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An energy-efficient home needs energy-efficient lightbulbs and air conditioners and refrigerators and other gadgets to fill it up. But it all starts with the structure itself. That’s why we recommend you take a good, hard look at your walls, ceiling, floors, windows, doors, roof, and electrical wiring as a first step towards decarbonizing your home life. (Embarking on a renovation? Heatmap has a guide for that.)
When you add air sealing and insulation, get energy efficient windows, or a cool roof that reflects heat back into the environment, you’re either preventing heat from entering or escaping. This stabilizes your indoor air temperature, thereby reducing your heating and cooling loads, which account for 55% of a household’s total energy use, on average. Making these improvements is not only good for the environment, it’s also a boon to your quality of life. Plus, it allows you to get the most bang out of one of Heatmap’s other favorite decarbonization upgrades: replacing your furnace with an electric heat pump, which operates most efficiently in a well-insulated home.
And lest we forget the electrification upgrades, they’re certainly a different beast than the aforementioned ways to seal up your house. But adding new electrical circuits is a prerequisite to installing energy-efficient appliances such as electric stoves, dryers, heat pumps, heat pump water heaters, or EV chargers. And depending how much space is on your electric panel, you might need to upgrade that too.
None of the investments mentioned here (often referred to as weatherization upgrades) will directly decarbonize your space. Insulating your attic won’t free you from fossil fuels, and installing new wiring doesn’t actually electrify anything in and of itself, although they will lower your energy-related emissions. But what these renovations do do is prime you to consume less energy at home just keeping yourself comfortable.
“The weather that you can expect to see where you live is changing over time and changing in a pretty unpredictable manner,” Michael Gartman, a manager at RMI on their carbon-free buildings team, told me. “The benefit of weatherization, unlike some of the other decarbonization measures that you might be thinking about, is it really just shelters you from whatever that change means over time.”
None of this sounds very thrilling, I know. These types of upgrades certainly won’t lead to the same oohs and ahhs that you’d get for buying a shiny new electric vehicle or induction stove. “You often can't see weatherization after it's been completed, and even if you can, I don't think many people are going to be taking guests into their basement and pointing at their floor joists and saying, look at all that insulation,” Gartman told me.
Probably not, but once folks spend some time inside your house, the benefits will become apparent in cooler summer days and cozier winter nights — and lower energy bills. “Even if it’s not sexy, that's something that you're going to feel every year that you're in your home,” Gartman said.
These upgrades that you’re considering — and the attendant reductions in energy use — will have impacts that ripple out beyond your home’s walls and onto the grid at large. After all, residential energy consumption makes up 21% of total energy use in the U.S., and 15% of total emissions.
“Weatherization can reduce peak demand on the grid, which reduces the likelihood of the grid going down in the coldest winter nights or hottest summer days,” Gartman told me. This makes the grid greener, too, as utilities often meet demand spikes by calling on fossil fuel sources such as gas plants, which can ramp up and down quickly. A smoother demand curve can thereby increase the share of renewables in the mix. And in the case that the grid does fail and the power goes out, a fully weatherized home is a safer home, protecting you and your family from the elements for as long as possible.
Depending on what weatherization measures you go with, as well as your specific circumstances, your savings could eventually surpass your upfront costs. The upgrade that’s most likely to pay for itself is air sealing and insulation, which can lead to energy bills that are 10% to 20% smaller, leading to net savings in just a few years. The Green Building Alliance says cool roofs — which are not suited to every environment — can also pay for themselves in as little as six years. And while complete window replacements are a particularly pricey upgrade, if you opt for storm windows that are installed on top of an existing window, you could see payback as soon as three years time post-installation.
No matter what you choose to do, the absolute best time to do it is when prices are low — and when it comes to energy efficiency upgrades, the discounts have arrived. “A lot of energy performance improvements to houses right now are on sale, and they're going to be on sale until the end of the decade,” Eric Werling, former national director of the Department of Energy’s Zero Energy Ready Homes program, told me. He’s referencing the $1,200 federal tax credit for weatherization, which is available now, and the home efficiency and electrification rebates that will be rolling out this year and next.
But even with this years-long sale, we know that the upfront costs can be tough to shoulder. So don’t feel pressure to drop thousands in the name of decarbonization right now. If you stay in your spot long enough, you’ll eventually need to undertake at least a few home improvement projects. “Anytime anybody does a renovation project or fixes a problem in the house,” Werling told me, “I implore them to think about, is there an opportunity for me to make improvements to the house that will pay for themselves in utility cost savings, but also improve the health and safety and comfort of the house that we live in?”
You’ll find the answer is often yes, and we encourage you to let your friends, family, and neighbors know about it. Because while we trust that you, as a reader, care deeply about the climate, you don’t actually need to give a hoot to benefit from energy efficiency upgrades. As Werling put it, “It's just not about energy, and it's just not about the climate. It's about your home.”
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Welcoming the world’s first clean energy trillionaire.
SpaceX is now a public company. The rocket and satellite maker’s shares began trading this morning, surging 19% from their initial price of $135 to more than $160 at the market close. With the sale, Elon Musk became the world’s first trillionaire; his wealth has roughly tripled since President Donald Trump won re-election in 2024.
I’ll let other observers judge the IPO’s success, the firm’s long-term prospects, and the meaning of a world where we now have trillionaires. So I will make a few other points:
I remain agog at Musk’s ability to raise enormous amounts of cash from public equity markets to do hardware and manufacturing development. To some degree, the idea of a venture-backed firm doing hardware engineering — or what some now call “deep tech” — is Musk’s most impressive creation. The SpaceX IPO raised $75 billion today. That money will now go in part to scaling and commercializing rockets, factory equipment, and allegedly, at some point in the future, orbiting data centers.
Let’s not forget how crucial the U.S. government is to Musk’s story. In the world of climate, energy and manufacturing, we wail about financing’s “missing middle,” the elusive type of investment that can help scale and deploy early-stage technologies by bridging the gap between expensive venture capital and cheap bank lending. But this is at least partially a solved problem. SpaceX and Tesla survived the valley of death with government help: The Energy Department’s Loan Programs Office (which the Trump administration has dubbed the Office of Energy Dominance Financing) extended a $465 million loan to Tesla to build its Fremont, California, factory in 2010; NASA’s 2008 commercial resupply contract gave SpaceX guaranteed offtake for its Falcon rocket. Neither firm would likely have survived without those key injections of financial certainty.
To some degree, Musk has already made his mark on the American economy by creating a new culture of manufacturing engineering. I cannot recommend enough my colleagues Matthew Zeitlin and Emily Pontecorvo’s report on the new cadre of climate tech founders who came up at SpaceX and Tesla. As it happens, I spent Wednesday touring a clean energy factory founded by a Tesla alumnus, and I was struck by how many signs of Musk’s bottlenecks-focused management approach were visible, even at a company seemingly run more humanely than Musk’s famously “hardcore” firms.
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To that point, Emily and Matt asked a number of clean tech executives who worked for SpaceX or Tesla what they learned from the experience. Their responses are fascinating; you can read them in full here. These comments from Justin Lopas, the COO of Base Power, stuck out — he was asked the “one thing” he learned from working for Musk:
You can get way more done in a day and can move way faster than you think. This does not mean necessarily more hours (although solving any hard problem requires that too), but instead being thoughtful about sequencing work, not accepting delays from suppliers or external counterparties without solid rationale, parallel pathing, accelerating critical learnings to early in the project, etc
To step back, one irony of Elon Musk’s situation — at least to me — is that relatively few American politicians are eager to talk about what has actually driven his wealth. I’m not just talking about his firms’ reliance on public financing, although that counts too. I mean Tesla itself. Although Musk now describes that business as a “robotics company,” it is and remains an electric vehicle and battery manufacturer. (It recently began high-volume production of the Tesla Semi, a potentially game-changing long-haul electric truck.) After today, Musk’s Tesla stake makes up less than half of his wealth, but, still, he would not be a trillionaire without EVs, solar panels, and batteries.
But that is not a particularly convenient fact. That Musk is a clean energy trillionaire remains unpalatable to Republicans, who would prefer to cast EVs as an inferior substitute made to satisfy government mandates. And Musk’s antisemitism, far-right politics, and gleeful destruction of the U.S. Agency for International Development — not to mention Tesla’s violation of labor law — have obviously destroyed his reputation among Democrats.
Yet his elevation to a 13-digit net worth nonetheless marks a new era in American capitalism. The richest Americans in history have almost always been oilmen: John D. Rockefeller became the country’s first billionaire by creating the Standard Oil trust; when he died in 1937, his net worth of $1.4 billion represented 1% to 2% of the country’s gross domestic product. In the 1960s, J. Paul Getty became the country’s richest person by negotiating Saudi and Kuwaiti oil concessions. Yet Musk became a billionaire not by harnessing commodities, but through his mastery of software, hardware, and clean energy.
Musk’s fortune now exceeds 3% of U.S. GDP. He is the richest American in history, judged as a share of national production. And it was electricity, lithium, and modern factory production — and, if you wish, the kerosene and methane that fuel SpaceX’s rockets — that got him there. As the science fiction writer William Gibson almost said, the future is already here; it’s just not evenly distributed in your retirement portfolio yet.
Many thanks for reading, and have a wonderful weekend.
Plus SAF, another SPAC, and more of the week’s biggest money moves.
With SpaceX’s historic IPO dominating headlines this week, Heatmap turned its attention to the impact Elon Musk’s protégés have had on the climate tech landscape. Right after we published the story, an underwater geothermal startup founded and staffed by SpaceX alumni announced a sizable Series A, with its founder telling TechCrunch that his “experience at a very hardcore company like SpaceX” helped shape his approach to this new endeavor.
In other news, one of the biggest players in the sustainable aviation space, Twelve, opened its first commercial fuels plant and is preparing to begin supplying low-carbon jet fuel to Alaska Airlines later this month. Meanwhile, the battery sector saw two SPAC announcements: In a bid for survival, Factorial Energy officially went public this week through a SPAC merger, while ZincFive announced plans to do the same later this year. And finally there was some positive news for Germany’s heat pump market, as the startup Galvany raised fresh funding to simplify the end-to-end process of buying, installing, and operating a heat pump.
Drawing from an increasingly familiar playbook for Musk alumni, Endurance Energy founder and former SpaceX engineer Andrew Redd applied the lessons he learned from the rocket company’s notoriously “hardcore” culture and rapid pace of development to something completely different. Now that he’s pivoted away from rocket tech, Redd wants to harness geothermal energy from underwater volcanic activity, and his startup just raised a $54 million Series A to make it happen While a growing crop of geothermal startups including Fervo and Zanskar are focused on tapping into the heat beneath our feet, no other company in the sector has sought to develop the resource beneath the ocean floor.
There are good reasons for that, of course. Offshore infrastructure is notoriously difficult and expensive to build, maintain, and repair, and saltwater is corrosive. But if Endurance can crack the code, Redd told TechCrunch he thinks the company could unlock about 6 terawatts of geothermal energy in the coming decade.
Investors seem to be convinced: Peter Thiel’s Founders Fund led the startup’s latest funding roundSeries A, its second capital raise since launching less than two years ago. Other backers include First Round Capital, Felicis Ventures, and Voyager Ventures. EnduranceThe startup is initially targeting remote islands, where electricity costs are often far higher than on the mainland. It’s already launched an initial pilot off the coast of Tonga, which still gets about 80% of its electricity from imported diesel.
Twelve, one of the best capitalized sustainable aviation fuel startups, opened its first e-fuel facility in Washington State this week. The demo plant has officially started production, and the company’s strategic partner and investor, Alaska Airlines, expects to begin using it on commercial flights as soon as this month. The plant’s launch comes roughly two years later than originally planned, a delay that’s hardly unusual for first-of-a-kind industrial projects like this. Last September, Twelve raised $645 million to complete buildout of the facility, as well as to jumpstart development of future plants, which it says will be orders of magnitude larger.
The company’s process begins with renewable-powered electrolysis. Using a proprietary catalyst, Twelve’s electrolyzer splits apart CO2 captured from a nearby ethanol plant at a lower temperature than conventional approaches, making it better suited to running on renewable energy. The company combines the resulting carbon monoxide with hydrogen to create a syngas, which gets refined into sustainable jet fuel. Airlines can blend the resulting product with conventional jet fuel (the Federal Aviation Administration allows a maximum 50% blend) to create a drop-in replacement that requires no engine modifications.
To cover the cost premium of SAF, Twelve and Alaska partnered with Microsoft. The tech giant is buying SAF certificates — essentially carbon credits — from the project to help offset Scope 3 emissions associated with employee travel. “We are seeing strong demand from the corporate offtake side, not only for employee travel, but also for freight and logistics,” Twelve’s CEO, Nicholas Flanders, told me. “Everything from pharmaceuticals to data centers use a lot of air travel.” There are also some policy tailwinds — the European Union now has a sustainable fuels mandate that requires the use of synthetic e-fuels like Twelve’s beginning in 2030.
The plant also comes online at a moment of heightened volatility in the jet fuel market. As my colleague Alexander C. Kaufman noted in Wednesday’s morning newsletter, the closure of the Strait of Hormuz has led to soaring fuel prices, prompting domestic refiners to ramp production to record highs. By contrast, Flanders argues that SAF offers customers greater price certainty via long-term offtake agreements. “You can fix the cost of our key inputs like electricity and CO2 and so that actually makes it a more attractive project from a project financing perspective,” he explained.
SPACs are back. But this week, it’s not just another pre-revenue nuclear company that’s looking to get to market as quickly as possible. Solid-state battery startup Factorial Energy, which has yet to develop a commercial product, has merged with the blank check company Cartesian Growth Corporation III, netting it $100 billion at a $1.3 billion valuation.
The company was upfront about needing the SPAC to stay afloat after racking up losses since its founding in 2013. Factorial’s SEC filing states that prior to this new capital, “its liquidity wasn’t sufficient to fund twelve months of operations.” Yet it does have real traction in the industry — Mercedes-Benz, Stellantis, Hyundai, and Kia have all made strategic investments, looking to use Factorial’s tech in their electric vehicles to achieve higher energy density, longer range, and faster charging.
Solid state batteries typically use a solid electrolyte in place of the flammable liquid electrolytes found in conventional lithium-ion cells, but Factorial is starting with more of a hybrid approach. Its initial design relies on a “quasi-solid” gel-like electrolyte, which allows it to use an energy dense lithium metal anode while preventing the needle-like dendrite growth that predisposes solid-state batteries to short circuit. Factorial is manufacturing these cells at a pilot plant in Massachusetts, while working on a prototype with a fully solid electrolyte that could offer even greater performance gains.
Factorial isn’t the only battery company with SPAC news this week. ZincFive, a nickel-zinc battery producer, also announced plans to go public via SPAC in a deal expected to close in the second half of this year. Unlike Factorial, however, ZincFive is already making money, selling its batteries to hyperscalers and other data center operators as a backup power solution to bridge the gap in between when the power goes out and when the backup generator turns on. As the company’s CEO Tod Higinbotham told Bloomberg, “We have the backlog. We have the capacity. We have the demand. We really need capital.”
Navigating the maze of consumer clean energy incentives and coordinating home energy upgrades is hardly a U.S.-specific challenge. Just a few years ago, heat pump sales in Germany were falling precipitously despite generous subsidies and proven tech. One startup, Galvany, theorized the problem wasn’t the heat pumps themselves, but rather the unnecessary complexity of the surrounding ecosystem. Now it’s raised roughly $11.5 million to help streamline the process of getting heat pumps into consumers’ homes and apartments.
“In Germany, heat pumps do not fail because of the technology, but because of the gap between subsidy bureaucracy, installation capacity, and economic viability for the end customer,” the company’s CEO, Raik Belka, said in a press release. This is exactly the gap we are closing.” The approach is already paying off — Galvany has installed more than 2,500 heat pumps to date and became profitable last year after increasing its revenue sevenfold.
The startup produces its heat pump in partnership with Panasonic, but its real innovation lies in the way it streamlines sales, procurement, installation, and ongoing heat pump operations into a single platform. Potential customers enter their building data online and, after a feasibility check, get a quick quote that factors in subsidies. They can then purchase a standardized kit that’s simple for installers to assemble. Once operational, the heat pump’s energy management system, which launches this summer, will automatically adjust heating loads based on the cost of electricity, saving customers money without them having to actively manage the system.
The administration filed to dismiss an appeal of a December ruling that overturned its wind permitting freeze.
Trump’s Department of Justice is giving up on defending the president’s wind permitting moratorium.
The DOJ filed a motion on Wednesday to dismiss its appeal of a federal court’s December decision vacating the order to halt wind energy approvals. The plaintiffs in the case — New York and 16 other states, as well as the Alliance for Clean Energy New York, a trade group — did not oppose the motion. The case will not be officially dismissed, however, until the First Circuit Court of Appeals approves the request, which typically happens quickly when both parties support the dismissal.
The case stems from an executive order President Trump issued on the first day of his current term temporarily withdrawing all areas of the outer continental shelf from offshore wind leasing and pausing all federal authorizations for onshore and offshore wind projects while the administration conducted a review of leasing and permitting practices.
States took the administration to court last May, arguing that the order was arbitrary and capricious and violated the Administrative Procedures Act. They claimed it harmed their ability to source reliable and affordable energy and threatened billions of dollars in investment in supply chains, workforce development, and wind industry-related infrastructure.
On December 8, Judge Patti B. Saris of the U.S. District Court for the District of Massachusetts ruled in the states’ favor and vacated the wind order. More specifically, the judge vacated the portion of the order directing agencies to pause permits and other authorizations. The withdrawal of areas eligible for new leases remains in effect.
What it means is that federal agencies will now have to proceed with permitting wind projects using the existing statutory and regulatory framework, Kit Kennedy, the managing director for power, climate, and energy at the Natural Resources Defense Council, told me in an email. “The door to federal permitting is now unlocked again and each developer will be able to make the case for permitting their individual project based on the facts and the law,” she said.
The Trump administration appealed the ruling to the First Circuit in February, but never submitted an opening brief. The initial deadline was May 11, but on May 4, the DOJ requested additional time to file the brief. The judge gave the defendants until June 10. On that date, the defendants filed the motion to dismiss.
This is a developing story and we’ll update it as we learn more about the administration’s actions and their effects.
Editor’s note: This story has been updated to reflect that the freeze and ruling apply to onshore as well as offshore wind. It also adds a quote from Kit Kennedy.