No matter how much generating capacity is installed, there will be times when wind and solar cannot meet all demand, and large-scale storage will be needed. Historical weather records indicate that it will be necessary to store large amounts of energy (some 1000 times that provided by pumped hydro) for many years.
GB will need large-scale energy storage to complement high levels of wind and solar power. No low-carbon sources can do so at a comparable cost. Construction of the large-scale hydrogen storage that will be needed should begin now. royalsociety.org/electricity-storage.
Global capability was around 8 500 GWh in 2020, accounting for over 90% of total global electricity storage. The world’s largest capacity is found in the United States. The majority of plants in operation today are used to provide daily balancing. Grid-scale batteries are catching up, however.
Grid flexibility and storage required to achieve very high penetration of renewable electricity Appropriate storage for high penetration grid-connected photovoltaic plants The role of large scale energy storage design and dispatch in the power grid: a study of very high grid penetration of variable renewable resources
Great Britain’s demand for electricity could be met largely (or even wholly) by wind and solar energy supported by large-scale storage at a cost that compares favourably with the costs of low-carbon alternatives, which are not well suited to complementing intermittent wind and solar energy and variable demand.
When no over-generation is allowed, the smallest storage capacity (115.1 TWh) is found with a mix of 79% wind + 21% solar PV. In contrast, if 15% of over-generation is allowed, the smallest storage size (43.2 TWh) is found with an 84-16% mix of wind and solar PV.