(Note: See also The remarkable energy transition in South Australia – could renewables head to 70 per cent within a decade)

South Australia will in the next week reinforce its position as the leading mainland state on renewable energy as the completion of a major new wind farm brings its wind and solar energy production to around 40 per cent of its total generation.

The $450 million Snowtown 2 wind project, which as we reported last month is due to open several months ahead of schedule, will add 270MW capacity and estimated output of 985GWh per year.

That, in combination with nearly 550MW of small scale solar PV on the state’s rooftops, will take the state to more than 40 per cent renewables over the year, one of the highest penetration of “variable” renewables in the developed world.

Right now, there is little base-load coal-fired capacity operating in the state given the mothballing and seasonal closure of its two brown coal generators. Only one of the Northern Power station’s generating units is operating during winter. (Tasmania, of course, is close to 100 per cent renewables but relies on mostly hydro resources)

Most of the turbines being built at Snowtown by New Zealand company TrustPower have already been completed and are feeding into the grid. The last 5 turbines are due to be completed in the next week, with the formal handover brought forward several months to September.

The addition of Snowtown – which will operate at a capacity factor of around 42 per cent – will take total wind capacity in the state to more than 1,500MW and total output of wind energy to more than 4,400GWh.

This is equivalent to 34-35 per cent of the state’s electricity demand, and rooftop solar accounts for another 5-6 per cent.

South Australia has one of the highest penetrations of rooftop solar PV, with nearly 550MW of rooftop systems installed over the past few years, giving it a penetration rate of more than 22 per cent.

The growth of wind and solar over the last five years has forced the two major coal fired power stations to be mothballed and closed for summer months. Contrary to doomsday’s, it has helped reduce the state’s wholesale power prices, and lower emissions dramatically. And, of course, it has attracted billions of dollars of investment and thousands of jobs.

The state seems certain to head to more than 50 per cent renewables by 2020 as the interconnector with neighbouring states is upgraded, and presuming that the Abbott government does not completely wreck the renewable energy target, as the coal-fired generators owners, Alinta Energy, amongst others, is urging it to do.

Alinta,in fact, wants the renewable energy target to be brought to an immediate halt, with no new generation – wind farms or rooftop solar – receiving any further subsidy.

This graph is drawn from their submission to the RET Review panel, highlighting the amount of wind generation that has been built in the state in recent years.