A look at the energy companies Bill Gates is backing

As Microsoft (MSFT), Google (GOOGL), and Amazon (AMZN) build on their artificial intelligence ambitions, the tech giants are also entering the race for alternative energy to meet AI’s massive consumption of power.

Microsoft announced a 20-year power purchase agreement in September with Constellation Energy (CEG) — the owner of most of the country’s power plants — that will restart the Unit 1 nuclear reactor on Three Mile Island.

In 2015, the company’s billionaire co-founder Bill Gates launched his investment firm, Breakthrough Energy Ventures, to invest in sustainable energy companies and other technologies.

Here are six energy-focused companies Gates and Breakthrough Energy have invested in.

Commonwealth Fusion Systems

Breakthrough Energy invested in Commonwealth Fusion Systems’ $115 million Series A funding round in June 2019, according to PitchBook. The investment firm was a follow-on investor in the company’s $84 million Series A2 round in May 2020, and its $1.8 billion Series B funding round in December 2021, which also counted Gates as an investor, according to PitchBook.

Commonwealth Fusion Systems, the largest commercial fusion energy company in the world, uses high-temperature superconducting magnets to build tokamak fusion systems, which are small and low-cost.

The company is currently working with MIT’s Plasma Science and Fusion Center on a fusion device called SPARC, which can produce “plasmas which generate more energy than they consume, becoming the first net-energy fusion machine.”

After SPARC, CFS said it will build ARC, “the world’s first fusion power plant capable of producing net electricity.”

KoBold Metals

Gates was the lead partner in Breakthrough Energy’s investment in KoBold Metals’ $5 million Series A funding round in March 2019, which valued the company at $12.5 million, according to PitchBook.

KoBold uses AI to find deposits of high-demand metals, such as lithium, cobalt, and nickel, that can be used in the production of renewable energy products like solar panels and electric vehicle batteries. The company has over 60 projects on four continents.

Breakthrough Energy also invested in the company’s $200.8 million Series B funding round in February 2022, leading to a $517.83 million valuation, and in another Series B round in March 2023 where it raised $195 million, and was valued at $1 billion. Gates was listed as an investor in this Series B funding round on PitchBook.

Mainspring Energy

In January 2018, Gates invested in Mainspring Energy’s $83.3 million Series C, according to PitchBook, which led the company to a $208.3 million valuation.

Mainspring’s linear generator uses chemical energy to convert motion along a linear line into clean electricity at any scale, according to the company. The linear generator continuously adjusts compression and expansion to different fuel quality and fuels, so it can use fuels such as biogas and green hydrogen.

The linear generators can match power output with demand, and integrate on-site solar and energy storage. The technology can also continue providing power if an energy grid is down.

Gates was a follow-on investor in Mainspring’s $108.1 million Series D funding round, according to PitchBook, which led the company to a $458.1 million valuation in May 2021.

He invested again in Mainspring’s $290 million Series E funding round in September 2022, which led the company to a $1.04 billion valuation, according to PitchBook.

Fervo Energy

Gates and Breakthrough Energy are listed as investors in Fervo Energy’s $11 million Series A funding round in July 2019, according to PitchBook, which valued the company at $25 million.

Fervo Energy uses “precision directional drilling technology to drill horizontally in geothermal reservoirs,” so it can drill multiple wells for geothermal energy with a lower surface footprint. The company says geothermal technology, which uses hot water to produce electricity, is the “ideal” source to meet growing demand for 24/7 carbon-free electricity. Geothermal is also ideal to complement solar and wind energy, according to the company.

Breakthrough Energy was a follow-on investor in the company’s $28 million Series B funding round in April 2021, which valued it at $70 million, according to PitchBook, and invested again in its $138.2 million Series C in August 2022, which led to a $308.2 million valuation. Gates was also an investor in Fervo Energy’s $244 million Series D funding round in February, according to PitchBook. The Series D led the company to a $640 million valuation.

Seaborg Technologies

Gates invested in Seaborg Technologies’ $6 million seed funding round in April 2018, according to PitchBook.

The Danish company developed an alternative to conventional nuclear reactors called a Compact Molten Salt Reactor (CMSR). The CMSR has fuel mixed with a liquid salt coolant, whereas conventional nuclear reactors use solid fuel rods that are usually constantly cooled by water under high pressure.

Mixing fuel with the liquid salt “ensures it can always be cooled and it cannot melt down or explode,” the company said. Instead, the CMSR can shut itself down in case of an emergency.

Seaborg also developed floating power plants called Power Barges that it will deploy the CMSRs on. The Power Barges can produce between 200MW and 800MW of electricity, according to the company.

Koloma

Gates’s Breakthrough Energy is listed as an investor in Koloma’s $55.7 million Series A funding round in August 2022, which valued the company at $203.7 million, according to PitchBook.

The “geologic hydrogen company” uses technology to “source hydrogen in a clean, continuous, and cost-effective manner.” Geologic hydrogen comes from iron-rich source rocks, Koloma said, which are cleaner than carbon-rich mature and organic source rocks.

Breakthrough Energy and Gates are both listed as investors in the company’s $247.74 million Series B funding round in October, according to PitchBook, which led to an $845.74 million valuation.