Solar energy storage

By Matthew Wright

Every week Suntech, the world’s biggest photovoltaic manufacturer, is pumping out hundreds of thousands of solar panels to power households and businesses across the globe. Dozens of other companies in China, Germany, Korea and elsewhere are doing the same.

The solar photovoltaic manufacturing industry is a prime example of renewable energy’s growing success story. In 2010, the world’s solar PV factories could produce in excess of 38 gigawatts of panels in just one year. By the end of 2011, that production capacity will have expanded to 50GW of solar panels (24GW will be installed).

CLIMATE SPECTATOR reports: About 1000 experts from the emerging solar thermal energy industry have gathered in Grenada, Spain, for the IEA-sponsored SolarPACES conference, with several dozen Australians also in attendance. Groups from the Australian Solar Institute, the ANU solar thermal research centre, the CSIRO, the ACT government and technology developers such as Transfield Novasol and Wizard are also in attendance.

Matthew Wright, the head of Beyond Zero Emissions, says two major themes seem to be emerging from discussions – one is a concession that solar PV has won the day in terms of costs of electricity generated, and the other is that the future of solar thermal lies in storage. These themes are being played out in the US, where non-storage thermal projects funded by government loan guarantees are being substituted by solar PV because of costs, but projects with storage are going ahead.

Originally Published in Engineers Australia Magazine - Power Engineering Section Page 58 Using molten salt to store solar energy could provide electricity 24 hours a day, equivalent to baseload supply, according to Matthew Wright, executive director of Melbourne based company Beyond Zero Emissions.

"There are plants in Spain operating with energy storage right now, providing electricity all night long," Wright said.  Molten salt storage uses common salts, such as potassium nitrate, which are readily available and non-toxic.  Using the sun's energy, these salts are heated to high temperatures and stored in insulated storage tanks.   When electricity is needed, the heat in the molten salt is used to create steam to drive a turbine.

According to the company, this sort of electricity is dispatchable, meaning it can be sent out on demand at any time of day, so it can replace the baseload electricity generated from burning fossil fuels.

"Solar thermal power with storage is proven technology, which will reliably provide the backbone of modern renewable electricity grids," Wright said.