Suitability assessment of flywheel energy storage systems for providing new frequency response services in the UK

National Grid ESO has recently introduced three new frequency response services to the UK electricity market. The three services are Dynamic Containment (DC), Dynamic Regulation (DR) and Dynamic Moderation (DM). Each service has individual performance requirements and restrictions. This paper looks for the first time at how Flywheel Energy Storage Systems (FESSs) can be used to supply these services. Sensitivity analyses have been performed for each service to assess the suitability of FESSs of differing C-Rates to participate. It has been demonstrated that a FESS rated up to 18C is able to provide an average availability above 95% when performing high and low DC simultaneously, with the same threshold being reached up to 4C for DM. None of the C-Rates analysed were able to reach this threshold when performing DR. Hybridisation is shown to introduce performance benefits to the systems, allowing higher C-Rate systems to reach the 95% threshold than when performing individually.