South Australia has signed a deal to build a 150MW solar thermal power plant in the state with eight hours of molten salt energy storage.
The AUD650 million ($510m) Aurora Solar Energy Project, to be built and operated near the town of Port Augusta by US-based utility SolarReserve, is designed to supply all of the state government’s power needs, premier Jay Weatherill said.
The Aurora project follows July’s announcement that Tesla is to deliver the world’s largest lithium-ion battery in South Australia.
Construction of Aurora, modelled on SolarReserve’s Crescent Dunes facility in Nevada (pictured), will start next year and is scheduled for completion in 2020.
Weatherill said Aurora will be the world’s biggest such facility, offering 1,100MWh of energy storage capability – delivering 495GWh of power annually or 5% of the state’s overall energy needs.
Under normal operating conditions, the plant will have a net capacity of about 135MW, “with the ability to increase that output in favourable conditions, such as in the evening”, the premier said.
Peak government load is as high as 125MW but lower for most of the day and “far lower outside of business hours”, Weatherill said. “Throughout the day, whatever Aurora is producing in addition to the state government’s demand, can be sold into the market which will help other consumers.”
The agreement signed with SolarReserve was “the lowest-cost option” of shortlisted bids, Weatherill said. The government will pay an “expected levelised price” of AUD75/MWh and no more than AUD78/MWh.
SolarReserve said its concentrated solar power technology uses thousands of mirrors or heliostats to reflect and concentrate sunlight onto a central receiver on top of a tower. The process heats molten salt, pumped to the top of the tower and flowing through the receiver, to 565°C.
The company said molten salt provides a stored heat source, which is used to generate steam to drive a single turbine that generates electricity. The facility can generate power at full load for up to eight hours after sunset.
Energy minister Tom Koutsantonis said Aurora, in addition to the Tesla project, “will help to make our energy grid more secure”.