Western Australia’s biggest electricity system will need to roughly triple in size over the next 20 years, as the state seeks to wean itself off fossil fuels and go green.
In a landmark report released today, the West Australian government outlined the massive scale of building that would be required to replace coal-fired power stations and meet surging demand from customers — particularly industry — electrifying their operations.
The state's energy minister, Bill Johnston, revealed an extra 4,000 kilometres of new high-voltage transmission lines would need to be built by 2042 under the government’s central plans.
Within the same time frame, Mr Johnston said peak demand for electricity from the state’s main grid — the South West Interconnected System (SWIS) — would treble to about 13,000 megawatts.
Ten times more power needed
The minister also revealed the amount of generation capacity in the system would need to jump by a factor of 10, to account for rocketing demand and the intermittent nature of wind and solar power.
Despite the monumental scale of the flagged expansion, Mr Johnston said just $126 million would be initially set aside to help “kickstart early network planning”.
Mr Johnston said the report, titled the SWIS Demand Assessment, would be the blueprint to guide the overhaul of Western Australia’s biggest grid, which covers Perth and much of the state’s southern half.
“The SWIS Demand Assessment provides a vision of what the future grid might look like as industry seeks to decarbonise,” Mr Johnston said.
“An expanded grid is the most cost-efficient way of supporting decarbonisation as it can reach further for wind and solar.
“The SWIS cannot rely on other electricity systems to support it, so having a strong transmission backbone is critical for reliable supply.”
Cost of plans unclear
Under the plans outlined by Mr Johnston, several new high-voltage transmission lines would need to be built to connect renewable energy zones, particularly in windy and sunny areas north of current SWIS footprint.
However, Mr Johnston said how much the upgrades would cost and how they would be paid for — and by whom — were still open questions.
The minister acknowledged that big industrial users, such as mineral processors and manufacturers, would ideally help pay for the work.
He noted it was these customers who would drive much of the extra demand on the grid by using electricity — rather than fossil fuels such as gas — to power their operations.
According to Mr Johnston, it would be unfair to spread the costs of the required upgrades on to household and business customers who contributed much less to the increase in demand.
While anticipating a massive increase in the amount of renewable energy, Mr Johnston argued gas would continue to play a key role in keeping the system stable.
But he insisted this would not derail efforts to decarbonise the West Australian economy, noting electrification of gas-heavy industrial processes would have a much bigger effect.
'Transition plan does not work': Opposition
Speaking after the announcement, Shadow Energy spokesman Steve Thomas said today's report was embarrassing for the government.
"This document demonstrates that their transition plan does not work," he said.
"It's not costed, it's not funded, and it can't deliver the transition that government is talking about, and this document actually reinforces that."
Dr Thomas said he expected the total cost of the state's transition away from coal to be closer to $15 billion – with the 4,000 kilometres of new transmission infrastructure accounting for about $8 billion of that.
"You'd think with the biggest surpluses, the greatest boom in our history, if you were going to transition the electricity system you might have the money to do it, but the government has not invested anything like the amount of money necessary," he said.
"They've got the time frame wrong, they've got the infrastructure requirements wrong, they've got the budget wrong, there's not much they've actually got right on the transition to renewable energy and at this stage it will not work."
The ability to cope with the loss of generation that closing coal by 2029 would have was another significant issue, according to Dr Thomas, as well as finding the people and resources to drive the transition in a globally-competitive market.
