Rule change approved to reduce UK battery skipping
Source：pv magazine
UK BESS assets are expected to benefit from a grid code change aimed at improving the use of energy storage within Great Britain’s balancing market.
Ofgem has approved changes to how assets trading in the balancing mechanism communicate their availability to grid operator NESO. In its letter authorizing the changes to GC0166, the energy regulator said the change “will enable a more level playing field” between technologies and should allow NESO to “dispatch [BESS] assets in a more efficient and economic manner and should reduce the number of ‘skips’ occurring.” The grid code amendment will come into force on Nov. 5, 2025.
The rule change introduces new protocols that alter the way BESS assets will communicate their energy availability to NESO in a bid to improve the grid operator’s visibility of the BESS fleet’s true capabilities.
Batteries trading in the balancing mechanism submit “bids” to charge or “offers” to discharge during a set period. The current protocol sees asset owners communicate their maximum charge and discharge power to NESO – their Maximum Import Limit (MIL) and Maximum Export Limit (MEL) – over a 30-minute settlement period.
This limits NESO’s visibility of the true volume of energy available in the BESS fleet and has contributed to skipping – meaning NESO accepts a more expensive bid or offer price than a BESS asset could have provided.
The update to the grid code adds three new parameters: Maximum Delivery Offer (MDO) and Maximum Delivery Bid (MDB) and Future State of Energy (FSoE). This lets NESO see the availability of energy storage over a longer time frame, which the grid operator expects will result in more efficient decision making.