Fast reserve provides rapid and reliable delivery of active power through increasing output from generation or reducing consumption from demand sources. We use fast reserve, in addition to other energy balancing services, to control frequency changes that might arise from sudden, and sometimes unpredictable, changes in generation or demand.  

We do not procure Fast Reserve ahead of time, instead we secure our Fast Reserve product within day through the Optional Fast Reserve service.       

Providers are paid an availability fee (£/hour) if called upon to provide the service and a utilisation payment (£/MWh) if dispatched, based on the actual level of energy delivered in a given instruction.  

Further enquiries: 

Email: [email protected]

Technical requirements

The fast reserve service is open to both Balancing Mechanism (BM) and non-BM providers who can meet the technical requirements. This might include generators connected to the transmission and distribution networks, storage providers and aggregated demand side response. 

For fast reserve, providers must meet the following criteria: 

  • active power delivery must start within two minutes of the dispatch instruction; 
  • a delivery rate in excess of 25MW/minute; 
  • the reserve energy should be sustainable for a minimum of 15 minutes; and 
  • must be able to deliver minimum of 25MW. 

How will providers be dispatched? 

The fast reserve service is dispatched electronically. BM providers will be dispatched through the Balancing Mechanism, while non-BM providers will be instructed and metered through the Platform for Ancillary Services (PAS). 

Units providing optional fast reserve must declare themselves as available for the service and, if instructed to be ‘armed’, must be ready to receive instructions.  

New providers

Potential providers must complete Fast Reserve Registration (pre-qualification) as follows: 

  • Complete the pre-qualification assessment (link below)
  • Sign onto a framework agreement
  • Non-BM providers are required to have the necessary web-based solution in place (and tested) for communications with ESO via the Platform for Ancillary Services (PAS). Note: BM providers will use existing BM Grid Code EDL/EDT data

Download the assessment

Who can provide this service

The fast reserve service is open to both Balancing Mechanism (BM) and non-BM providers who can meet the technical requirements.

This might include generators connected to the transmission and distribution networks, storage providers and aggregated demand side response.

Service dispatch

When do providers need to be available to deliver this service?

The fast reserve service is required 24 hours a day, 7 days a week. However, there is a greater requirement for the service during the daytime, typically between 06:00-23:00. 

How often will providers be dispatched?

For fast reserve, utilisation can vary depending on system conditions, the demand profile and the generating plant on the system. However on average, providers are utilised for approximately five minutes at a time, ten times a day. The providers are still but are expected to have the capability to sustain reserve for 15 minutes.

Procurement

We do not procure Fast Reserve ahead of time, instead we secure our Fast Reserve product within day through the Optional Fast Reserve service.  

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