Source : https://www.abc.net.au/news/2020-10-12/future-of-wa-energy-system-half-coal-power-plants-shut-by-2025/12750068
More than half of Western Australia's remaining coal-fired electricity capacity could be phased out within five years, according to a landmark report which charts the extraordinary rise of renewable energy.
Energy Minister Bill Johnston will today release a 20-year blueprint for WA's biggest electricity system, which has been grappling with one of the highest rates of solar uptake in the world.
The blueprint, known as the whole-of-system plan, finds that between 520MW and 890MW of the state's coal-fired power capacity faces economic closure by 2025 as demand for renewable energy hollows out the market.
While the Government has already announced it will shutter Muja C's two units in 2022 and 2024, removing 392MW from the system, the report flags extra capacity may need to exit.
Two units at Muja power station are already due to close by 2024.(ABC News: Tom Edwards)The report does not specify which of the remaining coal-fired plants would be closed, but it is understood the 340MW Collie power station would be the most likely to go.
This is despite the fact Collie is the newest coal plant in state-owned electricity provider Synergy's fleet, having been commissioned in 1999.
There is currently 1569MW of coal plant in the grid.
Renewables to be built in WA's south
The report also predicts no major transmission lines would need to be built in the next two decades, that most new power plants would be renewable sources — such as wind — and that those new projects would be built south of Perth.
According to the report, renewable energy makes up about one third of the capacity on the South West Interconnected System (SWIS) — a figure projected to rise to almost 80 per cent within 20 years.
Despite the findings, the report suggests there could be a case for a new gas-fired power station if demand for electricity rose significantly.In these high-demand scenarios, the plan also said more of WA's coal-fired power capacity would stay online for longer.
Renewables must not compromise grid: Minister
Development of the blueprint follows warnings from the body that runs the market — the Australian Energy Market Operator (AEMO) — that the power system could become unstable as early as 2022 as the amount of renewable energy threatened to overwhelm demand. At the core of AEMO's concerns was the way in which vast quantities of rooftop solar power flooded uncontrolled on to the system during the middle of the day, often forcing out other generators such as gas and coal-fired plants.
AEMO said while the solar panels supplied emissions-free energy, it was the conventional generators that provided the "firming" services which helped to keep the grid stable. "The cost of starting up and shutting down a coal-fired generator can range between $50,000 and $150,000 for each start-up," the whole-of-system plan noted.
"Restart times are long, taking up to 24 hours."Mr Johnston said no one doubted renewable energy would become the mainstay of the grid, but he argued it was vital the switch away from traditional sources did not compromise the security of the system. "What it predicts is that renewable energy will become increasingly important to our system and therefore we have to make the changes to accommodate that," Mr Johnston said.
"In all the scenarios … renewable energy will become far more important in the future.
"This plan shows that with the right investments the South West system can be completely reliable with very, very high levels of renewable energy."
System needs to adapt: Energy specialist
The Minister also said the plan showed little investment was needed in WA's network of poles and wires — provided new sources of renewable energy were built south of Perth where there was spare transmission capacity.
Matthew Bowen, a partner at law firm Jackson McDonald specialising in energy, said coal was no longer able to compete with solar and wind on economic grounds as the costs of new technologies fell.
Furthermore, he said the gap between the two would only grow wider in time, especially if a price on carbon was introduced. However, Mr Bowen said coal still played a crucial role in keeping the electricity system stable and the plan was badly needed to help with the transition to when batteries and other technologies could do the job. "Our electricity system is a single integrated machine stretching from Geraldton to Albany," Mr Bowen said.
"And at the moment, we're trying to not only run that machine but modify the motors that drive it without a single, integrated plan as to how to do that. "To maintain a reliable power system so the lights come on when we throw the switch, we really need to adapt the way the system is run, we need to adapt the way it's regulated and we need to make sure people are investing in the right sorts of infrastructure to keep the system reliable."
Mining union welcomes clarity
Construction, Forestry, Mining and Energy Union (CFMEU) state secretary Greg Busson said coal workers would welcome any plan that provided greater certainty. Mr Busson said many of the workers and their families in the town of Collie, where the state's coal industry is based, were in limbo as they waited for guidance on when the industry would be wound down. He said the union accepted the Government could not save every job but it was keen to see support in the form of retraining opportunities and incentives for new industry in Collie. "What people are chasing, especially in the power industry and the coal industry in Collie, is certainty, a bit more information and realising there is a plan and people are looking for their future," Mr Busson said.
A former coal miner himself, Mr Busson said Collie had dealt with adversity before and would prove just as resilient again. "You can either sit back and do nothing and then you'll have a future that's forced on you," he said. "I'm of the opinion that we're in a perfect position to actually dictate and structure our own future going forward if we decide to take that up."And I'm sure Collie is up for that challenge."