Climate Tech Funding in 2025: More Money, Fewer Deals, and a Shift to Power

Climate tech venture and growth investment reached $40.5 billion in 2025, up 8% on 2024, according to Sightline Climate. Read on its own that number suggests a sector in recovery.

The same dataset records deal count falling 18% over the same period. Both things are true, and together they describe something quite different from a boom: the same pool of money going into roughly a fifth fewer companies.

The Total Went Up. The Number of Bets Went Down.

Of roughly $10.1 billion that went into mega-deals in 2025, $7.2 billion — and six of the ten largest — went to energy security and resilience. SVB’s read of the United States market found ten deals capturing 28% of all investment.

That is what a concentrating market looks like. Capital is not scarce; it is selective. Investors are writing larger cheques to companies that have already shown traction, and writing far fewer of them.

The stage-level detail says the same thing from the other end. Seed investment fell 20%. Series A investment fell only 7%, but Series A deal counts fell 22% — meaning the companies that did raise took noticeably bigger rounds, back to 2021 sizes. Series C was hardest hit: investment down 32%, with deal counts at an all-time low. Growth-stage investment, meanwhile, rose 78%.

So the money is pooling at the two ends that look safest: proven businesses scaling, and a smaller number of well-backed newcomers. The middle — companies past their first product but not yet at scale — is where the squeeze landed.

Electrons, Not Emissions

The clearest shift in 2025 was what the money was buying. Energy sector investment rose 31%, weighted toward nuclear and grid technology. Investment in the built environment rose 23%, largely into data centre infrastructure.

The driver is electricity demand from AI. Data centres need firm, dispatchable power on a timescale that suits gas, nuclear and grid flexibility rather than the longer build cycles of renewables plus storage. Capital has followed, into gridtech, virtual power plants and flexibility products that can be deployed quickly.

This is worth being precise about, because it is easy to report as an unambiguous climate win. Investment anchored to power demand is investment in energy, and it is only incidentally investment in decarbonisation. Some of it — nuclear, grid flexibility — cuts emissions. Some of it is simply meeting a load that did not exist five years ago.

Grid Storage Passed a Real Milestone

Battery storage did cross a genuine threshold in 2025: 112 GW of capacity installed globally, some 307 GWh of batteries, up 48% on 2024. BloombergNEF forecasts 158 GW for 2026.

Iron-air chemistries from Form Energy, flow batteries from ESS and continued cost declines in lithium iron phosphate are all part of that, but the economics did most of the work. Wider intraday power price spreads make storage pay on arbitrage, which is what lets it compete with gas peaking plant on cost rather than on emissions alone.

Direct Air Capture Nearly Lost Its Federal Backing

The United States Department of Energy’s regional direct air capture hub programme backs two flagship projects: Project Cypress in Louisiana, a Battelle, Climeworks and Heirloom collaboration targeting a million tonnes of CO₂ removal a year by 2030, and the South Texas hub in Kleberg County, developed by Occidental’s 1PointFive subsidiary.

In October 2025 a leaked list of grant terminations showed both marked to be cut, at roughly $50 million each — the first tranche of awards that could have reached $500 million or more per project. The Department denied any decision had been made. Reporting in May 2026 indicated both had been preserved.

The episode is a useful reminder for anyone reading funding totals as a proxy for momentum. A large share of carbon removal economics rests on policy that can change between administrations, and private capital prices that risk accordingly.

Why the Totals Disagree

You will see several different figures quoted for the same year, and the gaps are large enough to matter:

• Sightline Climate: $40.5bn for 2025 — venture and growth
• Dealroom: $39.0bn for 2025 — a different scope of what counts as climate tech
• SVB: $29bn for 2025 — United States only
• PwC: $56bn for 2024, down 29% — broader climate tech financing, not venture alone

None of these is wrong. They count different things over different geographies. The practical consequence is that a climate tech funding figure quoted without its source and its scope is not really a fact, and comparing two of them as though they measured the same quantity produces nonsense.

What This Means for a Small Business

Two things follow that are worth acting on rather than merely knowing:

• If you are raising. The bar at seed and Series C has risen materially, and the middle of the funding ladder is the thinnest part of it. Fewer, larger rounds means a longer runway between raises and more evidence expected at each one.
• If you are buying. Grid flexibility and demand-response products are where deployment capital is going, which usually means competitive pricing and vendors willing to negotiate. For a business with meaningful electricity load, that is a live procurement opportunity now rather than a future one.