This report presents an independent review of market outcomes from Western Australia’s Wholesale Electricity Market (WEM) in Q1 2025.
Download the full report (PDF, 3.4 MB)
The material contained in the review is based entirely on publicly available data and is intended to complement the data and insights published by AEMO and other WEM stakeholders.
Some highlights from Q1 2025:
A hot summer and new records
A new record peak operational demand of 4,486 MW was set at 6:30pm on 20 January 2025, breaking the previous record of 4,233 MW set last year on 18 February 2024.
- Temperatures reached over 43°C on 20 January 2025, followed by a string of 3 days above 38°C where peak demand hovered around 4,000 MW.
- The extreme late January weather led to pole-top fires, fuse trips and bushfires that left up to 38,000 homes without power.
Big batteries provide more competition in the FCESS markets
The following new facilities underwent commissioning in Q4 2024:
Since December 2024, Collie BESS1 (COLLIE_ESR1) has been participating in the Frequency Co-optimised Essential System Services (FCESS) markets. In Q1 2025, the two BESS providing FCESS (COLLIE_ESR1 and KWINANA_ESR1) captured a material share of the market:
| FCESS Market | BESS Market Share (%) |
| Contingency Lower | 48.72% |
| Contingency Raise | 23.39% |
| Regulation Lower | 56.77% |
| Regulation Raise | 39.06% |
However, the market cost impact is unclear as the FCESS Cost Review Amendments rule change also took effect on 20 November 2024, which also put downward pressure on FCESS costs:
Download the full report (PDF, 3.4 MB), which includes the following additional information:
- System demand duration curves and monthly time-of-day averages
- Generation mix
- Volume-weighted energy prices
- Average time-of-day Essential System Services prices and cleared quantities
- Total WEM spot market costs
- Facility level metrics (duration curves, time-of-day averages, capacity factors, spot revenues and average energy capture prices) for the following selected facilities:
- Bluewaters BW1-G2
- Collie G1
- Muja G7
- Kwinana GT2
- Newgen Kwinana CCG1
- Kwinana Swift GT1
- Alinta Pinjarra U1
- Kwinana ESR1 (KBESS1)
- Kwinana ESR2 (KBESS2)
- Collie ESR1
- Collgar Wind Farm
- Merredin Solar Farm
- Warradarge Wind Farm
- Yandin Wind Farm