Utilisation of waste heat from PEM electrolysers – Unlocking local optimisation

• Published in: International journal of hydrogen energy 2023-08, Vol.48 (72), p.27872-27891
• Main Authors: van der Roest, Els, Bol, Ron, Fens, Theo, van Wijk, Ad
• Format: Article
• Language: English
• Subjects: (Green) hydrogen; District heating; Electrolysis; System integration; Waste heat
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2023.03.374

Recovery of heat from electrolysers is potentially interesting to increase the total system efficiency, reduce CO2 emissions, and increase the economic feasibility of both hydrogen and heat production. This study examines different designs for the utilisation of (waste) heat from a 2.5 MWel polymer electrolyte membrane (PEM) electrolyser. Redundancy is important in the design, to ensure safe operation regardless of the heat demand of the heat consumer. We analysed cases with local heat consumption (with/without a heat pump) and coupling with a district heating network (DHN). Overall, 14–15% of the electricity input to the stack can be utilised by a heat consumer, increasing the total system efficiency to 90% (HHV) with CO2-savings of 0.08 (DHN)-0.28 (direct use) tonne CO2/MWhheat, used. We performed a first-order techno-economic analysis showing that the levelized costs of the electrolyser heat (8.4–36.9 €/MWh) fall within the range of other industrial heat sources and below lower-temperature heat sources. [Display omitted] •Redundant designs for utilisation of waste heat from electrolysers are presented.•Techno-economic analysis for a direct heat consumer and district heating grid.•Increased electrolyser system efficiency of 14–15% by waste heat utilisation.•The feasibility of heat utilisation is very sensitive to the transport distance.•LCOE of the electrolyser heat is within the range of other industrial heat sources.