Sector Snapshot: Cleantech Startup Funding Stabilizes As Energy Demand Grows

Cleantech isn’t the hottest space for startup funding these days. That title obviously goes to AI.

Nonetheless, amid a period of soaring electricity demand, rising EV adoption rates, and accelerating progress in fusion and other fields, cleantech investment activity isn’t slowing down.

In the first half of this year, investors poured $15 billion into seed- through growth-stage rounds for companies in Crunchbase cleantech, EV and sustainability-focused categories. That puts funding on track to slightly exceed the 2025 tally, which was the lowest in several years.

On a quarterly basis, funding is also on the rise. Around $8 billion went to companies in cleantech and related categories in the second quarter of this year, the highest quarterly total since 2024.

Even taking into account recent gains, however, cleantech funding remains far below its former peak in 2021 and 2022. Given that overall venture funding has risen with the AI boom, cleantech also accounts for a smaller share of total investment.

Where funding is concentrating

That’s not to say megarounds aren’t getting done in the sector. A look at the largest funding rounds of 2026 paints a varied picture of where capital is concentrating.

Stockholm-based green steel producer Stegra scored the largest financing of 2026, securing $1.6 billion in a round led by Swedish asset manager Wallenberg Investments. Stegra plans to use the money to complete the construction of its large-scale steel plant.

The next-biggest round went to Slate Auto, a Jeff Bezos-backed startup that has been generating buzz and reservations for a flagship electric pickup starting at around $25,000 that can be converted to an SUV. Troy, Michigan-based Slate raised $650 million in Series C funding in April and plans to deliver its first trucks to customers later this year.

The third- and fourth-largest financings were fusion deals. The latest of those went to Helion Energy, which raised $465 million in a June Series G funding to go toward building a fusion power plant. The Thrive Capital-led round set a $15.5 billion post-money valuation for the Everett, Washington-based company.

A few months earlier, fusion startup Inertia picked up $450 million in Series A funding led by Bessemer Venture Partners. The San Francisco-based company, formed around a fusion breakthrough at Lawrence Livermore National Laboratory, plans to build the world’s most powerful laser to further its goal of grid-scale energy production.

For a broader view of where large financings are concentrating, below we put together a list of 10 of the largest cleantech-related rounds this year.

Under the circumstances, the space looks underfunded

While sums going to cleantech-related startups aren’t tiny, looking at total investment tallies does leave one with the impression that the space looks underfunded.

After all, energy is a growth sector, and clean energy is leading the way. The IEA forecasts the share of renewables and nuclear in the world’s power mix will rise to 50% by the end of this decade. At the same time, global power demand is set to grow by more than 3.5% per year on average over the rest of this decade.

Exits of venture-backed companies are also happening, another source of encouragement for startup investors. The most recent Nasdaq IPO in the space was geothermal provider Fervo Energy, which went public in May, raising $1.9 billion. The Houston-based company had a recent market cap around $8.6 billion.

On the nuclear power front, X-energy, a developer of small modular reactors, carried out its own Nasdaq IPO in April, raising $1 billion. The Rockville, Maryland, company was recently valued at a little over $5 billion.

Looking ahead, it’s not far-fetched to see myriad factors that could power clean energy, sustainability and EV sectors higher. For clean power in particular, the voracious energy demands of AI are certainly a catalyst to consider. We’ll stay tuned to see if growing energy demand ultimately translates into greater startup investment.

Related Crunchbase query:

• Global Cleantech Startup Funding In 2026
• Largest 2026 Cleantech, EV And Sustainability Funding Rounds

Related reading:

• Crunchbase Data: Global Startup Investment Hit Record $510B In H1 2026 As AI Boom Accelerates Funding And Exits

Illustration: Dom Guzman