UK energy storage and determining the upper boundary of revenue available from the time-shifting of bulk electrical energy

Energy storage is a critical component of historical and future energy systems. The drivers behind the growing importance given to electrical energy storage in the UK has been investigated, with the development of an objective model to calculate the upper boundary of revenue available to storage operators that time-shift electrical energy through the UK's power exchange markets. The results display clearly that the UK is moving rapidly to greater import dependence of its primary energy needs, and that pre-conversion stores of energy in stockpiles of fuels available to the electrical network dwarf the post-conversion rechargeable pumped-hydro energy storage schemes with an indicative ratio of ~1300:1 in favour of fossil-fuel stocks (nuclear fuel stock data was not included in this ratio as it is unavailable). The time-shifting model contained a novel approach by including a timedependent efficiency loss that provided the ability to consider the self-discharge of a storage device, and uses a non-deterministic random walk approach. The results of the model revealed that there is a large annual variation of potential revenues from the time-shifting of electrical energy through power exchange markets in the UK (e.g. Figure 98, page 176). It is proposed that the added complexity of a model to include a time-dependent efficiency loss is probably not warranted for the study of bulk electrical energy storage arbitrage revenues, as in the UK, the storage device will default to a diurnal cycle of charging and discharging in order to maximise revenue. The self-discharge rate of a storage device would have to be impractically large to have a significant influence on a diurnal cycle (e.g. Figure 115, page 188) and therefore the results from the inclusion of a self-discharge variable are not thought to differ significantly from a simpler modelling approach that would not include a self-discharge element.Energy storage is a critical component of historical and future energy systems. The drivers behind the growing importance given to electrical energy storage in the UK has been investigated, with the development of an objective model to calculate the upper boundary of revenue available to storage operators that time-shift electrical energy through the UK's power exchange markets. The results display clearly that the UK is moving rapidly to greater import dependence of its primary energy needs, and that pre-conversion stores of energy in stockpiles of fuels available to the electrical network dwarf the post-conversion rechargeable pumped-hydro energy storage schemes with an indicative ratio of ~1300:1 in favour of fossil-fuel stocks (nuclear fuel stock data was not included in this ratio as it is unavailable). The time-shifting model contained a novel approach by including a timedependent efficiency loss that provided the ability to consider the self-discharge of a storage device, and uses a non-deterministic random walk approach. The results of the model revealed that there is a large annual variation of potential revenues from the time-shifting of electrical energy through power exchange markets in the UK (e.g. Figure 98, page 176). It is proposed that the added complexity of a model to include a time-dependent efficiency loss is probably not warranted for the study of bulk electrical energy storage arbitrage revenues, as in the UK, the storage device will default to a diurnal cycle of charging and discharging in order to maximise revenue. The self-discharge rate of a storage device would have to be impractically large to have a significant influence on a diurnal cycle (e.g. Figure 115, page 188) and therefore the results from the inclusion of a self-discharge variable are not thought to differ significantly from a simpler modelling approach that would not include a self-discharge element