Greenhouse uses seawater to grow crops in arid places

London-based Seawater Greenhouse has developed a specially designed greenhouse for arid environments that acts as a humidifier through a combination of seawater, cardboard and air.

Charlie Paton, founder of Seawater Green, told The Engineer: ‘If it’s too hot, too dry, too windy, and too sunny then a plant’s stomata closes up to prevent water loss and photosynthesis doesn’t happen.

‘However, if the temperatures are extremely high then plants can still survive on the condition that they have high humidity.’

In use, seawater is evaporated at the front of the greenhouse to create cool humid conditions inside.

The greenhouse has a porous wall at each end that contains a rigid cardboard lattice. Seawater is poured over the cardboard lattice, which temporarily retains the moisture before releasing it into the greenhouse due to hot prevailing winds that blow through the wall. The evaporated seawater then cools the temperature within the greenhouse and creates humidity. Salt and other minerals collect in the base of the wall where they can be harvested and sold.