Cleantech startup funding steadies as power demand climbs

Cleantech startups are not pulling in capital at AI’s pace, but funding has stopped sliding as electricity demand rises and investors keep backing energy-related bets. For retail investors, the signal is less about one hot company and more about where venture capital expects future power, transport and industrial demand to grow.

According to Crunchbase data, startups in cleantech, electric vehicle and sustainability categories raised $15 billion across seed through growth-stage rounds in the first half of 2026. Seed funding is early money for young companies, while growth-stage rounds usually back businesses that are further along and need capital to scale.

That first-half total puts the sector on track to edge above its 2025 fundraising level, which Crunchbase said was the weakest in several years. Funding also improved quarter to quarter, with about $8 billion raised in the second quarter, the highest quarterly total for these categories since 2024.

The recovery is still partial. Crunchbase said cleantech funding remains well below the sector’s 2021 and 2022 peak. Cleantech is also taking a smaller slice of the venture market because overall startup investment has risen during the AI funding boom.

Large rounds show where money is going

The biggest cleantech-related deal of 2026 so far went to Stegra, a Stockholm-based green steel company. Crunchbase said Stegra raised $1.6 billion in financing led by Swedish asset manager Wallenberg Investments. The company plans to use the capital to finish building a large-scale steel plant.

The second-largest round went to Slate Auto, an electric vehicle startup based in Troy, Michigan and backed by Jeff Bezos. Crunchbase reported that Slate raised $650 million in Series C funding in April. The company has drawn reservations for an electric pickup that starts at around $25,000 and can be converted into an SUV, with first customer deliveries planned for later this year.

Fusion companies took the next two spots. Fusion is a power technology that aims to generate energy by combining atomic nuclei, the same basic process that powers the sun, though commercial power plants remain a difficult engineering goal.

Helion Energy, based in Everett, Washington, raised $465 million in a June Series G round led by Thrive Capital, according to Crunchbase. The financing valued the company at $15.5 billion after the investment and is intended to support construction of a fusion power plant.

San Francisco-based Inertia raised $450 million in Series A funding led by Bessemer Venture Partners. Crunchbase said the company was formed around a fusion breakthrough at Lawrence Livermore National Laboratory and plans to build a powerful laser as part of its push toward grid-scale energy production.

Energy demand is the backdrop

The International Energy Agency expects renewables and nuclear to reach 50% of the world’s power mix by the end of this decade, according to Crunchbase. The IEA also forecasts global electricity demand will grow by more than 3.5% a year on average over the rest of the decade.

Some venture-backed clean energy companies have also reached public markets. Crunchbase said geothermal company Fervo Energy went public on Nasdaq in May, raising $1.9 billion, and recently had a market capitalization of about $8.6 billion. X-energy, which develops small modular nuclear reactors, listed on Nasdaq in April, raising $1 billion, and was recently valued at a little over $5 billion.

The open question for startup investors is whether rising power demand, including demand tied to AI data centers, will translate into more venture funding for clean energy, EV and sustainability companies. Crunchbase’s data shows the sector has stabilized, even if it remains far from its prior funding highs.

This story draws on original reporting from Crunchbase News.