Most areas which are highly suitable for solar power are located in the sun belt of the earth, near the equator. Incidentally, almost all areas which have high levels of sunlight exposure – 2,500 kWh to 2,800 kWh per square meter and year – also have very dry climates.
Only very few countries in Northern Africa and the Middle East, potentially excellent places for concentrating solar power applications with high local levels of solar irradiation, have natural freshwater supplies. Often the supply doesn’t even exceed the water poverty line of 1,000 cubic metres per person and year. In order to have enough freshwater available, natural reserves are overexploited beyond the point of replenishment.
In the mid- and long-term, only seawater desalination on an industrial scale will be able to counter-balance the ever growing water deficit.
Conventional industrial seawater desalination, as it is practiced in many countries, requires vast amounts of energy and is therefore very expensive when powered with fossil fuel.
Our Fresnel plant can accommodate CSP desalination on most any scale. Owing to the fact that CSP can guarantee a steady base load, the sun is perhaps the only renewable energy source which can be economically employed in desalination. The process used in large-scale CSP desalination is called solar thermal multi effect distillation (CSP/MED), which is a combined use of heat and power to produce freshwater.
According to various studies, even the most efficient water management and use will not suffice to counterbalance the water deficit in some countries, and CSP may very well be the only long-term alternative to prevent an already looming water crisis in many parts of the world.