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.

This prototype, along with the SeaWater Greenhouse mentioned in my previous post on desalination, is important because the current desalination plants being built use massive amounts of electricity to desalinate seawater. This requires more power plants to be built, in turn, creating more air pollution, which creates more water pollution, which further limits our freshwater supply, which creates more of a need for freshwater, which spawns more desalination plants, which….you see where I’m going. My point is, if more smart solutions like the windmill at Delft and the Seawater Greenhouse, are utilized to address the groing need for freshwater, people find themselves in an environmental win-win; creating fresh, clean water while using little or no energy, and creating little or no pollution, in the process.

To the team at Drinking with the Wind, Dank je wel (thank you)!

Steps to use less water:

• Turn off the water while you wash your face/hands, brush your teeth, or do the dishes.
• Water your lawn in the early morning or early evening so as not to lose water to evaporation.
• Plant drought resistant plants on your property–they thrive on less water.
• Use a rain barrel to capture rainwater for use in watering your lawn and garden.
• Purchase low-flow showerheads.
• Replace a broken toilet with a low-flow toilet.
• Insulate your water heater so it takes less time (uses less water) to get hot water for a shower.

Image source: Delft University of Technology