With rising reviewable energy, over half of the left coal-fired electricity capacity of Western Australia could phase out within 5 years.

Bill Johnston, the Energy Minister will launch a 20-year blueprint for WA's biggest electricity system, which was contending with one of the world’s highest rates of solar uptake.

The blueprint is known to be the whole-of-system plan, projected that between 520MW and 890MW of the coal-fired power capacity of the state might witness economic closure by 2025 as the renewable energy’s demand hollows out the market.

The government has already proclaimed that it will close the two units in Muja C in 2022 and 2024, releasing 392MW from the system, the reports state that additional capacity may need to exit.

It is not specified which coal-fired plants will be closed, but most likely the 340MW Collie power station would go, even though Collie is the newest coal plant in Synergy's fleet, state-owned electricity provider, having been commissioned in 1999.

It is not required to build major transmission lines in the next two decades as the newest power plants might be renewable sources like wind and these projects will be built in the south of Perth. 

Renewable energy makes around one-third of capacity on the South West Interconnected System (SWIS), which is expected to rise by 80% in 20 years, according to the reports.

In these scenarios, the plans also stated that most of WA's coal-fired power capacity might stay online for a longer time.

The blueprint’s development follows warnings from the Australian Energy Market Operator (AEMO), the body that runs the market. It states that the power system might become unstable by 2022 as the amount of renewable energy is endangered to overpower demand.

AEMO stated that while supplying emission-free energy, the solar panels were conventional generators that provided the firming services which supported the grids to be stable.

The whole-of-system plan noted that the starting up and shutting down the cost of the coal-field generator might range from $50,000 to $150,000, for each start-up with restart times taking longer than 24 hours.

Source: https://www.abc.net.au/news/2020-10-12/future-of-wa-energy-system-half-coal-power-plants-shut-by-2025/12750068