Quantifying energy storage requirements to decarbonise the electricity grid in the United Kingdom—influence of the share of dispatchable generation, storage efficiency, and curtailment

The decarbonisation of the electricity grid requires large scale deployment of renewable generation. Yet, most renewable generation is intermittent, and therefore large-scale energy storage may be needed to ensure supply availability. To guide future policies and system planning, it is important to know how much storage the future net-zero energy system will need. Previous attempts to estimate storage requirements have either focused on systems entirely supplied by renewables, or did not consider the increased demand due to expected electrification. In this work, we explore how much energy storage the future energy system in the United Kingdom may require and how much this requirement depends on future levels of demand, and the share of dispatchable generation in the grid, such as biomass or nuclear. We perform a simulation of energy flows for a typical year, for a range of energy mix scenarios, and two parameters – storage efficiency and renewable curtailment allowance. Our results anticipate a storage requirement for the UK ranging from 109 GWh to 9 TWh. Less storage is needed when a higher share of dispatchable generation is available, even if electricity demand is higher. Allowing for more renewable curtailment and less efficient storage may also reduce the requirements for storage capacity, at the expense of more energy dissipation.