Balancing Reserve

Balancing Reserve went live as a new ancillary service in March 2024. Batteries participate in both the positive and negative reserve service.

For more information on batteries doing Balancing Reserve, see here.

How we model Balancing Reserve

Balancing Reserve is included in the dispatch model as a new ancillary service with the following parameters:

• Throughput = 0 (it's a service that pays for availability, not utilization)
• Positive reserve (leading to availability for offers in the BM) is given 90% of the total volume as the negative service has much smaller volume requirements
• The service is (already) saturated, and we assume the same level of saturation as in Frequency Response services
• When providing negative Balancing Reserve, the battery’s headroom needs to be greater than or equal to the contracted volume (MW), and vice versa for positive Balancing Reserve and footroom.
• We also require headroom or footroom to be sufficient to allow a continuous response time at the contracted MW capacity for at least 30 mins. This is a constraint on MWh.

We also allow stacking with other frequency response services, as is permitted in the service rules:

• When providing positive Balancing Reserve (leading to offers or discharging the battery), you can only stack with high-frequency services (which lead to discharging).
• Vice versa for negative Balancing Reserve and low frequency response services.

Assumptions on price are given here.