Solar-powered cooling system for greenhouses

Solar powered cooling

11 April 2012

Researchers of the Sustainable Environment Research Group at Aston University have proven that it is possible to cool greenhouses using solar energy.

In hot countries this finding will enable crops to be cultivated outside the normal growing seasons. Though methods for cooling greenhouses already exist they are poorly suited to hot and humid places like the India and the Middle East. For his PhD project George Lychnos has developed a method for greenhouse cooling that relies on the properties of salts found in seawater. Magnesium salt attracts moisture and, by removing moisture from the air, makes it possible to cool the air by bringing it into contact with seawater. The magnesium chloride salt is recycled as a solution and kept concentrated by the action of sunlight which drives off moisture.

Writing in the journal Energy, Dr. Lychnos and his supervisor Dr. Philip Davies have reported that the solar-cooled cooling system permits cultivation of crops like lettuce, tomato, cucumber and soya all year round – even in the harshest climates. ‘The world’s population is growing most quickly in hot countries and climate change is now posing an additional threat to food security’, says Davies, ‘New technologies are needed to cultivate food intensively in protected environments and these technologies should use renewable energy sources like solar’.

Though there are many concepts available for solar-powered cooling, most of them rely on toxic fluids and heavy-duty pressure vessels.  In contrast, this new system needs only seawater and sunlight and it operates at atmospheric pressure.

Acknowledgements to the Royal Society and the Greek State Scholarship Foundation.

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G. Lychnos and P. Davies

For further media information contact Kreesha Pattani, Aston University Communications on 0121 204 4552 or k.pattani1@aston.ac.uk