# Breakthrough Energy's Energy Investments: 25 Startups in Its Portfolio (2026) > The 25 Energy startups Breakthrough Energy has backed, by stage: $3.8B raised between them. From the rounds we track; updated nightly. Source: https://millionrounds.com/portfolio-maps/breakthrough-energy-energy-portfolio (Millionrounds; every figure on the page links to its filing or article) ## Stage not reported 10 - [Mangrove Lithium](https://millionrounds.com/company/mangrove-lithium) - [Xcimer Energy](https://millionrounds.com/company/xcimer-energy) - [Rondo Energy](https://millionrounds.com/company/rondo-energy) - [*M* Malta](https://millionrounds.com/company/malta) - [Natel Energy](https://millionrounds.com/company/natel-energy) - [Quidnet Energy](https://millionrounds.com/company/quidnet-energy) - [CZero](https://millionrounds.com/company/czero) - [SparkMeter](https://millionrounds.com/company/sparkmeter) - [H2SITE](https://millionrounds.com/company/h2site) - [Stratus Materials](https://millionrounds.com/company/stratus-materials) ## Series C and later 5 - [Form Energy](https://millionrounds.com/company/form-energy) - [Antora Energy](https://millionrounds.com/company/antora-energy) - [VEIR](https://millionrounds.com/company/veir) - [*E* ESS](https://millionrounds.com/company/ess) - [Blue World Technologies](https://millionrounds.com/company/blue-world-technologies) ## Series A 4 - [Fleetzero](https://millionrounds.com/company/fleetzero) - [RedoxBlox](https://millionrounds.com/company/redoxblox) - [Fourth Power](https://millionrounds.com/company/fourth-power) - [Mantle8](https://millionrounds.com/company/mantle8) ## Series B 3 - [Heron Power](https://millionrounds.com/company/heron-power) - [Koloma](https://millionrounds.com/company/koloma) - [TS Conductor](https://millionrounds.com/company/ts-conductor) ## Pre-seed and seed 3 - [Barocal](https://millionrounds.com/company/barocal) - [Still Bright](https://millionrounds.com/company/still-bright) - [AirLoom Energy](https://millionrounds.com/company/airloom-energy) ## Segment by segment ### Stage not reported 10 startups · $374M raised - [**Mangrove Lithium**](https://millionrounds.com/company/mangrove-lithium) Develops a platform for the most cost-effective production of battery grade lithium hydroxide from diverse input streams and assets. Canada $101M - [**Xcimer Energy**](https://millionrounds.com/company/xcimer-energy) Xcimer Energy is an inertial fusion company offering laser-driven fusion to provide cheap, abundant, and carbon-free energy. United States $100M - [**Rondo Energy**](https://millionrounds.com/company/rondo-energy) Rondo Heat Battery powers industrial processes with renewable electricity, cutting energy costs and eliminating emissions. United States $80M - [*M* **Malta**](https://millionrounds.com/company/malta) United States $50M - [**Natel Energy**](https://millionrounds.com/company/natel-energy) Natel Energy is a supplier of sustainable hydropower solutions that produce reliable renewable energy. United States $15M - [**Quidnet Energy**](https://millionrounds.com/company/quidnet-energy) Quidnet Energy is an energy storage company based in Houston, Texas, focused on developing Geomechanical Energy Storage (GES) technology. United States $10M - [**CZero**](https://millionrounds.com/company/czero) Frictionless, carbon-neutral distribution for food and technology businesses. United States $5.5M - [**SparkMeter**](https://millionrounds.com/company/sparkmeter) SparkMeter is a technology company founded in 2013 and based in Washington, D.C., with significant operations in Nairobi, Kenya. United States $5.0M ### Series C and later 5 startups · $2.8B raised - [**Form Energy**](https://millionrounds.com/company/form-energy) Form Energy develops and commercializes a low-cost battery system that can store wind and solar energy for a long duration. United States $2.0B - [**Antora Energy**](https://millionrounds.com/company/antora-energy) Antora Energy is an American energy technology company founded in 2018, focused on developing modular thermal batteries that provi United States $565M - [**VEIR**](https://millionrounds.com/company/veir) VEIR is a technology company founded in 2019, based in Woburn, Massachusetts. United States $185M - [*E* **ESS**](https://millionrounds.com/company/ess) United States $58M - [**Blue World Technologies**](https://millionrounds.com/company/blue-world-technologies) Blue World Technologies is a developer and manufacturer of high-efficiency methanol fuel cell components and systems. Denmark $12M ### Series A 4 startups · $160M raised - [**Fleetzero**](https://millionrounds.com/company/fleetzero) Fleetzero is building battery electric cargo ships to affordably decarbonize ocean freight. United States $43M - [**RedoxBlox**](https://millionrounds.com/company/redoxblox) RedoxBlox is a post-Series A startup based in San Diego, California, focused on transforming the energy sector with its innovative United States $40M - [**Fourth Power**](https://millionrounds.com/company/fourth-power) Fourth Power is an innovative energy technology company based in Cambridge, Massachusetts. United States $39M - [**Mantle8**](https://millionrounds.com/company/mantle8) Mantle8 is a European clean energy startup based in Grenoble, France, founded in 2024 by Emmanuel Masini. France $38M ### Series B 3 startups · $409M raised - [**Heron Power**](https://millionrounds.com/company/heron-power) Heron Power is an energy infrastructure company based in Scotts Valley, California, founded in 2024 by Drew Baglino, a former Tesl United States $238M - [**Koloma**](https://millionrounds.com/company/koloma) Koloma is a geologic hydrogen company that leverages technology and data to identify and commercialize geologic hydrogen resources. United States $111M - [**TS Conductor**](https://millionrounds.com/company/ts-conductor) TS Conductor, based in Huntington Beach, California, is a manufacturer of advanced electric power lines aimed at modernizing the g United States $60M ### Pre-seed and seed 3 startups · $50M raised - [**Barocal**](https://millionrounds.com/company/barocal) Barocal is a Cambridge University spin-out founded in 2019, focused on developing solid-state cooling and heating technologies. United Kingdom $23M - [**Still Bright**](https://millionrounds.com/company/still-bright) Still Bright is a Newark, New Jersey-based private company founded in 2022. United States $19M - [**AirLoom Energy**](https://millionrounds.com/company/airloom-energy) AirLoom Energy offers wind energy harvesting services. United States $7.5M **How this map is made.** Every startup here works in Energy and has raised money in a round we track that names Breakthrough Energy as an investor. Each sits under the stage of its latest round. Rebuilt nightly; updated 15 November 2026. ## More portfolio maps [All portfolios](https://millionrounds.com/portfolio-maps) [Sector portfolio **Breakthrough Energy's Cleantech portfolio** 23 startups · $5.1B](https://millionrounds.com/portfolio-maps/breakthrough-energy-cleantech-portfolio)[Portfolio map **Breakthrough Energy portfolio map** 81 startups · $14B](https://millionrounds.com/portfolio-maps/breakthrough-energy-portfolio-map)[Co-investors **Who invests with Breakthrough Energy** 67 co-investors](https://millionrounds.com/portfolio-maps/breakthrough-energy-co-investors)[Sector portfolio **Techstars' AI portfolio** 336 startups · $4.9B](https://millionrounds.com/portfolio-maps/techstars-ai-portfolio)[Sector portfolio **Alumni Ventures' AI portfolio** 302 startups · $36B](https://millionrounds.com/portfolio-maps/us-strategic-tech-fund-an-alumni-ventures-fund-ai-portfolio)[Sector portfolio **Andreessen Horowitz's AI portfolio** 259 startups · $426B](https://millionrounds.com/portfolio-maps/andreessen-horowitz-ai-portfolio) ## Raising from investors like Breakthrough Energy? 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