Balancing Mechanism utilization for battery energy storage fell in May, the first drop since November 2023, with the in-merit dispatch rate of batteries reducing to 9.6%. This measures how much the control room used batteries when priced competitively. It is similar to a skip rate but takes dispatched volumes into account.
In this article, we explain how the in-merit dispatch rate is calculated and why it can move in different directions for Bids and Offers.
The in-merit dispatch rate is a measure of battery utilization in the Balancing Mechanism. It is calculated as the total dispatched battery volume divided by battery availability priced cheaper than the most expensive balancing action in that half-hour.
In-merit dispatch rates shift towards Offers in May
The overall in-merit dispatch rate for batteries fell from 11.0% in April to 9.6% in May, and dispatch volumes of Bids and Offers for batteries both fell by 12%. But when viewed separately between Bids and Offers, May saw an increase in the in-merit dispatch rate for Offers.
The in-merit dispatch rate for Offers increased from 8.9% in April to 11.1%, while the Bid in-merit dispatch rate fell from 10.6% to 8.0%.