Heuristic method for electric vehicle charging in a Spanish microgrid: Leveraging renewable energy surplus

The transition towards renewable energies has intensified due to the global energy crisis, climate neutrality goals, and the increase in electrical demand. Technologies such as wind and solar have driven this change, although they present challenges such as intermittency and volatility. To maintain grid stability, solutions such as microgrids and energy storage system are required, improving supply quality and energy efficiency. Electric vehicles have gained importance as energy storage system through Vehicle-to-Grid technology. This article describes the implementation of a heuristic method in the microgrid of CEDER-CIEMAT (Center for Renewable Energy Development – Center for Energy, Environmental and Technological Research) in Spain. This microgrid, with a diversity of components and consumption profiles, allows for the acquisition of accurate data in a real-world setting. The heuristic method optimizes the charging of electric vehicles by leveraging the surplus renewable energy from the center, achieving 78 % of charging with surplus power and 96 % with renewable energy. This results in annual savings exceeding 900 €, ensuring sustainable energy use in the microgrid.