This article written by:
Senior Account Manager
Contracts and Settlements
UK Transmission – Network Operations
National Grid House
Warwick Technology Park
Warwick CV34 6DA
National Grid is the National Electricity Transmission System Operator (NETSO) for England, Scotland, Wales and Offshore. Electricity cannot yet be stored on a large scale, and so one of our key roles as the NETSO is to balance the demand for electricity with supply on a second by second basis.
We do this partly through purchasing “Balancing Services”. Back-Up generation and/or load reduction has the ability to provide these services, potentially offering a further revenue stream for an existing asset.
More details on the suite of Balancing Services that back-up generation or load reduction might offer can be found on our website and specifically in a recent presentation given to a number of potential demand side providers. However the following summary offers an overview of the three main services.
Min Service Size
Max Notice Period before service delivered
Time limits around service delivery
Short Term Operating Reserve (STOR)
(smaller sites can be aggregated into a 3MW load)
Must be able to sustain delivery for minimum of 120min if required
£40,000 (per MW per year)
Must be able to sustain delivery for minimum of 15min if required
£50,000 (per MW per year)
Able to sustain up to 30min if required
£56,000 (per MW per year)
All of these services are procured through tender processes that National Grid runs several times each year.
The STOR service is the one in which we have seen by far the greatest involvement from the demand side (i.e. the customer / energy consumer side). As of December 2009, of 2369MW contracted to provide STOR, the demand side provides 839MW (35%) from 89 sites. Of this 839MW approximately 750MW is back-up generation, of which around 500MW is diesel generators – typically standby sets, with the secondary STOR function – with the remaining being load reduction services.
The above provides a flavour of the types of service back-up generators or load reduction can offer National Grid. Much more information regarding the services and tender information can be found on our website or by contacting Mark Duffield, Senior Account Manager at National Grid by email at firstname.lastname@example.org.
See Also -(Ed):
(Note also, it is variously estimated that there are about 20 – 100 GW of diesel generators that could be brought into this service in the UK at very low cost, since they are already bought and paid for. Clearly these will have a major contribution to meeting load balancing needs in the event of large scale introduction of intermittent renewable energy sources. – Ed.)