French energy tech startup Epyr announced today that it has raised €15 million (USD$16.8 million) in a Series A funding round, with proceeds aimed at accelerating the deployment of the company’s thermal energy storage technology to help industrial companies replace fossil fuels with electricity.

The financing comes as industrial heat accounts for around 20% of global energy consumption and remains largely dependent on fossil fuels, particularly natural gas in Europe. Electrifying industrial heat has become a priority for the EU, both to at reducing emissions and dependence on imported fossil fuels.

Founded in 2024 by Léa Dardenne and Bastien Oggeri, Paris-based Epyr develops thermal energy storage solutions that enable industrial companies to replace fossil fuels with low-carbon electricity for high-temperature heat generation. The company provides an integrated solution combining thermal storage technology, system integration, energy management and financing through a Heat-as-a-Service model.

Epyr’s technology uses electricity during periods of low prices to power electric heating elements that heat air, which in turn heats firebricks that store thermal energy at high temperatures. The stored energy can then be released as heat when needed for industrial processes, enabling companies to reduce energy costs and emissions while providing flexibility to the electricity grid.

Dardenne and Oggeri said:

“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.”

The company said that the new capital will be used to accelerate the rollout of new thermal storage projects, starting with a project for French hygiene paper manufacturer Papeco at its Orval-sur-Sienne site. The project, expected to be France’s largest thermal energy storage installation, will include Epyr’s 35 MWh thermal energy storage unit, designed to replace the site’s entire natural gas consumption.

The financing round was led by SlateVC, and included participation from existing investors AENU, Daphni, OVNI, WEPA Ventures and Aurum Impact.

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

“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.”