Background
In 2017, LCP were commissioned to support National Grid in modelling the contribution of limited duration storage plants to system security. This work was ultimately used to inform the de-ratings for different durations of storage in the capacity mechanism.
Since 2014, National Grid have used LCP’s Unserved Energy Model (UEM) to produce the analysis for its annual Electricity Capacity Report and to provide recommendations on the CM auction capacity requirement. This project allowed the UEM to reflect the impact on system security of differing storage capabilities.
Our solution
We worked with National Grid in the design, implementation and optimisation of four separate algorithms to model the possible ways that storage plant could operate, considering their durations, capacities and level of coordination. The model was used to determine the Equivalent Firm Capacities (EFCs) of incremental amounts of storage capacity of various durations, based on a system with a Loss of Load Expectation (LOLE) of 3 hours but using changes in Expected Energy Unserved (EEU) to determine the EFC.
The results
The results of this modelling were used to produce the “Duration-Limited Storage De-Rating Factor Assessment” final report by National Grid in December 2017, and inform the de-ratings used for storage’s participation in subsequent capacity auctions.
