This page will present the development stages. They are:
In order to fully understand the concept, lets have a look at the economics.
First of all, Sahara is a huge piece of land. The desert itself is app. 8.6 million km2, equivalent to app. 3.5 million square feet - covering areas in several countries - Mauritania, Western Sahara, Algeria, Libya, Egypt, Sudan, Chad, Niger and Mali, and touches Morocco and Tunisia. Obviously the land value is at present very low. By irrigating the land now being wasteland and turning it into grass, forest and farmland the value increases many folds. It has to be noted though, that Sahara raises from 400 to 1500 meters above sea level so that some areas can only be used as protection for the crops. In this consideration we are using 50% of the area as a basis, and calculate with 4.2 million km2
The calculations for the initial transport of water from the sea bottom to the area we suggested south of Agadir can be broken down as follows:
The cost of lifting water 5 meters at this massive volume is around 100 MWh, or in traditional energy consumption around £3 million a year. As we intend to use solar energy, the factual cost is as follows
For the ease of operation, the pumps will be leased, so the cost of maintenance will be part of the lease cost.
Desalination: The sea water is pumped into a pretty large factory (with 10,000 pumps the factory will cover at least 50 km2’s) where the salt is separated from the water. We intend to use the surplus salt as part of the energy production plant, and pump the concentrated seawater back into the ocean. The desalination plant cost is dependent upon the methods used.
How desalination works: Sydney Water presentation.
Other methods: To be considered.
Further transport: The cost of transporting the fresh water is depending upon the length of the pipes as well as the cost of drilling tunnels through the mountain range in combination with the energy cost of lifting the water the 500-1000 meters up. For simplicity causes we have calculated as such: 100 kilometers length with 5 meterŲ pipes and a lift of 1000 meters. The expected tunnel will be 10 kilometers.
As an energy benefit, the water will be guided through pipes to generators that will “save” us 50% of the energy cost of lifting the water to the tunnels.
We have used the D’Arcy-Weisbach formula as basis for the energy loss sending the water through pipes this way.
Stage one will be the plants in Tunisia: