The potential of hydrogen-battery storage systems for a sustainable renewable-based electrification of remote islands in Norway

Remote locations and off-grid regions still rely mainly on diesel generators, despite the high operating costs and greenhouse gas emissions. The exploitation of local renewable energy sources (RES) in combination with energy storage technologies can be a promising solution for the sustainable electrification of these areas. The aim of this work is to investigate the potential for decarbonizing remote islands in Norway by installing RES-based energy systems with hydrogen-battery storage. A national scale assessment is presented: first, Norwegian islands are characterized and classified according to geographical location, number of inhabitants, key services and current electrification system. Then, 138 suitable installation sites are pinpointed through a multiple-step sorting procedure, and finally 10 reference islands are identified as representative case studies. A site-specific methodology is applied to estimate the electrical load profiles of all the selected reference islands. An optimization framework is then developed to determine the optimal system configuration that minimizes the levelized cost of electricity (LCOE) while ensuring a reliable 100% renewable power supply. The LCOE of the RES-based energy systems range from 0.21 to 0.63 euro/kWh and a clear linear correlation with the wind farm capacity factor is observed (R2 equal to 0.87). Hydrogen is found to be crucial to prevent the oversizing of the RES generators and batteries and ensure long-term storage capacity. The techno-economic feasibility of alternative electrification strategies is also investigated: the use of diesel generators is not economically viable (0.87-1.04 euro/kWh), while the profitability of submarine cable connections is highly dependent on the cable length and the annual electricity consumption (0.14-1.47 euro/kWh). Overall, the cost-effectiveness of RES-based energy systems for off-grid locations in Northern Europe can be easily assessed using the correlations derived in this analysis.