Constraint management in Great Britain cost £1.5 billion in 2023, much of which is through curtailing wind in Scotland. Battery energy storage capacity in Scotland has more than doubled in the last twelve months, and the growing capacity of these systems has the potential to begin to offset wind curtailment.
So, what does the data tell us about how far this is happening so far in 2024?
System-flagged actions, almost all directly linked to constraint management, accounted for half of Balancing Mechanism dispatch volume in 2024. The majority of this is Bids, with system-flagged Bid volume accounting for 30% of all Balancing Mechanism volume.
By contrast, just 6% of battery Balancing Mechanism volume is system-flagged - however, this has been growing in 2024.
Almost all of battery system-flagged volume comes from Bids. These are actions to turn down generation or increase demand when a constraint is active on a transmission boundary. System-flagged Offers are mostly for voltage or inertia control - actions batteries do not currently provide.
In this article, we focus on what is driving the use of batteries behind constraints in the Balancing Mechanism and how this differs by region.
Constraint management turn-down actions almost all happen in North Scotland
90% of Balancing Mechanism Bid dispatches to manage constraints in 2024 have occurred in Scotland. This is where wind generation is highest and where there is limited transmission capacity to flow this power south.