Can a fully renewable system with storage cost-effectively cover the total demand of a big scale standalone grid? Analysis of three scenarios applied to the Grand Canary Island, Spain by 2040

The extensive use of carbon-free energy sources is essential to achieving zero CO2 emission goals in electricity generation. But these systems are not yet used to cover 100% of the energy demand in areas with many inhabitants. This study answers the question "Can a fully renewable system with storage cost-effectively cover the total demand of a big scale standalone grid?" The system is applied to Grand Canary Island by 2040, with forecasts of approximately 1 million inhabitants by then. Given the high variability of weather conditions, renewable systems have to be used with storage technologies to meet demand with high reliability. Three energy demand scenarios are analyzed: Business as usual plus efficiency measures, partial electrification, and finally, total electrification scenario. For modeling the scenarios, HOMER software was used. The best generation mix has been estimated according to engineering, land occupation, and economic criteria, obtaining the lowest Levelized Cost of the Energy. Focusing on the last scenario, the most realistic one according to Canary Island Government, the feasibility of electrifying the economy in an off-grid location with high energy needs (6.4 TWh/ year) at affordable prices and using exclusively renewable energy has been analyzed. The optimized results propose installing a 2.5 GWp photovoltaic system, a 1.2 GWp wind power system, a 9.73 GWh pumped storage (607 MW), and a 5.82 GWh Lithium-ion battery system (2.3 GW), obtaining an LCOE of 13.4 ceuro/kWh. The results quantify and show the need to bring a reliable autonomous system to store energy. Even having a significant capacity to store energy, 33.4% of the produced energy cannot be used or stored because the system is based on renewable sources. The cost of the batteries is a limitation for a more profitable system.