Fourth Power Secures $19M Series A Funding

BOSTON–(BUSINESS WIRE)–To meet the growing demand for renewable energy on the grid, Fourth Power has received $19 million in Series A funding to scale its cost-effective groundbreaking thermal battery technology. The investment round was led by the venture capital firm DCVC, with participation from Breakthrough Energy Ventures and Black Venture Capital Consortium. 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, with a 2026 anticipated completion date. 

Without energy storage, renewable energy sources such as wind and solar must be used when they are generated, making it difficult to end our reliance on fossil fuels while maintaining a reliable energy supply. 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. We are energized by the opportunity to create a better, more sustainable future.”

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. With Fourth Power’s solution, the renewable energy that would otherwise be wasted due to curtailment can be stored for over a month and discharged over any period from a few hours to a few days while maintaining the lowest possible cost. 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. “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.”

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.”

To learn more about how Fourth Power’s thermal battery works and how the company works to power the world with clean energy, visit

About Fourth Power

Backed by more than a decade of R&D, Fourth Power provides utility-scale thermal battery solutions that store renewable energy as heat for short and long durations to dispatch electricity to the grid in seconds. Developed by MIT and Georgia Tech scholars, the company aims to supply affordable and reliable clean power using innovative thermal technology with thermophotovoltaic (TPV) solar cells, turning the light from heated carbon blocks into electricity. The company holds several records, including the record for thermophotovoltaic efficiency at 41% and a Guinness World Record for the highest temperature pump at 1200°C degrees. Fourth Power’s extremely high temperature system ensures maximum efficiency with readily available materials, making its technology the lowest-cost option for grid decarbonization. For more information on Fourth Power, visit


DCVC is deep tech venture capital. Over more than a dozen years, the firm has backed brilliant entrepreneurs using computational approaches to solve trillion-dollar problems in the real world across a broad set of industries, especially those that haven’t seen material progress in decades. With billions of dollars of assets under management, DCVC builds long-term relationships with the founders it backs. The firm has been with many of its companies from their very start — and through to their recognition by the public markets as category-defining businesses. For more information, please visit

About Breakthrough Energy Ventures

Backed by many of the world’s top business leaders, BEV has raised more than $2 billion in committed capital to support cutting-edge companies that are leading the world to net-zero emissions. BEV is a purpose-built investment firm that is seeking to invest, launch and scale global companies that will eliminate GHG emissions throughout the economy as soon as possible. BEV seeks true breakthroughs and is committed to supporting these entrepreneurs and companies by bringing to bear a unique combination of technical, operational, market and policy expertise.

BEV is a part of Breakthrough Energy, a network of investment vehicles, philanthropic programs, policy advocacy and other activities committed to scaling the technologies we need to reach net-zero emissions by 2050. Visit to learn more.