Techno-economic analysis of off-grid residential hybrid renewable energy systems utilizing excess energy for small-scale green hydrogen production

Off-grid renewable energy systems face feasibility challenges due to high initial investment costs. To enhance their economic viability, excess energy can be converted into green hydrogen via electrolysis and sold to emission-intensive industries seeking decarbonization. Therefore, this study conducts a techno-economic analysis of off-grid hybrid renewable energy systems utilizing surplus energy for hydrogen production. An optimal PV-wind-battery system is designed in HOMER software to meet the energy demand of a residential community with 100 vacation homes while using excess energy for green hydrogen production. The results indicate that the net present cost (NPC) of the system is $1.09 million without an electrolyzer. However, incorporating an electrolyzer and selling hydrogen at $6.5/kg reduces the NPC by 24 % to $0.83 million. A break-even analysis shows that off-grid PV/wind/battery systems with electrolyzers become more economical than those without when hydrogen prices exceed $4.5/kg. The levelized cost of hydrogen (LCOH) is found to be $10.3/kg due to the reliance on surplus energy. If the system were fully dedicated to hydrogen production, the LCOH would become $5.9/kg. The findings of the study demonstrates that utilizing surplus energy for green hydrogen production provides a pathway to improve the economic sustainability of off-grid renewable energy systems.