We are becoming a separate company

In April 2019, the Electricity System Operator is becoming a separate company within the National Grid Group. Find out more about what this change will mean.

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 have issued an OCP (OCP-10) which looks to incorporate the requirements set out in P354 "Use of ABSVD for non-BM Balancing Services at the metered (MPAN) level” into the STOR SCTs.
The deadline for responses to this modified OCP is 5pm on 29th November.

November update to the STOR OCP. We are in position to proceed with implementing changes from the OCP, however before this next phase, we are concluding some analysis of the impact of EBGL to the proposed changes. We aim to provide an update by 30th November.
We have published a modified OCP which in addition to the proposals in the original OCP, published on 6th June 2018, includes simplified contract terms and requirements as part of the Demand Connection Code.
The deadline for responses to this modified OCP is 5pm on 30th August.
Responses provided to the initial OCP will be considered as part of this modified OCP.
An update on the implementation plans for OCP-9A and 9B will be provided in due course.

We have published documents on the new PAS project that we are developing to provide a new dispatch system for Non-BM STOR. These can be found under the Technical Requirements tab under the PAS Documents heading.

Where it is economic to do so, we will procure sources of extra power ahead of time through the STOR service. Providers of the service help to meet the reserve requirement either by providing additional generation or demand reduction.

The requirement for STOR varies depending on time of year, week and day.

Providing STOR

Both Balancing Mechanism (BM) and non-BM participants with a connection to either the electricity transmission or distribution network are able to provide STOR.

The service is open to any technology with the ability to increase generation or reduce demand by at least 3 MW.

Current STOR providers are located throughout Britain, although providers closer to high demand areas, including south east England and Wales, are more desirable.

Service dispatch

There are particular times of the day when the STOR service is more likely to be required. These are known as ‘availability windows’.

Providers are required to be available to operate at their contracted volume during these windows.

Availability windows

Typically, the service is used over two pre-defined windows:

  • morning window; and
  • evening peak window.

STOR may be required outside of these times.

STOR dispatch

BM providers will be dispatched through the Balancing Mechanism, while non-BM participants will be instructed and metered through STOR Dispatch (SRD PC). 

The installation of STOR dispatch is undertaken by external parties and takes six months to complete.