Sign In or Create an Account.

By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy

The Insiders Survey

This Is the Most Promising Climate Tech Company, According to People Who Know

Plus, the technology our experts say is least ready for primetime.

•
Geothermal and fusion technologies.
Heatmap Illustration/Fervo Energy, Getty Images

Regardless of what 2025 was like in the U.S., the transition to clean energy is still progressing, both abroad and at home. It is not, however, advancing at the same pace across all clean energy sectors.

As part of our annual survey of energy world insiders, Heatmap asked dozens of climate experts which key decarbonization technologies they thought were furthest from widespread deployment.

By far the most common answer — with about two in five experts agreeing — was fusion energy.

As Heatmap’s Katie Brigham has reported, even the technology’s most optimistic proponents don’t expect fusion plants to hit the grid for at least another decade. And even if fusion becomes commercially ready, bringing down its cost to a level where it can compete with existing renewable sources of electricity will be yet another challenge.

“Even though scientifically we may get there in the next few years, I don’t know if it will result in a rapid shift in our power sector in a decade,” Ilaria Mazzocco, an expert in China’s energy policy, told Heatmap. “Can we restructure our entire power sector to deal with this completely novel technology then? And on top of that, can we make it cheap enough so that it makes sense?”

Another respondent who works in energy policy was more skeptical. “I won’t believe it ’til I see it,” they said.

Costa Samaras, the director of the Scott Institute for Energy Innovation at Carnegie Mellon University, named fusion as his pick, but said he hasn’t given up hope that it will one day come to fruition. “Having been part of the fusion energy leadership team at the White House,” Samaras said, “I'm a firm believer we should ramp up federal efforts to accelerate the fusion development timeline.”

Though sustainable aviation seems to be closer to deployment than fusion, experts don’t expect that industry to take off anytime soon, either. Both sustainable aviation fuel and electric aircrafts face significant challenges to getting off the ground — so to speak. SAF relies on scarce feedstocks, requires a lot of energy to produce, and costs far more than petroleum-based jet fuel. And batteries are heavy, making them impractical for commercial air travel.

Respondents also beefed, so to speak, with lab-grown meat and were reluctant to gas up on hydrogen. Cultivated meat technology has advanced rapidly, but key members of the Trump administration have no love for the product. Hydrogen has struggled to bring its cost in line with other energy sources such as natural gas, and the Trump administration has rolled back federal support for the technology.

There are a few companies, however, that are making advances in some key decarbonization technologies. When Heatmap asked experts which looked the best to them, geothermal energy companies took the top two spots: Fervo Energy, which is slated to open a 100-megawatt enhanced geothermal system next year, and Zanskar, a startup that utilizes artificial intelligence to find naturally-occurring reservoirs. Quaise Energy, which uses a process known as millimeter-wave drilling that involves using very high frequency radio waves to heat and vaporize rock, also scored a mention.

Respondents named more than two-dozen companies in total. Answers spanned an array of industries, from nuclear energy (Kairos Power and Westinghouse — “While they are a legacy company, if they engage successfully to scale their proven nuclear design, the impact could be massive,” Armond Cohen, executive director of Clean Air Task Force, told us), long-duration energy storage (Form Energy, Hydrostor, Antora Energy, and Rondo Energy), and grid software (GridAstra, which has created a digital platform to alleviate grid congestion, and ConnectDER, which manufactures meter socket adapters to accelerate clean energy device connection), to sustainable agriculture (Nitricity, which produces plant-based fertilizer, and Pivot Bio, which makes microbes that deliver nitrogen to plants).

Rather than naming just one company, one solar advocate chose the half-dozen leading Chinese solar panel and battery manufacturers. “These guys are together producing more energy now than the Seven Sisters of the oil industry,” they said.

Despite President Trump’s full-throated support, the U.S. oil industry hasn’t significantly boosted production in the past year. Faced with steep tariffs on supplies and equipment and increased production from OPEC+ countries, crude oil prices sank in 2025, which means that U.S. companies aren’t exactly rushing to ramp up drilling.

Editor’s note: This story has been updated to correct Samaras’ professional affiliation.

The Heatmap Insiders Survey of 55 invited expert respondents was conducted by Heatmap News reporters during November and December 2025. Responses were collected via phone interviews. All participants were given the opportunity to record responses anonymously. Not all respondents answered all questions.

Green
🔒

You’ve reached your free article limit

Subscribe to Heatmap News for unlimited access to daily energy and climate coverage.
To continue reading
Create a free account or sign in to unlock more free articles.
or
Please enter an email address
By continuing, you agree to the Terms of Service and acknowledge our Privacy Policy
Heatmap Is Hiring a Senior Editor

Heatmap News is looking for an ambitious, energetic senior editor to join our growing newsroom.

The senior editor will report to the deputy editor of the website and will be tasked with assisting in running all aspects of our coverage. This individual will be the primary editor on many of the site’s stories, including breaking news, features, and long-term projects, on topics ranging from permitting reform to decarbonized fuels to greenhouse gas accounting to the electric vehicle market. This person will also play a role in overseeing and furthering our cross-platform efforts such as newsletters, events, and podcasts. Additional duties will include managing and maintaining the site’s social media presence and digital production on stories, newsletters, and podcasts.

Keep reading...Show less
Yellow
AM Briefing

The Three Storms

On Canadian retrofits, Polish nuclear, and Latin American hydro

Storm-damaged homes.
Heatmap Illustration/Getty Images

Current conditions: Japan is bracing for two major storms as Typhoon Nolo and the newly formed Typhoon Koguma barrel toward the country • A brief heat wave in Chicago is driving temperatures up past 85 degrees Fahrenheit today • It’s a sunny day in San Salvador Island, where the Genoan explorer Christopher Columbus first set foot in the Americas exactly 534 years ago today, when the indigenous Lucayan people called the smallest inhabited part of the Bahamas “Guanahani.”


THE TOP FIVE

1. A trio of powerful storms slam into North America

In the Gulf of Mexico, Hurricane Isaias plunged thousands along the Alabama and Florida coastlines into darkness and left at least four dead. In the Pacific off Southern California, Tropical Storm Rachel stirred a surf that badly battered Long Beach’s iconic boardwalk. Further south in the eastern Pacific, Hurricane Simon pounded Mexico’s west coast as a Category 4 storm with sustained winds topping 150 miles per hour. Isaias, the only one of the tempête a trois in the Atlantic, forced nearly two-thirds of U.S. oil and gas production in the Gulf offline, as I told you last week.

Keep reading...Show less
Blue
Politics

Jared Huffman Wants to See Some Changes to the Senate’s Permitting Bill

The California Democrat and current ranking member of the House Natural Resources Committee is suspicious of all the “now or never.”

Jared Huffman.
Heatmap Illustration/Getty Images

The most important voice in Congress criticizing the Senate’s bipartisan energy permitting deal is Representative Jared Huffman.

A California Democrat who previously worked in environmental legal advocacy, Huffman has long been among the most impassioned lawmakers on climate issues. Under the first Trump administration, his voice was often the loudest calling for oversight and accountability on energy and climate policy. Under the second Trump administration, he has been a spirited defender of offshore wind.

Keep reading...Show less
Blue