Thermal battery technology specialist Fourth Power raises $19m in series A funding

December 13, 2023

US-based Fourth Power has raised $19 million in Series A funding to scale its thermal battery technology.

The investment round was led by the venture capital firm DCVC, with participation from Breakthrough Energy Ventures (BEV) and Black Venture Capital Consortium.

In addition to helping scale the company’s thermal energy storage technology, the investment will initiate the construction of a 1 MWh-e prototype facility outside Boston, with a 2026 anticipated completion date.

Fourth Power’s technology uses renewable energy to heat carbon blocks to temperatures so hot they glow like the sun and later release that heat on demand to the grid as electricity. The thermal battery heats liquid tin and moves it through a piping system to heat stacks of carbon blocks until they glow white hot. The system then exposes thermophotovoltaic (TPV) cells to the light and converts it into electricity. Fourth Power said it’s technology “can meet today’s short-duration (five-hour) needs and the future’s longer-duration (100-hour) needs”.

“Our vision has always been to tackle climate change by making renewable energy – which is the most cost-effective form of power – a reliable resource for the grid to use at all hours of the day,” said Fourth Power’s CEO, Arvin Ganesan. “We need utility-scale energy storage that can grow with the grid to make this a reality on a global scale. With the support of our investors, Fourth Power will accelerate our mission and reshape the clean energy landscape by making grid-scale thermal battery storage the most cost-effective solution for power production.”

Zachary Bogue, co-founder and managing partner at DCVC, said: “Fourth’s Power’s solution is an engineered sun-in-a-box. We are thrilled to join forces with this exceptional team, whose best-in-class technology can greatly increase the production and use of renewable energy.”

Carmichael Roberts, investment committee business lead at Breakthrough Energy Ventures, commented: “Clean energy storage that is reliable and scalable will be a cornerstone of a zero-carbon future. Fourth Power’s years of research and technological breakthroughs leave them well-positioned to accelerate the development of its innovative storage solutions and achieve significant milestones in the coming years.”