Rooftop solar now accounts for 2.6% of Australia demand

Rooftop solar – once amounting to a handful of installations on the households of true believers or determined off-gridders as recently as a decade ago – now accounts for 2.6 per cent of Australia’s total electricity demand, or nearly 10 per cent of household electricity use.

According to Hugh Saddler, energy analyst with Canberra-based consultants Pitt & Sherry, small solar systems supplied 5 terrawatt hours (TWh) of electricity in the year to April, 2016 – out of a total of 185.9TWh.

This means that the total share of renewable energy is 16.4 per cent, although most official data put this at 13.1 per cent because that includes only “large-scale” renewables “sent out” in the National Electricity Market.

The highest share of “new” renewable energy electricity – from wind and solar – was recorded in South Australia. Wind and solar accounted for around 41 per cent of total local generation in 2014/15, a figure that is expected to rise above 50 per cent later this year.

However, Saddler said that when electricity through the interconnectors with Victoria is included – and much of this is brown coal – the renewable share in NEM generation supplied to South Australia is 29.5 per cent, and the total share available to consumers is 35.3 per cent.

Small-scale solar accounts for most of this difference, supplying 5.6 per cent of total electricity in the year to April, 2016.

Saddler notes that most estimates put the current share of “behind the meter” consumption – the output from rooftop solar which is consumed within households or businesses without ever being exported back into the grid – at below 50 per cent.

The volume of exports from residential solar installations is largely a legacy of the diverse array of feed-in tariff schemes introduced by state governments in past years.

“The general expectation is that, as these arrangements come to an end and, particularly, as larger installations on commercial buildings account for a growing share of new solar installations, behind the meter consumption will account for a steadily growing share of total small scale solar generation,” Saddler says.