Sahara Forest Project Will Generate Fresh Water, Solar Power & Crops in African Desert

Last week, a trio of visionaries launched the Sahara Forest Project to combine two innovative technologies, concentrated solar power (CSP) and seawater greenhouses, to produce renewable energy, water and food in the Sahara -the hottest place on earth.

The Sahara Forest Project aims to provide a new source of fresh water, food and renewable energy in hot, arid regions, as well as providing conditions that enable re-vegetating areas of desert. The Sahara is used here as a metaphor for any desert that formerly supported vegetation and could do so again, given sufficient water.

The lack of fresh water is the root cause of much suffering and poverty. Present methods of supply in arid regions include; over-abstraction from ground reserves, diverting water from other regions and energyintensive desalination. None of these are sustainable in the long term and inequitable distribution leads to conflict. Climate change is tending to make dry areas drier and wet areas wetter. Since the 1980’s, rainfall has increased in several regions, while drying has been observed in the Sahel, the Mediterranean, southern Africa, Australia and parts of Asia.

The growth in demand for water and increasing shortages are two of the most predictable scenarios of the 21st century. Agriculture is a major pressure point. A shortage of water will also affect the carbon cycle as shrinking forests reduce the rate of carbon capture, and the regulating influence that trees and vegetation have on our climate will be disrupted, exacerbating the situation further. Fortunately, the world is not short of water, it is just in the wrong place and too salty. Converting seawater to fresh water in the right places offers the potential to solve all these problems.

The project combines two established technologies – the Seawater Greenhouse and
Concentrated Solar Power – to achieve highly efficient synergies. Both processes work optimally in sunny, arid conditions. Seawater Greenhouses have been built in some of the hottest regions on earth, Abu Dhabi and Oman for example, where they create freshwater from seawater, while providing cooler and more humid growing conditions, enabling the cultivation of crops all year round.

Concentrated solar power is increasingly seen as one of the most promising forms of renewable energy, producing electricity from sunlight at a fraction of the cost of photovoltaics. The process uses mirrors to concentrate sunlight to create heat which is used to drive conventional steam turbines to generate electricity. Less than 1% of the world’s deserts, if covered with concentrating solar power plants, could produce as much electricity as the world now uses. By combining these technologies there is huge commercial potential to restore forests and create a sustainable source of fresh water, food and energy.

Currently there are some 200,000 hectares of conventional greenhouses in Mediterranean region and this area has been growing at around 10% a year. Most of these, if not all, face water quality and availability issues and indeed many contribute to the depletion of ground water. By using greenhouses to create fresh water from seawater, the problem is reversed.

Posted by Jason McManus.

Adapted from: http://www.thefutureofscience.org/speaker/abstract/PatonCharlie.pdf