Successfully growing crops in the desert using salt water and solar power.

Successfully growing crops in the desert using salt water and solar power.

The heart of the SFP concept is a specially designed greenhouse. At one end, salt water is trickled over a gridlike curtain so that the prevailing wind blows the resulting cool, moist air over the plants inside. This cooling effect allowed the Qatar facility to grow three crops per year, even in the scorching summer. At the other end of the greenhouse is a network of pipes with cold seawater running through them. Some of the moisture in the air condenses on the pipes and is collected, providing a source of fresh water.

One of the surprising side effects of such a seawater greenhouse, seen during early experiments, is that cool moist air leaking out of it encourages other plants to grow spontaneously outside. The Qatar plant took advantage of that effect to grow crops around the greenhouse, including barley and salad rocket (arugula), as well as useful desert plants. The pilot plant accentuated this exterior cooling with more “evaporative hedges” that reduced air temperatures by up to 10°C. “It was surprising how little encouragement the external crops needed,” says SFP chief Joakim Hauge.

The technology development here is wonderful, but it is unclear from the article whether these crops would be competitive on the open market with ordinary farm crops. The cost for this operation is not outlined.