Salt: Gone with the Wind — The Traditional Windmill Tries its Hand at Desalination
As populations grow and the amount of clean, fresh water decreases, we are increasingly motivated to find new ways of creating/capturing and using fresh water. Of course, we could all begin by using less water (see footnote). According to the United Nations Development Program in a chart I found on www.data360.org, as of 2006, the average American uses approximately 151 gallons of water/day. That includes, drinking, showering, flushing, cleaning, cooking, irrigating, etc. I propose that if we were each given 25 gallons of water to use per day we’d be OK. But, water isn’t dropped off at your doorstep by the water man, so we are not inclined to think much about our consumption (until something drastic occurs, like the droughts the Atlanta area faced this past summer). Then, how can people get more of what they are all using way too much of without drawing from other overused freshwater sources? An increasingly viable option is to take the salt out of the ocean’s roughly 315 million trillion gallons of saltwater. I posted last month on a low-energy solar desalination plant, so it’d be neglectful of me not to point out this no energy windmill desalination system as well.
In the Netherlands, at the Delft University of Technology, a traditional windmill is being tested to drive seawater through a reverse-osmosis membrane, thus directly producing freshwater from seawater. On their website, www.drinkingwiththewind.nl they share the following:
On the basis of the windmill’s capacity at varying wind speeds, it is estimated that it will produce 5 to 10 m3 (1,321-2,642 U.S. gallons) of fresh water per day: enough drinking water for a small village of 500 inhabitants. A water reservoir will have to ensure that enough water is available for a calm period lasting up to five days.
