Sunday, November 3, 2013

Solar Device Purifies Saltwater and Contaminated Water

If water covers about three-quarters of our planet, why do some 750 million people in 45 countries have little access to clean drinking water?

“About 97 percent of the world’s water is saltwater or polluted water,” explains the CEO of SunDwater, an Israeli company that is ready to market its solar-powered distiller to provide clean water for drinking and agriculture. 
The SunDwater unit converts contaminated, unsafe or saltwater into potable water without any need for infrastructure or an external energy source. 

The device was invented by a  couple of childhood friends patents were applied for in June 2011. Today there is a pre-market operational unit..

Mimicking nature

Here’s how the low-cost, low-maintenance system works: Saltwater or polluted water is pumped into the unit. The sun’s rays heat the water until it evaporates. The water vapor flows into a cylinder where it gets condensed back into freshwater, just like in the natural cycle of rainwater to clouds.

New water is constantly pumped back into the closed system as the water evaporates, so the device produces clean water at five times the rate of similar systems -- 400 liters (423 quarts) per day, or thousands of liters if multiple units are joined together as a water farm.

The basic premise is old as the hills. “You could go back 2,000 years and find sailors taking seawater and putting it in flat beds to let it heat and evaporate to separate from the salt,” says the CEO, Zimels. “But with the technology we’ve used until now, you’d need a very big footprint of space to get a small amount of water.”
The breakthrough was to make this process workable on a commercial level by concentrating the sunbeams on a four-square-meter (43-square-foot) round dish to make the water heat and evaporate quickly.

“There is no need for electricity,” Zimels emphasizes. “We are just using nature to improve nature itself, not creating new environmental problems.”

The device will be targeted to urban, rural and remote communities for basic fresh water needs.

Deslination not practical for spread-out populations

“Taking in account that the vast majority of the people in need reside in developing countries, our focus through the development process was to deliver a smart but very simple-to-operate and relatively cheap solution to assure that they are able to purchase and operate the units on their own,” Zimels says. 

Israel is not one of the target markets.

“Here we’ve built mega plants to desalinate enough seawater for our needs, but we are a small country,” Zimels points out. 

“For a country where people are more spread out, desalination plants won’t resolve the problem because they are too expensive to build and it’s too expensive to transport the desalinated water. Today these populations drill wells, or get transport of bottled water, or even use contaminated water despite the huge health risks. Our solution is efficient, green and easy to implement.”

A demonstration and research SunDwater unit is set up in an industrial park at Kfar Adumim, a sunny Judean Desert town not far from the Dead Sea. The distiller can convert the salty, mineral-rich water from the Dead Sea into a clean glass of drinking water within half an hour.

“The system is working very nicely,” Zimels reports. “In the last six to nine months we’ve had a lot of ideas of how to improve it, making it smaller and quicker. We want to build a much larger unit, about 20 square meters [215 square feet] to generate 5,000 liters per day Now we need capital to start building the whole supply chain, to train the communities in need how to operate the unit and to continue the development and improvement of our solution”

Customers in Madagascar, Nigeria and other African and Indian countries have expressed interest in the product. SunDwater is working with an Israeli water consultancy for rural areas, WaterWays, to implement the solution most efficiently for those potential buyers.

“We believe in the long run the unit could be manufactured in the country where it will be installed; we’d send somebody to install it and train the local operators,” says Zimels. “That offers an added financial advantage to those countries.”

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