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

The Series A follows the commissioning of Epyr's first installation at WEPA Group's paper mill, which now supplies up to a quarter of the site's steam requirements.
French startup Epyr raises €15M following successful industrial heat storage deployment

French industrial energytech company Epyr has raised a €15 million Series A round led by  SlateVC. Existing investors AENU and Daphni are doubling down, alongside WEPA Ventures, OVNI  Capital and Aurum Impact. 

Industrial heat accounts for around 20 per cent of global energy consumption and is still largely produced by burning fossil fuels, mostly natural gas in Europe.

Electrifying it has become an EU priority, both to cut emissions and to reduce dependence on imported fuels. But industrial sites will switch only if electric heat costs less than gas.  Market conditions are now tipping in electricity's favour. After repeated crises, fossil fuels remain expensive and volatile, while the growth of renewables makes electricity cheaper whenever the sun shines, or the wind blows, and supply exceeds demand. 

Epyr develops innovative thermal energy storage solutions that help industries move away from fossil fuels. By making decarbonised high-temperature industrial heat competitive and easy to deploy.

During low-cost hours, smart controls power electric resistors that heat air, which in turn heats firebricks that store the energy at high temperature, ready to release as heat whenever the process needs it. This flexibility also helps balance the power grid. 

Epyr offers an all-in-one solution covering technology, system integration, energy management and,  where needed, third-party financing, delivered as Heat-as-a-Service.

This model, supported by trusted partners, adapts to each client’s situation, takes the complexity off their hands and accelerates deployment.

According to Léa Dardenne and Bastien Oggeri, co-founders of Epyr, 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.” 

Epyr’s first installation has already demonstrated the technology’s potential. Inaugurated in May 2026 at WEPA Group’s paper mill in Troyes, France’s first industrial thermal energy storage unit was built and commissioned in less than six months and now supplies up to 25 per cent of the site’s steam requirements.

According to Andreas Krengel, Member of the Management Board at WEPA:  

“Together with Epyr, we have shown that innovative energy solutions can be implemented quickly and successfully in an industrial environment.

The first installation has demonstrated the value of both the technology and the partnership. We are excited to build on this success and help accelerate the adoption of clean, reliable  and competitive industrial heat solutions across Europe.” 

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

Epyr is now exploring several additional deployments, with further announcements expected in the coming months. The startup is targeting industrial steam applications in energy-intensive sectors, particularly paper, food and beverage, and chemicals.

Sébastien Léger, co-founder and GP at SlateVC, shared:

“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 €100bn industrial heat market. We are delighted to enable their growth in France  and beyond.” 

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

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