Paris, France-based energy technology startup Epyr has raised €15 million in Series A funding to expand the deployment of thermal energy storage systems designed to replace fossil fuels in industrial heating.
The oversubscribed round was led by SlateVC, with participation from existing investors AENU, Daphni, WEPA Ventures, OVNI Capital and Aurum Impact. The financing comes 18 months after Epyr’s pre-seed round and will support the company’s next industrial projects.
Using Thermal Storage to Electrify Industrial Heat
Founded in 2024 by Bastien Oggeri and Léa Dardenne, Epyr develops thermal energy storage systems that help industrial facilities replace natural gas with electricity.
Its technology uses electric resistors to heat air, which then transfers heat to firebricks that store energy at high temperatures. Industrial facilities can charge these systems when electricity prices are low and release the stored energy as heat when needed for production.
Epyr provides an integrated service covering technology, installation, energy management and, where required, third-party financing through a Heat-as-a-Service model.
The company initially focuses on industrial steam applications in sectors including paper manufacturing, food and beverages, and chemicals.
Expanding Industrial Projects in France
Epyr’s first industrial installation began operating at WEPA Group’s paper mill in Troyes, France, in early 2026. The system was inaugurated in May after being built and commissioned in less than six months.
According to Epyr, the installation now supplies up to 25% of the facility’s steam requirements.
The company has also been selected to deploy a 35 MWh thermal energy storage system at Papeco’s paper mill in Orval-sur-Sienne, France. The project is designed to replace the site’s entire natural gas consumption, with Energy Pool supporting the project from initial studies through operations.
“In France, there have already been more hours of near-zero or negative power prices this year than in 2025. That electricity is the cheapest, cleanest energy source European industry has. Our mission is to harness it, and this Series A lets us do it at scale.”
— Léa Dardenne and Bastien Oggeri, co-founders of Epyr
Beyond these installations, Epyr is studying several additional projects as it prepares to expand its thermal storage technology across European industrial facilities.