Reserve services
At certain times of the day, we need access to sources of extra power in the form of either increased generation or demand reduction. This enables us to manage a greater than forecast electricity demand on Britain's transmission system. These additional power sources available to us are called 'reserve services.'
Different sources need different timescales in order to be ready to deliver the required service. In this section, we list reserve services according to their timescales (shortest timescales first):
Balancing Reserve
We utilise a product called 'Regulating Reserve' to correct energy imbalances (differences between generation and demand) on the the GB power system.
BM start up
The BM start up service gives us on-the-day access to additional generation. Balancing Mechanism (BM) participants who expect to be unavailable within BM timescales of 89 minutes.
Fast reserve
Fast reserve provides rapid and reliable delivery of active power through increasing output from generation or reducing consumption from demand sources.
Short term operating reserve (STOR)
Short term operating reserve (STOR) is a service that provides additional active power from generation or demand reduction.
Super SEL
The ability for synchronous generation to reduce their minimum generation level (SEL) in times of low demand on the system.
Slow reserve
Slow Reserve, separated into Negative Slow Reserve (NSR) and Positive Slow Reserve (PSR).
Quick reserve
Quick Reserve, separated into Negative Quick Reserve (NQR) and Positive Quick Reserve (PQR), is aimed primarily for reacting to pre-fault disturbances to restore the energy imbalance quickly.
Future reserve services
A smart, flexible system that makes the best use of all the energy resources available will enable us to meet our customers’ needs in a balanced, efficient and economical way.