Tech & Science

Drought-proof cooling houses grows tons of healthy produce in the desert

Greenhouses can grow plants indoors in almost all climates from frozen Iceland to Caribbean islands.

Image: Freethink

Image: Freethink

Now, a new type of greenhouse called a cooling house allows crops to grow in hot dry climates using the sustainable cooling and humidifying ability of water vapor from the evaporation of saltwater.

These special cooling houses are produced by the UK startup Seawater Greenhouse LTD and have been used in Abu Dhabi in the United Arab Emirates. Oman, Australia, and in their latest project in Somaliland where temperatures can exceed 40 degrees Celsius in the summer.

The company said that they can specially designs to units for areas that could not otherwise support agriculture. They do so by using modeling software to simulate the exact growing environment and creating a customized design for each greenhouse depending on where it is going.

This new innovation uses the water vapor that is produced from evaporating saltwater that was developed at Aston University in Birmingham, England. This method reduces the temperature and increases the humidity that reduces evaporation by 90 percent and greatly reduces the amount of water needed for irrigation.

The company's founder and director Charlie Paton came up with the idea for the cooling greenhouses after having worked for as a theatre and TV lighting designer according to Ingenia. After spending several holidays in Morocco, Paton started thinking about the composition of light and how plants grow using light.

He used his knowledge about the makeup of light to design a new type of growing environment that excludes the harmful infrared in sunlight and utilizes wind and solar energy to power the evaporative cooling in his cooling houses.

The first pilot projects were launched in the 1990s in Tenerife in Spain's Canary Islands. Then the Seawater Greenhouse team moved onto hotter and more arid environments in the Middle East. The materials and designs used were constantly being tweaked.

The latest project in Somaliland has been supported by a grant from Innovate UK and a collaboration with the Pastoral and Environmental Network in the Horn of Africa, an NGO established in 1989. This latest cooling house version had to be sturdy, inexpensive, and able to be used by smallholding farmers.

The climate of Somaliland is so arid and harsh that only 1.8 percent of the land is cultivated. The coast is very windy and temperatures in the summer are brutal. This project was an extreme challenge.

Paton told Ingenia that the two cooling houses that were designed for Somaliland as, "basically a Bedouin tent covering a thousand square meters with a soggy wall of cardboard at either end.”

The soggy cardboard walls are actually the evaporator panels that were designed to be used in air conditioning systems. The panels form the walls of both sides of the structure and each wall is used to evaporate the seawater that is used to irrigate crops in the greenhouse.

The projected was completed in 2017 and each of the greenhouses can produce 300 to 750 tons of tomatoes per hectare. If this project is scaled up, Paton estimates that it would only take 2,000 hectares (10 square miles) to feed the entire four million people of Somaliland. If adapted by other countries, it would go a long way to feed the estimated world population of 9.8 billion in 2050.

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