Feasibility study and assessment of a solar-powered hydrogen electrolyser-fuel cell integrated system for building electrification

Despite their potential to utilise renewable energy sources like solar power, green hydrogen generation technologies are still under development. This study demonstrates the feasibility of a solar-powered hydrogen electrolyser-fuel cell integrated energy system to supply electricity to an office building in London. A techno-economic-environmental integrated assessment model is presented for comprehensive system evaluation, emphasising building applications. The system can meet approximately 72 % of the office building's annual energy demand, assuming unconstrained hydrogen storage with no round-trip storage losses; under a realistic storage round-trip efficiency of 85–95 %, this figure reduces to approximately 61–68 %. The water generated by the fuel cell can fully meet the consumption of the electrolyser during hydrogen production, demonstrating closed-loop water self-sufficiency. The overall energy conversion efficiency is close to 80 %, reflecting the round-trip conversion efficiency of the PV-to-electrolyser-to-fuel-cell pathway and excluding auxiliary loads such as compression and pumping. The levelised cost of energy (LCOE) of the system is estimated to be 4.7654 £/kWh. The GHG emissions of the electrolyser and the PEMFC are 4.615 kgCO₂ eq/MJ and 0.384 gCO₂ eq/MJ, respectively. This study is positioned as a technical feasibility demonstration; while the current LCOE exceeds grid parity, projected reductions in PEM electrolyser and fuel cell capital costs are expected to substantially improve the economic case over the coming decade.