x Abu Dhabi, UAEThursday 18 January 2018

Greenhouses cooled by seawater to grow crops in the UAE desert

A seawater-cooled greenhouse project could help countries that rely on food imports, such as the UAE.

ABU DHABI // Scientists are working on a greenhouse project that could reduce the reliance on food imports for desert countries such as the UAE.

The Sahara Forest Project involves a seawater-cooled greenhouse in which crops can be grown throughout the year despite the harsh climates, said Virginia Corless, science and development manager for the project, which she presented at this week’s Global Forum for Innovations in Agriculture in Abu Dhabi.

A pilot greenhouse in Qatar produced a crop yield that rivalled greenhouses in cooler climes like Europe, despite “the most challenging condition you could ever put any evaporative system into,” Ms Corless said.

Though the greenhouse relies on evaporation, the heat and humidity didn’t halt growing operations at the Qatar facility, which opened in November 2012.

“The greenhouse was very successful. It grew straight through the summer with great success,” she said.

Based on the crop yields from the 1-hectare greenhouse, Ms Corless claims an 8-hectare facility could produce as many cucumbers as Qatar imports every year. A 60-acre facility could match the cucumber, tomato, aubergine and pepper imports.

The UAE relies heavily on food imports as, according to the Food and Agriculture Organisation, only 0.01 hectares of arable land or land with permanent crops are available per person.

As the world’s population rises, fertile land is growing more scarce because of desertification, with land in drier climates becoming more arid and less productive.

“How are we going to feed 9 billion people in a world of increasing water scarcity, increasing desertifcation and in a world where we have to reduce carbon emissions?” Ms Corless asked.

The system works by piping seawater into the greenhouse then evaporating it over honeycomb-shaped pads. Solar-powered fans blow desert air across the pads, evaporating the seawater and cooling the greenhouse air.

The structure is surrounded by hedgerows, that protect the greenhouse from the hot desert winds. The evaporation system is powered by solar panels.

So far, the team have grown 19 varieties of crops for food and other uses such as biofuel. Salicornia plants, which can be turned into biofuel for airplanes, grew particularly well in the greenhouse, Ms Corless said.

A follow-up project is now planned for Jordan.