UK-based Exergy3, a thermal energy storage startup, has raised £10 million (~$13.5 million) in a seed funding round, led by Axeleo Capital through its Article 9 Green Tech Industry I fund, with participation from Bayern Kapital and Kibo Invest.
Existing investors Scottish Enterprise, Zero Carbon Capital, and Old College Capital, the University of Edinburgh’s in-house venture investment fund, also participated in the round.
The company will use the funding to accelerate commercialization, including scaling its modular thermal energy storage systems and expanding its presence across industrial markets in Europe.
According to Exergy3, industrial heat accounts for a significant share of global energy demand and emissions but remains difficult to decarbonize because it relies on high, continuous temperatures across a wide range of processes.
The company aims to address this gap by linking excess renewable generation to industrial energy demand through modular thermal energy storage units that convert renewable electricity into high-temperature heat.
Exergy3 states that its technology is designed to deliver process heat ranging from 50°C to 1,200°C, allowing it to adapt to a wide range of industrial processes, from direct heat applications to steam generation, making it applicable across energy-intensive industries.
Markus Rondé, CEO at Exergy3, said: “These are two sides of the same problem. Industry needs reliable, high-temperature heat, while large amounts of renewable electricity are going to waste. Exergy3 brings them together, turning surplus renewable power into reliable, low-cost heat for industry. That means lower emissions, lower energy costs, and a more resilient energy system. This funding allows us to move rapidly from pilot to commercial deployment.
According to Mercom’s Annual and Q4 2025 Funding and M&A Report for Energy Storage report, VC funding in the Energy Storage sector in 2025 increased 30% YoY, to $4.8 billion across 75 deals, up from $3.7 billion across 84 deals in 2024.
In March 2026, MGA Thermal, a provider of thermal energy-based long-duration energy storage systems, secured A$17 million (~$12 million) in funding. The latest round brings the total capital raised to more than A$50 million (~$35 million).
