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:
Silicon Valley is betting better design will bring heat pumps to the masses.

Gleaming solar panels, soaring wind turbines, sleek electric cars. These are the Avengers of the climate technoverse, the most widely recognized symbols of the fight to kick fossil fuels and halt global warming. But the lineup is incomplete. Clean electricity and transportation are covered, but what about heat?
There’s a clear emerging hero waiting in the wings to warm our buildings without emissions. It’s called a heat pump, and it’s a technology that’s been around for decades. The problem is that heat pumps are still largely unfamiliar to most Americans, and the process of trying to get them installed can be a nightmare.
A new cohort of Silicon Valley entrepreneurs is trying to change that by applying a proven formula. The idea is not just to build a better heat pump, but to make one that’s as attractive, convenient, and envy-inducing as a Tesla.
“That’s the only way you win, right?” said Paul Lambert, the founder and CEO of the startup Quilt, which recently raised $9 million in seed funding from Lowercarbon Capital and other investors. “You almost need, like, this Trojan horse. You need to be able to convince people who are skeptical. It needs to be better on its own merits.”
Heat pumps are key to tackling climate change because they run fully on electricity, are far more energy efficient than furnaces and boilers, and function as air conditioners in addition to heaters. Rather than warming a room by means of an electrical current or a flame, they move latent heat around, transferring it either inside or outside of the building, depending on the season.
Only about 16 percent of American homes use heat pumps today, according to the advocacy group Rewiring America. In a recent report, the organization estimated that in order to achieve the U.S. climate goal of net-zero emissions by 2050, heat pump sales need to grow three times faster than they’re expected to by 2032 and to take over the entire residential heating market by 2035. New federal tax credits and rebates created by last year’s Inflation Reduction Act will help, but likely won’t be enough.
“It's going to require lots of new choices for people and continued improvement in all aspects of product design,” Rewiring America’s head of market transformation Stephen Pantano told me. “So the more people investing in this and paying attention to this, the better.”
Despite their technological wizardry, heat pumps are rather dull looking. Some are big metal boxes that get hidden in an attic or closet and push hot or cool air through ducts and vents, while other models require mounting a rectangular hunk of plastic on the wall of every room. Quilt is redesigning the latter.
It’s unclear whether a heat pump could ever achieve the cultural capital of a sports car, no matter how nice it looks. Pantano recalled the scene in Home Alone where Kevin goes looking for his parents in the basement, and the glowing maw of the furnace sends him running. “I think that represents the way a lot of people think about their heating systems, which is that they don't, until they have to, which is usually when it breaks.”
Nonetheless, the heat pumps on the market now aren’t exactly turning heads.
“Whenever we do want to put a unit on the wall, we always get pushback from the consumer regarding the aesthetics,” said Larry Waters, the president of Electrify My Home, a heat pump installation company in Northern California. That’s one of many reasons Waters prefers selling systems that use ductwork. But every building is different, and that isn’t possible in all cases.
That’s especially true for small apartments or for renters who have no power over their HVAC system. Another startup, Gradient, is trying to serve those segments of the market with an attractive heat pump that sits in the window like an air conditioner. It doesn’t require a professional to install, and hangs over the sill like a saddle, solving a key drawback of the average AC by allowing continued use of the window. Last year, the company won a contract to provide 10,000 units for New York City public housing developments.

When I spoke to Gradient’s founder Vince Romanin in the summer of 2021, he also compared his approach to Tesla’s. “People didn’t start off buying electric cars because they’re better for the environment, but because they provided a dramatically different and better experience,” he told me.
Gradient’s heat pump recently hit the market. Emily Grubert, a civil engineer and sociologist at the University of Notre Dame, told me she got one for an unheated and un-air conditioned room in her house where her pet rabbits spend most of their time, and where the temperature fluctuates from below freezing in the winter to more than 100 degrees in the summer. It cost $2,000, took about an hour to install, and so far has maintained a comfortable temperature “through multiple days of 90-plus degree weather.”
A third design-forward heat pump startup, Electric Air, was founded by a former Tesla thermal engineer, and is literally advertising itself as “The Tesla of home heating and cooling.” The company’s other selling point is that it plans to combine regular heat pump functionality with improved air purification.

I recently visited Quilt’s headquarters just south of San Francisco to see how the company’s device was shaping up. There I met Lambert along with his two co-founders, Bill Kee and Matthew Knoll. The trio got acquainted while working at Google, and also all recently became fathers, which they said was a big part of what inspired them to leave the tech giant to work on climate solutions. They guided me over to a wall mounted with a few iterations of heat pump designs, as well as a Mitsubishi mini-split, one of the most popular models currently on the market.
Lambert praised the unit’s efficiency, near-silent operation, and ability to heat and cool a room very quickly. “On the other hand, it’s kind of cheap plastic,” he said, rapping his knuckles on the casing. “And it’s quite tall, which is an issue because in a lot of American homes you can’t fit this in the place where people most want it.”
Quilt’s design is certainly more sleek, but it’s by no means a total overhaul. The company doesn’t plan to make its design public until early next year, so I can’t share much, but the improvements are subtle: A slightly smaller frame, a customizable aesthetic, and a few other bells and whistles added based on feedback from focus groups.
Design wasn’t the only factor in Tesla’s success, and Quilt is working on a number of other upgrades, like user experience. Today, when people install wall-mounted heat pumps in multiple rooms in their house, they each come with a separate remote control that has a ton of buttons and looks straight out of the 1980s. In addition to building a more convenient app to control the settings, the company is developing software that will help customers optimize efficiency based on how they use their homes.
“The areas of efficiency that have been exploited in this space have largely been at the mechanical level,” said Kee. “But we think there's a major gain to be made in efficiency by managing the system with intelligence.”
Quilt is also trying to improve the sales process. In addition to being new fathers, Lambert, Kee, and Knoll all recently went through a great deal of trouble trying to get heat pumps installed in their own buildings. “I had people telling me categorically that they wouldn’t work, or that I had to use my ducts, or that I couldn’t use my ducts,” Kee said. “I was totally disempowered. I just became obsessed with the idea that like, this has to be easier for people to do.”
They hope that the direct-to-consumer model, with transparent pricing and predictable scheduling, will help. But it hinges on building an army of ace partner contractors who know the systems inside and out, which could be quite a challenge. The team at Electrify My Home runs heat pump trainings for other contractors in California. Alex Sloan, the company’s vice president of business operations, told me it’s already an uphill battle getting the workforce to adopt existing technology, and to learn to do higher quality installations.
That just may be the one issue a Tesla makeover alone can’t solve.
Log in
To continue reading, log in to your account.
Create a Free Account
To unlock more free articles, please create a free account.
The Trump administration’s rollback of coal plant emissions standards means that mercury is on the menu again.
It started with the cats. In the seaside town of Minamata, on the west coast of the most southerly of Japan’s main islands, Kyushu, the cats seemed to have gone mad — convulsing, twirling, drooling, and even jumping into the ocean in what looked like suicides. Locals started referring to “dancing cat fever.” Then the symptoms began to appear in their newborns and children.
Now, nearly 70 years later, Minimata is a cautionary tale of industrial greed and its consequences. Dancing cat fever and “Minamata disease” were both the outward effects of severe mercury poisoning, caused by a local chemical company dumping methylmercury waste into the local bay. Between the first recognized case in 1956 and 2001, more than 2,200 people were recognized as victims of the pollution, which entered the population through their seafood-heavy diets. Mercury is a bioaccumulator, meaning it builds up in the tissues of organisms as it moves up the food chain from contaminated water to shellfish to small fish to apex predators: Tuna. Cats. People.
In 2013, 140 countries, including the U.S., joined the Minamata Convention, pledging to learn from the mistakes of the past and to control the release of mercury into the environment. That included, explicitly, mercury in emissions from “coal-fired power plants.” Last month, however, the U.S. Environmental Protection Agency retreated from the convention by abandoning the 2024 Mercury and Air Toxics Standards, which had reduced allowable mercury pollution from coal-fired plants by as much as 90%. Nearly all of the 219 operating coal-fired plants in the U.S. already meet the previous, looser standard, set in 2012; Trump’s EPA has argued that returning to the older rules will save Americans $670 million in regulatory compliance costs by 2037.
The rollback — while not a surprise from an administration that has long fetishized coal — came as a source of immense frustration to scientists, biologists, and activists who’ve dedicated their careers to highlighting the dangers of environmental contaminants. Nearly all human exposure to methylmercury in the United States comes from eating seafood, according to the EPA, and it’s well-documented that adding more mercury to the atmosphere will increase levels in fish, even those caught far from fenceline communities.
“Mercury is an extremely toxic metal,” Nicholas Fisher, an expert in marine pollution at Stony Brook University, told me. “It’s probably among the most toxic of all the metals, and it’s been known for centuries.” In his opinion, it’s unthinkable that there is still any question of mercury regulations making Americans safer.
Gabriel Filippelli, the executive director of the Indiana University Environmental Resilience Institute, concurred. “Mercury is not a trivial pollutant,” he told me. “Elevated mercury levels cost millions of IQ points across the country.” The EPA rollback “actually costs people brain power.”
When coal burns in a power plant, it releases mercury into the air, where it can travel great distances and eventually end up in the water. “There is no such thing as a local mercury problem,” Filippelli said. He recalled a 2011 study that looked at Indianapolis Power & Light, a former coal plant that has since transitioned to natural gas, in which his team found “a huge plume of mercury in solids downwind” of the plant, as well as in nearby rivers that were “transporting it tens of kilometers away into places where people fish and eat what they catch.”
Earthworms and small aquatic organisms convert mercury in soils and runoff into methylmercury, a highly toxic form that presents the most danger to people, children, and the fetuses of pregnant women as it moves up the food chain. Though about 70% of mercury deposited in the United States comes from outside the country — China, for example, is the second-greatest source of mercury in the Great Lakes Basin after the U.S., per the National Oceanic and Atmospheric Administration — that still leaves a significant chunk of pollution under the EPA’s control.
There is, in theory, another line of defense beyond the EPA. For recreational fishers, of whom there are nearly 60 million in the country each year, state-level advisories on which waterways are safe to fish in based on tests of methylmercury concentrations in the fish help guide decisions about what is safe to eat. Oregon, for example, advises that people not eat more than one “resident fish,” such as bass, walleye, and carp, caught from the Columbia River per week — and not eat any other seafood during that time, either. Forty-nine states have some such advisories in place; the only state that doesn’t, coal-friendly Wyoming, has refused to test its fish. One also imagines that safe waterways will start to become more limited if the coal-powered plants the Trump administration is propping up forgo the expensive equipment necessary to scrub their emissions of heavy metals.
“It’s not something where you’re going to see a dramatic change overnight,” Tasha Stoiber, a senior scientist with the Environmental Working Group, a research and advocacy nonprofit that focuses on toxic chemicals, told me. “But depending on the water body that you’re fishing in, you want to seek out state advisories.”
For people who prefer to buy their fish at the store, the Food and Drug Administration sets limits on the amount of mercury allowed in commercial seafood. But Kevin McCay, the chief operations officer at the seafood company Safe Catch, told me the FDA’s limit of 1 part per million for methylmercury is outrageously high compared with limits in the European Union and Japan. “It has to be glowing red before the FDA is actually going to do anything,” he said. (Watchdog groups have likewise warned that the hemorrhaging of civil servants from the FDA will have downstream consequences for food safety.)
McCay also told me that he “certainly” expects mercury levels in the fish to rise due to the EPA’s decision. Unlike other canned tuna companies that test batches of fish, Safe Catch drills a small test hole in every fish it buys to ensure the mercury content is well below the FDA’s limits. (Fish that are lower on the food chain, like salmon, are the safest choices, while fish at the top of the food chain, like tuna, sharks, and swordfish, are the worst.)
The obsessive oversight gives the company a front-seat view of where and how methylmercury is working its way up the food chain, and McCay worries his company could face more limited sourcing options in the coming years if policies remain friendly to coal. (An independent investigation by Consumer Reports in 2023 found that even fish sourced by an ultra-cautious company like Safe Catch contain some level of mercury. “There’s probably no actual safe amount,” McCay told me, recommending that customers should eat a diverse range of seafood to limit exposure.)
Even people who don’t eat fish should be concerned, though. That’s because, as Filippelli told me, “a lot of [contaminated] fish meal is being incorporated into pet food.”
There are no regulatory standards for mercury in pet foods. But avoiding mercury is not as simple as bypassing the tuna-flavored kibble, Sarrah M. Dunham-Cheatham, who authored a 2019 study on mercury in pet food, told me. Even many brands that don’t list fish among their ingredients contain fish meal that is high in mercury, she said.
Different species also have different sensitivities to mercury, with chimpanzees and cats being among the most sensitive. “I don’t want to be alarmist or scare people,” Dunham-Cheatham said. But because of the issues with labeling pet food, there isn’t much to be done to limit mercury intake in your pets — that is, short of dealing with the emissions on local and planetary scales. “We’re expecting there to be more emissions to the atmosphere, more deposition to aquatic environments, and therefore more mercury accumulated into proteins that will go into making the pet foods,” she said.
To Fisher, the Stony Brook professor, the Trump administration’s decision to walk back mercury restrictions makes no sense at all. The Ancient Romans understood the dangers of mercury; the dancing cats of Minamata are now seven decades behind us. “Why should we make the underlying assumption that the mercury is innocent until proven guilty?” he said.
On Qatari aluminum, floating offshore wind, and Taiwanese nuclear
Current conditions: Upstate New York and New England are facing another 2 inches of snow • A heat wave in India is sending temperatures in Gujarat beyond 100 degrees Fahrenheit • Record-breaking rain is causing flash flooding in South Australia, New South Wales, and Victoria.
The war with Iran is shocking oil and natural gas prices as the Strait of Hormuz effectively closes and Americans start paying more at the pump. “So despite the stock market overall being down, clean energy companies’ shares are soaring, right?” Heatmap’s Matthew Zeitlin wrote yesterday. “Wrong. First Solar: down over 1% on the day. Enphase: down over 3%. Sunrun: down almost 8%; Tesla: down around 2.5%.” What’s behind the slump? Matthew identified three reasons. First, there was a general selloff in the market. Second, supply chain disruptions could lead to inflation, which might lead to higher interest rates, or at the very least slow the planned cycle of cuts. Third, governments may end up trying “to mitigate spiking fuel prices by subsidizing fossil fuels and locking in supply contracts to reinforce their countries’ energy supplies,” meaning renewables “may thereby lose out on investment that might more logically flow their way.”
The U.S. liquified natural gas industry is certainly looking at boom times. U.S. developers signed sale and purchase agreements for 40 million tons per year in 2025 from planned export facilities, according to new Department of Energy data the Energy Information Administration posted. That’s the highest volume since 2022, when Russia’s invasion of Ukraine sent demand for American LNG soaring. That conflict, too, is still having its effects on global fossil fuel supplies. A Russian-flagged LNG tanker is on fire in the Mediterranean Sea as the result of a drone strike by Ukraine, The Independent reported Wednesday.
It’s not just fossil fuels. Qatari smelter Qatalum started shutting down on Tuesday as 50% shareholder Norsk Hydro issued a force majeure notice to customers. “The decision to shut down was made after the company’s gas supplier informed it of a forthcoming suspension of its gas supply,” the company said in a statement to Mining.com. QatarEnergy — which owns 51% of Qatalum’s other shareholder, Qatar Aluminum Manufacturing Co. — had previously suspended production after halting output of natural gas due to Iranian drone attacks.
Sign up to receive Heatmap AM in your inbox every morning:
Panel manufacturer Silfab Solar paused production at its South Carolina factory in Fort Mill after a chemical spill triggered a regulatory investigation. The plant accidentally spilled approximately 300 gallons of a water solution containing less than 0.3% potassium hydroxide. Experts told WCNC, the Charlotte-area NBC News affiliate, that the volume of the caustic chemical that spilled will be harmless. But the state Department of Environmental Services “asked Silfab to cease receipt of additional chemicals at their facility until an investigation is complete.” Such accidents risk political backlash at a time of heightened public health anxiety over clean energy technologies. As Heatmap’s Jael Holzman wrote last summer, the Moss Landing battery factory fire sparked a nationwide backlash.
Two-thirds of offshore wind potential is located at sites where the water is too deep for traditional turbine platforms. But the first wind farm with floating platforms only came into operation nine years ago. The largest so far, located in Norway’s stretch of the North Sea, is just under 100 megawatts. So, if completed, Spanish developer Ocean Winds’ in the United Kingdom would be by far the largest plant. The company took a step forward on the 1.5-gigawatt project when the company signed the lease agreement this week, according to OffshoreWIND.biz.
In Denmark, meanwhile, right-wing politicians are campaigning against the country’s offshore wind giant, Orsted. The country’s conservative Liberal party campaigned on divesting from the company, which claims the Danish government as its largest shareholder, back in 2022. Now, Bloomberg reported, the party is once against renewing its calls to exit Orsted after this year’s election.

Facing surging electricity demand and mounting threats of blackouts from Chinese attacks on energy imports, Taiwan is taking yet another step toward reversing its nuclear phaseout. Nearly a year after the island nation’s last reactor shut down, Taiwanese Premier Cho Jung-tai, a member of the ruling Democratic Progressive Party that has long opposed atomic energy, announced new proposals to allow the state-owned Taiwan Power Company to submit plans to restart at least two of the country’s three shuttered nuclear stations. (A fourth plant, called Lungmen, was nearly completed in the late 2010s before the DPP government canceled its construction.) The government report also said Taiwan may consider building new nuclear technologies, such as small modular reactors or fusion plants.
In June 2023, thousands of lightning strikes in heat wave-baked Quebec sparked more than 120 wildfires that ultimately scorched nearly 7,000 acres of parched forests. Lightning, in fact, starts almost 60% of wildfires. Now a Vancouver-based weather modification startup called Skyward Wildfire says it can prevent catastrophic blazes by stopping lightning strikes through cloud seeding. MIT Technology Review found some good reasons to doubt the company’s claims. But experts said preventing wildfires is cheaper than putting them out, so it may have some merit.
The attacks on Iran have not redounded to renewables’ benefit. Here are three reasons why.
The fragility of the global fossil fuel complex has been put on full display. The Strait of Hormuz has been effectively closed, causing a shock to oil and natural gas prices, putting fuel supplies from Incheon to Karachi at risk. American drivers are already paying more at the pump, despite the United States’s much-vaunted energy independence. Never has the case for a transition to renewable energy been more urgent, clear, and necessary.
So despite the stock market overall being down, clean energy companies’ shares are soaring, right?
Wrong.
First Solar: down over 1% on the day. Enphase: down over 3%. Sunrun: down almost 8%; Tesla: down around 2.5%.
Why the slump? There are a few big reasons:
Several analysts described the market action today as “risk-off,” where traders sell almost anything to raise cash. Even safe haven assets like U.S. Treasuries sold off earlier today while the U.S. dollar strengthened.
“A lot of things that worked well recently, they’re taking a big beating,” Gautam Jain, a senior research scholar at the Columbia University Center on Global Energy Policy, told me. “It’s mostly risk aversion.”
Several trackers of clean energy stocks, including the S&P Global Clean Energy Transition Index (down 3% today) or the iShares Global Clean Energy ETF (down over 3%) have actually outperformed the broader market so far this year, making them potentially attractive to sell off for cash.
And some clean energy stocks are just volatile and tend to magnify broader market movements. The iShares Global Clean Energy ETF has a beta — a measure of how a stock’s movements compare with the overall market — higher than 1, which means it has tended to move more than the market up or down.
Then there’s the actual news. After President Trump announced Tuesday afternoon that the United States Development Finance Corporation would be insuring maritime trade “for a very reasonable price,” and that “if necessary” the U.S. would escort ships through the Strait of Hormuz, the overall market picked up slightly and oil prices dropped.
It’s often said that what makes renewables so special is that they don’t rely on fuel. The sun or the wind can’t be trapped in a Middle Eastern strait because insurers refuse to cover the boats it arrives on.
But what renewables do need is cash. The overwhelming share of the lifetime expense of a renewable project is upfront capital expenditure, not ongoing operational expenditures like fuel. This makes renewables very sensitive to interest rates because they rely on borrowed money to get built. If snarled supply chains translate to higher inflation, that could send interest rates higher, or at the very least delay expected interest rate cuts from central banks.
Sustained inflation due to high energy prices “likely pushes interest rate cuts out,” Jain told me, which means higher costs for renewables projects.
While in the long run it may make sense to respond to an oil or natural gas supply shock by diversifying your energy supply into renewables, political leaders often opt to try to maintain stability, even if it’s very expensive.
“The moment you start thinking about energy security, renewables jump up as a priority,” Jain said. “Most countries realize how important it is to be independent of the global supply chain. In the long term it works in favor of renewables. The problem is the short term.”
In the short term, governments often try to mitigate spiking fuel prices by subsidizing fossil fuels and locking in supply contracts to reinforce their countries’ energy supplies. Renewables may thereby lose out on investment that might more logically flow their way.
The other issue is that the same fractured supply chain that drives up oil and gas prices also affects renewables, which are still often dependent on imports for components. “Freight costs go up,” Jain said. “That impacts clean energy industry more.”
As for the Strait of Hormuz, Trump said the Navy would start escorting ships “as soon as possible.”