Short-term operating reserve (STOR)

At certain times of the day we may need access to sources of extra power to help manage actual demand on the system being greater than forecast or unforeseen generation unavailability.

We hold three competitive tenders each year for the STOR service. Providers submit their prices for availability and utilisation during these tenders. We consider the value and costs of each submitted tender, and compare these with the economic costs of procuring the same volume of reserve from alternative sources. In addition, we may also consider a number of other factors, including the historic reliability and geographical location of a unit or site.