Constraint Management Intertrip Service

Reducing the need for build solutions

Reducing the cost of managing constraints means we can mitigate the consequences of unplanned events (post-fault constraint management services), which could help reduce the need for build solutions.

Seeking services from new providers 

Constraint service providers are vital to meeting system needs. We’re looking for new providers to help us reduce constraint costs on the electricity system.

We’ll invite potential providers and relevant network owners to submit proposals that address specific system needs. This is a collaborative process between providers, NESO and the relevant network operators, assessing the proposal’s feasibility and commercial value.

Following technical and economic assessment we will recommend solutions to move forward either via commercial contracts or regulated arrangements.

The EC5 Constraint Management Intertrip Service (CMIS) aims to reduce network congestion costs in the East Anglian (EC5) region by building post-fault intertrip links between generation across the East Anglia region and the East Anglia Operational Tripping Scheme (EAOTS). By doing so, the ENCC can facilitate more power to flow on the existing transmission infrastructure pre-fault, thus reducing the amount of generation being curtailed pre-emptively when the expected flow exceeds the current capability of the circuits.

NESO have launched a market-wide tender, that will now aim to contract for a CMIS EC5-Enduring service to begin in mid-2026.

The project team previously identified that there was a value opportunity to begin the service early, i.e. set up ‘interim’ contracts, and these will run until mid-2026, from which point the CMIS EC5-Enduring service will then begin.

One of the key areas of congestion currently on the system is the Anglo-Scottish boundary (B6) which is limited by a constraint, and therefore sometimes requires renewable generation to be turned down pre-fault.

During times of network congestion, we take action to reduce generation pre-fault which can lead to higher constraint costs even though the likelihood of a network fault is very low.

We are aiming to reduce the impact of network constraints, maximise renewable generation on the system and lower costs for the end consumer.