National Grid ESO awards contracts to maximise renewable generation and deliver consumer savings worth millions of pounds

In a successful tender process, National Grid ESO is set to deliver substantial constraint cost savings for consumers. Initial estimates suggest the service could deliver annual savings of £20m to £40m, all the while supporting GB’s transition to operating a 100% zero carbon grid.

Ten companies with fifteen generating units, including windfarms and battery storage, have been awarded contracts to provide new ‘post fault’ services. This will enable the companies to be connected to constraint management equipment, which is designed to maximise renewable generation on the system and reduce constraint costs on the key B6 English/Scottish border.

The contracts – which will run from October 2023 through to September 2024 – are part of the ESO’s Constraints Management Pathfinder project. The project aims to enable renewable generation to continue  on the system, rather than being pre-emptively curtailed.

Currently, the main mechanism to constrain generation is to bid generators off the system. This approach is used by system operators around the world, but it can be expensive as it is done prior to a fault occurring.

Instead of paying constraint costs to turn off generation when there is the risk of a fault, the technology enabled through these contracts will provide an option of allowing generation to continue for longer. This results in reduced constraint costs, which would ultimately be paid for by consumers.

This pathfinder project, which procured 1.7GW of transmission connected generation, will see up to 800MW available to be tripped off at any one time. When the ESO identifies a constraint on the B6 boundary, the generation is armed to be ready to reduce output in the event of a fault. This approach avoids constraining off the generation pre-emptively as is currently the case.

Should a fault occur, the generating units respond quickly, reducing their output within 150 milliseconds. The ESO will then reconnect the units to the system as quickly and safely as possible.

Julian Leslie, Head of Networks at National Grid ESO, said:

These services give our control room more flexibility, enabling renewable generation to stay on the system for longer and taking us another step closer to 100% zero carbon operation.

They’re part of the ESO’s wide-ranging 5-point plan which will allow us to manage constraints on the system more effectively in the years ahead, reduce balancing costs and ultimately save consumers millions of pounds.

ESO’s pathfinder projects are designed to find new ways of the operating the system to reduce costs for consumers. This service is an innovative way of managing the risk of very rare network faults. The Constraints Management Pathfinder project is part of National Grid ESO’s 5-point plan to manage network constraints in the years ahead.