Home: Renewable Energy News: Friday 13 March, 2009

Renewable Energy News

FRIDAY 13 MARCH, 2009 |

Solar Powered Desalination For South Australia

The future of clean, potable water for Australia generally looks very grim and desalination plants are being built to cope with increased demand coupled with the effects of what seems to be an never-ending drought.

A major challenge for desalination plants is electricity consumption - and in creating that electricity, huge amounts of water are required at the power generation source. This is an area where solar power can again come to the rescue.

Acquasol 1,' currently under construction by Adelaide based Acquasol Infrastructure Ltd., is a concentrated solar power desalination plant located outside Port Augusta, South Australia that will create drinking water for the city of 15,000.

Acquasol 1 utilises parabolic trough concentrating solar power, combined cycle gas turbines, multi-effects desalination and solar salt harvesting - what the company states to be near to a 'closed loop' process.

In multi-effects distillation, sea water is boiled under pressure and then the vapour is recondensed to produce fresh water. As concentrating solar power can create temperatures of 400 - 1,000+ degrees Celsius, it's well suited to desalination purposes.

Unlike the mains powered Port Stanvac plant near Adelaide that will use the energy intensive reverse osmosis method and discharge the saline waste product directly back in the ocean - which has alarmed some environmentalists - the Acquasol 1 project will direct waste brine from the desalination process into land-based holding ponds. After evaporation by the sun, a commercially viable salt product will be all that remains, which can then be sold to create additional revenue.

While historically an expensive way to create fresh water, increasing costs are making desalination technology more competitive. According to the company, research carried out for the Western Australian government in 2004 estimated that desalinated water will become cheaper to source than groundwater in some parts of that state as early as 2020, with other states perhaps not too far behind.