In addition to helping scale the company’s thermal energy storage solution, which can store energy for both short- and long-term durations to be put back on the grid as electricity, the investment will initiate the construction of a 1 MWh-e prototype facility outside Boston, Massachusetts, 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.
“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.”
Fourth Power’s system converts renewable energy to heat, or thermal energy, which can be stored until needed. 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. The solution is designed to maximize the value of renewable energy generation and offer grid operators control and flexibility at the lowest cost compared to other energy storage options. The system is also modular and scalable by adding more carbon blocks to increase storage duration, allowing growth with the grid as renewable generation increases.
“Fourth’s Power’s solution is an engineered sun-in-a-box,” said Zachary Bogue, co-founder and managing partner at DCVC. “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.”
Fourth Power's approach to utility-scale energy storage considers the expected growth of wind and solar generation. Fourth Power can meet today’s short-duration (5-hour) needs and the future’s longer-duration (100-hour) needs. Its flexibility to discharge within seconds is unique and helpful to grid operators as they try to ensure a reliable grid and 24/7 power.
“Clean energy storage that is reliable and scalable will be a cornerstone of a zero-carbon future,” said Carmichael Roberts of Breakthrough Energy Ventures.
Developed by Asegun Henry, Ph.D., when he was a professor at Georgia Tech and now at the Massachusetts Institute of Technology (MIT), Fourth Power’s thermal battery technology holds several records, including the Guinness World Record for the highest temperature pumping of liquid metal at 1200°C degrees.
Beyond the development of its initial 1 MWh-e facility, the funding will facilitate rigorous durability tests and expand the company's engineering team to meet the market's growing demands.
“After more than ten years of research and development, we are grateful to reach this crucial milestone in our journey thanks to our funding partners who recognized the innovation and potential of Fourth Power’s thermal battery technology,” said Asegun Henry, founder and chief technology officer of Fourth Power.
“I'm proud to lead this team of engineering experts and look forward to continuing our work to develop a long-duration energy storage solution that can be significantly cheaper than existing solutions, reliable, and, importantly, scalable without the necessity of mining for lithium.”
