System Inertia

Summary

NESO dataset publishing outturn and market-provided inertia estimates for the GB transmission system. Excludes contributions from Stability Pathfinder contracted units, so it understates total system inertia.

Why it matters

Inertia is a scarce system service that used to come free from synchronous thermal plant. As coal and CCGT retire, NESO must procure it — and this dataset is the evidence base for how much the market is delivering versus what the system needs.

Key facts

• •Covers outturn inertia and market-provided inertia for GB Transmission System
• •Excludes Stability Pathfinder unit contributions
• •Published by NESO as an ongoing dataset

Areas affected