French startup Epyr raises €15M following successful industrial heat storage deployment

French industrial energytech startup Epyr has secured a €15 million Series A funding round, led by SlateVC. Joining the investors are AENU, Daphni, WEPA Ventures, OVNI Capital, and Aurum Impact. Industrial heat constitutes roughly 20% of global energy consumption, predominantly generated through fossil fuels, particularly natural gas in Europe.

Electrifying this sector is a top priority for the EU due to emissions reduction and curbing reliance on imported fuels. However, industrial sites will only transition if electric heat proves cheaper than gas. Market conditions are now favoring electricity. Epyr creates cutting-edge thermal energy storage solutions to assist industries in transitioning away from fossil fuels, making decarbonized high-temperature industrial heat competitive and simple to deploy.

Smart controls power electric resistors during low-cost hours to heat air, which then heats firebricks to store energy at high temperatures, ready to release as heat when required. This flexibility also aids in balancing the power grid. Epyr provides a comprehensive solution, encompassing technology, system integration, energy management, and, if necessary, third-party financing, all under a Heat-as-a-Service model.

Supported by trusted partners, this model caters to each client's needs, alleviating complexity and expediting deployment. Co-founders Léa Dardenne and Bastien Oggeri note that in France, there have been more hours of near-zero or negative power prices this year than in 2025, making electricity the cheapest, cleanest energy source for European industry.

Epyr's inaugural installation, inaugurated in May 2026 at WEPA Group's paper mill in Troyes, France's first industrial thermal energy storage unit, was constructed and commissioned in under six months and now supplies up to 25% of the site's steam requirements. WEPA's Member of the Management Board, Andreas Krengel, highlights that in collaboration with Epyr, they have demonstrated the rapid and successful implementation of innovative energy solutions in an industrial setting.

Epyr has also been chosen to deploy a 35 MWh thermal energy storage unit at Papeco's Orval-sur-Sienne site, part of what is projected to become France's largest thermal energy storage project. The installation will replace all of the site's natural gas consumption, with Energy Pool supporting the project from initial studies to operations.

Epyr is now exploring additional deployments, with further announcements anticipated in the coming months. The startup aims to target industrial steam applications in energy-intensive sectors, specifically paper, food and beverage, and chemicals. SlateVC co-founder Sébastien Léger praises Epyr's team, speed, and customer-centric approach, emphasizing the potential for Epyr to become a European leader in electrifying the €100 billion industrial heat market.

The new capital will enable Epyr to embark on the next wave of industrial projects, starting with the recently announced 35 MWh unit at Papeco.