What a battery can sell
What ancillary services can a battery sell in Great Britain electricity market?
Great Britain electricity market has 10 ancillary-service products, across 3 families — fast frequency response, operating reserve and other services: Balancing Reserve, Dynamic Containment, Dynamic Moderation, Dynamic Regulation, Fast Reserve, Mandatory Frequency Response, Quick Reserve, Slow Reserve, and 2 more. Response timing, direction and eligibility for each are in the cards below, as the official sources state them. Fast Reserve and Short Term Operating Reserve have ended; the cards below give each status in full.
Facts below are stated as the official sources state them. A missing line means the
source does not state that value — never that the value is zero.
Fast frequency response
-
Dynamic Containment
operational
Rapidly contain frequency after a fault at the edge of the operational range.
- Direction
- high-frequency and low-frequency services procured separately
- Full activation
- 1 s
- Sustain
- up to 15 min
- Trigger / range
- dynamic response curve around 50 Hz; service-specific technical envelope
- Eligibility
- NESO prequalification and performance monitoring
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- pay-as-clear availability
-
Dynamic Moderation
operational
Rapidly correct sudden frequency deviations before they become large containment events.
- Direction
- high-frequency and low-frequency services procured separately
- Full activation
- 1 s
- Sustain
- up to 30 min
- Trigger / range
- dynamic response curve inside the operational range
- Eligibility
- NESO prequalification and performance monitoring
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- pay-as-clear availability
-
Dynamic Regulation
operational
Continuously regulate small frequency deviations around 50 Hz.
- Direction
- high-frequency and low-frequency services procured separately
- Full activation
- 10 s
- Sustain
- up to 1 h
- Trigger / range
- continuous response around nominal frequency
- Eligibility
- NESO prequalification and performance monitoring
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- pay-as-clear availability
Operating reserve
-
Balancing Reserve
operational
Hold additional headroom/footroom to manage forecast uncertainty close to real time.
- Direction
- positive and negative procured separately
- Full activation
- 10 min
- Sustain
- at least 60 s
- Trigger / range
- NESO Balancing Mechanism instruction
- Eligibility
- prequalified Balancing Mechanism units meeting ramping and availability requirements
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- pay-as-clear availability
-
Fast Reserve
operational legacy service in 2025; ceased 17 April 2026 and was replaced by Quick Reserve
Rapidly increase or decrease active power to control frequency changes and balance the system.
- Direction
- positive and negative
- Full activation
- 2 min
- Sustain
- at least 15 min
- Trigger / range
- NESO instruction
- Eligibility
- prequalified providers meeting ramp and delivery requirements
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- contracted
Legacy contract variants can differ; verify any asset-specific obligation against its contract.
-
Quick Reserve
operational; phase 1 began 19 November 2024 and phase 2 first non-BM auction was 2 September 2025
Restore energy balance rapidly after a deviation and reduce reliance on slower reserve.
- Direction
- positive and negative procured separately
- Full activation
- 60 s
- Trigger / range
- NESO dispatch instruction
- Eligibility
- prequalified Balancing Mechanism units and, from phase 2, eligible non-BM units
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- pay-as-clear availability; utilization through applicable dispatch/settlement route
The five-minute figure constrains the provider's minimum activation period; it is not a maximum delivery duration.
-
Slow Reserve
approved/developed but not operational during 2025; launched 1 April 2026
Recover the system after a large event using slower reserve and replace legacy STOR arrangements.
- Direction
- positive and negative procured separately
- Full activation
- 15 min
- Trigger / range
- NESO instruction
- Eligibility
- minimum 1 MW and service prequalification
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- service-specific auction
This product was not operational in 2025; it is shown here because it explains the 2025 product transition.
-
Short Term Operating Reserve
operational in 2025; service ended 1 April 2026
Provide additional active power or demand reduction when actual demand exceeds available synchronized supply.
- Direction
- upward generation or demand reduction
- Full activation
- 20 min
- Sustain
- at least 2 h
- Trigger / range
- NESO instruction
- Eligibility
- minimum 3 MW capability, individually or aggregated, meeting response and duration requirements
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- availability and utilization prices
This is not a current product after April 2026; it is shown for 2025 context.
Other services
-
Mandatory Frequency Response
operational
Grid-code frequency response from obligated large generators and other contracted providers.
- Direction
- bundled upward and downward/high-frequency response
- Expected within
- 10 seconds
- Trigger / range
- frequency-deviation response curve set through Grid Code/service requirements
- Eligibility
- Grid Code obligated units and accepted providers
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- provider holding-price submissions and NESO dispatch
MFR contains multiple response profiles, so one duration would be misleading.
-
Static Firm Frequency Response
operational legacy product
Deliver low-frequency response after a defined frequency event.
- Direction
- low-frequency/upward response
- Full activation
- 30 s
- Sustain
- up to 30 min
- Trigger / range
- contracted low-frequency trigger
- Eligibility
- prequalified service providers
- Typical procurement
- Dynamic or not publicly stated
- Pricing
- contracted availability
Procurement arrangements can change as dynamic services replace legacy products.