Unlocking nuclear flexibility through hydrogen production

• A combined hydrogen and power configuration is proposed for nuclear plants. • This hybrid concept improves profitability during low electricity price periods. • The electrolyzer operates when market prices fall below a threshold. • A hydrogen cost of 4.42 €/kg is achieved at 65 €/MWh electricity cost. • This hybrid system significantly boosts total cash flow. 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.