Friday, 24 October 2008
A prophecy waiting in the wings?
In the desert regions of the world there is the potential to grow food and supply enough power for the entire world, impossible? Well actually no, because there are two projects already in progress showing just how that can be done.
Desertec, see here, concentrates sunlight, solar power, (CSP) via mirrors onto steam turbines to drive generators, as in a conventional power station, the bottom image shows how little area would be required to supply the world, the smaller squares show the corresponding areas for the EU and the Middle East and North Africa. The middle image shows a solar collector panel, this is not pie-in-the-sky technology as there are already similar plants in the US and Spain, see here and here.
As for growing food in the desert the same clean CSP technology would pump seawater into the greenhouses in the top image where it would desalinate in solar collectors, leaving the salt behind and so allowing the now clean water to be used in cultivation. Interestingly enough for the overnight storage of heat to enable electricity production when the sun is down, then large saline (salt) filled tanks are needed.
In the words of Michael Pawlyn, who worked on the Eden Project for seven years and is now part of the Sahara Forest team, (see here) "Both technologies work extremely well in hot, dry, desert locations. CSP produces a lot of waste heat and we'd be able to use that to evaporate more seawater from the greenhouse. CSP needs a supply of clean, de-mineralised water in order for the [electricity generating] turbines to function and to keep the mirrors at peak output. It just so happens the Seawater Greenhouse produces large quantities of this."
In the words of Isaiah C35 v1&2
The desert and the parched land will be glad; the wilderness will rejoice and blossom. Like the crocus, it will burst into bloom; it will rejoice greatly and shout for joy...
That day certainly can't come too soon for me!
Posted by Rev. Peter Doodes at 04:54