Maximizing self-sufficiency and minimizing grid interaction: Combining electric and molecular energy storage for decentralized balancing of variable renewable energy in local energy systems

The increase of renewable electricity from variable sources, such as solar PV and wind turbines, leads to increasing need for energy storage to maintain balance between demand and supply, and decrease peak load on electricity grids. Energy storage options to achieve this include electric energy storage such as batteries, and molecular energy storage such as hydrogen. In this research, we use a model to simulate the behavior of a local residential grid in the Netherlands supplied exclusively by decentralized solar PV and wind energy. Our model includes combinations of batteries and hydrogen as energy storage options to investigate synergies between them. The simulation results indicate that combining the characteristics of battery and hydrogen energy storage in a single grid leads to a more resilient and flexible system compared to one in which only one of the two technologies is deployed. In our simulations of combined storage options, local demand can be met with less installed capacity, and less energy exchange with external grid takes place. However, we also conclude that diversity of storage options alone is insufficient to reduce the highest peak load on external grids, and additional measures are required to ensure net residual load remains within specific bandwidths.