A deal between Origin Energy and French company GENIE will see the mothballed second 240MW gas generator at Pelican Point come back on stream by July.
ENGIE, which is also currently in the process of closing down the Hazelwood plant in Victoria, says it has signed a gas supply deal with Origin to revive generation at the unit which has been mothballed since the beginning of 2015.
The extra capacity is close to the 250MW the SA Government has announced as part of its new energy plan.
ENGIE says it will begin work immediately on upgrading the second unit, improving the efficiency of the turbine at a cost of $40 million.
Pelican Point was at the centre of controversy in February, when the SA Government attacked the national market operator for not turning on the generator to meet demand.
SA Premier Jay Weatherill backed the deal and said it would provide more energy security for the state.