France-based thermal energy storage provider Epyr has raised €15 million (~$17 million) in an oversubscribed Series A round led by SlateVC to expand its industrial thermal energy storage projects.

Existing investors AENU and Daphni participated alongside WEPA Ventures, OVNI Capital, and Aurum Impact.

Epyr develops thermal energy storage systems that use electricity during periods of low prices to generate and store heat for industrial applications. Its technology uses electric resistors to heat air, which transfers thermal energy to firebricks. The bricks store energy at high temperatures, allowing industrial facilities to use the heat when required.

Sébastien Léger, co-founder and GP at SlateVC, said, “We were convinced by the quality of the entire Epyr team, their speed and their customer-centric approach. They deliver climate impact, energy cost savings and resilience to industrial sites. Epyr has the potential to become a European leader in electrifying the €100 billion (~$118 billion) industrial heat market. We are delighted to enable their growth in France and beyond.”

The funding comes 18 months after Epyr’s pre-seed round, in which the company raised €3 million (~$3.1 million), co-led by AENU and Daphni. OVNI Capital, WEPA Ventures, and several other European angel investors also participated.

Epyr has been selected to deploy a 35 MWh thermal energy storage unit at Papeco’s Orval-sur-Sienne facility in France. The company described the installation as France’s largest thermal energy storage project, replacing all natural gas consumption at the Papeco facility.

The company said it is prioritizing industrial steam, mainly in paper, food and beverage, and chemicals. Epyr deployed an industrial thermal energy storage unit at WEPA Group, a hygiene paper manufacturer, in Troyes, which went into operation in early 2026.

According to Mercom’s 1H 2026 Funding and M&A for Energy Storage report, VC funding for energy storage companies in 1H 2026 totaled $1.6 billion across 51 deals, representing a 6% YoY decline compared to the $1.7 billion raised across 36 deals in 1H 2025.