The big impact of small PV in a remarkable year

There have been positive signs throughout the year, but now the data confirms it: 2023 may well be a record year for rooftop installations in Australia. Melbourne-based consultancy SunWiz reported its latest numbers in the first week of December, and they make for happy reading. But they are just the beginning of a year of remarkable results on the back of distributed PV.

Drawing on small-scale technology certificate (STC) data, SunWiz reports that 330MW of “small-scale” – meaning sub 100kW – rooftop solar systems were installed in November, squeaking past the previous monthly record of 314MW of installations achieved back in December 2020.

Source: SunWiz

The November 2023 tally is up 57MW, or 20%, on installations for October 2023, demonstrating a strong rally towards the end of this year. Speaking to RenewEconomy, Sunwiz’s Warwick Johnston said that he was particularly pleased to see installation rates return to normal after a short period of supply-chain disruption.

“This is the kind of record that has me dancing in the hallway,” Johnston told RenewEconomy.

The previous record-setting year for small-scale installations was 2021. Johnston noted that it will be “tight” for 2023 to top 2021, as December installation volumes can underwhelm. However, a number of sources are pointing to this year being a growth year for rooftop solar around the country.

PV system finance origination site Solar Nerds tracks STCs and it puts the 2023 rooftop installation data as creeping towards 3GW – representing growth of almost 12% over 2022. The site puts the monthly average increase from across the country at just below 250MW.

Source: Solar Nerds

On a state basis, NSW continues to be the dominant marketplace for rooftop solar, accounting for almost a third of installations and could surge past the 1GW mark – again, according to the Solar Nerds site. QLD and VIC take the second and third place in the state-tally, with a little over 25% and 20.5% respectively.

Being a long-term West Australian, I’m personally pleased to see WA go past the 250MW mark for annual rooftop installations, accounting for almost 8.6% of the national total, followed by SA with close to 8.5%.

Source: Solar Nerds

Records continue to tumble

Aside from 2023’s push to set a record for installations of rooftop solar in Australia, there have been a host of notable milestones driven by small-scale PV. And it’s hard to look past South Australia.

In spring, with bright sunny conditions and the mercury having not yet begun to rise above 30C, SA recorded record low electricity demand on three separate occasions. Paul McArdle from Global-Roam charted monitored the development and noted that “market demand” for electricity in the state tipped over into negative territory.

The record-low demand in SA was registered on Saturday Sept. 16, Saturday Sept. 23 and Sunday Oct. 1 – with no surprise that low demand occurred during the weekend, when demand falls from commercial and industrial businesses. Yet even as this OpenNEM chart shows, across the whole month of September, 83% of SA’s electricity demand was met with renewables – with the impact of solar most profound between 10am and 2pm.

Source: OpenNEM

And the major driver of electricity demand being pushed to below zero on more than one occasion? Almost entirely rooftop solar, in the bright (and not too hot) spring sunshine.

Speaking to RenewEconomy, Geoff Eldridge from GPE NEMLog said that the result is unparalleled not only in Australia, but anywhere in the world. He noted that rooftop PV supplied over 100% of SA’s electricity demand at certain points of each of the record-setting days.

What’s truly remarkable is that the SA network was able to sustain such high levels of rooftop solar production, without the grid crashing. The state is relatively weakly interconnected with neighbouring states, and the combination of supporting grid kit – namely synchronous condensers – and increasing amounts of energy storage allowed SA to ride through such high solar electricity saturation events, as observed by RenewEconomy.

It's also worth noting that it appears that rooftop solar systems weren’t remotely switched off by the network operator AEMO, despite the solar surge. McArdle on Watt Clarity reported that some PV householders, on the Whirlpool forum page, suspected that their systems were being remotely switched off. However, he investigated and found no official notifications from AEMO nor SA Power Networks of any such intervention. He concluded that it may have been a local network issue, rather than anything state-wide.

Following SA’s lead, NSW, VIC, and QLD all racked up record-low electricity market demand events throughout the spring, beginning as early as mid-August, and speaking to the powerful impact rooftop solar is having.

To round out this wrap of notable rooftop PV moments in 2023, it’s worth taking a closer look at another encouraging trend. In its analysis, SunWiz picked up that small-scale rooftop system sizes are increasing. Long gone at the days of 3kW solar roofs, with the November national average approaching 10kW.

Source: SunWiz

“The average system size for November 2023 grew to 9.92kW, courtesy of commercial growth outpacing residential growth,” said SunWiz in its report. But there’s also evidence that increasing Electric Vehicle (EV) uptake will cause homeowners to either increase the size of their home solar system when installing a new system or upgrading their existing PV.

It does appear that 2023 has been somewhat of a turning point for EV adoption by Australian drivers. In December, the Federal Chamber of Automotive Industries reported that EV sales had almost tripled doubled this year, from 28,326 in 2022 to 80,446 in 2023 – as reported in the Guardian Australia. The driver, pardon the pun, of the rapid acceleration in EV adoption is the increase in models being imported in Australia. Chinese car makers such as BYD have begun introducing sub-$50,000 models to rival Tesla, which remains the biggest EV supplier to the country. 

2023 has truly been a year for rooftop PV to truly shine and it’s exciting to see the powerful contribution being made by distributed solar right around the country. But that’s not to say there aren’t challenges ahead. We’ll address some of these, along with opportunities, in our next blog.