Changing generation is resulting in lower system inertia and increasing costs, with residual inertia making up a larger percentage of the total system inertia. The ability to measure real-time inertia will enable both synchronous and residual inertia to be known, improving decision making and reducing the risk of the system running insecure. There is currently no best practice or standardisation for measuring system inertia. This project will analyse and verify data from new commercial inertia monitoring tools and compare to NGESO operational data, establishing different generation and demand scenarios for inertia and Rate of Change of Frequency (RoCoF). Through development of measurement parameters and specifications for reference instrumentation, the project will build on existing data and use cases with the goal to establish standardisation for inertia measurement.

Benefits

The ability to measure real-time inertia will enable both the synchronous and residual inertia to be known, resulting in improved knowledge and better informed decision making. More accurate inertia values, especially against different generation and demand use cases, will reduce the risk of the system running insecure.

Managing RoCoF as a result of low inertia is costing approximately £200m per year, a more accurate measurement could result in a reduction in these costs and provide added transparency to decision making.

Improved measurement and forecasting capability will be able to feed into pathfinder assessments, helping to define the required volume, where it should be purchased and potentially enable the future despatch of inertia services.