Charlie Paton had the idea to use the sun to distill water in arid zones while on honeymoon on a bus in Morocco. His aim was to provide a low-cost means of farming crops in dry areas close to the coast.
In 1995 with colleagues he built a greenhouse in Tenerife, the water for which was entirely supplied by distilled seawater. Besides providing a good crop yield, the distillation produced more than enough water thus allowing some to be sold locally.
The project was held up for four years after an application for an EU grant stalled. “I believe we didn’t get all our funding because they considered that European farmers would face competition from arid countries if our project succeeded.”
A Design Sense Award for best practice in sustainable design, and a £40,000 cheque, restarted the project, leading to the building of greenhouses in Abu Dhabi and Oman. Solar distillation techniques are also being developed to extract nutrients from the sea.
In Australia, a project valued at AUS $1.48 million is expected to have an annual production of about 1,000 tons of vegetables per year.
The Sahara Forest is the most ambitious of current projects. Users who use Flash can see details here.
Update 2012/2/28: The Sahara Forest Project and Seawater Greenhouse to part ways
Seawater Greenhouse - main site
Science and Innovation - Charlie Paton - The Guardian
Growing veges in the desert - Adelaide Now
Seawater crop ready in October - The Transcontinental Port Augusta