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Conjuring water out of air

03/10/2010

  • Energy efficiency,
  • Technology,
  • Water
  • Netherlands
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Innovator Dutch Rainmaker has married wind-turbine technology with water production and purification expertise to create a sustainable method for extracting water from air.

The idea of collecting water from air is not new. However, Friesland-based Dutch Rainmaker was attracted to the idea of harnessing wind power to extract water vapour from air. The company has spent the last two years refining a technique – which they claim is unique - for harvesting water without using external energy supplies.

Dutch Rainmaker’s innovative approach was highlighted by the European Committee of Environmental Technology Suppliers Associations (EUCETSA), at the 5th European Forum on Eco-innovation. The project has also been endorsed by Ashok Bhalotra, architect of Heerhugowaard’s City of the Sun – the world’s largest CO2 -neutral residential area.

“Energy is needed to produce water out of air. By using wind energy, our system is not dependent on electricity,” explains Gerard Schouten of Dutch Rainmaker. “The wind turbine drives a heat pump which cools the air down – similar to the process in air-conditioning systems.”

Depending on local ambient temperatures and humidity conditions, air always contains a certain amount of water. For example, 1 kg of air at 20°C with a relative humidity (RH) of 50% contains around 7 g of water, while at 30°C and 50% RH, it contains almost 14 g.

Dutch Rainmaker's air-to-water system is especially suited to areas lacking rain or even briny water bodies. It functions best in areas of high humidity (above 50% RH) with temperatures of 20-40°C rather than arid climates. “The mill is 10 to 20 times smaller than the average windmill in the Netherlands and has a daily production of 7 000 litres,” says Schouten. Its compact dimensions yet high yield makes this product suitable for domestic and small scale agricultural use.

The company has also developed a wind-turbine system for extracting drinking water from salty or polluted water. “The system is primarily meant to desalinate water and is not a purification installation,” he explains. “However, water from rivers can be purified with this system.’’ The water-to-water mill has a higher drinking-water production capacity – approximately 50 000 litres a day.

By relying on sustainable energy, these products – with an estimated lifespan of 20 years – reduce the environmental impact of water production and purification. They are constructed in accordance with cradle-to-cradle principles and have the environmental benefit of creating no waste, no by-products and no CO2 emissions.

With commercialisation now underway, the company is searching for partners to become suppliers in suitable regions. In addition to targeting the Mediterranean, the Middle East and North Africa, the company has also established links with the USA.

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