenly cool, and the desire to quickly put on an extra layer of clothing can be quite real. These quick micro-changes in the weather are a constant, yet pleasant, challenge, and are utterly delightful.

Which leads me to consider the extent to which humans have influenced our current weather beyond the natural variability introduced by climate cycles such as ENSO, not only locally but across the entire planet. Our winters seem less severe, the summers seem increasingly warmer, and rainfall comes less frequently, although more intensely when it does. These observations are confirmed by the climate models used by universities and research institutions to predict the impacts of global warming, and also by direct weather observations.

Here is a graph from the International Energy Agency (IEA) on how global carbon dioxide (CO₂) emissions have increased nearly every year since 1900, showing particularly rapid increases occurring after the end of World War II.

Annual Global CO₂ Emissions (GT CO₂) from energy combustion and industrial processes (Source: IEA).

As reported in an earlier SunBurst post, CO₂ emission levels during the past half-century are well correlated with more atmospheric CO₂ concentrations during the same period, as shown, here based on data from Scripps:

The good news is that recent data indicate these curves may be tapering off somewhat, due largely to the substitution of clean energy technologies such as renewables in global electricity supply and the proliferation of electrified transport. However, it is likely too late to prevent global warming from exceeding 1.5 ⁰C above preindustrial levels (1850 – 1900), the ideal target set in the Paris Climate Agreement of 2015. The scientific community broadly acknowledges that potentially catastrophic weather impacts can be expected should this target be exceeded. But remaining below 1.5 ⁰C would have required overall CO₂ emissions to have peaked by 2025 and then decline rapidly (43%) by 2030. The figures above clearly show we are not yet on that pathway.

The bad news is that the Trump Administration, following its official policy to declare climate change as a “hoax”, has taken expansive steps that actually increase CO₂ emissions. His latest moves reiterate the archaic views of his administration by announcing plans to invest up to $350 million of U.S. taxpayer money to build, restart, and modernize coal plants and expand coal exports, and to ask the military to prop up 13 existing coal plants with increased coal supplies, requiring an additional taxpayer investment of up to $500 million. These moves are in the name of “national security” and “grid reliability”; two issues clearly achieved through renewable technologies, at much lower cost.

In reporting on these steps, the U.S. Energy Association (USEA), an energy lobbying organization, referred to these measures as “Promoting Domestic and International Consensus on Clean Fossil Energy Production” (emphases mine)[1].

Even George Orwell would be envious of this level of doublespeak.

And the attack on climate research continues. The U.S. National Science Foundation (NSF), in line with the Administration’s policies, just announced plans to decommission 900 deep sea observation systems that comprise the Ocean Observatories Initiative (OOI). These systems were installed ten years ago off the U.S. Pacific Northwest coast, the North Carolina coast, and the Erminger Sea between Greenland and Iceland. Among many tasks, the OOI was installed to better understand and predict the effects of global warming on changes in ocean circulations, which can have dramatic impacts on weather regimes worldwide. One task in particular is to monitor the apparent weakening of the Atlantic Meridional Oscillation Current (AMOC), a north-south “conveyor belt” of deep ocean currents that brings warm surface waters via the Gulf Stream northward from the tropical Atlantic, where they cool and then sink to return to the tropics along the ocean floor. The AMOC is largely responsible for the relatively mild climate in Europe. Should this cycle end, the warm Gulf currents will be shut off from Europe. A much colder climate would result for the continent for years and even centuries to come. The ability to raise crops in this region would suffer dramatically, and the continent’s entire infrastructure would have to be quickly restructured to accommodate the much colder climate.

But the NSF argues, cryptically, that decommissioning the $368 million OOI “aligns with NSFs wider strategy to have a nimbler approach to prioritizing support for evolving scientific priorities and emerging technologies as well as a deliberate approach to smart life cycle management within its portfolio of research infrastructure.”

My sympathies to the NSF bureaucrat who came up with this tongue twister.

The good news is that there is a growing movement to undo the steps the administration is taking to halt climate change research. The movement is occurring at many levels: state and local initiatives, civil society, the Congress, and especially the judiciary. For example, just last week a Federal judge blocked the transfer of the National Center for Atmospheric Research (NCAR) supercomputer to the University of Wyoming, a step that would have begun the dismantling of NCAR as a premier world-class research center, as I reported on March 11. There are already movements in the U.S Congress to stop the scuttling of the OOI.

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And there is good news regarding renewables. Despite Trump’s coal policies, the Associated Press reported today, using data from Ember and the Solar Energy Industries Association (SEIA), that in May solar, for the first time, provided more electricity (12.8%) in the U.S. than coal (12.2%). Further, SEIA reports that over 90% of all new electricity capacity in the U.S. came from solar plus storage during the first quarter of 2026. Clean energy development in the U.S. faces a bumpy road for the next few years, but it nevertheless has remarkable momentum and resilience.

We can all contribute to more good news by rejecting backward-moving energy policies and embracing the clean energy transformation.

[1] Adding a bit more irony: in their report the USEA uses an icon of a cloud labeled “CO₂” with two arrows pointing downward.

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We have family visitors here this week, so there is no time to prepare a SunBurst. The column should resume next week.

You are welcome to listen to this podcast interview that Paulette and I did on October 28, 2025 with author, solar trainer, and speaker Sean White, founder of White House Solar. Sean is a NABCEP (North American Board of Certified Energy Practitioners) Board Certified Energy Storage Installation Professional and has been designated Clean Energy Trainer of the Year by the Interstate Renewable Energy Council (IREC). Thank you for all you do, Sean!

La Niña, the cool side of a natural multi-year ocean heating and cooling cycle in the eastern Tropical Pacific, has had its final days. Soon it will be replaced by El Niño, when eastern tropical Pacific waters become warmer than average in this cyclical phenomenon. Climatologists and oceanographers call this cycle the El Niño-Southern Oscillation, or ENSO.

Historically El Niño events have resulted in potentially harmful and serious climate impacts throughout the world, although La Niña can certainly come with its own unfavorable climate patterns. El Niño events have traditionally produced poor fishing conditions along the coastal equatorial regions of South America, since the thick layer of warm water prevents upwelling of nutrients from the ocean depths, decimating fish populations. The phenomenon traditionally is most intense around Christmas time; hence Peruvian fishermen named this phenomenon El Niño, or Christ Child.

Perhaps the worst El Niño on record occurred in 1877-1878 when severe droughts throughout the world caused famines and large-scale death in disperse regions such as south Asia and Brazil. In other regions, disastrous flooding occurred. Nearly 5% of the world’s population was lost during that unusually severe event.

But there have been notable El Niño events in recent decades as well. The El Niño of 1972-1973 resulted in global repercussions on global commodities markets. More recently, the El Niño events of 1982-1983 and especially of 1997-1998 are considered the most severe of the 20^th century, producing deep droughts in some regions, and flooding and high snowfall in others. The upper U.S. Midwest had abnormally warm winters. However, as with all El Niño events, some regions around the world did not experience any abnormal weather.

The 1982-1983 El Niño event was particularly relevant to the wind energy resource assessment work I was doing at the Pacific Northwest National Laboratory (PNNL) in eastern Washington State. These were the very early days of commercial wind farm development in the U.S. The infant industry was targeting well-known windy regimes along the California and Oregon coastlines. Typically, the temperatures of the cool near-shoreline waters contrast significantly with the heated land surfaces during summer days, producing strong daily onshore winds, particularly in the afternoon and evening hours, when electricity loads were also typically high. I conducted analyses for several companies that were targeting projects in areas such as Altamont and San Gorgonio passes in California and coastal regions of Oregon. I found that the normally high winds expected in the afternoons in these regions seemed to be largely suppressed in 1982-1983, due to the weaker temperature gradients caused by the warmer water temperatures along with storm-related cloudiness suppressing the heating of the land. Some early wind farm developers of that time experienced financial issues due to the lower-than expected wind speeds and loss of revenue, just as their projects went online.

But now, many research organizations and climate watchers are warning that the coming El Niño could potentially be the most extreme in recorded history, even surpassing the 1877-1878 event.

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The strength of an El Niño has traditionally been characterized by the Ocean Niño Index (ONI) which accounts for temperature anomalies compared with a 30-year average in a specific rectangular region of the central and eastern equatorial Pacific Ocean, known as the “Niño3.4” region. However, the ONI did not factor changes in the surrounding ocean waters. So now the U.S. National Oceanic and Atmospheric Administration’s (NOAAs) Climate Prediction Center (CPC) is shifting to a Relative Ocean Niño Index (RONI) that addresses how the Niño3.4 warming or cooling anomaly compares with the average tropical ocean anomaly as a whole.

The results of numerous climate modeling runs, referred to as the North American Multi-Model Ensemble (NMME) conducted by the CPC and the European Centre for Mid-range Weather Forecasting (ECMWF), show a wide range of outcomes for the coming months. Below is a depiction of these outcomes as prepared by Climate Central in their April update. The mean results from all the model runs indicate a RONI of over 2 ⁰C, or about 4 ⁰F, (a strong El Niño), by Christmas 2026. The threshold for an El Niño is +0.5 ⁰C, which means one is already starting to form.

To be fair, the spread of model results indicates significant uncertainty in the strength of this impending El Niño at this time; some model predictions show it will likely be of record-breaking strength; other result show it will be relatively weak, and perhaps not very significant. This is why multiple models from different sources are used in the analysis: to obtain a suite of predictions representing a wide range of possible outcomes.

These model results will obviously improve as we approach the end of the year. But for now the Climate Prediction Center has developed a table of probabilities of the strength of the El Niño for upcoming three-monthly periods, shown here.

The probability of a very strong El Niño (RONI >2 ⁰C) is 30% or greater during the period October 2026 – February 2027; quite a high probability at this stage of El Niño development.

Strong El Niño events have been correlated with strong droughts in areas such as south Asia, parts of Africa, and Brazil. The weather patterns from a strong El Niño event are not conducive for hurricane formation in the western Atlantic but are very conducive to typhoon formation throughout the Pacific Ocean. Conditions for above normal precipitation are favorable along the US. west coast and across the southern U.S. However, significant correlations between El Niño events and abnormal weather conditions are not always found in many regions, such as Colorado. Furthermore, the impacts on weather patterns can vary considerably from one El Niño event to the next.

There does seem to have been a connection between the recent La Niña event and the severe western U.S. drought, however. This drought began back in October when the La Niña was at its strongest. Even this past April, weather remained abnormally warm and dry throughout most of the region. And March was truly an abnormal month: at our off-grid mountain home the average temperature in March was actually 1.8 ⁰F (1.0 ⁰C) warmer than April.

But as La Niña weakened in recent weeks, the weather patterns changed back to more normal patterns. Specifically, we have had two late spring snowstorms to the Colorado Rockies, producing some of the most significant snow of the season in some areas.

I reported on the first snowstorm, and its impact on our off-grid solar system, a couple of weeks ago. The storm caused the power to be shut off inside the house due to a prolonged period of time in which the solar PV panels were completely snow-covered. The battery state of charge (SOC) ultimately dropped below 20%, signaling the inverter to shut power off to the house to protect the batteries from over-discharging. Then, just this past week another significant snow event created a second power shutoff after the panels had been snow-covered for over three days. This time we ran the emergency backup generator for about an hour to get 2.7 kWh of battery storage. This brought the power back on and charged the batteries to a safe level.

What is the relationship of global warming to the formation of El Niño events? It is clear from historical observations that El Niño events occur naturally regardless of atmospheric temperature trends, which are clearly increasing due to human-caused climate change. Furthermore, for those years with El Niño events, global temperatures are even higher than non-El Niño years, due to the abnormally warm Pacific Ocean temperatures.

But even more can be at play with respect to the impact of El Niño events on global weather patterns. Recently the Washington Post published two images of global sea surface temperatures: one from the disastrous El Niño of 1877 and the other of the projected 2026 ocean temperatures for the currently forming El Niño, which many scientists fear could be worse than 1877.

One significant difference between the two images is the extensive areas of warm temperature anomalies outside of the equatorial Pacific region, and in particular in the mid-latitudes and extreme western tropical Pacific. Surface ocean temperatures have a dominant influence on global weather patterns. If the projected 2026 sea-surface temperature map is accurate, different, and potentially substantially different, weather patterns around the globe will likely occur compared with the 1877 El Niño. We cannot necessarily expect the weather pattern shift in the upcoming El Niño to be similar to 1877.

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The ability to predict El Niño events and their impacts have certainly improved since 1877. The chances for a strong 2026-2027 El Niño remain concerningly high, but how this event influences global weather patterns and potential catastrophic weather events still remains highly uncertain at this stage of its development. For sure, human caused climate change will have a big role on the degree of its influence. The world will be carefully monitoring this unfolding event.

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Spring arrived early here. We hardly had winter at all; at least the kind of winter we would normally expect to have high in the Colorado Rockies. The broad-tailed hummingbird has already returned; that is, we can hear their high-pitched ringtone high above us (they are quite difficult to spot). The aspen are mostly in full leaf. I have begun to clear some of the many fallen Ponderosa Pine and Douglas Fir trees that were blown over from the ferocious windstorms that occurred rather frequently. The patches of snow that are still visible on the mountains of the nearby Continental Divide are mainly from an unusual strong late-season storm a couple of weeks ago, one of the largest of the entire season. And now another, even later storm, has rolled in as I write this.

These storms are a big help to our severe ongoing drought. But, not having followed my own load management protocols, this latest storm was the cause of the second power outage of the month at our mountain home. Once again, the battery state of charge dropped below 20% thanks to persistent snow cover and limited sunlight on the rooftop solar photovoltaic (PV) panels.

The severe drought continues to make local headlines amid heightened concerns over low water flows in the Colorado River Basin. And Climate Central, as well as most other climate-related organizations and institutions, are demonstrating how the ongoing drought is being exacerbated by human-caused climate change.

Last week, however, national headlines focused on President Donald Trump’s state visit to China for high-level talks with President Xi Jinping…the first visit by a U.S. President to China in nine years (the last one was also by Trump). When diving into the details of the press releases, one conclusion is quite clear: each side had different, and in some cases, radically divergent views of the outcomes and substance of these discussions, especially with respect to trade agreements, the Iran war, and the subject of Taiwan’s status. The two-day trip featured lots of pageantry and a nice tourism outing to the Forbidden City, but little in the way of concrete political and economic agreements. A few billionaire tech bros and a disgraced movie director also accompanied Trump on this 14,000 mile (22,400 km) odyssey; they perhaps fared somewhat better, returning home with maybe a few business deals, along with lots of accumulated frequent flier miles on Air Force One.

My take on the two-day meetings focuses on what obviously did not occur…any discussion of the role the two countries currently play in global renewable energy markets. The clear reason for this is that the two countries are essentially moving in the opposite direction on clean energy development. China’s central government has clearly embraced the philosophy that reducing greenhouse gas emissions to mitigate harmful climate change is not contradictory to a developing economy. Successive five-year plans have propelled China to become the world’s leader in renewable energy development and climate change mitigation; even as China continues to develop coal-fired power plants to feed its growing energy-thirsty population and industry. As stated in a recent Guardian article, the world is shifting from molecules to electrons, and China is clearly in the driver ‘s seat of this shift. More and more of the global energy growth and use is being met by electricity which can be cost-effectively supplied by renewable technologies. China clearly sees this. Unfortunately, the Trump administration is dedicated to maintaining dominance through the outdated use of 20^th Century fossil fuel policies. It is no wonder that Trump would not want to raise this topic during his charm offensive with the Chinese leader.

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China’s rise to renewable energy dominance has been striking. By the end of its last 5-year plan, in 2025, China’s renewable energy capacity had reached 2,340 GW, far exceeding the 1,300 GW goal spelled out in their previous 5-year plan. Of this capacity, 1,800 GW consists of solar and wind energy technologies. Solar is the clear winner: According to the International Energy Agency, China installed an estimated 350 to 415 GW of solar PV in 2025 alone, roughly half of all global installations and nearly ten times the amount installed in the U.S. during that same time period. China continues to dominate world solar PV markets. The U.S. market share in 2025 ranked fourth globally...behind China, the European Union and India. This is despite China’s electricity demand slowing in 2025, while U.S. electricity demand grew.

China also dominates wind energy markets, installing 130 GW of wind power in 2025, or 77% of the world market share.

The IEA’s Global Energy Review for 2026 confirms “the arrival of the Age of Electricity”: electricity demand grew 2.3 times faster than total energy. These trends are indicative of an energy transformation that is occurring globally; a transformation dominated by zero-emission energy sources in a more distributed and flexible grid providing electricity services as our dominant end-use energy supply and bringing with it the ancillary benefit of mitigating a growing climate crisis caused by fossil fuel use.

As noted by the Guardian, China is taking a leadership role in this transformation, while the U.S. is going backwards to mid-20^th Century fossil energy dominance and, as exemplified in its recent attack on Venezuela and takeover of its vast oil reserves, 19^th century gunboat diplomacy.

China has taken the road to renewable energy dominance these past few years. What road has the Trump administration taken? Here are some highlights, including those in the Guardian article, of steps Trump has taken to reverse our own renewable energy ambitions:

On his first day in office in 2025 he (again) pulled the U.S. out of the 2015 Paris Climate Agreement. He has also removed the U.S. from the important work of the United Nations Framework Convention on Climate Change and the Intergovernmental Panel on Climate Change work, and other key United Nations organizations, such as the International Renewable Energy Agency (IRENA). He is even threatening to pull out of the International Energy Agency because of their ongoing reporting on renewable energy and climate trends.

The Trump administration recently repealed the Endangerment Finding that has provided the legal basis for climate regulation in the U.S. over the past 17 years (see my SunBurst article on this action).

Trump has populated the leadership of key federal agencies (Department of Energy, Department of the Interior, Environmental Protection Agency, and others) with oil executives and fossil fuel proponents who have close ties to the industry. These appointments have resulted in a systematic and vast weakening of pollution prevention controls on fossil fuel exploration and extraction, especially on protected lands and fragile offshore ecosystems, and increasing pollutants emitted into our air and water by the use of these fuels. In parallel these agencies are dismantling many renewable and other clean energy programs of the Biden Administration.

Trump has ordered as much as 17 GW worth of aging and inefficient coal-fired power plants to keep operating, and to ask the Pentagon to purchase vast levels of new coal-fired electricity supplies. At the same time, he and his administration have convinced oil companies such as TotalEnergies to drop their plans for offshore wind development in place of fossil fuel projects, and the Pentagon to hold up virtually all onshore wind projects for questionable reviews on their impact on military radar systems. These actions are holding up and stopping at least 6 GW, and possibly much more, of clean electricity capacity.

Despite headwinds such as these (and elsewhere in other countries), the renewable energy transformation is clearly moving forward rapidly not only in China, but also throughout Europe, much of Asia and south Asia, many countries in Africa and South America, numerous island nations, even here, still, in the U.S. But Trump clearly does not care to see this, and for sure to acknowledge this transformation with other world leaders. President Xi Jinping ‘s goal to dominate global renewable energy markets were certainly not threatened by the U.S. leader in their summit last week.

On the other hand the fossil fuel industry is understandably threatened as the world transitions to this clean renewable energy economy, and for this reason it is beholden to governments to ensure that the transformation continues forward in a way that is just for all peoples and industry.

This is where our hope lies...a proper and expedited phase-out of fossil fuels.As articulated so elegantly at the end of the Guardian article, the opposition to a fossil fuel economy that keeps pushing us back to the 20^th and even the 19^th centuries is clearly evident within “...the vast majority of the world’s people, all of nature, virtually all climate scientists and the fastest-growing, greatest-job-creating chunk of the global economy: the clean energy sector” (italics are mine).

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In this article I dive into the topic of battery State of Charge (SOC), a calculation that serves as the fuel gauge for a battery energy storage system (BESS), such as the lithium ferrous phosphate (LFP) batteries we installed in our off-grid solar-powered home in the Colorado Rockies. SOC is defined as the percentage of full charge remaining in the battery at any given time. For those readers who may not have much interest in this topic, which is of critical importance to an off-grid dwelling as well as to electric vehicle (EV) drivers, you may be excused.

A simple Google search will bring up a lot of information on the topic. Knowledge of the SOC is critically important to both a battery’s user experience, such as knowing when the battery needs to be recharged, and to its safety and longevity. But unlike a fuel gauge, SOC cannot be measured directly; one or more several methods must be used to provide an accurate estimate of the SOC.

SOC is calculated within the Battery Management System (BMS), the “brain” of a rechargeable lithium battery, also known as a battery protection board. The BMS is an electronic circuit board that monitors not only the SOC but also the voltage, current, and temperature to ensure the battery’s safety and longevity. The BMS instructs the battery to operate within specified conditions, and to optimize its performance.

The two most common methods for determining SOC, often used in combination, are the Coulomb Counting, or Current Integration methods, and the Open-Circuit Voltage (OCV) method.

Coulomb Counting tracks the net current, as measured in amperes, flowing to and from the battery over time (“Coulomb” is the basic unit for electric charging). Although this method is easy to implement and requires only limited computation power, it is subject to drift over time and can become increasingly inaccurate as batteries age.

The OCM method relies on the relationship between a battery’s resting voltage (i.e., battery voltage when the battery is not in use) and an SOC curve established for the battery. This method is highly accurate and is also easy to calculate but is obviously impractical while the battery is in use.

Other more elaborate methods can also be put into use, such as model-based Kalman Filter-Based Estimation techniques, including Extended Kalman Filter (EKF) and Unscented Kalman Filter (UKF) methods. These have become widely adopted in the BMS installed in EVs. And now Machine Learning and Artificial Intelligence (AI) methods are being developed, although not yet widely available. A description of all of these methods can be found here.

For stationary batteries, the Coulomb Counting and the OCM methods are often used in combination in BMS. However, in order to maintain accuracy over time, the BMS may need to occasionally “recalibrate” the SOC calculation. This recalibration first requires the battery to be fully charged, although the recalibration does not actually occur until the battery has been in use for a while following 100% charge.

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We recently had an experience with our off-grid solar home system that appears related to a recalibration phenomenon. I will describe the incident here, but I am open to the comments of others who have more detailed knowledge of the recalibration phenomenon than I have.

Our solar plus storage system was originally installed in the summer of 2023 and was commissioned on August 21 of that year. The battery system recommended by our solar installer, Independent Power Systems of Boulder, Colorado, was Blue Planet Energy’s™ Blue Ion HI LFP storage system. The system consists of a cabinet containing up to 16 kW of removable battery modules. Two cabinets can be stacked when capacity of more than 16 kW is desired. We initially configured our system to consist of two stackable cabinets containing a total of 24 kW battery storage (see the figure below). In October of 2024 we expanded the storage to 32 kW, filling up both cabinets. A 7.4 kW rooftop solar array is the charging source for these batteries, and a Sol-Ark™ 15 kW inverter (which can also be seen in the figure) converts the direct current coming out of the panels and batteries into 60 Hz alternating current to supply the house.

The Blue Ion HI storage system is controlled by a BMS that calculates the SOC, prevents the batteries from over charging, and shuts off the power to the inverter when SOC drops below a specified value (the company recommends 20%, but is user specified). The reason is to prevent the batteries from dropping to 0% SOC, which would then require a manual “black start” of the entire system; something definitely to be avoided. The BMS also turns power back on when the batteries are recharged to 49% SOC (also user specified). Clearly these control features rely on an accurate SOC calculation.

The primary way I monitor the solar system performance is through the MySol-Ark™ app provided by Sol-Ark™. Blue Planet Energy™ also provides an app that monitors the batteries themselves called Stellar Microgrid OS™, but I only use this app on occasion to supplement the information provided through the MySol-Ark app.

Until just a few weeks ago I had never seen evidence of a system recalibration, which would presumably show up as a sudden change in SOC values. Since the system frequently recharges to a full 100% almost every day, I had assumed the recalibration took place at that time and would not show up in the SOC readings. But then, on April 26 at 04:05 in the morning, the SOC suddenly jumped inexplicably from 77% to 99%, according to the MySol-Ark app; however, the SOC provided by the Stellar app did not show the sudden SOC change. Then, less than 24 hours later the batteries stopped sending data through the Stellar app altogether.

On May 5 we had the largest snowfall of the entire season. Although this is pretty late in the season for a storm of this size, it was very welcome, given the seriousness of the persistent western drought we are experiencing. Approximately 30 cm (1 foot) of snow fell, resulting in the rooftop solar PV panels being completely covered for several days. Unable to obtain any charge from the sun, the battery SOC dropped from 100% on the evening of May 4 to 46% on the afternoon of May 7. We turned the heat down in the house to shut off the HVAC system and preserve battery life. Under these reduced loads the SOC drops by about one percentage point per hour. However, at 4:15 PM on May 7 the MySol-Ark app showed SOC suddenly dropping from 46% to 30%. SOC then continued to fall at the 1% per hour rate until 2:20 AM on May 8. At that time the SOC dropped below 20%, and power to the house was automatically shut off.

Power remained out for over 10 hours. But May 8 was a sunny, warm day, and by mid-morning the PV panels were mostly clear of snow. The batteries quickly recharged, and at 12:40 PM reached a SOC of 49%...enough charge for the BMS to instruct the Sol-Ark to turn the power to the house back on.

Nearly 3 days had passed between the last time the battery SOC was 100%, and when the SOC had dropped from 46% to 30%. I suspect that this drop was associated with a recalibration of the SOC calculation. However, other factors could also be coming into play. For example, and inexplicably, the Stellar app, which ceased to transmit data after the sudden SOC increase event on April 26, suddenly began sending data from the battery at precisely the time the SOC drop occurred on May 7. Thus, there is no record of the actual SOC drop in the Stellar app. The failure of the battery communication system during this time could have been an internet issue, or an issue with the BMS or batteries themselves.

Thus, it remains to be determined if the SOC drop on May 7 was cause by the SOC value going through a recalibration.

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Unfortunately, within months of our system upgrade in 2024, Blue Planet Energy’s founder, Dutch-born video game designer and entrepreneur Henk Rogers, posted on their web site that their battery company Murata (formerly Sony) decided to cease manufacturing the module that was the foundation of the Blue Ion HI. Rather than changing to another lower cost supplier in China, Blue Planet Energy™ has made the decision to explore an entirely new chemistry for their storage systems. My efforts to contact the company have so far not been successful, leaving us in a bit of limbo regarding any future service for our battery system. Fortunately, our solar installer, Independent Power Systems, a five-star company in my view, still provides us with support on our Blue Ion HI system.

Last Saturday Spirit Airlines, a U.S. low-budget airline in business for over 30 years, suddenly and permanently ceased all operations.

Spirit is (or was) only the ninth largest U. S. air carrier in terms of passenger boardings. So, unless you were an unlucky ticket holder for a seat on Spirit that day (I was not), or one of the airline’s 17,000 employees, the news probably had little impact on your Saturday plans.

The airline had already gone into bankruptcy twice and recently had warned anyone who would listen that rising airline fuel costs resulting from the Trump war on Iran were rapidly jeopardizing its very existence. But following its Saturday demise, Secretary of Transportation Sean Duffy blamed the airline’s troubles on the Trump administration’s favorite punching bag, former President Joe Biden. He accused the Biden administration for blocking Spirit’s efforts to merge with the more profitable JetBlue airline. Such a merger would undoubtedly have cost consumers millions in increased air fares, and weakened airline trade unions, but this is of no matter to the current administration: Duffy needed a scapegoat to hide the fact that rising jet fuel prices caused by his boss’s war were the direct result of Spirit’s final downfall.

And gasoline prices are soaring. The American Automobile Association now says that average gasoline prices in the U.S. have reached $4.47 per gallon, up by $1.49 (49%) since the start of the Iran war on February 28. In California the average price exceeds $6.10. But the war’s impacts here pale in comparison with other countries, especially in Asia, which rely heavily on fossil fuels and other goods imported by ships that must first pass through the Strait of Hormuz, not to mention the human suffering and tragic loss of life in the region caused by this war of choice.

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April 30 marked the closing of the first conference on “Transitioning Away from Fossil Fuels”, held in Santa Marta, Colombia. The Conference, chaired jointly by Colombia and the Netherlands, was an outcome of the most recent climate negotiations at the 30^th Conference of the Parties (COP 30) in Belém, Brazil, last November. Negotiators in Belém were unsuccessful in getting language related to a phasing out of fossil fuels in order to mitigate climate change into the final COP 30 statement. In the words of Carbon Brief, the Santa Marta conference was organized to establish “a forum for countries and other stakeholders to discuss practical steps to move away from fossil fuels”. Outcomes from such a forum would help inform future COP negotiators with language that could be included in fossil fuel phase-out statements.

Fifty seven countries attended. Not surprisingly, some key oil-producing countries, including the U.S., did not. Yet some meaningful, if not preliminary, outcomes were achieved. Several workstreams were created to provide outcomes that will complement future COP climate negotiations, such as developing national and regional roadmaps for transitioning away from fossil fuel use, changing the financial system to eliminate unwarranted fossil fuel subsidies, and formulating progressive trade policies. A “just transition”, emphasizing the need for equity and respect to human rights for those who currently depend on a fossil fuel economy, is a pillar of all the workstreams.

As one would expect, another key outcome was to announce plans for a second conference on this topic, to be held in the Pacific island nation of Tuvalu, co-hosted by Ireland, in 2027.

I confess I have become somewhat skeptical of international processes such as these, even though I have participated in some COPs in the past. It took 21 years of intense global negotiations to finally achieve the Paris Climate Agreement at COP 21 in 2015. This Agreement calls for all nations to develop Nationally Determined Contributions (NDCs), which spell out a country’s plans for reducing greenhouse gas (GHG) emissions. Ideally the collective action of all countries would ensure global warming to remain well under 2.0 ⁰C and ideally would not exceed 1.5 ⁰C above preindustrial levels (defined as the average during the period 1850 – 1900). At the time of the Agreement’s enactment, this would have meant for global GHG emissions to peak by 2025 and decline 43% by 2030. But at that time global warming had already reached 1.1 ⁰C and atmospheric concentrations of CO₂ were nearly 400 ppm. And now, nearly eleven years later, GHG emissions are still rising, and we are close to surpassing the 1.5 ⁰C marker. Current GHG emission trends have us well on a path to reach 2.0 ⁰C as soon as the end of the next decade. Many nations have come nowhere near to achieving their original or even revised NDCs. It is easy to see why more and more stakeholders in the climate change arena, including myself, are growing increasingly frustrated with the COP process.

These sobering trends emphasize the need for an effective phase-out strategy for fossil fuels. Last year the International Renewable Energy Agency’s Coalition for Action published the report “Achieving 100% Renewable Energy by 2050”. Colleague and good friend Rainer Hinrichs-Rahlwes of the European Renewable Energies Federation and I served as co-Chairs of the Working Group that produced this report. In the report Rainer penned a chapter titled “A Fossil Fuel Exit Strategy” that articulates many of the same arguments coming out of the Santa Marta Conference. Importantly, a just approach to the transition is perhaps the highest priority. Some policies, such as carbon pricing and even cap-and-trade mechanisms, designed to internalize the negative costs of health and environmental impacts, can be perceived as an unjustified burden on those economies that rely heavily on fossil fuels for electricity generation. Any exit strategy will require early and strong support and engagement of those most impacted by the strategy, including programs such as worker “reskilling”. These principles were at the heart of the Biden Administration’s Inflation Reduction Act, which the Trump Administration has systematically gutted in his nonsensical attempt to plunge the U.S. backwards into an outdated and high-risk fossil fuel-driven economy.

Beyond the COP-style climate negotiations, what gives me hope in phasing out our fossil fuel dependency is the tangible and accelerating progress towards clean energy developments occurring around the world at the grass roots level. For example, the International Energy Agency’s (IEA’s) Photovoltaic Power Systems (PVPS) Programme just published a PV global market report for 2025 showing the world’s PV capacity has now surpassed 3 TW, with over 600 GW installed in 2025 alone. Solar PV’s share in total generation has now reached 8%. As recently reported by Ember, 75% of electricity demand growth in 2025 was met by solar energy, and now over one third of global power generation is from renewables, surpassing the share from coal for the first time.

This remarkable growth is driven largely by real-world economics and practical solutions to our global energy access and security anxieties, although concerns about climate change remain a key driver. The costs of installing and operating renewable electricity have plummeted to the point where solar and wind technologies are now the lowest cost and most rapidly deployable source of new electricity supply throughout much of the world.

These trends make the Trump administration’s recent efforts to stifle wind energy development in the U.S. by paying off the leases of energy companies lined up to build offshore wind farms come off as sheer lunacy. Collectively these wind farms could have been operational within the next two years and would have added over 5 GW of electricity generation capacity. One of the developers, TotalEnergies, based in France, will receive $1B of U.S. taxpayer money for paying off their leases and stopping their offshore wind farm developments off the coasts of New Jersey and North Carolina, and worse, redirect their investments to oil and natural gas production in the U.S. As reported in the New York Times, TotalEnergies has also reaped profits of $5.4B due to rising U.S. gas prices resulting from the war in Iran, raising a strong argument for establishing a windfall tax on oil and gas companies to help cover the consequential costs of this administration’s follies.

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Trump’s actions in Iran have created a fossil energy crisis; but (and I am sure unwittingly), his policies are helping to highlight the opportunities in transitioning to a renewables-based economy.

In closing: Our off-grid solar powered cabin in the Colorado Rockies is a microcosm of the clean energy paradigm shunned by the Trump team. Here is an image of our Nissan Leaf™ being charged at the house, for free, directly from the sun.

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This week I’m switching topics from what I have written in recent posts.

I am writing about geothermal energy, the only renewable energy source the Trump administration apparently does not consider to be dangerous to whales.

This is not about utility scale geothermal energy, an important renewable technology that has had success throughout the world, thanks to the ability to go deep underground to tap into pressurized steam or inject water over hot dry rock to produce steam. For years successful commercial-scale geothermal power systems have been operating in a number of locations worldwide. The International Renewable Energy Agency reports 15.7 GW of global geothermal electricity capacity in 2025. Much of this capacity is located in the U.S., the Philippines, Indonesia, and Türkiye. Although the cost of installing a geothermal electricity plant remains relatively high, when compared with other renewable technologies, at USD $4000/kW (over four times the cost of installed solar PV), the high capacity factors for geothermal plants (~88%) keeps electricity costs around USD $6/kWh, competitive with other renewable energy technologies as well as traditional fossil fuel power plants.

I’m writing about the ability to passively supplement the heating and cooling of a home using natural earth heating and cooling principles; what I call passive geothermal energy. Typically, over land, especially in the mid-latitudes, the temperature of underground soil and rock within a few tens of meters below the earth’s surface can remain relatively constant throughout the year. Utilizing this feature can provide supplemental household heating in winter and cooling in summer. At our off-grid solar powered home in the Colorado Rockies, which we call Vista del Oro, unintentional consequences led us to be able to benefit from this phenomenon and improve the overall performance of the rooftop solar PV plus battery storage system that provides all of our electrical power needs.

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What exactly were these “unintentional consequences”? Well, our original home design was to build the majority of the house on a concrete slab foundation. There would be a small crawl space, but only under the kitchen, utility room and bathroom. Heating and cooling would come from a series of heat pump-driven mini-splits, and a wood-burning stove. But as the excavation began, we ran into a stark reminder as to just why the mountains out here are called the Rockies. Having encountered a giant underground boulder field, the only way to complete the excavation was to hire a blasting crew. They did their work in one day.

I will not go into the heart-rendering sight of watching a scenic portion of our beloved property being pulverized in a matter of seconds, or of the justified reactions we received from distraught neighbors.

But once all the rubble was removed from the building site, we discovered that we now had a deep enough hole to build a full crawl space under the entire house. For a few tens of thousands of dollars more we could have actually gone deep enough to allow for a full basement. But, perhaps mistakenly, we did not go with that option.

Nevertheless, having a full crawl space changed many other design parameters. The crawl space enabled us to install a ducted heating system, driven by an air exchanger, serving the entire house. A variable speed cold weather heat pump located outside next to the house provides the heat source in winter, and occasionally a source of cooling during the few warm summer days. A ducted system, rather than a series of mini-split units, is a far more efficient and comfortable way to heat an entire house.

And geothermal heating or cooling coming from below ground level serves to enhance the overall performance of the heating, cooling and ventilation (HVAC) system. The crawl space is “conditioned”, meaning it is insulated from the cold outside air. Being nearly 2 m (over 5 ft) deep in some places, where the underground temperature is typically warmer than the outside air during winter (and cooler in summer) the crawl space remains warmer than the outside air temperatures. Since a ducted system helps exchange air between the crawl space and the house interior, the result is to moderate the upstairs temperatures as well.

As I wrote in earlier posts, during prolonged periods when we are away from the house, we still want to take every necessary step to maintain an adequate interior temperature to avoid freezing conditions without draining down the batteries. If the solar panels are covered with snow and air temperatures remain very low for extended periods, we could lose power. But with the modest heating benefit we get from the conditioned crawl space we can turn the heat pump off for extended periods and rely on the air exchanger to circulate the conditioned air in the crawl space into the main part of house. This strategy helps us prolong the life of the battery while still maintaining a desired interior temperature.

The air exchanger includes an Energy Recovery Ventilator (ERV), required for highly efficient houses to maintain acceptable indoor air quality. The ERV continuously circulates pre-conditioned fresh air into the house using recovered energy from the exhaust air system to help maintain indoor air quality, whether or not the heat pump is running. Our ERV is programmed to run continuously in cycles of 10 minutes on, 5 minutes off. The ERV continuously circulates passive geothermal warmth throughout the entire house, whether or not the heat pump is running.

The house is already very efficient. Exterior walls have R values of 27, while the ceiling is R = 54. All windows are rated at U = 0.16. The Home Energy Rating System (HERS) Index is minus 57; a net-zero house would have an index of zero. The negative number demonstrates that the off-grid house produces more energy than it consumes.

Following a blower test shortly after construction, an Air Changes per Hour at 50 Pascals pressure (ACH50) Index of 1.73 was measured. An ACH50 rating of less than 3.0 is categorized as “highly energy-efficient”. Building codes in many parts of the U.S. require all new houses to meet or exceed this rating (the lower the index, the better). Although an Index of 1.73 is a bit higher than we anticipated, this is most likely due to the existence of outside air exchange in the crawl space as a result of the ducted HVAC system, plus additional air exchanges associated with the wood stove, fans in the kitchen and bathrooms, and the passive radon system.

In addition to the high efficiency ratings, the house benefits from certain passive design features, such as large south- and west-facing windows that enhance interior solar gain during winter, and the passive geothermal effect.

Using the actual temperature measurements obtained from our outdoor Davis™ weather station and from those provided by the Ecobee™ Thermostat...the sensor within the thermostat itself and a second external sensor which I installed in the crawl space...there are a number of analyses I can perform to quantify the home’s energy performance using 5-minute data collected both from the HVAC system (accessible through the thermostat) and from the solar plus storage system (accessible through the inverter).

Here I present some analysis based on monthly averaged data.

First, here is a plot of the average monthly outdoor temperatures, along with the temperatures inside the house itself and the crawl space showing how we are able to keep the house and crawl space much warmer by managing the thermostat settings:

Of course, the unusually mild winter we just had has helped. But we learned to use excess solar energy during daylight hours to run the heat pump more frequently without jeopardizing battery storage levels, so that there is plenty of reserve battery to maintain comfort when the panels are snow-covered or under prolonged cloudy conditions. Note the large differences between interior and exterior temperatures, especially for the two most recent winters.

This second plot shows how total HVAC loads have increased since the winter of 2024:

We have been running the heat pump more during recent winters to achieve this improved interior warmth as well as make use of excess available solar energy.

These plots are not intended to demonstrate the passive geothermal effect on household comfort levels; I will analyze some episodes using the 5-minute data in future posts to examine this attribute more closely.

But one point to say here is that by taking advantage of these passive sources, all-electric homes become even more feasible and ultimately support a carbon-free electricity system.

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In closing I share with you a photo that we took on our property on April 25. The aspen trees are already leafing out, nearly a month earlier than anticipated.

It has, indeed, been a mild winter.

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Today is April 22, 2026, the 56^th anniversary of Earth Day.

The emergence of fossil fuels as a low cost and abundant energy resource over the past two centuries has unmistakably led to a remarkable growth in the material well-being and economic condition of the world’s citizenry. But as economies and populations grew, the adverse consequences of burning these fossil fuels to drive the industrial revolution became more and more apparent, and, in many cases, even dire. By 1970 environmental conditions in many parts of the world had degraded to such an alarming level that a special day was designated to raise awareness and seek solutions before matters became even much worse. That day is called Earth Day.

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Earth Day was first proposed by a peace activist named John McConnell at a UNESCO Conference in San Francisco in 1969. The intention was for the first earth day to occur on the vernal equinox of March 21, 1970. Mr. McConnell wrote this proposal into a proclamation that was signed by United Nations Secretary General U Thant.

A month after his proposal Senator Gaylord Nelson from the state of Wisconsin proposed to hold a national environmental teach-in on April 22, 1970. The Senator hired Denis Hayes, a young activist, to convert Senator Gaylord’s vision into a national event.

However, the term “teach-in” was not garnering much public support. So, Mr. Hayes met with a copywriter named Julian Koenig, well known for his work on numerous advertising campaigns, who came up with the idea for calling the event Earth Day.

The first Earth Day was an immediate success, with 20 million people, or about 10% of the population, participating in events around the U.S. The event triggered a national awareness that helped inspire some of the most important environmental legislation ever passed in the U.S. Three months after this first Earth Day the U.S. Environmental Protection Agency was formed. The Clean Air Act of 1963 was amended and strengthened in 1970 to require all states to develop approved air quality control implementation plans. A sweeping Clean Water Act followed in 1972, and the Endangered Species Act in 1973. Concurrently, many private and non-profit groups sprung up, creating robust opportunities for civil engagement.

Mr. Hayes went on to serve as the first Director of the Solar Energy Research Institute (later known as National Renewable Energy Laboratory; and now the National Laboratory of the Rockies). He became president of the Bullitt Foundation in Washinton State in 1992. In 2009 the Foundation began developing the Bullitt Center, tagged as “the greenest office building in the world”. To this day Mr. Hayes continues as an environmental advocate.

For many years Denis Hayes was associated with the American Solar Energy Society (ASES), the oldest, continuously operating pro-solar energy organization in the world. ASES had its start in 1954, when it was first known as the Association for Applied Solar Energy, or AFASE. In the 1960s AFASE changed to the Solar Energy Society (SES). Then, in 1970, following a successful international solar conference in Melbourne, Australia, the Board of SES agreed to form the International Solar Energy Society, or ISES, to be headquartered in Australia. ASES and its counterpart in Melbourne, the Australia/New Zealand Solar Energy Society, or ANZSES, subsequently became the first “Sections” of ISES. ANZSES is now the Australian Smart Energy Council. All of these organizations remain very active to this day.

In 1993 Mr. Hayes received the prestigious Abbott Award from ASES, and in the early 2000s chaired the ASES Board of Trustees.

Thanks to Mr. Hayes’ activism, Earth Day became an international phenomenon by the 1990s and remains so to this day. Events are now organized in over 140 countries.

Early Earth Day events tended to focus on raising awareness of local and regional environmental problems: air quality degradation, river pollution, losses in biodiversity, harmful land use practices, and protection of natural resources. This remains the case to this day, but another environmental issue has clearly taken hold.

In 1970 the notion of climate change was hardly being discussed, other than within the scientific community. But over the years climate change has now become a major focus of local and regional Earth Day events.

As shown in a plot of annual temperature anomalies provided by Berkeley Earth, global warming had barely reached 0.3 ⁰C above preindustrial levels (generally accepted as the measurement period from 1850 – 1900) by 1970. In fact, from the end of World War II to the early 1960s global temperatures remained relatively constant, despite large year-to-year variations.

Some of this global warming slow-down has been attributed to a rising concentration of particulate matter in the atmosphere resulting from the intense industrialization that occurred post-World War II. The cessation in global warming during this period can be explained, in part, by the lack of meaningful air pollution controls prior to the 1960s, resulting in increasing concentrations of atmospheric particulate matter. Although atmospheric CO₂ concentrations increased steadily during this period, as shown in the chart below, atmospheric particulates reflected some of the incoming sunlight back to outer space and therefore created a cooling effect that potentially offset the warming that resulted from the increasing CO₂ concentrations. Global efforts to reduce particulate air pollutants grew in earnest in the late 1960s, and significant air quality controls have been implemented since the early 1970s. With less particulate matter, warming began to accelerate in the early 1970s. Since the first Earth Day, CO₂ concentrations have increased from about 325 ppm to around 430 ppm today.

In 1970 renewable technologies, especially solar and wind energy technologies for producing electricity, were largely in the experimental phase with a limited commercial presence. The only widely used renewable power technology at the time was hydropower.

But since 1970 other renewables, specifically wind and solar, or Variable Renewable Energy (VRE) technologies, have experienced great commercial success. The world now has 5.15 TW of installed renewable capacity. Although much of that capacity is hydropower, about 35% can be categorized as VRE, as recently reported by IRENA. Nearly half of the world’s total power capacity now comes from renewables (there are strong movements worldwide to see total renewable energy capacity be 100%). In recent years 90% or more of newly installed electricity capacity is categorized as renewable.

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But the headwinds pushing against a renewable energy transformation have become stronger. The fossil industry, seeing threats to its profits and expansion opportunities, and even to its very existence, is lobbying hard with many governments, especially in the U.S., to protect their interests, with varying degrees of success. Although these efforts are to the detriment of clean energy programs, in reality the transformation to a renewable energy system is not stoppable.

There is good reason as to why the majority of all new electricity capacity being installed around the world is based on renewable technologies. Costs have dropped dramatically, deployment times are much shorter than what is possible with fossil technologies, and, when combined with battery storage, offer substantial grid flexibility.

Although the International Energy Agency calls the current war in Iran “the mother of all energy crises”, it is in reality a fossil energy crisis, and not a renewable energy crisis. As pointed out by David Wallace-Wells in today’s New York Times, the war has, in many ways, boosted green energy programs; a “green lining” in an otherwise very “dark cloud”.

The fossil industry has reason to feel threatened by the energy transformation, and given the benefits society has obtained through the fossil-driven industrial revolution, it would be unfair, and obviously unwise, just to kick this industry aside, applying a stick without offering a carrot. Much of our economy is built around the existing fossil infrastructure. Millions of people have thrived with the industry, and billions have benefited in quality of life improvements. Talk of a true “fossil fuel phase-out” has been raised at the annual climate negotiations that take place at the Conferences of the Parties (COPs), but the challenges of a just phaseout that offers proper remuneration to affected communities and workforce re-training to all the effected workers has prevented national governments from signing off on this language in the negotiated COP agreements.

A step in that direction may be taking place this coming week at the First Conference on Transitioning Away from Fossil Fuels, being held in Santa Marta, Colombia on April 24-29.

Earth Day has long been about accountability. Who pays the costs of environmental impacts? Is it governments, or the polluting industries, or the citizens whose lives are being impacted? Besides the efforts of global climate negotiations, Earth Days of the future must continue to strive to highlight and debate these issues.

We need Earth Day more than ever now. And in a sense, every day needs to be an Earth Day. Even my 14-year-old grandson, Max, told me this recently. So I urge all of the readers of the SunBurst Almanac to take actions and make personal commitments towards achieving a fossil-free future every day.

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