The State Government has announced its intention to retire Synergy’s Muja and Collie coal-fired power stations by 2030 as part of its energy transformation strategy. An estimated $3 billion will be invested by the State Government in new electricity infrastructure in the South West Interconnected System (SWIS), including wind generation and battery storage. 

This plan is projected to see Synergy’s carbon emissions reduce by 80 per cent (from 2021 levels) by 2030 and is a significant step towards achieving the State Government's long-term ambition of net zero emissions by 2050. The State Government has also committed to not commissioning any new natural gas-fired power stations in the SWIS after 2030.

Household and business regulated electricity tariffs are determined by the State Government each year as a part of the State Budget process.

The State Government has stated that without the decision to retire the power stations, over the next decade WA would either see major electricity price hikes or taxpayers would be forced to fund billions of dollars of subsidies to keep the system running.

The State Government has stated that the $3.8 billion investment in new renewable energy infrastructure is expected to pay for itself by 2030-31 relative to increasing electricity subsidies payable under the status quo.

The State Government has stated that maintaining electricity reliability is a priority. 

In WA, the Australian Energy Market Operator (AEMO) is responsible for managing the SWIS, ensuring there is sufficient generation to meet demand, as well as operating the wholesale electricity market.

Synergy is expanding renewable generation capacity and storage projects in the SWIS with a range of new projects including wind farms and BESS projects. The combination of BESS and wind farms contributes to network reliability by providing energy storage, grid stabilization, and a cleaner energy source. These technologies are essential components of a modern, resilient, and sustainable energy infrastructure.

Discover more about these new investments. 

Muja and Collie power stations are State Government-owned assets. The State Government’s intention to retire these assets is to ensure future reliability and affordability of electricity supply as part of the transition to a more renewable energy future. 

The continued uptake of rooftop solar and renewables across the State’s main electricity grid, the SWIS has reduced demand for electricity at certain times during the day. This means we need ways to quickly increase or decrease the amount of power supplied to reduce overloading or undersupplying the electricity grid. The cost of starting up and shutting down a coal-fired generator can range between $50,000 and $150,000 for each start-up and restart times are long, taking up to 24 hours. Because of this and other factors, generation from Muja and Collie is no longer able to compete economically with renewable generation technologies like solar and wind, where costs continue to fall.

Over the past few years, more renewable electricity generation such as wind farms, solar farms, and rooftop solar PV systems , have joined the grid. This has impacted the viability of traditional coal-fired power stations.

Retiring Synergy's coal generation enables the State Government to accelerate WA’s clean energy transition and support its commitment to reaching net zero emissions by 2050.

Generation from Muja and Collie is no longer able to compete economically with renewable generation technologies like solar and wind, where costs continue to fall.

The cost of starting up and shutting down a coal-fired generator can range between $50,000 and $150,000 for each start-up and restart times are long, taking up to 24 hours.

Whilst there is a significant cost to transitioning to renewable electricity generation and storage, the State Government has stated that the $3.8 billion investment in new renewable power infrastructure is expected to pay for itself by 2030-31 relative to increasing electricity subsidies payable under the status quo. 

The South West Interconnected System (SWIS) is Western Australia’s main electricity network, extending from Kalbarri in the north to Kalgoorlie in the east and Bremer Bay in the South, and serves more than 1.1 million households and businesses.

Within the SWIS, electricity demand has traditionally been met by a mix of generation sources including coal, gas, wind, and solar. 

In WA, the Australian Energy Market Operator (AEMO) is responsible for managing the SWIS and ensuring there is sufficient generation to meet demand as well as operating the wholesale electricity market. The State Government is reforming the Wholesale Electricity Market as part of its Energy Transformation Strategy, which aims to ensure the delivery of secure, reliable, sustainable and affordable electricity to Western Australians for years to come. 

While it is not a static picture, in the last 12 months coal represented approximately 27 per cent of the SWIS generation capacity mix, with renewable generation comprising approximately 33 per cent of installed capacity, with about half made up by residential rooftop solar.

Learn more about our electricity generation sources.

The electricity system is transforming as we explore renewable energy solutions for a more decarbonised energy future. We’re expanding renewable generation capacity in the SWIS with a range of new projects, including wind farms such as King Rocks Wind Farm and BESS projects such as KBESS1 and KBESS2.

Synergy plans to develop at least 410 megawatts (MW) of new renewable generation capacity and 4.4 gigawatt-hours (GWh) of energy storage infrastructure to help support WA's transition to more renewables. 

New wind assets will most likely be built in zones where the wind profile is best, subject to agreements with landowners and environmental approvals. Batteries are more likely to be located on Synergy land close to existing population centres and network infrastructure.

The State Government has considered the appropriate mix of technologies that can be deployed by 2030 at lowest cost. As hydrogen is an emerging technology, there is still significant analysis being undertaken. 

Synergy is investigating the feasibility of using hydrogen to power existing gas generation assets, and working with Water Corporation to assess the feasibility of a pumped hydro project to form part of the State’s energy system.

Synergy is proud to be Western Australia’s largest integrated electricity generator and energy retailer. Our purpose is clear – to lead Western Australians to their intelligent energy future. This intelligent energy future includes adopting environmentally sustainable practices across the business for future generations.

We have already reduced our carbon emissions by more than 50 per cent since 2005, but we know our customers want us to do more to produce cleaner and cost-efficient electricity. The State Government's announcement that it will retire Synergy's coal-fired power stations by 2030 is projected to reduce Synergy’s carbon emissions by 80 per cent (from 2021 levels) by 2030.

The retirement of Muja and Collie coal-fired power stations will be a significant step in progressing the decarbonisation of our business and supporting the achievement of the WA Government’s goal of net zero carbon emissions by 2050.