EC5

ESO to deliver consumer savings through early start of new constraint management service


  • ESO is awarding early-start contracts to manage constraints in the East-Anglia region. The service is expected to start in February 2024.
  • The service has previously proven its value by saving consumers £95.2m in constraint costs across the Anglo-Scottish border in the first year alone.
  • By allowing units already connected to the East-Anglian scheme to commence service delivery early, the ESO will be able to generate additional savings for consumers, ahead of the wider, enduring go-live of the service in April 2025.
  • By the end of the decade this new service is expected to deliver savings worth hundreds of millions of pounds for the end consumer and will also help contribute to reducing CO2 emissions. 

The interim Constraint Management Intertrip Service (CMIS) for the East Anglia (EC5) area has been awarded to three generating companies with a total of 10 units, starting in February 2024 and will continue until the enduring service begins next year.  

The Constraint Management Intertrip Service (CMIS) was first launched across the Anglo-Scottish (B6) boundary in April 2022. In its first year it enabled 367GWh of extra renewable electricity generation, saving 144kilotons of CO2 and £95.2m in costs which are ultimately borne by end consumers. 

The new CMIS in the East Anglia (EC5) region was proposed in the ESO’s Network Options Assessment 2021/22 refresh, to tackle constraints in the region due to network capacity. 

The interim service launching this month (February 2024) is expected to generate in the region of £20m of extra consumer savings, depending upon the generation background driving the constraint and system conditions, while the enduring service is forecasted to save hundreds of millions. 

This new service will enable the ESO’s control room more flexibility by allowing renewable generation to remain on the system, rather than being pre-emptively curtailed. Instead of paying constraint costs to turn off generation when there is the risk of a fault, this service allows clean renewable generation to continue exporting energy for longer. This results in reduced constraint costs which would ultimately be paid for by consumers and lowers the overall carbon intensity of the electricity produced.  

The ESO is launching an enduring, competitive CMIS tender for the East-Anglia (EC5) region with an expected service start date of April 2025. 

Julian Leslie, Director of Strategic Energy Planning and Chief Engineer at the ESO, said: 

 “The constraint management intertrip service is fundamental towards solving a heavily constrained area of the grid, reducing balancing costs. 

“The ESO is driving forward innovative solutions to manage constraints on the system, whilst maximising our ability to utilise renewable generation, supporting the journey to 100% zero carbon operations by 2035.

“As part of our wide-ranging five-point plan to manage system constraints this service, alongside other workstreams, will be key to reducing balancing costs and ultimately saving consumers millions of pounds.”