The future of frequency response in Great Britain

Abstract

Electricity grids around the world are rapidly changing to accommodate an increasing penetration of renewable generation. Grid ancillary services, such as frequency response, are important tools an electricity system operator has at their disposal for maintaining grid stability. In Great Britain, the electricity system operator recently proposed new frequency response services (dynamic regulation, dynamic moderation, dynamic containment, and static containment) designed for the future needs of the system. Here we analyse the efficacy of these new services using a month-long case study and use the current services as a comparison. We calculate that the total frequency response capacity needed is 450 MW of high response (needed when Δf > 0) and 550 MW of low response (needed when Δf < 0), including 150 MW of dynamic regulation and 150 MW of dynamic moderation to reproduce frequency volatility levels seen currently. We also investigate how the new services perform in a future reduced inertia scenario, developed using National Grid ESO’s Future Energy Scenarios. The inertia in this future scenario is provided by nuclear and demand only and has a median value 5 times smaller than current values. We find that the new services can successfully mitigate against the reduced inertia with a 50 MW addition of capacity to dynamic regulation.

Keywords

• Grid stability
• Frequency events
• Frequency response
• Renewable penetration