There are various ways to make the electricity system more flexible. In many places, wind and solar generation are complementary on a daily and a seasonal scale. There is more wind during the night and in winter when solar energy production is low. Linking different geographical regions through long-distance transmission lines also makes it possible to reduce variability. It is possible to shift energy demand in time. Energy demand management and the use of smart grids make it possible to match the times when variable energy production is highest. Sector coupling can provide further flexibility. This involves coupling the electricity sector to the heat and mobility sector via power-to-heat-systems and electric vehicles.
Battery storage facility
Energy storage helps overcome barriers to intermittent renewable energy. The most commonly used and available storage method is pumped-storage hydroelectricity. This requires locations with large differences in height and access to water. They typically store electricity for short periods. Batteries have low energy density. This and their cost makes them impractical for the large energy storage necessary to balance inter-seasonal variations in energy production. Some locations have implemented pumped hydro storage with capacity for multi-month usage.
