Summary:
This paper proposes a novel strategy to enhance the profitability of long-term operated nuclear power plants during periods of low electricity market prices by co-producing hydrogen. The approach integrates a proton exchange membrane electrolyzer sized to utilize up to 50 % of the plant’s nominal capacity (500 MW). This configuration effectively divides the nuclear facility into two conceptual units: a power-only plant and a combined hydrogen-and-power plant. The latter is capable of directing electricity to either the electrolyzer or the grid, depending on market conditions. The model employs real data from the Spanish day-ahead electricity market. Results show that, based on typical values for Spanish nuclear assets and market prices, a competitive levelized cost of hydrogen of 4.42 €/kg can be achieved. The analysis demonstrates that this combined hydrogen and power configuration significantly improves economic performance and provides a feasible pathway to enhance the competitiveness of nuclear assets in unfavorable electricity market conditions.
Spanish layman's summary:
Se propone acoplar a una central nuclear existente un electrolizador PEM (hasta 50% de 500 MW) para, cuando el precio de la luz sea bajo, desviar energía a producir H2. Con datos del mercado español se estima LCOH 4,42 €/kg y mejora la rentabilidad.
English layman's summary:
A PEM electrolyzer is added to an existing nuclear plant (up to 50% of 500 MW) so that, when power prices are low, electricity is shifted from the grid to hydrogen production. Using Spain’s day-ahead data, it estimates LCOH €4.42/kg and boosts plant economics.
Keywords: Cogeneration; Nuclear hydrogen; Electrolysis; Nuclear flexibility
JCR-JIF Impact Factor and WoS quartile: 11,800 - Q1 (2025)
DOI reference:
https://doi.org/10.1016/j.enconman.2025.120934
Published on paper: February 2026.
Published on-line: December 2025.
Citation:
J.I. Linares, J.R. Pérez-Domínguez, E.M. Arenas, B.Y. Moratilla, "Unlocking nuclear flexibility through hydrogen production", Energy Conversion and Management, Vol. 349, pp. 120934, February 2026. [Online: December 2025] doi: 10.1016/j.enconman.2025.120934