Fourth Power is a technology company.
Fourth Power has raised $39.0M across 2 funding rounds.
Fourth Power has raised $39.0M in total across 2 funding rounds.
Fourth Power has raised $39.0M in total across 2 funding rounds.
Fourth Power's investors include Breakthrough Energy Ventures, Rachel Slaybaugh, Zachary Bogue, DCVC (Data Collective), DFJ, Future Ventures, Galaxy Digital, Gigascale Capital, HOF Capital, Innovation Endeavors, Khosla Ventures, Kleiner Perkins.
Fourth Power is a technology company developing utility-scale thermal battery energy storage systems that convert intermittent renewable energy into reliable, on-demand power for the grid.[1][2] Its core product stores electricity as heat using abundant domestic materials like carbon blocks and liquid metal (molten tin), delivering it back via thermophotovoltaic (TPV) cells at costs up to 10 times cheaper than lithium-ion batteries and competitive with natural gas.[1][2][3] The modular system provides 5-10 hours of storage initially, scaling to 100 hours, with a compact 1-acre footprint for a 100MW/10-hour unit, serving utilities and grid operators to reduce energy bills, enhance reliability, and support energy independence.[2][3]
Founded in 2023 (with roots in 2021 per some records), Fourth Power has raised $45 million from investors like Munich Re Ventures, DCVC, and Breakthrough Energy Ventures, building on over a decade of R&D from Georgia Tech and MIT labs funded by U.S. Department of Energy grants.[1][4]
Fourth Power emerged from breakthroughs in its founders' academic labs at Georgia Tech and MIT, where Dr. Asegun Henry, the Founder and Chief Technologist, pioneered key innovations over 10+ years, including high-temperature pumping of liquid metal with all-graphite mechanical pumps (earning a Guinness World Record) and strategies to prevent emitter deposition on TPV cells.[1][3] This R&D, largely grant-funded by the U.S. Department of Energy, produced a 1 kWh-e prototype, de-risking the technology for commercialization.[1]
In 2023, Henry teamed with CEO Arvin Ganesan to launch the company in Cambridge, Massachusetts, spinning out from MIT to address grid-scale energy storage needs.[1][4][5] Early traction came swiftly with $45 million in funding from top VCs, validating the tech's potential amid rising renewable deployment.[1]
Fourth Power rides the global surge in renewables, where wind and solar intermittency demands affordable long-duration energy storage (LDES) to replace fossil fuels and stabilize grids.[2][6] Its timing aligns with U.S. energy independence pushes, leveraging domestic materials amid supply chain vulnerabilities in lithium and rare earths, while policy like DOE grants and IRA incentives accelerate thermal tech adoption.[1][2]
Market forces favor it: renewables now outpace fossil growth, but storage lags; Fourth Power's low-cost, high-density solution undercuts peaker plants and imported batteries, fitting neatly into grid modernization for net-zero goals.[2][3] As a World Economic Forum Technology Pioneer, it influences the ecosystem by enabling wasted renewable energy capture, reducing consumer costs, and scaling with infrastructure—potentially accelerating the clean energy transition.[6]
Fourth Power is poised to disrupt grid storage with its proven, peer-reviewed tech, targeting first commercial deployments soon after prototype validation and major funding.[1][3] Next steps include scaling pilots to utility contracts, leveraging modularity to capture LDES market share as renewables hit 50%+ grid penetration by 2030.
Trends like AI-driven grid demands, extreme weather resilience, and policy-driven decarbonization will propel it, evolving its role from innovator to infrastructure staple—delivering on the promise of cost-effective, reliable renewables that power the energy transition.[2][6] This positions Fourth Power to lead where lithium falls short, securing a cleaner grid for decades.
Fourth Power has raised $39.0M across 2 funding rounds. Most recently, it raised $20.0M Series A in September 2025.
| Date | Round | Lead Investors | Other Investors |
|---|---|---|---|
| Sep 1, 2025 | $20.0M Series A | Breakthrough Energy Ventures, Rachel Slaybaugh, Zachary Bogue, DCVC (Data Collective), DFJ, Future Ventures, Galaxy Digital, Gigascale Capital, HOF Capital, Innovation Endeavors, Khosla Ventures, Kleiner Perkins, Lowercarbon Capital, NEVA SGR, Safar Partners, Starlight Ventures, Bill Gates, Stanley Druckenmiller | |
| Dec 1, 2023 | $19.0M Series A | Breakthrough Energy Ventures, Rachel Slaybaugh, DCVC (Data Collective), DFJ, Future Ventures, Galaxy Digital, Gigascale Capital, HOF Capital, Innovation Endeavors, Khosla Ventures, Kleiner Perkins, Lowercarbon Capital, NEVA SGR, Safar Partners, Starlight Ventures, Bill Gates, Stanley Druckenmiller |