Balancing Services Overview

NG procures a range of balancing services in order to balance demand and supply:

-Ancillary Services.
-System Ancillary Services (Part 1) - mandatory services, Frequency Response, Reactive Power

- System Ancillary Services (Part 2) - Black start, Fast Start and System to Generator Operational Inter-tripping (Hinkley B)

-Commerical Ancillary Services - required from some generators and provided if agreement is reached, Fast Reserve (provides rapid and reliable delivery of active power through an increased output from generation or a reduction in consumption, following a despatch instruction from NG), Standing Reserve, BMSUS, Commerical Intertrips (HOTS).

- Offers and Bids made in the BM

Other Services include:

• Short Term Operating Reserve (STOR) - a service for the provision of additional active power from generation and/or demand reduction.
• Capped Output - NG may contract a provider to cap the level of generation at a station during a period of export constraint
• Minimum Output - a generator must ensure that their output is above an agreed level for a period of import constraint.
• Minimum Output - a generator must ensure that their output is above an agreed level for a period of import constraint.
• Option contract - NG may consider entering into an Option Contract for either Capped or Minimum Output. Referred to as Special Action in EDFE.
• Maximum Generation (MaxGen) - a service that allows access to capacity which is outside of the Generator's normal operating range in emergency circumstances.
• Trading - NG may trade energy related products (in advance of the BM)

The table below summarises which stations provide each type of balancing service:

• Unplanned or unforseen events - e.g. weather, breakdowns
• Demand Control
• NRAPM
• Black Start
• MaxGen 
• Unplanned outages to the electronic communication systems.

Reserve is held to ensure that NG can manager foreseeable deviations from the intentions of generators/supplies.

Reserve is split up into 4 categories:

• Contingency - essentially BMSUS which ensure BMU's are available in the shorter term. Day ahead to gate closure
• Regulating - covers for short term deviations (post gate closure)
• Standing - covers post gate closure losses and is short run plant (<20 mins) which can be started at short notice
• Fast - a subset of the standing and regulating reserve. Required to ensure frequency remains within operational limits. Generally BMU's with short delivery fast response (2-5mins)