"Energy Oases" to Green the World's Deserts?

Algae Ponds

Image courtesy Sahara Forest Project

Lowly algae, usually bad news for ecosystems, are actually a boon for biofuels: Lab-grown algae can generate up to 30 times more oil per acre than other plants used to make the sustainable fuel, according to the National Renewable Energy Laboratory.

Farming algae doesn't take up valuable agricultural land, and the resulting product can be easily exported, according to the Bellona Foundation's Hauge.

The Sahara Forest Project's photobioreactors (pictured in an illustration) would cultivate algae through photosynthesis in open, shallow saltwater pools. The plants' fatty oils could then be harvested as energy-rich biofuel.

January 22, 2010

Seawater Greenhouse

Image courtesy Sahara Forest Project

So-called seawater greenhouses (pictured) are basic and cheap, making them a cornerstone of the Sahara Forest Project.

In the above diagram, air going into a greenhouse is cooled and humidified by seawater. This humid air nourishes crops growing inside the greenhouse, then passes through an evaporator, where sun-heated seawater flows. When the now warm, humid air meets a series of tubes containing cool seawater, fresh water condenses on the outside of the tubes as droplets that can be collected.

Only 10 to 15 percent of the humid air gets condensed into fresh water. The rest flows outside to water surrounding trees, so that the "greenhouse will create a large area around it that will be become green," Hauge said.

January 22, 2010

Concentrated Solar Power Farm

Image courtesy Sahara Forest Project

Concentrated solar power will create efficient, clean energy for the Sahara Forest Project. A solar tower (pictured, right) uses mirrors to focus light on water pipes and boilers. The concentrated light creates superheated steam inside the pipes that can power conventional steam turbines, generating electricity.

Hauge said he has gotten "fantastic response" about the project from some governments, and—based on the success of the research center—he hopes to build the first full-scale facility within the next couple years.

January 22, 2010