What a battery can sell
What ancillary services can a battery sell in National Electricity Market (NEM)?
National Electricity Market (NEM) has 10 ancillary-service products, across 3 families — regulation, fast frequency response and other services: Delayed Lower FCAS, Delayed Raise FCAS, Fast Lower FCAS, Fast Raise FCAS, Regulating Lower Service, Regulating Raise Service, Slow Lower FCAS, Slow Raise FCAS, and 2 more. Response timing, direction and eligibility for each are in the cards below, as the official sources state them.
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.
Regulation
-
Regulating Lower Service LREG
operational
Support control of system frequency and accumulated time error for ordinary supply-demand variations within a trading interval.
- Direction
- lower generation; raise load
- Full activation
- 5 min
- Trigger / range
- AEMO AGC Lower Signals; not a fixed public frequency threshold.
- Eligibility
- AEMO-registered and enabled FCAS facilities meeting MASS, telemetry, control and minimum-offer requirements.
- Typical procurement
- Requirements vary by interval and region; no stable official typical range is prescribed.
MASS defines the offered quantity as response delivered progressively over the five-minute trading interval; AGC requests may change during that interval, so there is no separate fixed hold duration.
-
Regulating Raise Service RREG
operational
Support control of system frequency and accumulated time error for ordinary supply-demand variations within a trading interval.
- Direction
- raise generation; lower load
- Full activation
- 5 min
- Trigger / range
- AEMO AGC Raise Signals; not a fixed public frequency threshold.
- Eligibility
- AEMO-registered and enabled FCAS facilities meeting MASS, telemetry, control and minimum-offer requirements.
- Typical procurement
- Requirements vary by interval and region; no stable official typical range is prescribed.
MASS defines the offered quantity as response delivered progressively over the five-minute trading interval; AGC requests may change during that interval, so this is not a step-response guarantee and there is no separate fixed hold duration.
Fast frequency response
-
Very Fast Lower FCAS L1
operational
Arrest an over-frequency excursion in the first second after a contingency and transition to Fast Lower FCAS.
- Direction
- lower generation; raise load
- Full activation
- 1 s
- Trigger / range
- Enabled resource responds automatically when local frequency moves outside the normal operating frequency band; the MASS uses a verification ramp rather than one universal relay setting.
- Eligibility
- Registered FCAS facilities capable of automatic local-frequency response and MASS-compliant high-speed metering.
- Typical procurement
- Dynamic constraint requirements; no stable typical range.
Offer measurement uses response from disturbance time to 1 s and transition from 1 s to 6 s; no independent fixed hold duration is specified.
-
Very Fast Raise FCAS R1
operational
Arrest an under-frequency excursion in the first second after a contingency and transition to Fast Raise FCAS.
- Direction
- raise generation; lower load
- Full activation
- 1 s
- Trigger / range
- Enabled resource responds automatically when local frequency moves outside the normal operating frequency band; the MASS verifies against the applicable frequency ramp, not one universal relay setting.
- Eligibility
- Registered FCAS facilities capable of automatic local-frequency response and MASS-compliant high-speed metering.
- Typical procurement
- Dynamic constraint requirements; transition caps have changed over time and are not a typical volume.
Offer measurement uses response from disturbance time to 1 s and transition from 1 s to 6 s; no independent fixed hold duration is specified.
Other services
-
Delayed Lower FCAS L5
operational
Return frequency toward 50 Hz within five minutes and sustain response until central dispatch can rebalance the system.
- Direction
- lower generation; raise load
- Full activation
- 5 min
- Sustain
- at least 5 min
- Trigger / range
- Automatic local-frequency response after a contingency.
- Eligibility
- Registered MASS-compliant generation, storage or responsive load.
- Typical procurement
- Dynamic constraint requirements.
MASS offer calculation measures the delivered response over 1-5 min and again over 5-10 min; 300 s is the verification sustain window after full response.
-
Delayed Raise FCAS R5
operational
Return frequency toward 50 Hz within five minutes and sustain response until central dispatch can rebalance the system.
- Direction
- raise generation; lower load
- Full activation
- 5 min
- Sustain
- at least 5 min
- Trigger / range
- Automatic local-frequency response after a contingency.
- Eligibility
- Registered MASS-compliant generation, storage or responsive load.
- Typical procurement
- Dynamic constraint requirements.
MASS offer calculation measures the delivered response over 1-5 min and again over 5-10 min; 300 s is the verification sustain window after full response.
-
Fast Lower FCAS L6
operational
Arrest an over-frequency excursion within six seconds and transition to Slow Lower FCAS.
- Direction
- lower generation; raise load
- Full activation
- 6 s
- Trigger / range
- Automatic local-frequency response after a contingency; provider-specific droop or switching settings apply.
- Eligibility
- Registered MASS-compliant generation, storage, responsive load or aggregated facilities.
- Typical procurement
- Dynamic constraint requirements.
Measured over 1-6 s and 6-60 s transition windows; no separate fixed hold duration.
-
Fast Raise FCAS R6
operational
Arrest an under-frequency excursion within six seconds and transition to Slow Raise FCAS.
- Direction
- raise generation; lower load
- Full activation
- 6 s
- Trigger / range
- Automatic local-frequency response after a contingency; provider-specific droop or switching settings apply.
- Eligibility
- Registered MASS-compliant generation, storage, responsive load or aggregated facilities.
- Typical procurement
- Dynamic constraint requirements.
Measured over 1-6 s and 6-60 s transition windows; no separate fixed hold duration.
-
Slow Lower FCAS L60
operational
Stabilise over-frequency within 60 seconds and transition to Delayed Lower FCAS.
- Direction
- lower generation; raise load
- Full activation
- 60 s
- Trigger / range
- Automatic local-frequency response after a contingency.
- Eligibility
- Registered MASS-compliant generation, storage or responsive load.
- Typical procurement
- Dynamic constraint requirements.
Measured over 6-60 s and 60 s-5 min transition windows; no separate fixed hold duration.
-
Slow Raise FCAS R60
operational
Stabilise under-frequency within 60 seconds and transition to Delayed Raise FCAS.
- Direction
- raise generation; lower load
- Full activation
- 60 s
- Trigger / range
- Automatic local-frequency response after a contingency.
- Eligibility
- Registered MASS-compliant generation, storage or responsive load.
- Typical procurement
- Dynamic constraint requirements.
Measured over 6-60 s and 60 s-5 min transition windows; no separate fixed hold duration.