Systemic analysis of the potential for utilising excess heat from electrolysers (Hy) and data centres for an efficient energy system for the future (SAPHyR)

At present, most of the heat produced by district heating networks comes from fossil fuels. Decarbonising these networks is essential for achieving climate targets. One way to conserve resources, reduce the costs of transformation and achieve a high degree of diversification in district heating generation is to integrate current and future excess (or waste) heat into district heating networks. This project aims to conduct a comprehensive investigation of future excess heat sources and their potential for supplying district heating networks. The focus will be on two sources of excess heat: excess heat from hydrogen production and excess heat from data centres. Using excess heat from hydrogen production could reduce the cost of producing hydrogen and increase the efficiency of combined hydrogen and heat generation systems. However, excess heat has so far received little attention in research on the optimal locations for electrolysers. Energy system models do not yet capture the utilisation of excess heat from electrolysers in detail. There are also no analyses of the system effects of utilising excess heat from data centres. This will become increasingly relevant in the future as data centre capacities grow. Although there are already some practical examples of excess heat utilisation from data centres in Germany, as well as an excess heat platform, the potential synergies have not yet been sufficiently investigated. For example, the total (and future) excess heat potential in Germany has not yet been quantified. The project plans to conduct an analysis of both excess heat sources from three perspectives: (1) systemic analyses, (2) location-specific analyses and (3) a comprehensive qualitative analysis of existing legal frameworks in Germany and barriers. Combining these three perspectives will ensure the large-scale utilisation of excess heat sources.

Duration: May 2026 – April 2029

Funded by: Ministry for Economic Affairs and Energy (BMWE)

Project partners: Fraunhofer-Institut für System- und Innovationsforschung ISI (Fraunhofer ISI), Energiewirtschaftliches Institut an der Universität zu Köln gGmbH (EWI), Deutsche Unternehmensinitiative Energieeffizienz e. V. (DENEFF)