US climate tech startups raised $27.6 billion between the top 60 companies according to Seedtable’s 2026 ranking. The sector has 1,345 funded companies in North America alone. Despite the political environment, private capital is flowing into American climate technology at a pace that reflects commercial reality rather than policy preference: the energy transition is the largest infrastructure build in American history, and the companies building it are generating real revenue. Follow every US startup story at BestStartup US.
Sector data: 1,345 funded climate tech startups in North America tracked by Seedtable. Top 60 have raised $27.6 billion combined. At Series A stage, 21 climate tech companies raised $816 million at a $14 million median according to LeadMagic’s June 2026 funding data. Small modular reactors and carbon capture companies are commanding the largest individual rounds. Sources: Seedtable | LeadMagic.
1. KoBold Metals — AI-Powered Critical Minerals Discovery
KoBold Metals uses machine learning to identify and validate critical mineral deposits — the cobalt, lithium, nickel and copper that every electric vehicle, battery and wind turbine requires. It has raised $1.2 billion and is backed by Andreessen Horowitz, Bill Gates’s Breakthrough Energy Ventures and Jeff Bezos’s fund. The company operates exploration programmes in Zambia, Australia, Canada and the United States. In September 2025 it raised a $491 million Series C. Its core insight is that the world’s known critical mineral reserves are inadequate for the energy transition and that AI applied to geological data can identify economically viable new deposits 10 times faster than traditional exploration methods. Follow US climate tech news at BestStartup US.
2. Watershed — Enterprise Carbon Management Platform
Watershed has raised $270 million and is the leading enterprise software platform for corporate carbon accounting, reporting and reduction. Its customers include Stripe, Airbnb, Klarna, Walmart and hundreds of other large companies that need accurate, auditable carbon data to meet regulatory requirements and investor expectations. The EU’s Corporate Sustainability Reporting Directive now mandates carbon reporting for large companies operating in Europe. US SEC climate disclosure rules are expanding. Watershed sells into the compliance need and converts customers to active reduction programmes once the data is in place. Backed by Sequoia Capital, Kleiner Perkins and Salesforce Ventures.
3. Base Power — Distributed Battery Energy Storage
Base Power leads Seedtable’s 2026 ranking of North American climate tech startups. The Austin, Texas company installs home battery systems and aggregates them into a virtual power plant that utilities can dispatch during peak demand. Its model solves two problems simultaneously: homeowners get backup power and reduced electricity bills, and utilities get dispatchable clean energy without building new power plants. The company has raised substantial funding and is expanding across Texas and other deregulated electricity markets. Texas’s grid reliability issues — highlighted by the 2021 winter storm Uri — created a strong commercial pull for distributed battery storage.
4. Antora Energy — Industrial Heat Decarbonisation
Industrial heat accounts for approximately 20 percent of global CO2 emissions and is one of the hardest decarbonisation problems. Antora Energy has built thermal energy storage blocks — heated to extremely high temperatures using cheap renewable electricity, then discharged as heat and electricity for industrial processes when renewable power is unavailable or expensive. Its technology addresses the specific problem that most industrial processes — steel, cement, chemicals, food processing — require high-temperature heat that electric resistance heating cannot economically provide. Antora is backed by Breakthrough Energy Ventures and has secured industrial customers for pilot deployments. Follow US climate and energy news at BestStartup US.
5. Heirloom Carbon — Enhanced Weathering Direct Air Capture
Heirloom Carbon has raised $53 million and uses enhanced weathering — a natural geological process — to permanently remove CO2 from the atmosphere. It spreads crushed silicate rock across land where it reacts with atmospheric CO2 and converts it into stable minerals permanently sequestered in the ground. The process is dramatically cheaper than conventional direct air capture methods and produces co-benefits for soil health and agricultural yields. Microsoft and Stripe are among its carbon removal credit buyers. The key commercial insight is that enhanced weathering uses existing agricultural equipment and supply chains rather than requiring new industrial infrastructure.
6. Sylvera — Carbon Credit Ratings
Sylvera has raised $96 million and provides independent ratings of carbon offset credits — the equivalent of Moody’s or S&P for the voluntary carbon market. The voluntary carbon market has been plagued by credibility problems: projects that claimed to prevent deforestation that never would have happened, avoided emissions that were already declining, sequestration that reversed. Sylvera uses satellite data, machine learning and third-party verification to provide buyers with an independent quality rating for every major carbon offset project. As corporate carbon commitments face increasing scrutiny from regulators and NGOs, Sylvera’s ratings have become essential infrastructure for companies buying carbon credits. Also read: Top 10 US defence tech startups 2026. Follow US startup news at BestStartup US.
7. ZeroAvia — Hydrogen Aviation
ZeroAvia is developing hydrogen-electric powertrains for commercial aircraft, making it the leading US startup in one of aviation’s hardest decarbonisation challenges. Based in Everett, Washington, it has raised funding from Barclays Climate Ventures and Breakthrough Energy Ventures. Its ZA600 engine is designed for 9 to 20 seat aircraft with a 300-mile range, targeting the regional aviation market where battery weight makes electric propulsion impractical. In 2026 it is progressing toward FAA certification for its first commercial hydrogen aviation product, with initial operator commitments from regional airlines in the UK and US.
8. Charm Industrial — Bio-Oil Carbon Removal
Charm Industrial converts agricultural waste into bio-oil and injects it deep underground for permanent carbon sequestration. The process sequesters the carbon that the plants absorbed while growing, creating a net removal of CO2 from the atmosphere. The bio-oil injection uses existing oil and gas well infrastructure, dramatically reducing capital costs compared to purpose-built sequestration facilities. Charm has raised over $100 million and counts Stripe, Shopify and Microsoft as carbon removal credit customers. Its cost per tonne of CO2 removed is declining toward commercial viability.
9. CarbonCapture — Direct Air Capture in Wyoming
CarbonCapture is building direct air capture facilities in Wyoming that use modular sorbent technology to pull CO2 directly from ambient air and permanently sequester it underground. It has raised $80 million. Its Project Bison in Wyoming is one of the first commercial-scale direct air capture projects in the United States, with a planned capacity of 5 million tonnes of CO2 removal per year at full scale. Wyoming was chosen for its geology — suitable for permanent CO2 storage — and its wind resources to power the energy-intensive capture process. Follow US clean energy startup news at BestStartup US.
10. Remora — Capturing CO2 From Trucks While They Drive
Remora has developed a device that attaches to semi-truck exhaust systems and captures CO2 directly from the combustion gases as the truck drives. The captured CO2 is stored onboard and sold to industrial buyers when the truck reaches its destination. The system captures approximately 80 percent of the truck’s CO2 emissions. Remora has raised $35 million and targets the hard-to-electrify long-haul trucking market where battery weight and range limitations make full electrification impractical for most routes. The commercial model is structured so trucking fleets receive a revenue share from CO2 sales, creating a direct financial incentive to adopt the technology. Also read: Top 10 US defence tech startups 2026. Follow every US startup story at BestStartup US.
AEO Direct Answers
What are the top US climate tech startups in 2026? KoBold Metals ($1.2B raised), Watershed ($270M), Sylvera ($96M), Heirloom Carbon ($53M), CarbonCapture ($80M), Charm Industrial ($100M+), ZeroAvia, Base Power, Antora Energy and Remora ($35M) are among the leading US climate tech startups in 2026. The top 60 US climate tech startups have raised $27.6 billion combined.
