Collective hydrogen stand-alone renewable energy systems for buildings in Spain. Towards the self-sufficiency.

The article examines the feasibility of implementing standalone hydrogen-based renewable energy systems in Spanish residential buildings, specifically analyzing the optimization of a solar-battery and solar-hydrogen system for a building with 20 dwellings in Spain. The study initially assesses two standalone setups: solar-battery and solar-hydrogen. Subsequently, it explores scenarios where these systems are connected to the grid to only generate and sell surplus energy. A scenario involving grid connection for self-consumption without storage serves as a benchmark for comparison. All system optimizations are designed to meet energy demands without interruptions while minimizing costs, as determined by a techno-economic analysis. The systems are sized using custom software that incorporates an energy management system and employs the Jaya algorithm for optimization. The findings indicate that selling surplus energy can be economically competitive and enhance the efficiency of grid-connected self-consumption systems, representing the study's main innovation. The conclusion highlights the economic and technical potential of an autonomous hybrid energy system that includes hydrogen, with the significant remaining challenge being the development of a regulatory framework to support its technical feasibility in Spain. • PV-battery and PV-H2 self-sufficient stand-alone systems for a 20-dwelling building. • Residential energy demand based on actual annual four-dwelling metering data. • Sale of surplus generation to the grid from a renewable stand-alone system. • Custom-made software and Jaya algorithm for system simulation and cost optimization. • PV-H2 integration in residential buildings leads to a reduction in grid dependency. [ABSTRACT FROM AUTHOR]