Rooftop Solar Cells in Australia to Outperform Demand

[Fuzz]

'Staggering' rise of rooftop solar to put all other power generation in the shade, report finds

https://www.abc.net.au/news/2024-02-21/rooftop-solar-cells-in-australia-to-outperform-demand/103489806

 

Solar panels are a standard part of new home builds in many parts of Australia.(ABC News: Briana Shepherd)

• In short: The capacity of rooftop solar will soon exceed that of coal, gas and hydro combined in Australia's main grid, a green energy report finds.
• There is already almost 20GW of rooftop solar in Australia, but this is forecast to more than triple in coming decades.
• What's next: The report's authors argue rooftop solar will play an outsized role in helping Australia meet its climate goals.

The capacity of rooftop solar in Australia will eclipse the country's entire electricity demand in coming decades, according to a report that charts the technology's "staggering" rise.

Almost 20 gigawatts of small-scale solar has already been installed across Australia's biggest electricity system, but a report from Green Energy Markets predicts this will more than triple by 2054, even by conservative assumptions.

The firm said the rapid increase in the number of photovoltaic cells across the roofs of Australian homes and factories would be a key plank in government efforts to decarbonise the economy.

In a report due out today authors Tristan Edis and Ric Brazzale say the capacity of rooftop solar will far overshadow the amount of large-scale conventional generation currently installed in the national electricity market (NEM).

The national electricity market services about 10 million customers across Queensland, New South Wales, Victoria, South Australia and Tasmania.

"These are staggering levels of capacity," the authors wrote.

"They go well beyond the levels of installed capacity in the NEM we have now for coal, gas and hydro power plants combined of [about 41GW], and also well above typical historical daily averages in electricity demand."

In a growing number of Australian suburbs a majority of homes have solar panels.(Supplied: Project Symphony)

Solar a runaway freight train?

According to Green Energy Markets, combined rooftop solar capacity will rise to 66GW over the next three decades, even under the most pessimistic scenario.

In scenarios where governments took more aggressive action on carbon pricing and incentives for green technology, the forecast uptake would reach almost 100GW over the same period.

By comparison, the total capacity of the NEM was about 55GW.

"For many, such a large amount of rooftop solar capacity seems to stretch the boundaries of credibility," the authors said.

"Why would we install more rooftop solar capacity than typical total electricity demand across not just residential customers, but every sector of the economy?"

Despite the forecast surge in capacity, the report's authors qualified their conclusions by pointing out that solar panels only produced energy during daylight hours.

Moreover, they said there was already so much rooftop solar in the system that it was driving spot electricity prices into negative territory – where generators pay to stay online – for significant amounts of time.

But the authors argued that a number of things were driving and would continue to drive the take up of solar panels in Australia.

For starters, they noted solar panels typically lasted up to 20 years, meaning their capacity steadily accumulated.

On top of this, consumers were increasingly buying bigger systems, with the average installation rising from about two kilowatts in size in 2011 to eight kilowatts in 2023.

The rooftop solar industry in Australia is expected to need thousands of extra workers.(Reuters: Tim Wimborne)

Demand growth 'with a catch'

The authors also said that falling prices for solar exports meant households faced little financial risk from "curtailment", which involves the market operator switching off their systems during periods of peak production.

The authors said poles-and-wires companies had also demonstrated an ability to accommodate ever growing amounts of capacity despite warnings of "solar traffic jams".

"Already five million Australians live in postcodes where 50 per cent or more of households have a solar system," they said.

"Postcodes with a combined population of around 750,000 have 70 per cent of households or more with a solar system."

Underpinning the forecasts was an expectation that batteries would become much cheaper.

Green Energy Markets said the widespread adoption of batteries would enable the surge in rooftop solar capacity.

It said this would allow customers to take better advantage of their own generation and help to keep the electricity stable.

Green Energy Markets also predicted batteries prices would fall and said the mass-manufacture of the technology by the likes of car-makers would help drive down costs.

"The key caveat to this finding, though, is that it is heavily contingent on an assumption that home battery storage systems will decline dramatically in price over the next decade and become a standard part of a new solar system install," the authors said.

 

I've had solar on my house since 2009, upgraded from a 5.4kw to a 13.7kw array at the end of 2022, and recently added two Tesla Powerwall 2 solar batteries. After the array upgrade and despite generating a lot more electricity, I was still paying for electricity, though at a reduced cost. Night time usage was just too high, and not offset by daytime production. My ROI calculations estimated I'd have paid off the new array in 8-10 yrs. Now that I have the two Powerwalls, I haven't paid a single electricity bill, and in fact, have been getting credits on my account. Even on the days I drain the battery and use grid power, what I generate and return to the grid offsets my usage. I estimate the whole system will now pay for itself in 7-8 years (also taking into account the increasing cost per kw for grid energy).

For a long time, I was the only house on my street with solar. Heck, I'm also the only house with CCTV and fiber to the premises broadband. Now my neighbour has added a system, though smaller than mine. Considering the much lower cost of solar panels than when I first installed my array in 2009, I'm surprised it is not something new home builders are installing upfront. Once solar batteries become cheaper and more prevalent, the demand for grid based electricity is going to fall dramatically for residential customers. Industry though, especially manufacturing, will still need reliable grid power. Renewables like wind and solar at the moment cannot handle those mega users (eg aluminium smelters), unless they are right next to a hydro-electric plant.