You’re out of free articles.
Log in
To continue reading, log in to your account.
Create a Free Account
To unlock more free articles, please create a free account.
Sign In or Create an Account.
By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
Welcome to Heatmap
Thank you for registering with Heatmap. Climate change is one of the greatest challenges of our lives, a force reshaping our economy, our politics, and our culture. We hope to be your trusted, friendly, and insightful guide to that transformation. Please enjoy your free articles. You can check your profile here .
subscribe to get Unlimited access
Offer for a Heatmap News Unlimited Access subscription; please note that your subscription will renew automatically unless you cancel prior to renewal. Cancellation takes effect at the end of your current billing period. We will let you know in advance of any price changes. Taxes may apply. Offer terms are subject to change.
Subscribe to get unlimited Access
Hey, you are out of free articles but you are only a few clicks away from full access. Subscribe below and take advantage of our introductory offer.
subscribe to get Unlimited access
Offer for a Heatmap News Unlimited Access subscription; please note that your subscription will renew automatically unless you cancel prior to renewal. Cancellation takes effect at the end of your current billing period. We will let you know in advance of any price changes. Taxes may apply. Offer terms are subject to change.
Create Your Account
Please Enter Your Password
Forgot your password?
Please enter the email address you use for your account so we can send you a link to reset your password:

Why isn’t rooftop solar cheaper in America? In Australia in 2024, a standard rooftop system can cost as little as 90 cents per watt. In the U.S., a similar system might go for $4 per watt. If America could come even close to Australia’s rooftop solar prices, then we would be able to decarbonize the power system much faster than we are now.
Mary Powell has the answers. She is the chief executive officer of Sunrun, a $2.6 billion company that is the country’s largest rooftop solar and battery installer. Sunrun has set up or managed more than 900,000 rooftop systems across the U.S. Powell previously led Green Mountain Power, Vermont’s largest investor-owned power company.
On this week’s episode of Shift Key — a continuation, of sorts, to one of our most popular early episodes — Rob and Jesse talk about how the rooftop solar business works and what’s driving America’s higher costs. Shift Key is hosted by Robinson Meyer, the founding executive editor of Heatmap, and Jesse Jenkins, a professor of energy systems engineering at Princeton University.
Subscribe to “Shift Key” and find this episode on Apple Podcasts, Spotify, Amazon, or wherever you get your podcasts.
You can also add the show’s RSS feed to your podcast app to follow us directly.
Here is an excerpt from our conversation:
Jesse Jenkins: And so, just some stats to start off the conversation. The latest quarterly solar update from the Department of Energy notes that the average cost of a 2 to 10 kilowatt residential rooftop system in the U.S. is roughly $4 per watt, DC, installed. That’s the full installed system costs, not just the modules.
I just looked up solarchoice.net.au, the Australian site that tracks bids and costs in Australia, which has one of the most vibrant rooftop solar industries in the country. There, you can now install a rooftop solar system in Sydney for just under $1 U.S. per watt, which is quite remarkable — you know, dramatically cheaper than it was a few years ago, but also dramatically cheaper than the U.S residential solar market, by a factor of four.
And so obviously, if we could knock the cost of rooftop solar in the U.S. down by another 75%, it would be an incredible value proposition all over the country. So, how do we get there, Mary? What explains why solar in the U.S., rooftop solar, is much more expensive than it is in places like Australia — I should say, it’s not just Australia. It’s also, you know, the U.K. and Germany and Belgium and other places. Why is it so much more expensive here now than it is in these other countries? And how do we drive down the cost of residential solar installations in the U.S. so that we can unlock that potential here, too?
Mary Powell: Yeah, for sure. I mean, that is so exciting when you think about it, Jesse. What gets me so excited when you say that is I think, ‘Oh my gosh, we are selling all across America now with savings against what people are paying for utility power.’ So customers — even at our current costs. So back to your question on how I see the future, just think about how powerful that will be as we continue to innovate and figure out ways to drive down the cost.
Now, that said, the biggest driver of the cost difference is the way the American energy system is built. And not just that, but we have 40,000 AHJs in the United States that each have their own distinct solar process and rules. And in Australia they have fewer than 600.
Robinson Meyer: And those are like cities?
Powell: It’s housing jurisdictions. It’s like — let me give you an example. In DuPage County, Illinois, we have to have a full time employee pull permits all day. Only one permit at a time.
You know, the other big thing in the U.S. is our whole energy system, as we know, it is very much driven by state and regional rules. Like rules of the road, a lot of regulatory differences from one jurisdiction to another, a lot of massive differences from one utility to another. So, you know, interconnection for residential is still costly, time consuming, and is even prohibited in some areas. Interconnection fees for home solar systems from utilities range from $100 to $10,000. So, one of the bright spots is the work that Sunrun was involved in, a lot of players were involved in, and that Secretary Jennifer Granholm is really focused on, which is SolarAPP+. So, that is one way to drive down the cost, Jesse.
Back to the difference: So really, I would say, the biggest difference is bureaucracy. When you talk about Australia and you talk about the U.S., that’s the biggest difference.
This episode of Shift Key is sponsored by…
Watershed's climate data engine helps companies measure and reduce their emissions, turning the data they already have into an audit-ready carbon footprint backed by the latest climate science. Get the sustainability data you need in weeks, not months. Learn more at watershed.com.
FischTank PR uses its decade-plus experience working in the climate tech space to introduce clients to top-tier journalists at the right time, for the right story. We don’t tire-spin — we take action and understand we are hired to get results. To learn more, visit fischtankpr.com.
Music for Shift Key is by Adam Kromelow.
Log in
To continue reading, log in to your account.
Create a Free Account
To unlock more free articles, please create a free account.
On energy inefficiency, global green H2, and New Hampshire’s guerrilla solar
Current conditions: Super Typhoon Bavi is slamming into Guam and the Northern Mariana Islands as the equivalent of a Category 5 hurricane, with sustained wind speeds topping 178 miles per hour • The record-shattering heat dome over the central and eastern United States is easing and shifting westward until mid July • In Europe, however, the heat is continuing, with temperatures hitting 108 degrees Fahrenheit in southern Spain over the weekend.
America’s next nuclear reactor is coming to life via resurrection. For the past two years, Holtec International has been working to bring the single reactor at the decommissioned Palisades nuclear plant in western Michigan back into service. It would be the first time in U.S. history that a permanently shuttered nuclear plant came back online. If successful, a growing list of projects are lining up to follow in Palisades’ footsteps. On Friday, Holtec announced that the Palisades crew had completed “the last of the major projects,” marking a “watershed moment” in the restoration effort. “We’re now focused on safely executing the remaining testing, verification, and operational readiness activities required before startup,” Michael Schultheis, Holtec’s vice president of the plant, said in a statement. “The plant is coming back together, and the professionalism and dedication demonstrated by our workforce continue to move the project forward.”
The news came just days after the U.S. District Court for the Western District of Michigan dismissed a lawsuit challenging the procedure by which the Nuclear Regulatory Commission approved Palisades’ restart. Started under the Biden administration, the revival project was one of the first the Trump administration allowed to move forward after taking office, part of a broader effort by the Department of Energy to spur a resurgence of reactor construction in the U.S.
Last week, the U.S. Court of Appeals for the Ninth Circuit blocked a challenge to California’s rules on emissions from industrial boilers, the latest legal victory for local regulations on planet-heating pollution from buildings. In 2024, the South Coast Air Quality Management District, the air pollution agency in charge of broad swaths of Southern California, set new restrictions on smog-causing nitrogen oxide from industrial boilers, appliances that either burn a fossil fuel such as gas or oil or use electricity to heat up water. The policy — which would slash the equivalent of half the nitrogen oxide produced by every car in Los Angeles combined — is part of the state’s long-standing effort to curb pollution. It’s not the only win for the fight to curb emissions from buildings. Since 2024, federal courts have repeatedly upheld local and state authority to regulate pollution from buildings in New York, Maryland, and Washington, D.C.
On Thursday, meanwhile, the Trump administration proposed a new rule to gut money-saving standards for appliances nationwide. “While the agency portrayed the move as bringing an end to appliance standards writ large, that is not, in fact, what it is doing,” Heatmap’s Emily Pontecorvo wrote last week. “The proposal would update the DOE’s so-called ‘Process Rule,’ which governs how the agency develops standards, adding onerous requirements that will make it much more difficult to make any changes at all.” When I spoke to the American Council for an Energy-Efficient Economy about the changes, the advocacy group told me the proposal would set minimum savings thresholds below which the new rule wouldn’t find federal support. It would also add a mandatory 180-day waiting period between before proposing new appliance standards based on novel testing procedures, require the Energy Department to show deference to industry-established standards, and force regulators to carry out extra analyses and rulemaking processes before enacting new rules.
Senator Angus King, the independent from Maine who caucuses with the Democrats, has urged the Federal Energy Regulatory Commission to reject the proposed utility megamerger between NextEra Energy and Dominion Energy. In a letter last week to the agency, King said the combination of the two giants risked putting too much power in the hands of one company. “The combination would create the largest electric utility in the United States, concentrating an unprecedented mix of merchant generation, rate-based generation, and transmission assets in the hands of a single company with a documented record of using its market position and political resources to suppress competition that threatens its merchant revenues,” King said in the letter, according to Utility Dive. Specifically, he cited NextEra’s lobbying to derail the New England Clean Energy Connect project in 2021, a transmission line to connect the Northeast’s grid to the almost entirely renewable hydroelectric system in Quebec.
Sign up to receive Heatmap AM in your inbox every morning:
Last week, the Environmental Protection Agency put out new regulatory guidance on the president’s “freedom to fix” agenda, reminding automakers of their “long-standing legal obligation to release the service information, training information, and tools necessary to diagnose and repair vehicles,” even if the driver could use what they learn to tamper with the emissions controls. Meanwhile, on Friday, President Donald Trump announced that he’d pardoned six people “who were persecuted by the Biden administration” and were either in prison or headed there for violating Clean Air Act prohibitions against rigging the vehicles’ emissions control systems. “While I know this sounds ridiculous, it is nevertheless a fact, and part of the Weaponization and Stupidity that our Country had to endure during four long years of Sleepy Joe Biden,” he wrote in a post on his Truth Social platform. “I AM SETTING THEM ALL FREE, RIGHT NOW!”
In non-emitting vehicle news, Rivian is eyeing a better sales year than expected. While the electric automaker previously said it would ship between 62,000 and 67,000 vehicles this year, it told investors on Thursday that it now expects to deliver between 65,000 and 70,000 vehicles, in what TechCrunch called “a small but potentially meaningful bump.” The announcement came the same week BYD crushed Tesla’s deliveries yet again, as I told you in my last newsletter.

Back in March, I told you that Chile’s most right-wing president since the fall of dictator Augusto Pinochet could take the country’s budding green hydrogen business in a different direction. Now President José Antonio Kast is doing just that. Last week, Chile’s state-owned Production Development Corporation, known by its Spanish acronym CORFO, announced plans to refocus the country’s strategy for green hydrogen on domestic use rather than exports, Hydrogen Insight reported.
China, as I have reported for you many times before, is going hard on green hydrogen, especially since the Iran War forced Beijing to ramp up efforts to find alternatives to imported fossil fuels. Here’s yet another data point: China just laid out plans to build the world’s largest green hydrogen plant using solid-oxide electrolyzers, which operate at higher temperatures. The facility will also produce, methanol, which uses hydrogen as a key ingredient. At peak capacity, the facility in rural Gansu province will produce 100,000 metric tons of renewable methanol per year for use in international shipping. Meanwhile, Spain is investing nearly $21 million into grants for hydrogen projects as the country seeks to make use of its booming solar industry. As I wrote last week, the surge in solar panels is creating problems for Spain, since its grid can’t handle all that power during peak daytime hours. Funneling that electricity into electrolyzers to make molecules that can be cleanly burned later may offer a solution.
Last month, I told you about a catchier term for the very small-scale solar panels being legalized to go on windowsills and balconies, opening the door to more apartment dwellers generating a small share of electricity themselves. That term, which I first read in Inside Climate News, is “guerilla solar.” Well, that solar rebel mindset is coming to the “Live Free or Die” state. On Thursday, New Hampshire Governor Kelly Ayotte, a Republican, put out a list of 74 bills she signed into law before Fourth of July weekend. Among them was SB-540, legalizing plug-in solar panels. The law will take effect on July 27, according to PluginSolarUS, an advocacy group.
Rob talks with Columbia’s Lily Bermel about where climate policy should go next.
Wait, is the climate policy landscape … in better shape than it looks?
Just over a year ago, President Trump passed the One Big Beautiful Bill Act. It repealed many of the Biden administration’s most aggressive climate policies, including tax credits for solar and wind energy.
Although those policies are gone, the emissions cuts they achieved remain largely intact — at least in the power sector, according to a new study that we’re covering exclusively at Heatmap. Lily Bermel, the report’s author and a visiting fellow at the Columbia Center on Global Energy Policy, argues that at least where energy generation is concerned, the glass is more than “half full.”
On this episode of Shift Key, Lily joins Rob to discuss what we learned from Biden’s big climate law, why it likely never would have achieved its projected emissions declines (at least not without a tremendous transmission buildout), and how studying its legacy changed her mind about policy going forward.
Shift Key is hosted by Robinson Meyer, the founding executive editor of Heatmap News.
Subscribe to “Shift Key” and find this episode on Apple Podcasts, Spotify, Amazon, or wherever you get your podcasts.
You can also add the show’s RSS feed to your podcast app to follow us directly.
Here is an excerpt from their conversation:
Robinson Meyer: Given that the IRA, in retrospect, in the power sector, kind of resolved any economic issue you would have making a project pencil out and revealed all these non-economic issues that actually constrain development, we are now looking at a political environment where we’re switching from mourning the IRA to saying, okay, what should happen next? And my colleague Emily Pontecorvo recently wrote a story about this question. But I think one of the big questions going forward, especially if Democrats take Congress at the end of this year is, well, should they fight to restore the tax credits? I can even see a world where restoring the tax credits becomes something people insist on to get permitting reform or something.
After writing this report, did you come to the conclusion that Democrats should restore the wind and solar tax credits? Is that the most urgent priority for climate policy?
Lily Bermel: In writing this report, I became quite confident that I don’t think it’s worth the bang for buck in restoring those wind and solar tax credits, and instead that the supply side constraints are the real issue that we need to focus on. I did this lag analysis where if you take a given year, say 2031, and you see that the IRA trajectory would have deployed like more than 300 gigawatts of solar, how many years later would the [OBBBA] scenario do that? There’s only a two and a half-year lag, or gap. And so in restoring the clean energy tax credits, you are only buying back two and a half years’ worth of deployment, which, at least for me, was a lot smaller than I had thought.
Meanwhile, both scenarios have a literal cap in them about how much they can build and how fast they can build it. So even if you buy back that little two and a half-year average annual lag, you’re going to run up to the exact same ceiling. So restoring the tax credits brings you closer to that ceiling, while permitting reform will completely lift the ceiling and be a rising tide that lifts all boats.
You can find a full transcript of the episode here.
Mentioned:
The “Glass Half Full” report
More from Rob on Lily’s findings
From Heatmap: The Wind and Solar Tax Credits Are About to Expire. Will They Come Back?
Heatmap’s cheat sheet on how the One Big Beautiful Bill Act changed America’s clean energy law
Previously on Shift Key: What Has All This Back-and-Forth Climate Legislating Bought Us?
Jesse Jenkins’ paper on transmission’s role in achieving the IRA’s goals
Brendan Duke’s policy affordability framework
This episode of Shift Key is sponsored by ...
Heatmap Pro brings all of our research, reporting, and insights down to the local level. The software platform tracks all local opposition to clean energy and data centers, forecasts community sentiment, and guides data-driven engagement campaigns. Book a demo today to see the premier intelligence platform for project permitting and community engagement.
Music for Shift Key is by Adam Kromelow.
A just-released MIT paper argues that the energy transition is still largely following the trajectory laid out in the Inflation Reduction Act.
When President Joe Biden signed the Inflation Reduction Act into law in 2022, climate observers — myself included — marked it as a landmark victory in the history of climate policy.
For the first time since global warming arose as a major issue more than three decades earlier, the United States had enacted a comprehensive policy to do something about it. America could boast a generous set of incentives meant to spur new solar farms, electric vehicle factories, and other zero-carbon industries nationwide. The law was projected to bring down U.S. emissions by at least 36% by the mid-2030s, compared to the all-time high they had reached in 2005.
Then Donald Trump declared that the law was in fact a “Green New Scam” and resolved to repeal it. Scarcely half a year into his second term, President Trump and Republicans in Congress terminated many of the climate law’s most important provisions in the One Big Beautiful Bill Act, their tax cuts and spending package passed last summer.
Was the Biden law a false dawn? A new report, released on Monday by MIT’s Center for Energy and Environmental Policy Research and entitled “Glass Half Full,” argues that its influence will live on — at least in the electricity system.
Most of the Biden policies’ expected climate benefits in the power sector — including the amount of renewables that will get built nationwide, and the projected declines in greenhouse gas emissions — are still likely to happen by 2035, even under the Trump administration’s policies, the report finds.
“The glass is substantially full,” Lily Bermel, the report’s author and a visiting fellow at the Columbia Center on Global Energy Policy, told me. “It’s not barely half full. It’s like three-quarters full.” Her study compared not only the effects of Biden and Trump’s tax and spending laws, but also the environmental rules that each administration fought for.
Roughly 74% of new clean energy capacity that would have gotten built under Biden’s policies by 2035 will still get built under Trump’s policies by that year, the report estimates. Those new renewables and zero-carbon power plants will generate about 71% of the electricity that would have been expected had Biden’s policies remained law.
About 67% of the decline in climate pollution that would have occurred over the next decade under Biden’s policies will still happen under Trump’s policies, the report estimates.
Coal- and gas-fired power plants are also likely to generate less electricity over time in both the Biden and Trump scenarios. But under Trump that story is not quite as rosy: The coal-powered fleet will retire more slowly than it would have had Biden’s laws stayed on the books, and the natural gas fleet will run more often than it would have needed to.
The report does not analyze what Trump’s climate and energy policies will do to emissions from every sector of the economy. It focuses only on the electricity system and omits, for instance, any discussion of transportation or heavy industry, even though Trump’s tax and spending law repealed incentives for electric vehicle buyers and hydrogen production.
But the power sector drove the largest share of emissions declines that were expected from the IRA, and other estimates of President Trump’s tax law have suggested that repealing the wind and solar incentives would do more harm to the climate than any other provision. In those studies, the law’s termination of the EV tax credits is often the No. 2 driver of higher emissions.
When Bermel began writing her paper, she wasn’t sure the results would be so optimistic. She compared two scenarios produced by a mathematical model prepared by Energy Innovation, a nonpartisan energy and climate policy think tank, which seeks to simulate the country’s energy system.
In the first scenario, the Biden administration’s climate law and other policies — such as Environmental Protection Agency rules restricting carbon emissions from coal and some natural gas power plants — remain on the books through 2035.
The second scenario looks more like the world we live in. In that run, the Trump administration passes the One Big Beautiful Bill Act, repealing the solar and wind tax credits but preserving incentives for other zero-carbon technologies, such as nuclear power plants and batteries. It also withdraws the EPA’s power plant rules and weakens other regulations on pollution.
The models do not simulate everything the White House has done to stymie renewables and climate policy. Simulations cannot capture, for instance, Trump’s bureaucratic and sometimes extralegal war on solar and wind power because the administration has changed tactics — and gotten blocked by courts — too often to model effectively, Bermel said.
But the models do try to estimate some of the real-world constraints that limit the construction of new clean power plants. In both scenarios, the country’s lack of new interregional transmission — and the long queues to connect new energy projects in many power markets — imposes a “speed limit” on new wind and solar construction, regardless of other incentives on the books.
Despite those constraints, the report finds that more than 80% of the utility-scale solar and battery storage that would have been built under the Biden scenario by 2035 will still be deployed under Trump’s policies.
Only one clean electricity technology stands to do much worse than it would have had the IRA remained on the books: onshore wind. The country will build less than half of the new onshore wind capacity that it would have built had the IRA remained on the books.
In the U.S., new onshore wind installation has declined every year since its peak in 2020. The lack of new large-scale power lines — and a deteriorating local permitting environment — has hampered wind energy’s expansion.
Ultimately, policymakers should prioritize easing construction of new transmission lines and other forms of energy infrastructure, Bermel asserts in the report. Amending the country’s permitting system — and raising the de facto speed limit on new clean energy construction — is likely far more important for lowering emissions than restoring the tax credits, she told me in a conversation for Heatmap’s Shift Key podcast.
“By solving one problem — by making clean energy a little bit cheaper and by incentivizing the demand of it — we therefore exposed how supply-side constrained we are and how awful and burdensome the permitting barrier process is,” she said.
Though there is broad agreement among researchers about the need for a smoother permitting process to allow more renewables development, Bermel’s direct comparison of counterfactuals is an unusually direct way of trying to answer policy questions. “In general, I think the findings are reasonably consistent with what we’d say, but this is a bit of a different way of looking at these questions than energy modelers typically take,” Ben King, an energy and climate analyst at the Rhodium Group, which also operates an energy system model, told me.
Energy analysts often try to examine a range of outcomes and assumptions in their models, such as by varying natural gas prices or electricity demand, he said. The new report does not do that, instead comparing the same baseline energy demand assumptions under the two differing policy regimes. That means the results are less likely to capture what will actually happen in the real world, but still “illustrate the economic competitiveness of these technologies no matter what,” King said — as well, for the moment, as the surging hunger for electricity from AI companies.
Noah Kaufman, a Columbia economist and senior research scholar, told me Bermel’s technical analysis made sense. But he differed sharply with her conclusion that the IRA’s most important benefits had been preserved, even in the power sector. The law’s most important benefits, he said, were never measured in gigatons alone.
“I don’t agree at all with the ‘glass half full’ framing of the situation,” he said. “To me, the importance of the Inflation Reduction Act wasn’t the tax credits or how many gigawatts of solar we will deploy. It was that, for the first time, the U.S. was able to go out to the world and say, ‘We have a strategy now.’”
“I don’t think we have 50% of that now, or 70% of that now,” he said. “I think we have basically none of that now.”
Repealing the IRA and the Biden administration’s other policies has returned the country to something closer to its pre-2021 status quo, he said, where the country is slowly reducing its emissions but not using the energy transition to generate new jobs or economic opportunities for fossil-fuel-dependent communities.
“If you’re not decarbonizing in a way that works for big parts of the country, then you’re not going to be able to sustain the strategy over long periods of time,” he said.
The MIT report does not try to examine whether clean energy manufacturing has declined under the Trump scenario, and concedes that “the Glass Half Full reading is limited to … the power sector, not the broader economic-transformation strategy a successful energy transition requires.” The One Big Beautiful Bill Act retained some of the Biden law’s manufacturing tax credits, including subsidies for solar panel and battery component production.
For at least one technology, Bermel believes the report is not optimistic enough.
The Trump tax law preserved tax credits for technologies such as enhanced geothermal and nuclear fusion — “clean firm” power plants that can produce electricity on a 24/7 basis, regardless of the wind or weather. These technologies will be essential to eventually replacing fossil fuel-burning power plants on the grid.
Yet the energy system models on which Bermel’s report depends hold that companies will build essentially no new sources of zero-carbon electricity by 2035. That’s partly because the policies to support those technologies still aren’t generous enough, because in some cases companies developing them are still building first-of-a-kind facilities.
“Tax credits are best for a technology that is mature enough to respond to price signals,” Bermel said. “They’re helpful, but ironically they’re more helpful for a later stage technology.”
Yet in this case, the real world is already diverging from the models. The artificial intelligence boom has driven hyperscalers to invest in clean firm technologies in ways the model does not predict. Even the models Bermel uses in her report, for instance, do not account for the more than 5 gigawatts of new nuclear power that is expected to come online due to new plant openings, canceled plant closures, and planned upgrades.
The models also don’t reflect the gigawatt of enhanced geothermal-produced electricity Google plans to buy from the energy developer Fervo by 2028. That deal could scale to 3 gigawatts in the 2030s.
Despite those additions, she argues that the next stage of federal climate policy should emphasize public investment that helps expand the power grid and commercialize the next generation of clean firm technologies. That could look like expanding the manufacturing tax credit to cover transformers and other grid equipment. It could also entail offering more direct financial support — either through cheap loans, federal guarantees, or even direct government procurement — to clean firm energy developers. Only through building the next generation of zero-carbon of power plants, she told me, will the country begin to retire its fossil fuel fleet in earnest.