Rooftop solar and home batteries could reduce the need for wind farms, research finds

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12 hours ago

At first blush, Suzanne Bradshaw and Greg Ash could be your typical household power consumers.
They live in a house they built six years ago on a battleaxe block in the inner Perth suburb of Mount Lawley.
Like so many households, theirs is one that increasingly relies on electricity — from the gadgets under their roof to the solar panels on top of it.
But look a little closer and a different picture emerges.
In a workshop attached to the house are a number of kilns — electric furnaces used by Ash to make glass.
"I've been working on glass, this type of glass, for 23 years now," the 72-year-old says.
"So they [the kilns] can consume a fair bit of power."
Given their power needs, the couple have had to take steps to mitigate their exposure to the grid — and its associated costs.
They were early adopters of solar power, forking out more than $20,000 for panels when the technology was still relatively expensive.
In 2019, when they moved into their new house, they installed an even bigger system and followed it up with a battery a couple of years later.
And to round it out, they have signed up for a type of dynamic pricing known as a time-of-use tariff, enabling them to draw dirt cheap power off the grid between 9am and 3pm every day.
It costs them about nine cents for every kilowatt hour they buy from their retailer during those hours — but up to 45 cents per kilowatt hour at other times.
"The good thing about that is if it's an overcast day and you're not getting as much solar coming in, you can top up your battery during the middle of the day," Bradshaw says.
"That also means we're not using electricity during the peak… that other consumers need."
The couple's circumstances are increasingly common among Australian consumers.
Australia has long led the world in its adoption of rooftop solar and Western Australia is no exception.
There are more than four million small-scale solar installations across the country's homes and businesses — equivalent to about one in three customers.
It's a similar figure in WA, where about 400,000 small-scale customers have solar.
And now, courtesy of generous subsidies led by the Commonwealth, uptake of batteries is booming, too.
For the first time, registrations for batteries under the Federal Government's small-scale green energy scheme exceeded those for solar panels in July.
A new report commissioned by the office of Brad Pettitt, the leader of the WA Greens, is urging the Cook Government to go much further.
The report, written by green power advocates Sustainable Energy Now, suggests WA has barely scratched the surface of its rooftop solar capacity.
It says "only 13 per cent of the potential capacity" for rooftop solar has been realised in WA's main grid, which spans the country's south-western corner.
And it notes that of those customers who have solar, fewer than one in 20 have a battery as well.
The lobby argues that better capitalising on WA's capacity for small-scale solar power and batteries could dramatically cut the need for large-scale projects required as part of the transition away from fossil fuels.
"Fully utilising suitable rooftops" could slash the need for wind and solar farms while halving the requirement for new high-voltage power lines and saving billions, it argues.
Crucially, it says small-scale solutions will also be much quicker than large-scale ones, a key advantage given the government's plan to get out of coal power by 2029.
Pettitt says the state's current plan, which relies on large-scale projects, is off track.
"The fastest and fairest way to decarbonise is actually utilising our rooftops," Pettitt says.
"There are savings in the billions around needing less transmission.
"We're saying 'let's get smart about this, using existing rooftops, we don't need to clear vegetation, we don't need to put in new transmission, we can do it now and we can do it quickly'."
Not everyone supports the proposal.
Greg Watkinson, the former chief executive of WA's economic watchdog and a director of Electricity Market Advisory Services, says there are risks for consumers in the plan.
He says there are significant costs incurred by households and small businesses when they invest in solar panels and batteries and many can over-capitalise.
By contrast, he says there are economies of scale when big businesses invest in large-scale projects such as major batteries and wind farms.
What's more, he says those big businesses are sophisticated investors "who know what they're doing and it's their money to burn — if they waste it, it's on them".
"The risk is that households end up spending too much," Watkinson says.
"If we ended up having solar panels on everyone's roofs, maybe we'd be spending too much.
"I expect we would be, so I don't think that's the way to go."
WA Energy Minister Amber-Jade Sanderson declined a request for an interview.
Instead, she issued a statement in which she said the government "recognises the importance of harnessing our vast rooftop solar resource".
The Minister noted the government is helping up to 100,000 households to get batteries through its — albeit watered down — subsidy scheme.
Glass artist Greg Ash thinks he's ahead of the game now he's got a battery along with his solar panels.
"All you have to do is look at what's happening in the eastern states as opposed to here," Ash says.
"We're better off with our power and gas than they are, but it will come back and bite us here, so people should be looking at solar and battery.
"And hopefully that will get cheaper for the average person."