WEPA and Epyr have commissioned what they describe as France’s first industrial-scale thermal energy storage system combining power-to-heat conversion with heat storage, installed at WEPA’s Troyes tissue mill.
The system converts low-carbon electricity into heat, stores it, and releases it as steam to meet process demand. At Troyes, where steam generation is one of the mill’s most energy-intensive operations, the objective is to displace a portion of fossil fuel use.
The unit is currently supplying about 25% of the site’s steam demand, giving it operational relevance beyond decarbonisation alone. It also adds a degree of flexibility to the mill’s energy management, allowing steam production to be partially decoupled from real-time energy supply.
WEPA indicated that the system was designed, installed and commissioned in under six months, with no reported disruption to production. The project received support under the France 2030 programme, via the DEMIBaC scheme targeting industrial decarbonisation technologies. Investment details have not been disclosed.
The installation aligns with Epyr’s broader push into industrial heat decarbonisation. The company secured €3 million in pre-seed funding in 2025 to advance its thermal storage technology, with WEPA Ventures participating in the round.
For the tissue and paper sector, the Troyes project offers a concrete example of integrating electrification and thermal storage into an operating mill. Its wider applicability will depend on several factors, including electricity pricing, grid stability, site-specific steam profiles, and the extent to which mills can reduce gas use without affecting reliability.
More broadly, the project underscores the growing role of flexible steam generation in decarbonisation strategies. For energy-intensive industries, thermal storage is emerging as a potential lever to reduce fossil fuel dependence while maintaining process stability.
WEPA Group is a German family-owned tissue and hygiene paper producer, operating 15 production sites in six European countries.
