On the 14th August a Generation Project Agreement (GPA) between SolarReserve, leading global developer of utility-scale solar power projects, and the State Government of South Australia. What is the goal? The construction of the world’s largest single-tower solar thermal power plant. The plant will also store energy in molten salt. It will make possible to generate electricity from renewable source 24 hours a day. The plant will be realized 30 kilometers far from the city of Port Augusta.
Construction on the plant will begin in 2018. Currently, SolarReserve states that the Aurora Solar Energy Project will be operating by 2020. Let’s analyze the main features of this plant, which will become one of the major renewable energy project for South Australia
The nominal size of the Aurora Solar Energy Project is 150 MW, more than the 110 MW’s production of Crescent Dunes in Nevada. The plant will incorporate a thermal energy storage system, using molted salt. This will increase of 8 hours the electrical daily production of the plant. The energy production will be equivalent to the energy demand of nearly 90000 houses. The annual production is estimated to 500 GWh, nearly the 5% of the eletrical demand of South Australia.
Using the “green” electricity produced by the Aurora Solar Energy, 200000 tonnes of CO2 will be displaced each year. Moreover, the Aurora project would also create more than 4000 jobs in South Australia.
The CSP technology
The Aurora Solar Energy Project will use the CSP Technology (Concentrating Solar Power) in order to produce electricity. The process is very simple and it’s explained in the video below by SolarReserve.
The concentrating part of the plant is made by arrays of tracking mirror called heliostats (as the one in figure). These particular mirrors are used to reflect concentrate sunlight toward a predetermined target. The heliostats are tracking which means that they can be controlled and moved on two axis in order to “follow” the sun during the day. All the rays of sun will be concentrate in one point on the top of a 200 m tower, where the receiver is. The solar energy is given to a thermovector fluid (molten salt) that flows into the receiver. The thermal energy is then given to water in order to produce electricity using a Rankine cycle. The cold molten salt mixture flows again in the cycle.
The thermal storage is made by two tanks to store the molten salt. The cold tank is maintained at 288° (more than the solidification temperature of the mixture); the hot tank is maintained at 566° (less than the evaporation temperature). This technology allows the facility to produce electricity 24/7.
Not only CSP for South Australia…
The Aurora Solar Energy Project isn’t the only renewable project for South Australia. Last July, the Government has decided to commission Tesla to realize the biggest storage system of the world. The plant will be at the service of the Hornsdale wind farm.