Forecasting Renewable Scenarios and Uncertainty Analysis in Microgrids for Self-Sufficiency and Reliability: Estimation of Extreme Scenarios for 2040 in El Hierro (Spain)

This study evaluates the feasibility of fully renewable energy systems on El Hierro, the smallest and most isolated Canary Archipelago Island (Spain), contributing to the broader effort to decarbonize the European economy. By 2040, the island’s energy demand is projected to reach 80–110 GWh annually, assuming full economic decarbonization. Currently, El Hierro faces challenges due to its dependence on fossil fuels and inherent variability of renewable sources, which fluctuate with weather conditions. To ensure system reliability, the study emphasizes the integration of renewable and storage technologies. Two scenarios are modeled using HOMER software with probabilistic methods to capture variability in generation and demand. The first scenario represents the current system enhanced with electric vehicles, while the second incorporates energy efficiency improvements and collective mobility policies to reduce demand. Both prioritize electrification and derive an optimal generation mix based on economic and technical constraints, aiming for the lowest Levelized Cost Of Energy (LCOE). The approach takes advantage of El Hierro’s abundant solar and wind resources, complemented by reversible pumped hydro storage and megabatteries. Results demonstrate that fully renewable systems can reliably meet demand with approximately 30% energy surplus and LCOE near 10 c€/kWh. Uncertainty analysis increases these figures by about 10% both in costs and excesses.