Flexible Certified Reserve Capacity
The 2025 Reserve Capacity Cycle introduced a new capacity product as part of the Reserve Capacity Mechanism review. Market Participants can apply for Flexible Certified Reserve Capacity with the aim to incentivise capacity that can start, stop, ramp up and ramp down quickly.
The need for Flexible Capacity is driven by the magnitude, slope, and duration of the ramp up from mid-day minimum demand to the evening peak required to manage the increasing penetration of renewable energy on the SWIS.
Facilities that can meet the minimum eligibility requirements will be assigned Flexible Certified Reserve Capacity based on the maximum output they can achieve within four hours from a cold state, with the quantity of Flexible Certified Reserve Capacity capped at the level of Peak Certified Reserve Capacity. It is important to note that it is not possible to be assigned Flexible Certified Reserve Capacity without receiving Peak Certified Reserve Capacity.
All technology types are potentially eligible for Flexible Capacity, with different minimum eligibility requirements for each technology type. Facilities in the Non-Scheduled Facility (NSF) class are not eligible to receive Flexible Certified Reserve Capacity under clause 4.11.1(bH) of the Electricity System and Market (ESM) Rules.
Flexible Capacity providers eligible for the Floating Flexible Reserve Price, under clause 4.29.1F of the ESM Rules, will be paid an additional amount for their Flexible Capacity Credits (when the Flexible Reserve Capacity Price is higher than the Peak Reserve Capacity Price) to incentivise investment in technologies that meet these requirements.
Under clause 1.63.10 of the ESM Rules, given the Peak Reserve Capacity Price was higher than the Flexible Reserve Capacity Price for the 2025 Reserve Capacity Cycle, all Flexible Capacity obligations have been waived for the 2027-28 Capacity Year.
Please contact the WA Capacity Investment & Assessment team at [email protected] with any queries.
Current Minimum Eligibility Requirements
| Requirement | Non-Intermittent Generating System | Intermittent Generating System | Electric Storage Resource | Demand Side Programme |
|---|---|---|---|---|
| The maximum allowed minimum stable loading level expressed as a percentage of nameplate capacity | 46% | 46% | N/A | N/A |
| The minimum allowed ramp up rate expressed as a percentage of nameplate capacity per minute | 3% | 3% | 3% | 3% |
| The minimum allowed ramp down rate expressed as a percentage of nameplate capacity per minute | 3% | 3% | 3% | 3% |
| The maximum time (in minutes) allowed between receiving a Dispatch Instruction when in a particular state and operating in a specific way | 30 | 5 | N/A | 5 |
| Capable from switching from charging to discharging (and vice versa) in a single Dispatch Interval | N/A | N/A | Y | N/A |
| Fast Start Facility | Y | N/A | N/A | N/A |
Determination of Minimum Eligibility Requirements for the 2026 Reserve Capacity Cycle
On 21 October 2025, AEMO determined the minimum eligibility requirements set for the 2025 Reserve Capacity Cycle will be retained. The WEM Procedure: Minimum Eligibility Requirements for Flexible Certified Reserve Capacity details the factors that AEMO will consider when reviewing the Minimum Eligibility Requirements.
AEMO’s assessment of the factors for the 2026 Reserve Capacity Cycle is as follows:
| Factors for AEMO to consider | AEMO’s assessment |
|---|---|
| (a) a change to the Benchmark Flexible Technology1; | On 30 September 2025, EPWA redetermined the Benchmark Technology2, and maintained the technology as a lithium battery energy storage system. This determination does not impact the minimum eligibility requirements for Flexible Capacity. |
| (b) a change to the technical parameters of the Benchmark Flexible Technology determined under clause 4.16.12(b); |
On 30 September 2025, EPWA redetermined the Benchmark Technology. The previous technical parameters were:
|
| (c) a change to the Performance Requirements for any relevant Frequency Co-Optimised Essential System Service as defined in the WEM Procedure: Frequency Co-Optimised Essential System Services Accreditation; | There are no planned changes to the Performance Requirements in the WEM Procedure. |
| (d) a material change to the forecast Four-Hour Demand Increase published in the most recent Statement of Opportunities Report; | N/A (first forecast Four-Hour Demand Increase published in 2025) |
| (e) the highest Four-Hour Demand Increase from the previous Cold Season; | Four-Hour Demand Increase is expected to be 1,918 MW in 2025, being an increase of only 10 MW from 2024. As such, there is no material impact. |
| (f) whether the existing fleet of Facilities assigned Flexible Capacity Credits is expected to meet the Flexible Reserve Capacity Target published in the most recent Statement of Opportunities Report for the relevant Reserve Capacity Cycle; and | No shortfall is projected at this time. |
| (g) any other factors AEMO considers relevant. | No other factors identified. |
2 As of 1 January 2026, the term Benchmark Technology will replace the term Benchmark Capacity Provider, in accordance with clause 4.16.9 of the Tranche 9: Proposed ESM Amending Rules.
The ESM Rules do not require AEMO to consult with Market Participants where AEMO does not propose changes to the last published eligibility requirements (clause 4.10.1A(c)).
Determination of Minimum Eligibility Requirements for the 2025 Reserve Capacity Cycle
AEMO determined the inaugural minimum eligibility requirements following consultation with Market Participants. Documents relating to AEMO’s review and the consultation are available at:
AEMO’s determination is available here: