The big surge in small scale rooftop solar installations over the past year continues to reshape the Australian grid, eating away at demand for coal in Queensland and capping grid demand across the country.
The latest Quarterly Dynamics Report issued by the Australian Energy Market Operator notes that average generation from small scale rooftop solar installations (less than 100kW) rose by 21 per cent across the National Electricity Market over the last 12 months, with Victoria and South Australia both recording increases of 32 per cent.
The average daily peak generation of small-scale solar PV in the third quarter of 2018 also increased by 21 per cent over the same quarter a year ago - from 2,714MW to 3,285MW (+21%).
It coincides with a record year of installation across the country, with the total already reach 1.25GW to the end of October and the Clean Energy Regulator expecting this could reach 1.6GW for the year. That would be a 45 per cent increase over the 2017 total of 1.1GW.
“One element was consistent across all NEM regions – the impact of small-scale PV in reducing operational demand in the middle of the day,” the report notes.
“Increased small-scale generation has the effect of offsetting consumption, thereby lowering the overall grid demand for electricity. This is a trend that has been increasing over time as the level of installed small-scale PV capacity continues to rise.”
It notes that South Australia's quarterly minimum demand record was broken and equalled the all-time record low. This occurred on September 30, when operational demand reached 661MW, 132MW lower than the previous Q3 record of 793 MW.
“Drivers of this new record included increased uptake of small-scale PV in South Australia as well as reductions in industrial load. (problems at BHP's Olympic Dam).
The depressing effect on wholesale prices also had its impact in Queensland, where coal output was reduced as price sensitive coal generators such as Tarong and Stanwell reduced their generation. This is despite an overall increase in available capacity from the state's fleet of coal generators.