SunWiz has released it Australian Battery Market Report for 2018. The report charts phenomenal growth in the residential storage segment: an expansion of 6,750 to 20,789 system installations from 2016 to 2017.
The leading state for installations in 2017 was NSW, accounting for 42% of installations, followed by Queensland (19%), Victoria (17%) and South Australia (11%).
The SunWiz figures far exceed official installation data, as collected by the Clean Energy Regulator. In January, the regulator reported that 3,763 residential storage systems were installed alongside solar PV in 2018. The CER figures are widely considered to capture only a fraction of the number of actual installations, as reporting by installers is on a voluntary basis.
Interestingly, the state-by-state shares of the residential market – as recorded by CER – are very similar to the SunWiz figures: NSW (43%), QLD (18%), Victoria (16%), and SA (11%).
IHS Markit analysis of the Australia’s residential storage market, shared with pv magazine Australia this month, has the CER data capturing between 40 – 50% of battery installations. The UK-based analysts believe between 7,000 – 8,000 units were installed in 2017.
The strong performance of SA is explained in the SunWiz report. Given high retail power prices in the state, SunWiz calculates average solar+storage ROI at 13.9% – representing a payback of around 7.2 years. As payback is dictated in part by tariff structure, SunWiz notes that the best solar+storage ROI in SA is 18.2%, or an impressive 5.5 years.
Western Australia’s poor showing is likely the result on continuing subsidized retail electricity rates, through its state-owned utility Synergy – as has been noted by local installers.
The number of solar arrays being installed with a battery is also rapidly growing, SunWiz finds. In 2016 5% of new residential arrays included a attery system, with that number increasing to 12% in 2017.
Financial returns are clearly not the motivating factor behind adding storage. The SunWiz analysis shows that in all states, the ROI of a residential solar system is far greater than when a battery is added.