Unlocking electrolysis waste heat for district heating: Potentials, barriers, and policy pathways

Hydrogen is a key pillar in the transition to carbon neutrality, with green hydrogen production through electrolysis playing a vital role in decarbonizing industry, transport, and heating. Since electrolysis generates significant waste heat, capturing and reusing this energy provides an underused renewable source for district heating networks (DHNs), improving overall energy efficiency and economic feasibility. This study reviews projected hydrogen demand and electrolysis capacities for 2030 and up to 2050 across IEA DHC member countries to assess country-specific waste heat potentials. A stakeholder survey (n = 71) involving district heating (DH) operators, electrolyser operators, researchers, and policymakers identifies key barriers and opportunities for integration into DHNs, providing a basis for targeted policy recommendations. The analysis revealed that waste heat from alkaline electrolysis (AEL) and proton exchange membrane electrolysis (PEM-EL) at low to moderate temperatures can serve as a valuable heat source for low-temperature DHNs. Integration with conventional DHNs, which operate at higher supply temperatures, would require temperature upgrading, such as the use of supplementary heat pumps. Main implementation barriers include the need for additional infrastructure and high investment costs, proximity constraints between electrolysers and DHNs, limited awareness of the concept, and regulatory hurdles. Future strategic coordination between the hydrogen production and DH sectors, supported by targeted infrastructure planning, financial mechanisms, and regulatory frameworks, is essential to realize this potential and advance the decarbonization of the heating sector. • Country-specific projections of electrolysis capacity developments. • Quantification of waste heat potential by country. • Stakeholder survey identifying barriers and integration opportunities. • Evidence-based policy guidance to enable district heating integration.