MODERATOR at EuroSun 2026: Scaling up Latent Heat Storage for Data-Centre Waste Heat Recovery

MODERATOR was represented at EuroSun 2026, held in Freiburg, Germany, from 14–18 September 2026. The international conference brought together researchers, engineers and industry representatives working on sustainable and solar energy solutions for buildings and industry.

During the Thermal Energy Storage III session on 16 September, Yannick Krabben from HSLU presented the MODERATOR work entitled “Pilot-scale Latent Heat Storage for Waste Heat Recovery from Immersion-cooled Data Centres within the Moderator Project.”

The presentation followed the development of MODERATOR’s latent heat storage concept from small-scale PCM material development involving only a few grams of material to the upcoming 240 kWh pilot system in Thessaloniki. Particular attention was given to the main technical challenges encountered during this scale-up process and to the results achieved so far.

The work includes the development and testing of phase-change materials (PCMs), including PCM45 developed in cooperation with COWA Thermal Solutions, together with the development of a scalable storage concept. MODERATOR is now progressing from material- and component-level testing towards the integrated 20-cell pilot demonstrator, bringing the project closer to demonstrating its complete approach to recovering, storing and reusing heat from immersion-cooled data centres.

The presentation also highlighted the potential end-use opportunities for recovered heat, including buildings, district heating, greenhouses and industrial processes, demonstrating how thermal storage can help connect data-centre waste heat with different forms of useful thermal demand.

EuroSun 2026 provided an important opportunity to present MODERATOR’s progress to the wider sustainable-energy and thermal-energy-storage community and to exchange knowledge with researchers and experts working on complementary technologies.

Special thanks to Andreas Hauer, who chaired the session, and to the EuroSun 2026 Committee for organising the conference and providing the opportunity to share MODERATOR’s work.

More information about the event here.