Epyr Raises €15M for Industrial Heat Storage

French energytech Epyr has secured €15 million after deploying a thermal battery that supplies part of a paper mill's steam demand, bringing an industrial decarbonisation concept into actual operation.

What happened

The Series A was led by SlateVC with participation from existing investors AENU and Daphni and other backers. Epyr makes high-temperature thermal storage systems that use inexpensive electricity to heat air and then firebricks. The stored energy can later be released as process heat or steam when a factory needs it. Its business includes system integration, energy management and an optional Heat-as-a-Service arrangement. At WEPA's paper mill in Troyes, a unit commissioned in May 2026 now reportedly supplies up to 25% of steam needs. Epyr has also been selected for a planned 35 MWh installation at Papeco's Orval-sur-Sienne site. That second project's intended gas displacement is a goal, not a completed outcome.

Why it matters

Many factories burn natural gas for heat even when low-cost renewable electricity is available at certain times. Thermal batteries allow power purchases and heat consumption to occur at different times, potentially improving costs and reducing emissions without interrupting production processes.

The bigger picture

Industrial heat is emerging as a major market for storage technology that does not need to return electricity to the grid. For Epyr, real customer installations are a meaningful milestone; expansion will depend on utilisation, electricity pricing, integration costs and proven reliability at larger sites.