Rooftop solar slumps in April, but PV system sizes just keep getting bigger

Rooftop solar growth across Australia hit a 12 month low in April, according to new data from PV analysts SunWiz, with total installations for the month slumping 23 per cent compared to March numbers.

The SunWiz monthly update on PV systems installed by homes and businesses reports that a total of 208MW was registered in April – 61MW down on what was registered in March and the the lowest figure observed within the last 12 months.

SunWiz managing director Warwick Johnston says that after two months of consecutive growth in February and March, the loss of momentum in April is most likely due to the backlog of small-scale technology cerificates (STCs) waiting to clear up.

School holidays and the Easter break might also have contributed to less activity in the sector.

The good news, however, is that despite the April stats dipping well below the 12-month straight-line trend, the trend for rooftop solar growth is still on the up and up, Johnston says. The Clean Energy Regulator predicted last week that annual sales could top 3GW.

“The market year-to-date figures are 21% ahead of the volumes seen at the same time last year … but are below those seen over 2020 and 2021,” Johnston says.

“The monthly pattern for 2023 looks identical to 2022 (just shifted up higher).”

For April 2023, SunWiz reports that all states observed a large decrease in rooftop solar volumes, most notably New South Wales, Queensland and Victoria, which fell by 21%, 23% and 23% respectively.

“These major states contributed the most to the ~23% month-on-month national decrease,” Johnston says.

All rooftop solar segment volumes have also dropped substantially over the past month, with the largest month-to-month drop seen in the sub-15kW residential market – down 25%.

Other segments also decreased, but not to that extent, the report shows.

Average system sizes also stayed on an upward trajectory, growing for the second month in a row to 9.18kW (+0.24kW M-o-M).