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The grid needs transformers, and transformers need foreign steel.

President Trump wants to unleash American energy dominance, reduce consumer costs, and lead on artificial intelligence. But his 25% steel and aluminum tariffs, which are set to go into effect next month, could work directly against all of those goals.
The reason has to do with a crucial piece of electrical equipment for expanding the grid. They’re called transformers, and they’re in critically short supply.
Transformers serve to reduce losses along power lines by regulating voltage as electricity travels between generators and end uses, and they are made using a specific type of steel called grain oriented electrical steel, or GOES. There’s only one domestic producer of GOES — Cleveland Cliffs — and at full capacity it cannot meet even half of the demand from domestic transformer manufacturers, according to Joe Donovan, the executive director of the Transformer Manufacturing Association of America.
“We’re forced into the international markets,” he told me. “Reliance on a single domestic supplier for this critical material is a national security risk,” he added later in an email. “The grid is the foundation of our entire economy and should not be reliant on a single source for such a critical component.”
In a fact sheet about the upcoming steel and aluminum tariffs, Trump said he wants to end the “global dumping” of cheap foreign steel into American markets. It’s not yet clear whether he will impose blanket fees on all steel imports from all countries or use a finer tooth comb. But GOES only accounts for 0.15% of global steel production, Donovan said. “Any new restrictive tariffs would not onshore domestic GOES manufacturing, but would instead increase electricity costs for American consumers and delay upgrades to the grid nationally, putting manufacturing projects and developments at risk,” he told me. He said his trade group is advocating for the tariffs to exclude GOES imports from allied countries including Italy, South Korea, Poland and Japan, as well as derivative products from Mexico and Canada.
The problem is not just that the U.S. doesn’t produce enough of this material, Donovan added. Cleveland Cliffs lacks the capacity to produce GOES “in the size or efficiency levels that are needed in modern, efficient large power transformers,” he said. “Thus, domestic transformer manufacturers are unable to procure this GOES from any domestic source.”
Transformers come in many varieties and sizes, from the small metal boxes that sit atop local power lines to the larger containers at substations that have big metal coils springing out of them. Adding anything to the grid — whether it’s a generator like a new solar farm or natural gas plant, or a new source of demand like an apartment complex or a data center — requires adding transformers.
For nearly two decades, electricity growth was stagnant in the U.S., and there wasn’t much reason to invest in transformer manufacturing or supply chains. But suddenly, the rise of artificial intelligence, coupled with a push to reshore manufacturing and electrify transport, plus worsening natural disasters that damage electrical infrastructure caused demand to soar. These pressures have not just affected the U.S., and transformer manufacturers globally have not been able to keep up. Over the past four to five years, lead times for procuring transformers went from just under a year to upwards of three years, and prices jumped 60% to 80%, according to Wood Mackenzie.
“The increase in equipment costs is both threatening the economics of projects and increasing the price of electricity,” analysts from the energy research firm wrote in October. “One small ray of light from a transformer cost perspective is that the price of grain oriented electrical steel, a key commodity input, has declined 60-70% recently.”
Trump’s tariffs will cut into those declines.
“A lot of utilities and all of our clients across the country are very nervous about the potential implications of this,” Ben Boucher, a senior analyst at Wood Mackenzie, told me. “I think everyone knows their costs are going to increase as a result, even if they source domestically, because there’s going to be more competition for domestically produced products.”
When Trump imposed tariffs on steel during his first presidency, it did not lead to new investment in domestic manufacturing of GOES. Instead, there was an uptick in imports of transformer cores, a component that already contains GOES, from Mexico and Canada, Boucher said.
I reached out to the Edison Electric Institute, the main trade group for utilities, for comment on how the transformer shortage has affected its members’ ability to meet rising electricity demand, and what the tariffs could mean for them. The group did not answer my questions and sent back a statement attributed to Scott Aaronson, the senior vice president for energy security and industry operations, which said the group supports the president’s goal of bolstering domestic manufacturing and looks forward to working with him “to ensure that any new tariffs don't raise customer energy bills due to higher commodity prices.”
Jonas Nahm, an associate professor at Johns Hopkins, who worked as a senior economist at the White House under Biden, told me there was a concerted effort to increase transformer production domestically over the past four years. Several manufacturers, including Siemens Energy and Hitachi Energy, announced new plants and plant expansions. Nahm wondered whether Trump’s tariffs on steel could end up undermining his goals by making those investments riskier. “In econ terms, it’s sort of a tariff inversion, where we’re tariffing the intermediate inputs more than we’re tariffing the import of the final product.”
We often talk about industries like the “oil industry” or the “steel industry” as if they are making homogenous, interchangeable products. In reality, neither oil nor steel is one, uniform thing, and in the context of policymaking — like President Trump’s tariffs — the differences are consequential.
My colleague Robinson Meyer wrote about this when Trump was threatening to put 25% tariffs on Canadian imports. The U.S. is the biggest producer of crude oil in the world, but the oil that comes out of our wells is “light and sweet,” meaning that it has relatively low viscosity and sulfur content. Meanwhile, many U.S. refineries are designed to process the “heavy and sour” crude oil extracted in Canada. Tariffs on imported oil would lead to spikes in gasoline prices. “You couldn’t create a better scenario to destroy the economics of U.S. coking refineries,” Rory Johnston, an oil markets analyst, told Robinson. Similarly, the U.S. is a major steel producer, but we’re still heavily reliant on imports for certain types of steel.
It’s unclear whether the administration is aware of the issue. Trump is imposing tariffs on steel and aluminum under Section 232 of the Trade Expansion Act of 1962, as he did during his first term, which requires the Department of Commerce to first conduct an investigation and confirm that the import of these products threatens U.S. national security. But there’s been no new investigation since Trump took office. In his proclamation announcing the tariffs, the President referenced the investigation his administration conducted in 2018, adding in some recent data points that make the case that the threats from then are still an issue.
“They’re operating with 2018 assumptions about the state of the world, and then threw some updated data in there in order to accelerate the process,” Nahm said. “You can see how maybe this wasn’t a big deal six years ago. Now electricity demand is going up, and it’s getting more expensive. That wasn’t something that was on the horizon in 2018 at all.”
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The sale of Ravenswood Generating Station closed at the end of January.
New York City’s largest fossil fuel-fired power plant has changed hands. The Ravenswood Generating Station, which provides more than 20% of the city’s generation capacity, was sold by its former parent company LS Power to NRG, an energy company headquartered in Texas that owns power plants throughout the country.
It’s not yet clear what this means for “Renewable Ravenswood,” the former owner’s widely-publicized plans to convert the site into a clean energy hub. Prior to the sale, those plans were hanging by a thread. NRG did not respond to detailed questions about whether it will abandon or advance that vision.
“Ravenswood has been an important part of powering New York City for decades, and we recognize how much the facility matters to the surrounding community and the region,” a spokesperson for the company told me in an email. “We’ve begun engaging with community stakeholders and look forward to continuing those conversations in the months ahead. Our leadership team is carefully reviewing all relevant information and is taking a thoughtful, measured approach to any future decisions.”
Ravenswood is made up of four generating units: a natural gas combined cycle plant built in 2004, and three steam generators built in the 1960s that run mostly on natural gas, though sometimes also on oil. The plant is responsible for a sizable chunk of the city’s climate footprint. In 2023, the most recent year for which data is available, the plant emitted nearly 1.3 million metric tons of CO2, or about 8% of the city’s emissions from electricity production.
The Renewable Ravenswood concept was largely celebrated by the surrounding community, which includes two of the largest public housing projects in the country and suffers from disproportionately high rates of chronic respiratory diseases like asthma. The plan, which a local subsidiary of LS Power called Rise Light and Power proposed in 2022, entailed replacing the plant’s three 1960s steam generators with a combination of offshore wind, batteries, and renewable energy delivered from upstate New York via new power lines.
By last year, however, the plan was increasingly looking like a distant dream. Its centerpiece was a proposed offshore wind farm called Attentive Energy, but the project has been on ice since 2024, with little chance of moving forward under the Trump administration. This past November, New York regulators rejected a proposed transmission line that would have connected Ravenswood to a hypothetical future offshore wind development, primarily because there was no longer any such development in progress. Earlier this week, state energy regulators delivered yet another blow to potential offshore wind development when they decided not to solicit offers from for new projects to enter the state’s energy market.
Battery development has also had a rocky few years in New York State, which has affected Ravenswood’s transition. Rise Light and Power initially proposed building a 316-megawatt battery project on the site in 2019, but it has yet to break ground. The former CEO, Clint Plummer, previously told me that the company was waiting on New York State regulators to open up their anticipated battery solicitation, which would enable the project to bid into the New York energy market, before building the project. That solicitation opened last July, but it’s unclear whether the company submitted a bid. NRG did not respond to a question about this.
NRG first announced its plans to buy a fleet of natural gas plants — 18 in total — from LS Power in May 2025. Ravenswood was not mentioned in the press release or investor materials, however. “We're acquiring these assets at a significant discount to new build cost, at an attractive valuation, and at the strategically opportune time to be adding high-quality, difficult-to-replicate resources into our portfolio as the sector enters into a period of sustained demand growth,” NRG’s CEO Lawrence Coben told investors at the time.
The purchase was subject to regulatory approval and officially closed a few weeks ago, on January 30. Documents filed with the Securities and Exchange Commission confirm that Ravenswood was part of the deal. Documents filed with the New York Public Service Commission describe the terms in more detail, but they do not mention the proposed transition of the site to a clean energy hub.
Local officials, community groups, and tenant associations were deeply involved in fleshing out the Renewable Ravenswood vision. The Queens Borough President worked with the former owner on a multiyear report called “Reimagine Ravenswood,” released last summer, based on extensive engagement with the community, including public workshops, focus groups, interviews with local leaders, and a community survey. The report is evidence of high hopes the community has for the site’s transition, describing the potential to create jobs, expand public space, and generally increase investment in the neighborhood.
I reached out to many of the local elected officials and community groups that have publicly supported Renewable Ravenswood to ask if they were aware of the sale and whether NRG had made any commitments in regard to the transition plan. Just one responded. State Senator Kristen Gonzalez’s office told me they were aware of the sale, but declined to comment further.
Heron Power and DG Matrix each score big funding rounds, plus news for heat pumps and sustainable fashion.
While industries with major administrative tailwinds such as nuclear and geothermal have been hogging the funding headlines lately, this week brings some variety with news featuring the unassuming but ever-powerful transformer. Two solid-state transformer startups just announced back-to-back funding rounds, promising to bring greater efficiency and smarter services to the grid and data centers alike. Throw in capital supporting heat pump adoption and a new fund for sustainable fashion, and it looks like a week for celebrating some of the quieter climate tech solutions.
Transformers are the silent workhorses of the energy transition. These often-underappreciated devices step up voltage for long-distance electricity transmission and step it back down so that it can be safely delivered to homes and businesses. As electrification accelerates and data centers race to come online, demand for transformers has surged — more than doubling since 2019 — creating a supply crunch in the U.S. that’s slowing the deployment of clean energy projects.
Against this backdrop, startup Heron Power just raised a $140 million Series B round co-led by Andreessen Horowitz and Breakthrough Energy Ventures to build next-generation solid state transformers. The company said its tech will be able to replace or consolidate much of today’s bulky transformer infrastructure, enabling electricity to move more efficiently between low-voltage technologies like solar, batteries, and data centers and medium-voltage grids. Heron’s transformers also promise greater control than conventional equipment, using power electronics and software to actively manage electricity flows, whereas traditional transformers are largely passive devices designed to change voltage.
This new funding will allow Heron to build a U.S.manufacturing facility designed to produce around 40 gigawatts of transformer equipment annually; it expects to begin production there next year. This latest raise follows quickly on the heels of its $38 million Series A round last May, reflecting hunger among customers for more efficient and quicker to deploy grid infrastructure solutions. Early announced customers include the clean energy developer Intersect Power and the data center developer Crusoe.
It’s a good time to be a transformer startup. DG Matrix, which also develops solid-state transformers, closed a $60 million Series A this week, led by Engine Ventures. The company plans to use the funding to scale its manufacturing and supply chain as it looks to supply data centers with its power-conversion systems.
Solid-state transformers — which use semiconductors to convert and control electricity — have been in the research and development phase for decades. Now they’re finally reaching the stage of technical maturity needed for commercial deployment, driving a surge in activity across the industry. DG Matrix’s emphasis is on creating flexible power conversion solutions, marketing its product as the world’s first “multi-port” solid-state transformer capable of managing and balancing electricity from multiple different sources at once.
“This Series A marks our transition from breakthrough technology to scaled infrastructure deployment,” Haroon Inam, DG Matrix’s CEO, said in a statement. “We are working with hyperscalers, energy companies, and industrial customers across North America and globally, with multiple gigawatt-class datacenters in the pipeline.” According to TechCrunch, data centers make up roughly 90% of DG Matrix’s current customer base, as its transformers can significantly reduce the space data centers require for power conversion.
Zero Homes, a digital platform and marketplace that helps homeowners manage the heat pump installation process, just announced a $16.8 million Series A round led by climate tech investor Prelude Ventures. The company’s free smartphone app lets customers create a “digital twin” of their home — a virtual model that mirrors the real-world version, built from photos, videos, and utility data. This allows homeowners to get quotes, purchase, and plan for their HVAC upgrade without the need for a traditional in-person inspection. The company says this will cut overall project costs by 20% on average.
Zero works with a network of vetted independent installers across the U.S., with active projects in California, Colorado, Massachusetts, Minnesota, and Illinois. As the startup plans for national expansion, it’s already gained traction with some local governments, partnering with Chicago on its Green Homes initiative and netting $745,000 from Colorado’s Office of Economic Development to grow its operations in Denver.
Climactic, an early-stage climate tech VC, launched a new hybrid fund called Material Scale, aimed at helping sustainable materials and apparel startups navigate the so-called “valley of death” — the gap between early-stage funding and the later-stage capital needed to commercialize. As Climactic’s cofounder Josh Fesler explained on LinkedIn, the fund is designed to cover the extra costs involved with sustainable production, bridging the gap between the market price of conventional materials and the higher price of sustainable materials.
Structured as a “hybrid debt-equity platform,” the fund allows Climactic’s investors to either take a traditional equity stake in materials startups or provide them with capital in the form of loans. TechCrunch reports that the fund’s initial investments will come from an $11 million special purpose vehicle, a separate entity created to fund a small set of initial investments that sits outside Material Scale’s main investing pool.
The fashion industry accounts for roughly 10% of global emissions. “These days there are many alt materials startups that have moved through science and structural risk, have venture funding, credible supply chains and most importantly can achieve market price and positive gross margins just with scale,” Fesler wrote in his LinkedIn post. “They just need the capital to grow into their rightful commercial place.”
Clean energy stocks were up after the court ruled that the president lacked legal authority to impose the trade barriers.
The Supreme Court struck down several of Donald Trump’s tariffs — the “fentanyl” tariffs on Canada, Mexico, and China and the worldwide “reciprocal” tariffs ostensibly designed to cure the trade deficit — on Friday morning, ruling that they are illegal under the International Emergency Economic Powers Act.
The actual details of refunding tariffs will have to be addressed by lower courts. Meanwhile, the White House has previewed plans to quickly reimpose tariffs under other, better-established authorities.
The tariffs have weighed heavily on clean energy manufacturers, with several companies’ share prices falling dramatically in the wake of the initial announcements in April and tariff discussion dominating subsequent earnings calls. Now there’s been a sigh of relief, although many analysts expected the Court to be extremely skeptical of the Trump administration’s legal arguments for the tariffs.
The iShares Global Clean Energy ETF was up almost 1%, and shares in the solar manufacturer First Solar and the inverter company Enphase were up over 5% and 3%, respectively.
First Solar initially seemed like a winner of the trade barriers, however the company said during its first quarter earnings call last year that the high tariff rate and uncertainty about future policy negatively affected investments it had made in Asia for the U.S. market. Enphase, the inverter and battery company, reported that its gross margins included five percentage points of negative impact from reciprocal tariffs.
Trump unveiled the reciprocal tariffs on April 2, a.k.a. “liberation day,” and they have dominated decisionmaking and investor sentiment for clean energy companies. Despite extensive efforts to build an American supply chain, many U.S. clean energy companies — especially if they deal with batteries or solar — are still often dependent on imports, especially from Asia and specifically China.
In an April earnings call, Tesla’s chief financial officer said that the impact of tariffs on the company’s energy business would be “outsized.” The turbine manufacturer GE Vernova predicted hundreds of millions of dollars of new costs.
Companies scrambled and accelerated their efforts to source products and supplies from the United States, or at least anywhere other than China.
Even though the tariffs were quickly dialed back following a brutal market reaction, costs that were still being felt through the end of last year. Tesla said during its January earnings call that it expected margins to shrink in its energy business due to “policy uncertainty” and the “cost of tariffs.”