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A practical guide to using the climate law to get cheaper solar panels, heat pumps, and more.

Today marks the one year anniversary of the Inflation Reduction Act, the biggest investment in tackling climate change the United States has ever made. The law consists of dozens of subsidies to help individuals, households, and businesses adopt clean energy technologies. Many of these solutions will also help people save money on their energy bills, reduce pollution, and improve their resilience to disasters.
But understanding how much funding is available for what, and how to get it, can be pretty confusing. Many Americans are not even aware that these programs exist. A poll conducted by The Washington Post and the University of Maryland in late July found that about 66% of Americans say they have heard “little” or “nothing at all” about the law’s incentives for installing rooftop solar panels, and 77% have heard little or nothing about subsidies for heat pumps. This tracks similar polling that Heatmap conducted last winter, suggesting not much has changed since then.
Below is Heatmap’s guide to the IRA’s incentives for cutting your carbon footprint at home. If you haven’t heard much about how the IRA can help you decarbonize your life, this guide is for you. If you have heard about the available subsidies, but aren’t sure how much they are worth or where to begin, I’ll walk you through it. (And if you’re looking for information about the electric vehicle tax credit, my colleague at Heatmap Robinson Meyer has you covered with this buyer’s guide.)
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There’s funding for almost every solution you can think of to make your home more energy efficient and reduce your fossil fuel use, whether you want to install solar panels, insulate your attic, replace your windows, or buy electric appliances. If you need new wiring or an electrical panel upgrade before you can get heat pumps or solar panels, there’s some money available for that, too.
The IRA created two types of incentives for home energy efficiency improvements: Unlimited tax credits that will lower the amount you owe when you file your taxes, and $8.8 billion in rebates that function as up-front discounts or post-installation refunds on equipment and services.
The tax credits are available now, but the rebates are not. The latter will be administered by states, which must apply for funding and create programs before the money can go out. The Biden administration began accepting applications at the end of July and expects states to begin rolling out their programs later this year or early next.
The home tax credits are available to everyone that owes taxes. The rebates, however, will have income restrictions (more on this later).
“The Inflation Reduction Act is not a limited time offer,” according to Ari Matusiak, the CEO of the nonprofit advocacy group Rewiring America. The rebate programs will only be available until the money runs out, but, again, none of them have started yet. Meanwhile, there’s no limit on how many people can claim the tax credits, and they’ll be available for at least the next decade. That means you don’t need to rush and replace your hot water heater if you have one that works fine. But when it does break down, you’ll have help paying for a replacement.
You might want to hold off on buying new appliances or getting insulation — basically any improvements inside your house. There are tax credits available for a lot of this stuff right now, but you’ll likely be able to stack them with rebates in the future.
However, if you’re thinking of installing solar panels on your roof or getting a backup battery system, there’s no need to wait. The rebates will not cover those technologies.
A few other caveats: There’s a good chance your state, city, or utility already offers rebates or other incentives for many of these solutions. Check with your state’s energy office or your utility to find out what’s available. Also, it can take months to get quotes and line up contractors to get this kind of work done. If you want to be ready when the rebates hit, it’s probably a good idea to do some of the legwork now.
If you do nothing else this year, consider getting a professional home energy audit. This will cost several hundred dollars, depending on where you live, but you’ll be able to get 30% off or up to $150 back under the IRA’s home improvement tax credit. Doing an audit will help you figure out which solutions will give you the biggest bang for your buck, and how to prioritize them once more funding becomes available. The auditor might even be able to explain all of the existing local rebate programs you’re eligible for.
The Internal Revenue Service will allow you to work with any home energy auditor until the end of this year, but beginning in 2024, you must hire an auditor with specific qualifications in order to claim the credit.
Let’s start with what’s inside your home. In addition to an energy audit, the Energy Efficiency Home Improvement Credit offers consumers 30% off the cost (after any other subsidies, and excluding labor) of Energy Star-rated windows and doors, insulation, and air sealing.
There’s a maximum amount you can claim for each type of equipment each year:
$600 for windows
$500 for doors
$1,200 for air sealing and insulation
The Energy Efficiency Home Improvement Credit also covers heat pumps, heat pump water heaters, and electrical panel upgrades, including the cost of installation for those systems. You can get:
$2,000 for heat pumps
$600 for a new electrical panel
Yes, homeowners can only claim up to $3,200 per year under this program until 2032.
Also, one downside to the Energy Efficiency Home Improvement Credit is that it does not carry over. If you spend enough on efficiency to qualify for the full $3,200 in a given year, but you only owe the federal government $2,000 for the year, your bill will go to zero and you will miss out on the remaining $1,200 credit. So it could be worth your while to spread the work out.
The other big consumer-oriented tax credit, the Residential Clean Energy Credit, offers homeowners 30% off the cost of solar panels and solar water heaters. It also covers battery systems, which store energy from the grid or from your solar panels that you can use when there’s a blackout, or sell back to your utility when the grid needs more power.
The subsidy has no limits, so if you spend $35,000 on solar panels and battery storage, including labor, you’ll be eligible for the full 30% refund, or $10,500. The credit can also be rolled over, so if your tax liability that year is only $5,000, you’ll be able to claim more of it the following year, and continue doing so until you’ve received the full value.
Geothermal heating systems are also covered under this credit. (Geothermal heat pumps work similarly to regular heat pumps, but they use the ground as a source and sink for heat, rather than the ambient air.)
Here’s what we know right now. The IRA funded two rebate programs. One, known as the Home Energy Performance-Based Whole House Rebates, will provide discounts to homeowners and landlords based on the amount of energy a home upgrade is predicted to save.
Congress did not specify which energy-saving measures qualify — that’s something state energy offices will decide when they design their programs. But it did cap the total amount each household could receive, based on income. For example, if your household earns under 80% of the area median income, and you make improvements that cut your energy use by 35%, you’ll be eligible for up to $8,000. If your household earns more than that, you can get up to $4,000.
There’s also the High-Efficiency Electric Home Rebate Program, which will provide discounts on specific electric appliances like heat pumps, an induction stove, and an electric clothes dryer, as well as a new electrical panel and wiring. Individual households can get up to $14,000 in discounts under this program, although there are caps on how much is available for each piece of equipment. This money will only be available to low- and moderate-income households, or those earning under 150% of the area median income.
Renters with a household income below 150% of the area median income qualify for rebates on appliances that they should be able to install without permission from their landlords, and that they can take with them if they move. For example, portable appliances like tabletop induction burners, clothes dryers, and window-unit heat pumps are all eligible for rebates.
It’s also worth noting that there is a lot of funding available for multifamily building owners. If you have a good relationship with your landlord, you might want to talk to them about the opportunity to make lasting investments in their property. Under the performance-based rebates program, apartment building owners can get up to $400,000 for energy efficiency projects.
For the most part, yes. But the calculus gets tricky when it comes to heat pumps.
Experts generally agree that no matter where you live, switching from an oil or propane-burning heating system or electric resistance heaters to heat pumps will lower your energy bills. Not so if you’re switching over from natural gas.
Electric heat pumps are three to four times more efficient than natural gas heating systems, but electricity is so much more expensive than gas in some parts of the country that switching from gas to a heat pump can increase your overall bills a bit. Especially if you also electrify your water heater, stove, and clothes dryer.
That being said, Rewiring America estimates that switching from gas to a heat pump will lower bills for about 60% of households. Many utilities offer tools that will help you calculate your bills if you make the switch.
The good news is that all the measures I’ve discussed in this article are expected to cut carbon emissions and pollution, even if most of your region’s electricity still comes from fossil fuels. For some, that might be worth the monthly premium.
Tax Credit #1 offers 30% off the cost of energy audits, windows, doors, insulation, air sealing, heat pumps, electrical panels, with a $3200-per-year allowance and individual item limits.
Tax Credit #2 offers 30% off the cost of solar panels, solar water heaters, batteries, and geothermal heating systems.
Rebate Program #1 will offer discounts on whole-home efficiency upgrades depending on how much they reduce your energy use, with an $8,000 cap for lower-income families and a $4,000 cap for everyone else.
Rebate Program #2 is only for low- and moderate- income households, and will offer discounts on specific electric appliances, with a $14,000 cap.
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Current conditions: The weekend’s polar vortex chill in New York City is over as temperatures are set to hit 70 degrees Fahrenheit today, your humble correspondent’s birthday • A winter storm blanketing the Sierra Nevadas with as much as four feet of snow on Interstate 80’s Donner Pass, the primary route between Sacramento and Reno named for the notorious 1846 episode of snowbound settlers driven to cannibalism • Days after thermometers finally slid from an almost sauna-like 118 degrees to somewhere in the 90s, thunderstorms are deluging India’s northern Uttar Pradesh state as dust storms blast cities such as Kanpur.
The Trump administration is bringing construction of virtually all new onshore wind turbines to a halt, putting as many as 165 projects on pause on the grounds that they may threaten national security. The projects, sited on private land, are being stalled by the Department of Defense, and include “wind farms which were awaiting final sign-off, others in the middle of negotiations, and some that typically would not require oversight” by the military, according to the Financial Times. Wind farms require routine approvals from the Pentagon to make sure turbines don’t interfere with radar systems. Normally these assessments are done in a few days. But developers told the newspaper they have faced a mix of setbacks since last August.
Back in December, the administration made a similar argument to justify an order to stop work on all offshore wind farms. Developers sued, and it only took weeks for federal courts to put a pause on the order. That legal strategy is now expected to play out once again on land.
Exxon Mobil and Chevron are resisting the White House’s pressure to increase oil production as the administration presses U.S. oil majors to ramp up supply to ease the demand shock from the closure of the Strait of Hormuz. In an interview with the Financial Times, Exxon’s finance chief Neil Hansen said there would be “no change” to the company’s strategy in the Permian Basin, while Chevron’s chief financial officer Eimear Bonner said “the crisis has not prompted any change to any of our plans.” The statements come days after the price per barrel of crude hit $126 last Thursday. “There’s really no need for us to shift up because we’re already up, we’re already in high gear,” Hansen said. “That doesn’t mean we aren’t looking at the potential to expand that but there are limitations.”
That doesn’t mean the industry isn’t happy to play along with Trump’s other foreign policy ventures. In a post on X last week, Bloomberg columnist Javier Blas highlighted the rapid shift of Exxon Mobil CEO Darren Woods’ views on Venezuela, which went from “uninvestable” in January” to, just four months later, “a huge resource that’s now opened up more freely to the world” where “we’ll be uniquely positioned and play an important role in bringing those barrels to market.” Meanwhile, the U.S. Senate candidate who could become the first Democrat to win statewide in Texas in 32 years has sought to ease the oil industry’s concerns about his political views. In an interview on Tejano singer Bobby Pulido’s podcast, Democratic Senate nominee James Talarico disavowed his party’s past rhetoric promising to phase out oil and gas production. “The idea that politicians in Washington think they can just eliminate this industry, eliminate these jobs, is something we had to fight against, something we have to fight against in our own party,” he said. “I’m a big fan of the renewable industry we’ve got in Texas … but it’s going to take an all-of-the-above approach.” Killing off the U.S. industry while global demand remains in effect is “not practical” and “it’d do so much damage to our state,” he said.
For all the hype over nuclear power in the United States, the Canadians are the North Americans on track to build the hemisphere’s first small modular reactor. On Friday, Ontario Power Generation’s project to expand its Darlington atomic station just east of Toronto with the world’s first BWRX-300 hit a critical milestone as the province-owned utility completed installation of the reactor’s basement some 35 meters, or about 115 feet, underground. The 300-megawatt unit was designed by GE Vernova Hitachi Nuclear Energy, the heir to General Electric’s 20th-century legacy of building the world’s fleet of boiling water reactors that today still makes up the second-largest share of all commercial fission plants after the Westinghouse-pioneered pressurized water reactor. If the reactor enters into service on time in 2029 — a big if — it will be the first on multiple counts: The first SMR from GE Hitachi. The first SMR in either Canada, North America, or the Western Hemisphere. Indeed, the first SMR in the entire democratic world, an overdue moment as China completes its Linglong-1 project in Hainan and Russia’s floating Akademik Lomonosov nuclear station remains in operation. “Ontario is building the Western World’s first small modular reactor,” Stephen Lecce, Ontario’s minister of energy and mines, said in a statement. “Ontario just executed with great precision the first foundation of a new nuclear reactor in Ontario in over 30 years. This is a major achievement as the world turns to Ontario to refurbish and build large scale nuclear on-time and on-budget.”
Ontario set a model for the rest of the region on how to pursue nuclear power despite modern development constraints. Its government-owned utility opted for the reactor over cheaper renewables and batteries by examining a whole systems-cost approach that included the transmission and back-up generation implied by a big solar and wind buildout. That ownership model also inspired neighboring New York to tap in its New York Power Authority, the largest state-owned utility the U.S., to lead the charge on building at least a gigawatt of new reactor capacity, as Heatmap’s Matthew Zeitlin explained last year. In December, as I wrote at the time, New York Governor Kathy Hochul forged a nuclear alliance with Ontario’s government to work together on issues related to building new reactors. The U.S. last year pumped $400 million into GE Hitachi’s plan to build America’s first BWRX-300 at the federally owned Tennessee Valley Authority’s Clinch River facility, as I reported for Heatmap.
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The Trump administration hasn’t abandoned its effort to kill New York’s congestion pricing scheme. On Friday, Secretary of Transportation Sean Duffy filed a notice of appeal to U.S. District Judge Lewis Liman’s March 3 decision to dismiss the administration’s lawsuit arguing that New York had overstepped its federal authorization by putting the toll in place. Before New York City implemented congestion pricing, experts warned that the apparent opposition captured in the pages of the New York Post was a paper tiger. Successful efforts to impose tolls on cars driving into dense urban areas with lots of public transit in Singapore and London had followed the same arc: Vehement blowback before the tolls take effect, contented acceptance once the charges become as normal as any other toll on the city’s roads and drivers start enjoying the easing of the gridlock. Within months of congestion pricing taking effect, polls showed that, already, support had flipped with more New Yorkers wanting to keep the tolls in place than eliminate them. But a year in, the results were hard to debate. As The City put it: “Less traffic. Faster buses. More subway riders.”
The latest legal challenge comes as New York grapples with mounting energy issues. In March, the Hochul administration proposed pushing back a key deadline in the state’s landmark decarbonization law. The state has yet to broker a final budget as legislators struggle to reach a deal with the governor’s office. Meanwhile, the state’s grid operator has issued a warning urging regulators to allow two barge-mounted power plants in Brooklyn to stay open past their planned closure.

The National Oceanic and Atmospheric Administration has ruled that The Metals Company’s deep-seabed mining application is fully compliant with U.S. regulations. On Friday, the Canadian company, which is aiming to harvest mineral-rich nodules from a 1.7-million-acre swath of the Pacific called the Clarion-Clipperton Zone, called the approval “a key milestone” toward commercialization that puts the firm on track to start producing metals by the first three months of next year. Under a new regulatory framework NOAA put out, which The Metals Company applied to use, “applicants with exploration-phase data to submit a consolidated application for both an exploration license and commercial recovery permit,” establishing “a more efficient” permitting timeline. “This determination marks an important step forward in NOAA’s transparent, rules-based process, and brings us ever closer to providing the U.S. with a new, abundant and lower-impact source of critical metals,” Gerard Barron, chairman and chief executive of The Metals Company, said in a statement. “It reflects the sheer scale of scientific, environmental, and engineering effort and expertise that have been brought to bear on this project over the last 15 years, which provides us with sufficient information to move efficiently and responsibly into commercial operations under NOAA’s oversight.” Shares in the company surged on Friday in response to the news.
In March, the United Nations’ International Seabed Authority vowed to establish a global framework for regulating deep seabed mining this year, as I wrote at the time. Japan, meanwhile, is stepping up its efforts to create its own seabed mining industry.
The kiwi disappeared from the hills around New Zealand’s capital more than a century ago. But now the country’s flightless national bird is once again living in Wellington. Last week, the Capital Kiwi Project, a charitable trust that aims to bring the birds back to the city, released its 250th kiwi. “They are a part of who we are and our sense of belonging here,” Paul Ward, founder of the Capital Kiwi Project, told Euronews. “But they’ve been gone from these hills for well over a century and we decided as Wellingtonians that wasn’t right.”
Plus news on cloud seeding, fission for fusion, and more of the week’s biggest money moves.
From beaming solar power down from space to shooting storm clouds full of particles to make it rain, this week featured progress across a range of seemingly sci-fi technologies that have actually been researched — and in some cases deployed — for decades. There were, however, few actual funding announcements to speak of, as earlier-stage climate tech venture funds continue to confront a tough fundraising environment.
First up, I explore Meta’s bet on space-based solar as a way to squeeze more output from existing solar arrays to power data centers. Then there’s the fusion startup Zap Energy, which is shifting its near-term attention toward the more established fission sector. Meanwhile, a weather modification company says it’s found a way to quantify the impact of cloud seeding — a space-age sounding practice that’s actually been in use for roughly 80 years. And amidst a string of disappointments for alternate battery chemistries, this week brings multiple wins for the sodium-ion battery sector.
One might presume that terrestrial solar paired with batteries would prove perfectly adequate for securing 24/7 clean energy moving forward, as global prices for panels and battery packs continue to fall. But the startup Overview Energy, which uses lasers to beam solar power from space directly onto existing solar arrays, thinks its space-based solar energy systems will prove valuable for powering large loads like data centers through the night. Now Meta is backing that premise, signing a first-of-its-kind agreement with Overview this week that secures early access for up to a gigawatt of capacity from the startup’s system.
Initial orbital demonstrations are slated for 2028, with commercial power delivery targeted for 2030. It’s an ambitious timeline, and certainly not the first effort to commercialize space-based solar, though prior analyses have generally concluded that while the physics check out, the economics and logistics don’t. Overview Energy thinks its found the core unlocks though: “geographic untethering,” which allows it to direct its beam to ground-based solar arrays anywhere in the world based on demand, and high-efficiency lasers capable of converting near-infrared light into electricity much more efficiently than pure sunlight.
The startup is targeting between $60 and $100 per megawatt-hour by 2035, at which point the goal is to be putting gigawatts of space solar on the grid. “It’s 5 o’clock somewhere,” Marc Berte, founder and CEO of Overview Energy, told me when I interviewed him last December. “You’re profitable at $100 bucks a megawatt-hour somewhere, instantaneously, all the time.”
Launch costs have also fallen sharply since the last serious wave of space-solar research, and Overview has already booked a 2028 launch with SpaceX. Solar power beamed from space also sidesteps two earthly constraints — land use and protracted grid interconnection timelines. So while this seemingly sci-fi vision remains unproven, it might be significantly more plausible than it once appeared. And Meta’s certainly not alone in taking that bet — Overview has already raised a $20 million seed round led by Lowercarbon Capital, Prime Movers Lab, and Engine Ventures.
Fusion startups are increasingly looking to nearer-term revenue opportunities as they work toward commercializing the Holy Grail of energy generation. Industry leader Commonwealth Fusion Systems is selling its high-temperature superconducting magnets to other developers, while other companies including Shine Technologies are generating income by producing nuclear isotopes for medical imaging. Now one startup, Zap Energy, is pushing that playbook a step further, announcing this week that it plans to develop fission reactors before putting its first fusion electrons on the grid.
Specifically, the startup is now attempting to develop small modular reactors — hardly a novel idea, as companies like Oklo, Kairos, and TerraPower have already secured significant public and private funding and struck major data center deals. Zap, however, thinks it can catch up to these new competitors in part by leveraging design commonalities between fission and fusion systems, including the use of liquid metals, engineered neutron environments, and high-power-density systems. “Fission and fusion are two expressions of the same underlying physics," Zap’s co-founder Benj Conwayby said in the press release. "This isn’t a pivot — by integrating them into a single platform, we can move faster, reduce risk, and build a more enduring company."
As the company outlines on its website, pursuing both pathways could eventually manifest in the development of a hybrid fusion-fission system, while also giving Zap practical experience interfacing with regulators and securing approvals. As The New York Times reports, the company is targeting an early 2030s timeline for its fission reactors, although Zap has yet to specify a timeline for fusion commercialization. Like so many of its peers, the company is eyeing data centers as a promising initial market, though bringing its first units online will likely require a significant influx of additional capital.
For all the concern surrounding geoengineering fixes for climate change such as solar radiation management, there’s one form of weather modification that’s been in use since the 1940s — cloud seeding. This practice typically involves flying planes into the center of storms and releasing flares that disperse a chemical called silver iodide into the clouds. This causes the water droplets within the clouds to freeze, increasing the amount of precipitation that falls as either rain or snow.
Alarming as it may sound for the uninitiated, there’s no evidence that silver iodide causes harm at current usage levels. But what has been far more difficult to pin down is efficacy — specifically, how much additional precipitation cloud seeding actually creates. That’s where the startup Rainmaker comes in. The company, which deploys unmanned drones to inject the silver iodide, says that its advanced radar and satellite systems indicate that its operations generated over 143 million gallons of additional freshwater in Oregon and Utah this year — roughly equivalent to the annual water usage of about 1,750 U.S. households. The findings have not yet been peer reviewed, but if accurate, they would make Rainmaker the first private company to quantify the impact of its cloud seeding operations.
Cloud seeding is already a well-oiled commercial business, with dozens of states, utility companies and ski resorts alike using it to increase snowfall in the drought-stricken American West and worldwide — China in particular spends tens of millions of dollars per year on the technology. Rainmaker has a particular aspiration: to help restore Utah’s Great Salt Lake, which has been shrinking since the 1980s amid rising water demand and increased evaporation driven by warmer temperatures.
In a press release, the company’s 26-year-old founder and CEO Augustus Doricko said, “With the newfound capability to measure our yields and quantify our results, Rainmaker will go forward and continue our mission to refill the Great Salt Lake, end drought in the American West and deliver water abundance wherever it is needed most around the world."
Sodium-ion batteries have long been touted as an enticing alternative — or at least complement — to lithium-ion systems for energy storage. They don’t rely on scarce and costly critical minerals like lithium, nickel, or cobalt, and have the potential to be far less flammable. The relatively nascent market also offers an opening for the U.S. to gain a foothold in this segment of the battery supply chain. But especially domestically, the industry has struggled to gain traction. Two sodium-ion startups, Natron and Bedrock Materials, both closed up shop last year as prices for lithium-iron-phosphate batteries cratered, eroding sodium-ion’s cost advantage, while the cost of manufacturing batteries in the U.S. constrained their ability to scale.
But one notable bright spot is the startup Alsym Energy, which announced this week that it has signed a letter-of-intent with long-duration energy storage company ESS Inc. for 8.5 gigawatt-hours of sodium-ion cells and modules, marking ESS’s expansion into the short and medium-duration storage market. Alsym’s CEO, Mukesh Chatter, told me this represents the largest deal for sodium-ion batteries in the U.S. to date — although it’s not yet a binding contract. Notably, it came just a day after the world’s largest-ever order for these batteries, as CATL disclosed a 60 gigawatt-hour sodium-ion agreement with energy storage integrator HyperStrong. Taken together, these partnerships suggest the sector is finally picking up durable traction both domestically and abroad.
ESS, however, is facing its own operational headwinds, nearly shuttering its Oregon manufacturing plant last year before securing an unexpected cash infusion and pivoting to a new, longer-duration storage product. Chatter remains exuberant about Alsym’s deal with the storage provider, however, telling me it represents a major proof point in terms of broader industry acceptance and an acknowledgement that “the benefits [sodium-ion] brings to the table are significant enough to overcome any stickiness” and hesitation around adopting new battery chemistries.
Chatter said that interest is now pouring in from all sides, citing inquiries from lithium-ion battery manufacturers, utilities, and defense companies and highlighting use cases ranging from data centers to apartment buildings and mining operations as likely early deployment targets.
A handful of startups are promising better, cheaper, safer water purification tech.
The need for desalination has long been clear in water-scarce regions of the planet. But with roughly a quarter of the global population now facing extreme water stress and drought conditions only projected to intensify, the technology is becoming an increasingly necessary tool for survival in a wider array of geographies.
Typically, scaling up desalination infrastructure has meant building costly, energy-intensive coastal plants that rely on a process called reverse osmosis, which involves pushing seawater through semi-permeable membranes that block salt and other contaminants, leaving only fresh water behind. Now, however, a number of startups are attempting to rework that model, with solutions that range from subsea facilities to portable desalination devices for individuals and families.
They could find potential customers across the globe. Many countries in the Middle East — including Saudi Arabia, Israel, Bahrain, Kuwait, and Qatar — rely on desalination for the bulk of their municipal water. Meanwhile, drought-prone regions from Australia to the Caribbean and California have also turned to the technology to shore up supply. But as the Iran war has underscored, this vital infrastructure is increasingly being treated as a military target, exposing a significant vulnerability in a resource relied upon by hundreds of millions.
One more resilient alternative is to move the plants underwater — making them more difficult to target while also harnessing subsurface pressure to do some of the energy-intensive work of desalination.
“I came up with the idea of using natural pressure to run the process,” Robert Bergstrom, a veteran of the water industry and CEO of the desalination startup OceanWell, told me. That meant “putting the membranes in a place where it’s already 800 pounds [of pressure] per square inch” — e.g. inside pods on the ocean floor, each capable of producing 1 million gallons of freshwater daily. By using the natural pressure of the ocean to drive the reverse osmosis process, this approach cuts energy use by about 40%, he said, thus slashing the system’s largest operating cost: electricity.
OceanWell’s design maintains a lower internal pressure within each pod than the surrounding environment, causing seawater to flow passively inside and push through membranes — just like on land, but without the high-pressure pumps. Compact pumps inside the pods then push the freshwater up a pipeline to the shore, while the resulting brine dissipates in the deep ocean.
The method also helps solve another problem with conventional desalination: environmental impact. Today’s facilities typically produce a more concentrated brine that they discharge at the ocean’s surface, which is more disruptive to marine ecosystems. The plants also frequently cause damage to organisms large and small by either trapping them against water intake screens or pulling them into the plant itself. That’s been a big sticking point when it comes to permitting these facilities, especially in California where the startup is based. OceanWell’s system, Bergstrom said, is able to filter out larger organisms while allowing microscopic ones to pass through the pods and return to the ocean.
The company began a trial last year in partnership with Las Virgenes Municipal Water District in southern California, testing its system in a freshwater reservoir full of marine life to verify its safety. Next it will test its pods in the ocean before undertaking a pilot in a to-be-determined location — California, Hawaii, and Nice in southern France are all contenders. If all goes according to plan, OceanWell will follow that up with a full-fledged commercial system targeted for 2030.
But it’s not the only startup pursuing underwater desalination — or even the one with the most aggressive timeline. Two years ago, Norwegian startup Flocean spun out of the subsea pump specialist FSubsea with a similar technical approach and a plan to deploy its first commercial system off Norway’s western coast this year. Flocean has already logged over a year of testing in the deep ocean, a stage OceanWell has yet to reach.
OceanWell thinks it can differentiate itself by meeting the unusually stringent permitting required in California. “If we can get it done in California, then the rest of the world will follow,” Bergstrom told me, meaning more resilient, more energy-efficient freshwater infrastructure for all. But it’s a high bar. The last major effort to build a desalination facility in the state led to a long-running fight that ended in 2022 with a rejection. Over 100 groups opposed the facility proposed for Orange County, citing risks to marine life, as well as high energy requirements and costs, with many arguing that alternatives — such as conservation and wastewater treatment — would be more superior options.
Megan Mauter, an associate professor of civil engineering at Stanford, thinks the groups may have a point, especially when it comes to overall system costs. The high capex of desalination can be hard to justify in California, she told me, since the state doesn’t need it 100% of the time, only in bad drought years. For example, just a few weeks ago, The Wall Street Journal reported that San Diego County’s desalination plant, by far the largest in California, now has a surplus of desalinated water that it’s looking to sell to drought-ridden Western states such as Nevada and Arizona.
And while desalination startups purport to cut overall system costs, she has her doubts about that. “The energy savings that they’re going to get are offset by some pretty high increased costs of the other elements of their plant designs,” Mauter told me. “In a subsea system, you’ve got these unproven and not mass-manufactured skids. You’ve got subsea installation, and then mooring it, and putting in pipelines that you’ve got to maintain all the way to land. You’ve got to convey water back to shore, which takes energy, and you are going to have significantly higher maintenance burdens in an open ocean environment.”
Despite her reservations, she certainly sees the appeal of non-traditional water sources, “even at costs that would have been totally infeasible a decade ago.” Municipal planners are staring down a future of worsening drought at the same time that states in the Colorado River basin remain locked in contentious negotiations over water rights, debating how to allocate cuts as river flows have declined nearly 20% since 2000. California’s narrow continental shelf also makes it an ideal environment for subsea desalination, as having deep water close to shore allows the system to harness pressure depths while minimizing the length of the pipeline needed to transport freshwater to land. Norway is also favored in this way.
“I don’t know whether the cost gaps can be solved, but I bet that the technology gaps could be solved,” Mauter told me.
Ultimately, she thinks the binding constraint is likely to be regulatory rather than technical. “Permitting is going to be a nightmare unless something fundamentally changes,” she said. Bergstrom told me that OceanWell is currently working with the California State Water Resources Control Board to revise its rules that govern desalination facilities in order to account for new technologies, though how long that process will take is anyone’s guess.
There’s one idea emerging in this ecosystem that largely sidesteps the regulatory constraints that control our land and seas. The startup Vital Lyfe has developed a portable desalination unit roughly the size of a small cooler that allows individuals and households to produce freshwater on demand with reverse osmosis — effectively decentralizing the desalination industry in the same way that the startup’s founders, former SpaceX engineers, helped decentralize internet infrastructure with Starlink.
“We’ve seen this paradigm shift coming out of Starlink that traditional, large, centralized, systems are very expensive,” Vital Lyfe CEO Jon Criss told me. “They’re hard to deploy and hard to scale up when you really need them.”
After raising a $24 million seed round in December, the startup launched its first product a few weeks ago, which retails for $750. At that price point, it’s a great deal for sailors spending days or weeks at sea, but likely too expensive for the individuals in remote communities far from water infrastructure that might need it most. Criss’s goal is to quickly iterate on this first product to bring more affordable models to the market in short order.
Portable desalination devices aren’t anything new in and of themselves — they’ve been used in military, maritime, and humanitarian scenarios for decades. The startup’s breakthrough, Criss explained, is more about manufacturing efficiency than technology. “We went all the way back, looked at why every component was designed and how to redesign it for high rate manufacturing. So we were able to substantially drop the cost of ownership and operation of these things.”
You’ll soon find Vital Lyfe’s product in big box retail stores, Criss said, though he also aims to partner with large-scale desalination facilities and utilities to help boost their output. Either way, the startup is already generating buzz — it’s seen significant inbound interest as of late, as the inherent resilience of its small system stands in sharp contrast to the vulnerability of conventional desalination infrastructure now being targeted in the Middle East.
The company is scaling up to meet the moment, building out a facility in Los Angeles county that Criss said will eventually produce 120 portable units per hour. He’s aiming to start production by summer’s end, ramping to full capacity by October. “Within the next three years we plan to account for about 10% of total membrane production at Vital Lyfe alone,” he told me, referring specifically to the production for the desalination industry.
The future of the industry, of course, could look like any combination of all of these approaches — portable devices, conventional plants on land, and modular systems at sea. What seems certain is that as the globe continues to heat up, so will desalination tech.