September was the month climate capital chased reliability. The 15 rounds we’ve picked out add up to roughly $489 million, and ten of them are pre-seed to Series A. Two patterns stand out. First, investors are backing anything that keeps power flowing: floating reactors, reversible fuel-cell plants, sensors that live on transmission lines, and software that shows utilities where the grid has room.
Second, strategic and public money is leading more rounds. Magna, AgriZeroNZ, Paulig’s venture arm, the NATO Innovation Fund and the US government all wrote lead or anchor cheques. And at the smaller end, biochar founders are building businesses around farms and food factories in the tropics.
Capital raised by sector, September 2026
Energy & Storage$262m · 5 rounds
Industry & Materials$144m · 2 rounds
Mobility$38m · 2 rounds
Food & Agriculture$19m · 2 rounds
Resilience$15m · 1 round
Buildings$7m · 1 round
Carbon & Removal$4m · 2 rounds
The round-up
Energy & storage
Reverion (Germany)
- Series B, $175m
- Lead: Kembara
- Builds container-sized, reversible solid-oxide power plants that run on biogas, natural gas or hydrogen, and can switch to electrolysis to store energy.
- Why it matters: The money goes into a German “megafactory” with 250 MW of annual capacity, a sign that European hardware is moving from pilot to production.
Bluecore Energy (United States)
- Seed, $50m
- Lead: Silverton Partners
- Develops small, water-cooled nuclear reactors mounted on floating barges to power ports and coastal sites. Its first planned system is 10 MWe.
- Why it matters: A $50m seed is rare. It shows how much appetite there is for firm, zero-carbon power, even at the earliest stage.
Gridsight (Australia)
- Series B, $26m
- Lead: Insight Partners
- An AI platform that gives utilities a real-time view of spare capacity on their distribution grids, so they can connect new demand faster.
- Why it matters: Grid connection queues are one of the transition’s biggest bottlenecks. This round funds Gridsight’s push into the US.
Laki Power (Iceland)
- Series A, €6m
- Lead: NATO Innovation Fund, with ReykVC
- Makes monitoring devices that draw power directly from the high-voltage lines they watch, so sensors, cameras and satellite links can run in remote places without battery changes.
- Why it matters: This is the NATO Innovation Fund’s first investment in Iceland, and grid resilience is now being treated as a security issue.
Rebaba (Sweden)
- Seed, about $4.6m
- Lead: Sistafund, with EIT Urban Mobility
- Builds battery storage systems for commercial and industrial sites from second-life EV batteries.
- Why it matters: Circular storage at a practical scale. The round grows its Stockholm production hub and gets it ready to manufacture outside Sweden.
Industry & materials
Hertha Metals (United States)
- Series A, $133.65m
- Leads: Khosla Ventures and Doerr Capital
- Makes high-purity iron and steel in a single continuous reactor instead of a blast furnace, with rare-earth magnet makers as early customers.
- Why it matters: $65m of the round is equity from the US government. Green steel is being funded as supply-chain security as much as decarbonisation.
CURA (Canada)
- $10m (round type undisclosed)
- Lead: Zacua Ventures
- Uses an electrochemical process, instead of fossil-fired kilns, to make low-carbon cement, and separates out the CO2 along the way.
- Why it matters: Cement makes about 8% of global emissions. The round funds a pilot plant near Taber, Alberta.
Buildings
Strong by Form (Spain)
- Series A first close, €5.8m (of a €10m target)
- Lead: boisei investments
- Engineers wood into structural composites, inspired by the structure of trees, as an alternative to steel and concrete in floor systems.
- Why it matters: This funds European manufacturing capacity and certification, which is what lets bio-based materials win real construction contracts.
Carbon & removal
Cotierra (Switzerland)
- $3m (round type undisclosed)
- Leads: PINC (Paulig’s venture arm) and Carbon Removal Partners
- Runs small biochar reactors with a digital platform for operating, monitoring and verifying them, so farms can turn crop residue into biochar on site. It started in coffee.
- Why it matters: A food company’s venture arm co-led, which shows buyers in the supply chain are now putting money into insetting.
Biochar Industrial Group (Sub-Saharan Africa)
- Pre-seed, $1.5m
- Lead: Breega, with Catalyst Fund
- Installs and runs pyrolysis units at food-processing factories at no upfront cost, turning nut shells, husks and cobs into biochar and carbon removal credits.
- Why it matters: “Biochar-as-a-Service” takes the capex off processors, which could make removal projects bankable across Africa.
Food & agriculture
ArkeaBio (United States)
- Series A2, $15m
- Lead: AgriZeroNZ, with Breakthrough Energy Ventures
- Develops a vaccine that cuts methane from cattle by targeting the microbes that produce it in the rumen.
- Why it matters: The company has narrowed its focus to New Zealand and cut costs: a realistic route to market, aiming for a regulatory submission in 2027.
MOA Foodtech (Spain)
- €3.3m
- Investors: EIC Fund, Swanlaab Innvierte Agri Food Tech, CDTI-Innvierte
- Uses AI-guided fermentation to turn agri-food by-products into yeast-based protein ingredients, including an egg replacer.
- Why it matters: It is already selling into pet food and bakery. Upcycled ingredients with paying customers stand out in a tough alt-protein market.
Mobility
Yuma Energy (India)
- Series A, $35m
- Lead: Magna International
- Runs a battery-swapping network for electric two- and three-wheelers, with 60 million swaps completed across 18 cities.
- Why it matters: A global automotive supplier is betting on swapping as the infrastructure for India’s high-utilisation EV fleets.
Depotcharge (Germany)
- Pre-seed, €2.7m
- Lead: High-Tech Gründerfonds
- Runs a marketplace that lets logistics companies share spare depot charging capacity with other electric truck fleets.
- Why it matters: Making better use of chargers that already exist is a cheap, quick way to speed up e-truck adoption. Its partnership with German freight association BGL gives it reach.
Resilience
Prime Minute (United States)
- Pre-seed, $15m
- Lead: Eclipse, with 8VC
- Builds integrated hardware and software for disaster response, starting with precision aerial wildfire suppression that can work at night and in high winds.
- Why it matters: Adaptation is attracting large first cheques, and wildfire is leading the way.
What this tells founders
- Reliability sells. If your technology keeps power on, connects load faster or protects critical infrastructure, frame your pitch around resilience as well as emissions.
- Strategics are leading, not just following. Corporates, development funds and governments led or anchored several rounds this month. Map the companies whose supply chain or security problem you solve, and approach them early.
- Business model matters as much as the tech. As-a-service biochar, shared depot charging and battery swapping all lower the upfront cost for customers. Investors are rewarding models that take capex off the buyer.
Raising? List your startup on Climate Marketplace for free. Investors can explore the climate startups raising there now.
Sources
- Reverion: Startbase · AF.net
- Bluecore Energy: World Nuclear News · ESG Today
- Gridsight: Latitude Media · Pulse 2.0
- Laki Power: Tech Funding News · Resilience Media
- Rebaba: Raising.fi
- Hertha Metals: Ecosistema Startup
- CURA: BetaKit · CemNet
- Strong by Form: 3BL Media · Raising.fi
- Cotierra: Tech.eu
- Biochar Industrial Group: AllAfrica
- ArkeaBio: AgFunderNews
- MOA Foodtech: Global AgInvesting
- Yuma Energy: YourStory
- Depotcharge: Tech.eu · Heuking
- Prime Minute: Dealroom
- Deal discovery: Climate Tech Navigator · Axios Pro Climate Deals
