National Grid ESO has awarded 15 contracts to ten companies to provide new ‘post fault’ services.
The contacts have gone to a range of generating units, including wind farms and battery storage, and form part of the operator’s Constraints Management Pathfinder project.
They are designed to reduce constraint costs on the key B6 English/Scottish border, while increasing the share of renewables on the grid.
Currently, generators are pre-emptively bid off of the system to manage constraints. While this is a common practice worldwide, it can be expensive as it is done prior to a fault occurring, National Grid ESO said.
As such, through its pathfinder project, the operator has now procured 1.7GW of transmission connected generation. This will allow it to trip off up to 800MW at any one time, if the grid becomes too constrained on the B6 boundary.
If a fault occurs, the contracted generating units will reduce their output within 150 milliseconds. National Grid ESO will then reconnect them as soon as it is safe to do so.
By avoiding pre-emptively curtailing generation, these technology contracts will reduce constraint costs by providing an option of allowing generation to continue running for longer.
Initial estimates suggest these contracts – which are set to run from October 2023 through to September 2024 – could save between £20 million and £40 million a year.
“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,” said Julian Leslie, head of Networks at National Grid ESO.
“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.”
National Grid ESO launched the first phase of its pathfinder in March 2021 to find new ways of operating the system. It sits within the operator's wider 5-point plan to manage grid constraints in the coming years.
Modelling from the ESO in June 2021 suggested that constraint costs could hit £2.5 billion per year over the next decade if changes to the system are not made, as the generation mix continues to change rapidly.