By Laura Anderson, Welp Magazine. Published and last updated October 9, 2026.
Climate technology startups are getting a very real test this year. A record El Nino is pushing global temperatures up, grids are straining, and investors are pouring billions into companies that store power, make clean heat and pull carbon from the air. Here are the startups to know, the latest funding, and the gaps most roundups miss.
Quick Facts: Climate Technology Startups 2026
- Funding: Climate tech venture funding reached $26.1 billion in the first half of 2026, up 55%, per CTVC.
- Biggest recent round: Base Power raised $1 billion at a $13 billion valuation in August 2026.
- Hot category: Thermal batteries have drawn $634.6 million across nine deals so far this year, per Axios.
- Scale: The top 60 US climate tech startups have raised $27.6 billion combined, per Seedtable via BestStartup US.
- Driver: AI data centers and hotter summers are pushing demand for storage and clean heat.
Why Are Climate Technology Startups Booming Now?
Two forces are colliding. Hotter summers and AI data centers are pushing electricity demand higher, and investors want companies that can add clean, dependable power. CTVC reports climate tech venture funding reached $26.1 billion in the first half of 2026, up 55% from a year earlier, with data centers driving much of the growth. If you have not read the science behind the heat, start with our guide to El Nino heat waves, then see the El Nino impact by region.
Which Climate Technology Startups Should You Know?
Our partner site BestStartup US, part of the Fair Media network, ranks the top 10 US climate tech startups of 2026. It reports that the top 60 US climate tech startups have raised $27.6 billion combined and that North America has 1,345 funded climate tech companies. Here is how several of them fit a hotter world.
| Startup | What it does | Why it matters in a hotter world |
|---|---|---|
| Base Power | Home batteries aggregated into a virtual power plant | Adds dispatchable power during peak heat demand |
| Form Energy | Iron air batteries for long duration storage | Keeps grids stable across multi day heat waves |
| Antora Energy | Thermal storage for industrial heat | Cuts emissions from industry, the heat problem behind the heat problem |
| Rondo Energy | Turns renewable power into steady industrial heat | Replaces fossil fuel heat in heavy industry |
| Heirloom Carbon | Removes CO2 from the air using rock weathering | Tackles the warming that makes El Nino hit harder |
| Watershed | Corporate carbon accounting software | Helps companies measure and cut emissions |
Base Power: The Biggest Recent Round
Base Power, based in Austin, Texas, installs home batteries and links them into a virtual power plant that utilities can call on during peak demand. In August 2026 it announced a $1 billion Series D at a $13 billion valuation and launched its Base Core home battery, according to its Business Wire release. This is newer than the funding detail in most earlier roundups.
Form Energy and the Rise of Thermal and Long Duration Storage
Form Energy, which makes iron air batteries for long duration storage, raised a $405 million Series F, bringing its total funding past $1.2 billion. Thermal batteries are also surging. Axios reports investors have put $634.6 million into thermal battery startups across nine deals so far this year, compared with $472.9 million across 32 deals last year. Antora Energy and Rondo Energy sit in this group, turning cheap renewable power into steady industrial heat.
Carbon Removal and Carbon Accounting
Heirloom Carbon uses rock weathering to remove CO2 from the air, and Watershed sells carbon accounting software to large companies, as profiled by BestStartup US. These companies address the warming that makes events like El Nino hit harder, though their impact is slower and harder to measure than a battery on a hot day.
More Climate Technology Startups and Deals to Watch
Beyond the headline names, smaller deals show where the money is moving. Certain Energy, a UK developer of manganese flow batteries, raised $14 million in a Series A led by investors including the British Business Bank and Centrica. Swift Current Energy, a Boston renewable project developer, raised $750 million in debt. Fervo Energy, a geothermal company named on MIT Technology Review’s 2026 list of climate tech companies to watch, went public in May and raised $2.2 billion in its IPO. One tracker counts 41 climate and energy startups with announced rounds this year, raising about $1.4 billion combined, though that count may be out of date.
Grants matter too. The Opalene Climate Challenge in Washington state picked six startups from nearly 40 applicants for recoverable grants, a reminder that early stage climate companies often depend on non dilutive money before venture funding arrives.
How Do You Judge a Climate Startup?
Not every climate technology startup is equal. Readers, founders and investors can use a short checklist when a new company makes big promises.
- Does it work at scale? Pilots are common. Look for paying customers and real deployments, not just lab results.
- Who buys it? Utilities, industrial plants and data centers are strong buyers. Consumer products depend on subsidies and prices.
- What is the unit economics story? Cost per kilowatt hour stored or per tonne of carbon removed should be falling over time.
- Is the funding round real news or a valuation story? Compare the new valuation with revenue and installed capacity.
- What if policy changes? Companies that survive without subsidies are more resilient.
What Does This Mean for Countries Facing El Nino?
This is our analysis, not a claim from the cited sources. Countries exposed to heat waves, drought and floods, including India, Indonesia, the Philippines, Nepal and Pakistan, have a growing need for cooling, resilient grids, water systems and early warning tools. Most of the startups profiled here are US or UK based, so the open question is how fast their products reach Asia and other heat exposed regions. For the science and country by country risks, read our guides to El Nino impact and El Nino heat waves.
References and Further Reading
- BestStartup US: Top 10 US Climate Tech Startups 2026
- CTVC: H1 2026 climate tech funding
- MIT Technology Review: 2026 Climate Tech Companies to Watch
- Axios Pro: Thermal battery investment
The Gaps Most Roundups Miss
- Funding concentration. CTVC notes a large share of recent money comes from just a few deals, so headline totals can hide a thin middle of smaller startups.
- Extreme heat and cooling. Most coverage focuses on storage and carbon. Heat resilience and cooling startups get far less attention and funding data.
- Proof at scale. Valuations are rising faster than many technologies have been proven in real heat waves.
- The El Nino link. It is our analysis that hotter summers raise demand for storage and clean power. The cited sources do not make that claim directly.
Should You Pay Attention to Climate Tech?
If you follow startups or invest in the space, yes, but with care. The money is real, the demand is real, and the risk of overhyped valuations is real too. For more ranked startup profiles, follow BestStartup US for US coverage and the rest of the Fair Media network for other regions. You can also browse our Environment section.
How We Reported This
This article is based on BestStartup US, CTVC, Axios, MIT Technology Review and company announcements, as of October 9, 2026. Where sources conflict on dates or valuations, we rely on the company’s own release. Read more from CTVC and MIT Technology Review. This is not investment advice.
Frequently Asked Questions
What are climate technology startups?
Climate technology startups build products that cut greenhouse gas emissions or help people adapt to a warming planet. Examples include grid batteries, thermal storage, carbon removal and carbon accounting software.
Which climate tech startups raised the most money in 2026?
Base Power raised a $1 billion Series D at a $13 billion valuation in August 2026. Form Energy raised a $405 million Series F, taking its total funding past $1.2 billion.
How is El Nino connected to climate technology?
El Nino brings extra heat, which raises electricity demand and strains grids. That increases demand for storage, clean power and cooling. This is our analysis, not a claim from the cited sources.
Is climate tech funding growing?
Yes. CTVC reports climate tech venture funding hit $26.1 billion in the first half of 2026, up 55% year on year, with data centers driving much of the growth.
Where can I read more about US climate tech startups?
BestStartup US, a Fair Media site, publishes a ranked guide to the top 10 US climate tech startups of 2026, including KoBold Metals, Watershed, Heirloom Carbon and Base Power.
How do climate technology startups help with heat waves and floods?
Many build grid batteries that keep power on during peak heat, thermal storage that cuts industrial emissions, and carbon removal that tackles warming itself. Early warning and resilience tools matter for floods, though they are less covered in funding roundups.
Are climate technology startups a safe investment?
No. Funding is booming, but valuations are rising quickly and a few large deals dominate totals. This article is not investment advice.
Which climate technology startups are based in the UK?
Certain Energy, a manganese flow battery developer, raised $14 million in a Series A, according to recent reports. Many other UK climate startups are covered by regional sites in the Fair Media network.
