Turning water into wine is a great idea, but how about turning wind into water? I have always loved windmills. Their graceful form and natural motion have always fascinated me. However, I know that many people also hate the sight of them as yet another of man’s intrusion upon a beautiful landscape. However, now that a new era of limited fuel supplies is upon us, harnessing the wind to provide a cheap and sustainable source of fuel to feed our unending desire for electricity seems much more attractive.
A drive to a Canarian village near my home, Pozo Izquierdo, near Vecindario, will provide a physics lesson that is not easily forgotten. Not only is it a great place for a good walk with the dog and some fresh air, but you will be in the centre of a wind farm that not only produces electricity from the wind, but also any excess electricity produced is used to desalinate water from the seawater that surrounds this island paradise.
Saving water, one of the island’s scarcest resources due to the lack of rain, has led to extensive research in the desalination of seawater and using wind power to operate small desalination plants. The islands are not short of wind power – the Trade Winds, with their moderate speed and direction, are constant throughout the year. This technology and ideas have since been exported to many other parts of the world.
One of the main objections to wind farms has always been that they produce a varying amount of electricity. This variability of supply in the electricity grid means that there must be other power generators, such as gas fired units, that can come ‘on line’ at short notice – in order to avoid wide fluctuations of power and your television or washing machine blowing up. Keeping these generators ‘at the ready’ is an expensive use of resources and is often the quoted reason for not using wind powered generators.
Now this is the clever part. The desalination of water is an expensive process and requires a lot of electricity. However, scientists found that the wind generation of electricity and the process of desalination of water can work together successfully for the simple reason that electricity cannot be cheaply stored, but water can. Using surplus electricity from wind farms such as the one in Pozo Izquierdo to desalinate seawater is the ideal solution. When there is a falling amount of surplus electricity, the number of desalination units operating is reduced. The water produced when the wind farms are in full production can then be stored relatively cheaply until required. Clever stuff, eh?
© Barrie Mahoney
From the 'Letters from the Atlantic' series by Barrie Mahoney
Living the Dream: ISBN 978-0992767198