Finland-based TheStorage, a provider of industrial thermal energy storage solutions, has raised €3.6 million (~$4.2 million) in a seed funding round to scale its technology and accelerate commercial deployment. To date, TheStorage has raised a total of €5.8 million (~$6.8 million) in funding.

The round was led by Voima Ventures, with participation from existing investors Superhero Capital and 2C Ventures, alongside new investor Momentum Partners.

The company is developing a sand-based thermal energy storage technology that converts electricity into heat using a “sand-in-motion” system designed to reduce industrial energy costs by up to 70% and emissions by up to 90% compared with fossil-fuel-based heat production.

Energy is stored when renewable electricity is available or when grid prices are low, and it can be used in any industrial process that requires hot steam or thermal oil. The company will use the funding for broader commercialization of its technology and to expand the team.

“One fifth of global energy consumption comes from industrial heat production, and hot steam is essential across virtually every industrial sector. We offer the best heat transfer solution on the market – up to ten times more efficient than competitors’ static alternatives,” said Timo Siukkola, CEO and co-founder at TheStorage.

The company has already commissioned a pilot facility at Nokian Panimo, a Finnish brewery, where the system is being used to produce steam for industrial processes. The plant has a storage capacity of approximately 1 MWh, with a charging power of 0.2 MW and a discharging power of 0.4 MW.

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, 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).