The world’s energy system is changing profoundly as we move towards a net-zero carbon future. Introducing more variable renewable energy sources (VRES), namely wind and solar PV generation into the energy mix puts pressure on the power system. So too does the increased demand for the electrification of transport, heating and cooling. We need more production facilities, new power plants, significant grid infrastructure, but also the application of storage and other flexibility options.
This paper explores the need for, and viability of, seasonal storage in the power system. Seasonal storage is a form of storage typically accommodating yearly cycles in electricity demand and VRES generation. It stores energy during one seasonal condition (summer or winter) and discharges the stored energy in the other seasonal condition, depending on the load demand. Seasonal storage is, therefore, closely related to seasonal variations in temperature, wind speed and solar irradiation as these mainly determine the need for heat- and cooling demand and the generation of solar and wind power.