AbstractThe potential role of any energy system component, including storage, can only be assessed within a whole system context. The whole system of demands, supplies and stores must be modelled over timescales from minutes to months in order to accurately calculate energy flows, costs and emissions. In this paper, a hypothetical future national energy system with high efficiency and large components of renewables and storage has been posited. Modelling includes ‘smart’ algorithms to control the stores and other system components as demands and renewable supplies vary over different time periods. Here, a sequential allocation (SA) algorithm has been applied and it is seen that it performs well in that stores reschedule energy flows to make good use of renewable energy. The performance of stores and their inputs, such as heat from a heat pump, can be highly non-linear and the challenge remains to better simulate and optimise the configuration of the energy system including storage at the same time as optimising dynamic system control.