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The West loves its wide open spaces. Utah, though, is something else.

Every state would like to think itself singular but, truly, there is no place like Utah. The Beehive State has long fascinated outsiders; today, that attention is largely trained on Netflix exposés about the Church of Jesus Christ of Latter-day Saints, ballerina farmers, and Crumbl cookies, but historically, the obsession has been with its land. Utah has the nation’s highest density of National Parks; its rivers, canyons, mountains, and deserts have stirred Mark Twain, John Wesley Powell, John Muir, and Edward Abbey. To quote a more contemporary literary conduit, Post Malone: “It’s a free country out there. You can buy suppressors in Utah. You can … walk into the grocery store with a handgun on your hip. Cowboy shit.”
More recently, Utah has sought out a different source of outsider attention — that of the United States Supreme Court. Two lawsuits that originated in the state are currently under consideration by the justices. The first, Seven County Infrastructure Coalition v. Eagle County, Colorado, concerns the scope of the National Environmental Policy Act with regard to the construction of a railroad spur that would link Utah’s oil fields to the national rail lines. (Though the tracks would be in Utah, the connection would ultimately increase hazardous waxy crude oil shipments through the Colorado county in the case citation.) The second lawsuit, Utah v. the United States — which the court has yet to decide whether or not it will hear — involves the state suing the federal government over its allegedly unconstitutional control of “unused” lands by the Bureau of Land Management. If Utah prevails in the case, it could mean the vast reshaping of the American West, about 47% of which is federal land.
“Utah is all crazy, all the time right now,” Stephen Bloch, the legal director of the Southern Utah Wilderness Alliance, a conservation nonprofit opposing Utah v. the U.S., told me.
While not immediately apparent, there is nevertheless a strange logic to the two lawsuits that otherwise appear to have little to do with one another beyond the fact of their geography. At their core, both cases are ultimately about who gets to decide to do what with Utah’s land.
To anyone familiar with land use issues in the Mountain West, all of this is fairly routine. A strain of libertarianism and anti-government individualism runs through the more conservative inland Western states, coloring everything from the gun ownership policies so colorfully observed by Post Malone to whom the states back for president. Yet in the extent to which it is willing to pursue this common ideal, Utah is still an outlier.
“Westerners revere their public lands,” Betsy Gaines Quammen, a historian and author of American Zion: Cliven Bundy, God & Public Lands in the West, told me. “This is what makes the West the West — that you can come out and just go hiking, and you’re not trespassing.” Take the recent Montana Senate race, in which incumbent Democrat Jon Tester wielded his opponent Tim Sheehy’s comparatively mild comments about privatizing public lands as a cudgel in a deep red state. (Tester, it must be added, lost his reelection bid.) But in Utah, instead of celebrating federal land as the embodiment of this Western inheritance, its politicians are trying to eliminate them.
In the case of Utah, this goal is immediate and obvious. State officials claim that the 18.5 million acres of “unappropriated” BLM land in the state — that is, public lands not already designated as national parks, monuments, wilderness areas, national forests and conservation areas, or Tribal lands — are held in violation of the U.S. Constitution, which doesn’t explicitly authorize the federal government to hold land indefinitely. “Utah deserves priority when it comes to managing this land,” the state’s Republican Governor Spencer Cox said at a news conference in August, adding, “Utah is in the best position to understand and respond to the unique needs of our environment and communities.”
While Utah’s crown jewel, its “Mighty Five” National Parks, would remain under federal management, the state of Wyoming — which has backed Utah’s lawsuit in an amicus brief along with Idaho, Alaska, and the Arizona legislature — wants even more. “In Wyoming’s filing, they’re like, ‘Oh no, we’re in for everything,” Bloch said. “‘There shouldn’t be any federal land in Wyoming’ — including national parks.” More than 95% of Yellowstone National Park — the nation’s first national park, designated in 1872 — sits within Wyoming’s borders.
It seems doubtful that the Supreme Court will take up this case. For one thing, Utah is attempting to leapfrog the lower courts by taking its complaints directly to SCOTUS, a shortcut it says is justified by its concerns being “of profound importance not just to Utah, but to all the States in the Nation.” For another, President Biden’s Department of Justice has pointed out that what Utah seeks is outside the powers vested in the judicial branch; only Congress has decision-making authority over public lands. On the other hand, “Anyone right now, I think, would hesitate to say definitively, ‘Here’s what the Supreme Court will do,’” Aaron Weiss, the deputy director of the Center for Western Priorities, a nonpartisan conservation advocacy group, told me.
Seven County Infrastructure Coalition is a different story. Opponents of the railway claim that the government’s environmental review took into account the remote economic benefits of the railway — including induced employment, a notoriously inexact projection — while not equally weighing the indirect health impacts of the rail line, such as the pollution of additional fracking wells in the Uinta Basin or frontline communities near the refineries on the Gulf, where the crude oil is ultimately headed. The Supreme Court (minus Neil Gorsuch, who recused himself at the 11th hour) heard oral arguments in the case this week, however, and appears on track to rule that the government’s NEPA review for the railroad was sufficient. That would ultimately be a win for the Uinta Basin Railway and the business coalition that brought the suit after the U.S. Court of Appeals for the District of Columbia Circuit ruled there were flaws in the upstream and downstream analyses.
“I’m really worried that the court could end up inadvertently blessing this fundamentally arbitrary, imbalanced result, where an agency is allowed to talk about all the indirect benefits that they want — to go as far down the line, as far upstream, to the ends of the Earth chasing these indirect benefits — but not bother talking about the corresponding costs,” Jason Schwartz, the legal director at the Institute for Policy Integrity at New York University’s School of Law, told me. “That undermines the very purpose of NEPA, which was to present the public and decision-makers with a full and balanced view of both the economic and environmental perspectives.” (Schwartz authored an amicus brief for the Institute of Policy Integrity against the government’s NEPA review.)
A ruling that reaffirms the current scope of NEPA wouldn’t be a shock — the court has always sided with the government in such cases, E&E News notes. What’s different this time is that the plaintiffs presented the court with a third option, an avenue that would severely limit the scope of the NEPA’s environmental review process going forward by restraining agency considerations only to what falls under their immediate purview. Chief Justice John Roberts has sounded skeptical of this pitch so far; it’s this third path, however, that the oil and gas producer Anschutz submitted an amicus brief to the court to support, drawing attention to the fact that “far more is at stake … than the 88-mile rail line in rural Utah.” (The company’s owner, Philip Anchutz, has close ties to Gorsuch.)
“There are so many ways to make NEPA more efficient without arbitrarily decreasing the sometimes crucial information related to indirect effects that NEPA currently provides,” Schwartz told me. Sam Sankar, the senior vice president for programs at Earthjustice, which is supporting the defense, added to me that his read on Seven County Infrastructure Coalition case is that it proves how this Supreme Court has “a pretty aggressive deregulatory, anti-environmental agenda.” The Seven County Infrastructure Coalition told Heatmap in a statement that with regards to the railroad, “we remain committed to advancing this critical infrastructure, which aims to unlock economic opportunities and support the region’s long-term development,” but that it could not comment further as the case remains under deliberation.
A threat to NEPA is also a challenge to who gets a say in what Utah does with its land, of course. Like Utah v. the U.S., the filing for Seven County Infrastructure Coalition bristles with indignation over the government’s determinations about how things should be done or what impacts should be considered, even if the Surface Transportation Board ultimately gave the railroad the green light. Utah, meanwhile, originated as a reaction to the BLM’s Public Lands Rule, in which the agency considers conservation as a land use on equal footing with those of energy development, mining, or grazing. (Specifically, Utah lawmakers were furious about the BLM closing some roads to motorized vehicles. “That’s something that Utah gets very worked up about,” Bloch, the legal director at SUWA, told me.)
There is always a risk of overascribing the state of Utah’s otherwise seemingly inexplicable actions to Mormonism — a religion that is far from monolithic and is often the subject of derision from outsiders. But Quammen, the historian, told me that you can’t separate today’s public land policies from the cultural and theological inheritances and beliefs reinforced over generations of Mormon tradition. “A lot of the people taking these stands [over public lands] come from families that have been in that area for generations, so they have stories and ideologies that have been passed down — as has their relationship with the land,” Quammen explained.
Weiss, of Western Priorities, concurred. “There are some folks in Utah who truly believe that this land belongs to them,” he said.
Quammen noted by way of example that Cliven Bundy, who led a standoff at the Malheur National Wildlife Refuge in Oregon in 2016 over the demand that the BLM cede its land to the states, told her his legal right to the public lands where he grazes his cattle in Nevada started when his ancestor’s horse drank from its Virgin River — although in fact it was a Southern Paiute river before that. (That’s not the only historically inaccurate ownership claim that might be at play in Utah; Bloch of SUWA noted that the lands within the exterior boundaries of the state were ceded to the federal government in 1848 through the Treaty of Guadalupe Hidalgo at the end of the U.S.-Mexico War, and in that sense, “they’ve never been ‘Utah lands’ so there’s nothing to ‘give back’ to Utah.”)
Preservationists and conservationists during the settlement era saw Utah’s landscape as untrammeled (“also not true, because it was Indigenous land,” Quammen added) and in need of protection, but early church belief viewed it differently. “They thought that the land being utilized, built, and made productive was pleasing to the eye of God,” Quammen said. Finally, Joseph Smith, the founder of LDS, emphasized the importance of his adherents understanding the U.S. Constitution inside and out. In the case of public lands disputes, this resurfaces in the claim that the federal government can’t own land indefinitely, Quammen told me. “That’s the piece about understanding the Constitution better than constitutional scholars.” Ironically, it disregards the state’s constitution, in which Utah explicitly agreed in 1894 to “forever disclaim[s] all right and title to the unappropriated public lands” in order to be granted statehood.
There is, of course, a significant small-government push in the Republican Party, too; privatizing land was part of the party’s presidential platform this year. It can be hard to tell, however, where one influence ends and another begins: William Perry Pendley, a key figure in the Reagan administration during the Sagebrush Rebellion fight over public lands in the 1970s and 1980s, authored the Project 2025 chapter on the Department of the Interior. Doug Burgum, Trump’s nominee for the head of the department, recently met with Utah’s Republican Senator Mike Lee, a devout Latter-Day Saint, who afterward posted, “Great meeting with @dougburgum and planning the return of American lands to the American people.” And if Trump attempts to walk back protections of Bears Ears and Grand Staircase Escalante National Monuments again, that land would be added to the pot of what Utah is seeking to acquire.
Utah’s organizers seem prepared to make an appeal to Congress or the Trump administration if the Supreme Court doesn’t make a move in their favor; funding for the messaging for Stand for Our Land, the publicity arm of the lawsuit, has reportedly outpaced the spending on lawyers. (A request for comment to the Utah Attorney General’s Office and Gov. Spencer J. Cox went unanswered.)
The implications of the Supreme Court’s decisions on limiting the scope of NEPA or hearing the public lands lawsuit are vast in both cases. The former could ease the way for expansive oil and gas development in Utah, which would be “a bona fide public health nightmare,” according to Brian Moench, an anesthesiologist on the board of Utah Physicians for a Healthy Environment, which is opposing the railroad, due to all the additional pollution. “If they’re allowed to do this and increase the oil and gas drilling production by 500% — I don't know what you would call the end result. Unlivable, as far as I’m concerned.”
In the case of the public lands, meanwhile, “I think [Utah is] trying to give the impression that these are scrubby lands that nobody cares about when, in fact, it concerns landscapes like Labyrinth Canyon or the Dirty Devil or the Fisher Towers — these very iconic red rock landscapes that Americans think about when they think about visiting the state,” Bloch told me. “Those are the types of places in the crosshairs with this lawsuit.”
Ironically, it’s doubtful that a transfer of public lands would even benefit most Utahns. Because states can’t run deficits, a disaster like a bad wildfire would drain the Utah budget. Additionally, ranchers would pay far more for grazing their cattle on state lands (as high as $19.50 per animal unit per month, per the BLM) than on federal lands, where the fee is a dirt-cheap $1.35. Ultimately, the state likely wouldn’t even possess much of the land it claims to want so badly.
Utah’s politicians “would much prefer to be able to sell off any lands that they want — whether it’s for oil and gas leasing, whether it’s for mansions near national parks. This is very valuable land and a very valuable resource that belongs to all Americans,” Weiss of Western Priorities said. “And Utah would prefer if it belonged to them.”
Public lands and pride in the natural environment are fundamental to many Westerners’ beliefs and identities. By that token, it would seem Utah has made a miscalculation that only an insider could truly appreciate the cost of; by taking over control of portions of its territory from the federal government, it would be, in effect, boxing Utahns out of their own lands —a craven, modern twist if ever there was one.
But to be able to hike or hunt, to pitch a tent, to fish, to stargaze, to graze one’s cattle on nearly 70% of the land in Utah, because it belongs to us, the public?
Now that’s cowboy shit.
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New research from Climate Central estimates the rise in heat-related emergency room visits due to climate change.
2027 is very likely to be the hottest year ever recorded. Though heat was the climate story of the summer — the ocean heat that dictates the severity of El Niño; the back-to-back heat domes in Europe that killed an estimated 35,000 people; the U.S. experiencing its hottest month in 130 years, breaking the Dust Bowl record — what lies ahead will be, in all likelihood, nothing our species has ever experienced before.
We need to get better at understanding and adapting to extreme heat because lives are on the line. But there is also a lot of bad stuff that happens to people before they actually die from the heat. While excess mortality rates are an important (albeit tricky) way of measuring how bad a heat wave is, climate change-related heat is also fueling an increase in emergency room visits, new peer-reviewed research by Climate Central found.
In a study released Wednesday looking at warm months in the years 2018 to 2025, Climate Central found that the observed rate of heat-related ER visits averaged 130 per 100,000 total visits, compared to a modeled rate of just 95 visits under counterfactual temperature conditions — that is, what temperatures would be without the influence of human-caused climate change. That means human-caused planetary warming directly accounts for about 35 visits per 100,000, or 27% of heat-related emergencies.
While the Sun Belt had the highest overall rates of heat-related ER visits, as expected, the largest relative climate fingerprint appeared in the Northeast (41%) and New England (37%), likely because these regions are far less acclimated to (or built for) extreme heat. Likewise, while July had the highest overall number of ER visits, being the hottest month of the year in the U.S., September showed the highest percentage attributable to climate change (33%) as heat impacts have begun to extend later into the fall.
Measuring emergency room visits might seem superfluous compared to measuring deaths, the latter being the more traditional headline number after an extreme weather-related tragedy. But Kristina Dahl, the vice president for science at Climate Central, told me that her group’s research is part of an emerging branch of attribution science called impact attribution.
“We’re trying to go beyond attributing the physical climate variables like high temperature and see how climate influence percolates into the whole chain of events,” Dahl said. “There’s a lot of literature that shows that heat-related illness increases when temperature increases, and there are a lot of studies that translate high temperatures into deaths and heat-related mortality. But we haven’t seen anything that looks at the lower-level health impacts related to heat exposure.”
Lower-level health impacts are crucial to understand, though. For one thing, more ER visits strain health systems in potentially lethal ways as wait times, premature discharges, and occupancy climb, resources dwindle, and care is rationed, earlier research has found.
Take the 2021 Pacific Northwest heat dome, the most extreme three days in the entire Climate Central record, with an observed rate of 6,763 heat-related ER visits per 100,000. About 1,834 of those visits, or 27%, are attributable to climate change, the researchers found. The Pacific Northwest “probably still would have seen a big spike in ER visits for heat-related illness during that event, even without climate change, because it was so extreme,” Dahl told me. But even a handful more heat patients than usual can gum up an ER, since treating conditions such as heat exhaustion and heat stroke requires lowering a person’s core body temperature slowly back to its normal range. Separate research has found that hospitals are more likely to discharge patients early to free up beds during heat waves, also raising mortality rates.
A visit to the ER isn’t just scary and disruptive; it can also be extremely expensive for whoever’s in the bed. “Our healthcare system is a really challenging system to navigate. It’s strained in a lot of ways, and people’s wallets are also strained because of it,” Dahl pointed out. Understanding how ER visits strain the health care system at large can also help administrators better stage ambulances and personnel ahead of extreme heat events — and invest in workforce expansion and infrastructure upgrades to prepare for the eventuality. Ideally, interventions can prevent people from end up in the hospital at all. Workplace heat protection policies, community cooling centers, and nature- and infrastructure-based cooling solutions are all vital.
There is a critical caveat to the Climate Central analysis, however: The data it uses to calculate heat-related ER visits comes from a Centers for Disease Control and Prevention initiative called the National Syndromic Surveillance Program. More than 85% of U.S. emergency departments report to the NSSP within 24 hours of a patient coming through the doors, conveying the chief complaint that a patient arrives with. “That could be someone saying, ‘I think I have heat exhaustion,’ or ‘I’m super dehydrated,’” Dahl said.
But because of that human element — and because a person having a heart attack isn’t likely to come in saying, “Hey guys, I think I’m having a cardiac event exacerbated by extreme heat” — Climate Central’s analysis faces the same limitations as other excess mortality reports that rely on reporting systems not designed to measure heat impacts. (This is also why NPR recently calculated that the number of people who die from extreme heat in the U.S. each year is likely five times greater than the official CDC numbers.)
When I pressed Dahl on the question, she agreed that Climate Central’s research offers “a conservative look” that could lead to an undercount. “We also know that in parts of the country where physicians don’t typically see heat illness, they tend to be a little less likely to code a visit as heat-related,” she added.
This isn’t a knock on Climate Central’s analysis — rather, it’s frightening to think that the real rates of heat-related hospital visits, much less all visits directly attributable to climate change, are probably much higher. Researchers, of course, need to be careful not to sensationalize, especially since sloppy data and poor science communication can lead to misconceptions and underestimations about the dangers of heat among the population. But it pays to understand what is happening; a surge in ER visits is another piece of the public health puzzle. Hopefully someone is paying attention, because the planet’s hottest summer — if prevailing trends bear out — is now only 41 weeks away.
Here are the major dates on the climate and energy calendar.
This is an edition of Heatmap Daily, an evening review of the day’s news written by our executive editor. Sign up for it here.
The Labor Day weekend is over, so today marks the unofficial start of fall in the United States — and my return to writing Heatmap Daily. Many thanks to Emily Pontecorvo for holding down the fort while I was on vacation.
As the seasons change (at least in a non-meteorological, non-astronomical capacity), I’ve been thinking about what the rest of the year might look like. Only 114 days separate us from the end of 2026, and between now and then, we're going to get answers about some of the country’s — and world’s — biggest ongoing climate and energy questions. By December 31, for instance, we’ll almost certainly know whether Congress has reached a deal on bipartisan permitting reform, and we’ll be watching a likely record-breaking El Niño kick into high gear around the world. The U.S. political system will also be gearing up for the next presidential election.
I’ll have more on some of the biggest questions I’m thinking about later this week, but first I wanted to lay out the map. Here’s a guide to the biggest remaining dates on the climate and energy calendar in 2026.
September 22 to September 28
Every year, world leaders descend on New York City for the UN General Assembly’s week of high-level meetings … at the same time that climate and energy wonks try to scrounge hotel rooms for New York Climate Week, the closest thing that the climate and decarbonization industrial-advocacy complex has to an annual confab.
This year, another event will be added to the mix. President Xi Jinping of China is supposedly skipping the UN meeting this year, but he will be staying just a few hundred miles away on the same exact days for what seems to be a Trump-hosted state visit in Washington, D.C. This will be the Chinese leader’s first state visit to America in more than a decade, and it will come, presumably, as U.S. relations with its neighbors and allies reach a recent nadir. Given the host country here, I wouldn’t expect to hear too much about climate change, but AI, trade, and Taiwan will all likely be on the schedule.
You can expect to hear a lot about climate change (and national energy policy, and the data center boom, and much more besides) at Heatmap House, our all-day gathering at New York Climate Week on September 23. Subscribers can register now, and speakers include former Vice President Al Gore, Secretary of Energy Chris Wright, and more.
October 4, 2026
Voters in Brazil will elect the country’s president, vice president, and members of its National Congress for the first time since former President Jair Bolsonaro attempted a military coup in 2022. Bolsonaro is under house arrest for his role in the attempted autogolpe, so he can’t run; instead, his son Flávio Bolsonaro is standing. The incumbent President Lula da Silva leads in the polls. Under Lula, Brazil has pledged to cut its greenhouse gas emissions by roughly two-thirds below their all-time high by 2035.
November 3, 2026
On the first Tuesday in November, Americans will vote for the full membership of the House of Representatives as well as one-third of the Senate. Democrats are expected to retake the House — it would, at this point, be a shock if they didn’t — but the president’s polling has become so dire that they’re hoping to beat the odds and take the upper chamber, too. If Democrats succeed in winning Congress outright, expect the second half of President Trump’s term to look quite different, with liberal lawmakers running aggressive oversight campaigns in the run-up to the 2028 presidential election. Interior Secretary Doug Burgum’s plan to overhaul the National Parks Service, for instance, seems like just the kind of effort that could falter in a more scrutinized environment; the Trump administration’s extrajudicial war on wind will also likely face more oversight than it has so far. Trump would also presumably have a much harder time making judicial and Executive Branch appointments.
Even though Election Day isn’t until November, early voting starts in less than a month in some states. Expect to hear a lot more about data centers and electricity bills between now and then. Some state-level races — particularly those in Michigan, Georgia, and Pennsylvania — could also shape the field for the upcoming 2028 presidential election. (Whether Senator Jon Ossoff of Georgia runs for president, for instance, will depend heavily on who wins that state’s governor’s race — and could appoint his successor.)
November 9 to November 20, 2026
The UN’s annual climate conference will be in Antalya, Turkey, this year and begin just a few days after the U.S. midterms. This is going to be a weird summit: Turkey is hosting the physical meeting, but Australia is nominally the “political” host. The conference is supposed to focus on clean energy, zeroing waste, and methane reduction. This will be the 31st meeting of the Conference of the Parties to the UN Framework Convention on Climate Change, and it may offer a look at what a post-Trump, post-1.5 degree Celsius UN meeting could look like.
The industry has gotten excited before, to no avail. Will it stick this time?
Over a decade ago, when the global price of silicon-based photovoltaic modules was roughly five times what it is today, the solar industry and media were already hyping up the next big thing: perovskites, a class of materials defined by their specific cube-like crystal structure. The technology promised to boost photovoltaic efficiency while driving down costs, and the industry was atwitter.
“All the cool solar-cell scientists are working on perovskites photovoltaics,” IEEE Spectrum proclaimed in a 2014 article. In the same piece, Oxford Photovoltaics predicted that it would have commercially available cells within four years. The Wall Street Journal profiled the tech that same year, and in 2015, The Guardian declared that perovskites could be “game changing.” The excitement centered around the potential for higher output at lower costs: Perovskite cells were seeing rapid efficiency gains, could be made from cheap materials, and were remarkably thin and lightweight. When the question of durability came up, it was often as an afterthought. But that has turned out to be the technology’s biggest obstacle.
“What the industry came to understand very quickly is that, yes, you could see higher efficiency, but that material is going to degrade pretty quickly,” Laureen Sanderson, chief communication officer at the perovskite startup Cubic PV, told me. “A lot of the efficiency records that you were seeing were records that were achieved on very small scale devices in a laboratory environment, potentially measured in the dark.” Not ideal for a technology designed to soak up the sun on a large scale.
It’s true that perovskite cells tend to break down rapidly on contact with moisture, heat, and light, a problem scientists have been slowly chipping away at in the lab. That fragility largely arises because perovskites are made of electrically charged ions held together mostly by the attraction between positive and negative charges, much like magnets snapping together. That’s an intrinsically looser structure than the covalent bonds in silicon, which fuse the atoms together via shared electrons. As a result, the ions in perovskites migrate when exposed to the elements, accumulating in places where they react with surrounding materials to form unwanted byproducts that gradually break down the cell’s structure.
But while durability has been its fatal flaw, efficiency is perovskite’s superpower. Silicon’s efficiency tops out at 29.4%, a fundamental physics limitation that no amount of engineering can overcome. But because perovskites can be tuned to absorb different wavelengths of light beyond what silicon can capture, stacking a thin perovskite cell atop a conventional silicon cell lets the combined device make use of more sunlight than either material could alone. In July, one of these silicon-perovskite tandem cells — the industry’s dominant architecture — set a new 35.5% efficiency record.
So while this new tech still doesn’t match the stability of conventional panels, it’s getting much better. Tandem cells hold up increasingly well when exposed to heat, light, and moisture in the lab, and early outdoor trials are starting to produce promising real-world performance data. With headlines about perovskites starting to roll in once more, scientists say there’s good reason to believe that, this time around, the hype might actually be justified.
“Over the better part of a decade, there’s been lots of, for want of a better word, device engineering to engineer the material to just be much more stable,” Sam Stranks, an energy materials professor at the University of Cambridge and co-founder of perovskite startup Swift Solar, told me. That includes swapping out an unstable chemical building block in perovskites called methylammonium with a more stable one called formamidinium, improving the connection point that binds the perovskite layer to the electrode layer, and improving the packaging of perovskite cells to seal them off from air and moisture.
“There’s still work to be done to really get it to the point where you could put it up on a rooftop for 25 years and you know it will last. But the trajectory is very promising,” Stranks said.
Scientists have managed to extend perovskite durability from mere hours to the point where cells and modules are now passing industry-standard tests that suggest they could survive outdoors for five to 10 years. That’s still a ways away from the standard 25-year warranties for silicon solar panels, which typically guarantee that a module will retain 85% to 90% of its original output by year 25. And because these latest perovskites simply haven’t been around that long, scientists have yet to test these more ambitious durability claims in the real world.
Industry experts say there’s no reason continued incremental improvements can’t get perovskites to that 25-year standard relatively soon, however. “If you look at silicon, it’s been 70 years of trial and error,” Scott Wharton, CEO of perovskite startup Tandem PV, told me. “Seventy years of constant tweaking and improvement, whereas perovskites have only had about 12.”
Wharton said that Tandem’s testing indicates its panels will degrade at a rate of less than 1% per year. Furthermore, he predicts perovskites will become the dominant solar technology by 2033, a more ambitious timeline than others in the industry typically project. But as he sees it, seven years is roughly enough time to build and deploy two generations of perovskite factories — the kind of iterative ramp-up he says new technologies typically need to achieve market dominance.
The economics just make sense, he told me. Because perovskites are more efficient, they will produce more power per unit — which means less land, hardware, wiring, and labor needed to achieve the same total energy output, driving down costs at every step of the process. Why wouldn’t everyone jump onboard immediately? “All of our customers have said that once we’ve proven it out, they’re going to move,” Wharton told me. “They’re going to move 100% to tandems because of the power of the efficiency gains.”
Others are somewhat more measured regarding how long this may take. Stranks predicted it would be about five years before perovskites with multi-decade warranties even begin hitting the market, while Sanderson estimated they’ll gain real commercial traction by 2029, with perovskites making up a “significant portion of the market” throughout the 2030s.
While the date of that tipping point remains up for debate, the industry appears to have largely settled the question of materials. At least for now, the preferred configuration is to pair a lead-based perovskite cell with silicon rather than build an all-perovskite cell, which would likely face even greater durability challenges. That’s because such a cell would also need a tin-based perovskite layer to capture lower-energy light like silicon does, but tin degrades even faster than lead. In other words, it’s easier to keep silicon — a proven, durable material — in the mix by building so-called “tandem cells” for the foreseeable future.
But there’s still plenty that remains unknown. Every startup’s exact chemistry is proprietary, and there’s no clearly dominant formula yet. There’s also no industry consensus on the architecture best poised to address perovskite’s stability challenge, either, with leading players typically taking one of two different approaches.
Stranks’ Swift Solar team is pursuing what’s known as a “two-terminal” tandem architecture, in which a manufacturer builds the perovskite layer directly on top of the silicon layer, with the two cells functioning as a single unit. That’s opposed to a “four-terminal” design, where companies build two independent perovskite and silicon cells and then mechanically stack them on top of each other rather than fusing them together.
Two-terminal is the more widely studied approach, pursued by other industry leaders such as Oxford PV — the same company that once predicted commercialization by 2018 — along with Chinese solar giants LONGi and JinkoSolar. Proponents argue that using fewer material layers means less light lost, which translates into greater efficiency and lower costs. In a blog post last year, Swift Solar’s team also argued that the four-terminal designs rely on laser cutting, which it says can create more entry points for degradation.
Two-terminal isn’t just the leading theoretical contender, it’s the first architecture to officially make it to market. Oxford PV’s finally executed its long-delayed commercial launch in 2024, shipping its modules to an undisclosed U.S. customer for use in a utility-scale solar project. It was the world’s first commercial sale of perovskite panels, which Oxford claimed could produce up to 20% more energy than standard silicon modules.
But newer market entrants such as Cubic PV and Tandem PV are bullish on the four-terminal approach. For one, while two-terminal designs use fewer materials, they are more difficult to manufacture. Building a perovskite layer directly onto silicon’s rough surface is more technically difficult than coating it onto smooth glass, as Cubic and Tandem do. And because four-terminal companies manufacture the perovskite and silicon cells separately, they can swap in whatever silicon cell is cheapest or most efficient at any given moment, rather than being locked into a single supplier’s tech.
That flexibility could prove important as the market moves beyond early adopters. For now, Stranks said, customers buying tandem modules are probably doing so for strategic testing purposes — placing small, one-off orders to trial the tech themselves. An installer today can’t simply go buy perovskites on the open market by consulting a public pricing list or product catalogue the way they can with silicon panels. “But it’s not too far away before that would be the case,” he explained.
For its part, Swift is moving … swiftly, acquiring the manufacturing assets and IP of the bankrupt Swiss silicon cell maker Meyer Burger this spring. The company plans to use those assets first to build a U.S.-based gigawatt-scale silicon cell and module factory to meet demand for domestically manufactured solar cells, eventually adding silicon-perovskite tandem module production to that same facility.
Tandem PV is also pushing ahead with plans to begin selling to customers by the end of this year “in a volume that would be big enough to hit bankability goals,” Wharton told me. It also plans to bring a gigawatt-scale factory online by 2028. The company is targeting the independent power producers who build, own, and operate most utility-scale solar projects today. And like Oxford, Swift, and Cubic, Tandem is focused primarily on the utility-scale solar market — by far the biggest opportunity for perovskite technology.
Cubic scrapped plans in 2024 to build a facility producing silicon wafers — the raw material used to make solar cells — amid collapsing wafer prices globally and surging construction costs domestically. While Sanderson says the company remains interested in building its own factory, it has no timeline for doing so. But in the meantime, it’s also interested in licensing its IP to other perovskite companies.
The outlook for domestic wafer production has improved in recent years, though, after the Biden administration provided stronger financial incentives for producing wafers in the U.S. The Trump administration has kept these in place, though it’s made domestic content requirements stricter and more complex overall.
There’s also another new policy variable in the mix: Section 232 tariffs on cheap silicon wafers from China. Going into effect this December, the tariffs could benefit producers like Swift and Cubic, which plan to manufacture silicon cells domestically, while potentially raising costs for companies like Tandem that hope to simply source the cheapest, most efficient silicon available on the market.
At any rate, perovskites give the U.S. a chance to secure a domestic supply chain for the next wave of solar tech. Because while Chinese perovskite producers are setting efficiency records, Wharton told me that they tend to be quieter on the question of durability. That could easily give a Western producer with a credible, multi-decade warranty the opportunity to jump to the front of the pack.
And that may happen sooner than you’d expect. “This always follows the same pattern,” Wharton said of technology breakthroughs generally. “You have a bunch of early entrepreneurs who overhype things, and then everybody goes, Yeah, that was a bunch of BS. And then it actually gets real, and then people go, It’s real, but it’s going to take forever. But then it doesn’t take forever because economics always wins.”