Finally, a greenhouse that grows its own power supply

September 21, 2018

By Prof Dr. Hassan El-Banna Fath

Food security – a nation’s ability to provide enough food for its population without being overly reliant on outside nations – is becoming an important issue for many countries around the world.

It is a particular concern in the UAE, where the hot, dry climate, and the shortage of water, make growing any crops an expensive, difficult and resource intensive endeavor. Currently, only around 1 per cent of the UAE’s land is used for agriculture, and some 80 per cent of our food is imported. To address this, efforts have been made to increase food storage, agricultural investment, hydroponics, aquaculture, and food manufacturing. But limited water resources, high temperatures, and high solar radiation, however, continue to pose an obstacle in raising the amount of farmland.

A research project at the Masdar Institute hopes to help address that by developing a unique greenhouse that is self sufficient for energy and irrigation water.

In cold climates, greenhouses are used to keep plants warm. But in hot climates, they can cause the plants to die. Air conditioned greenhouses are extremely expensive to run and environmentally unfriendly.

This project aims to integrate the latest in solar energy, desalination, and engineering systems and management to design a greenhouse that does not take electricity or water from the UAE’s utilities.

Instead, using transparent photovoltaic panels on the roof, the wholly self-sufficient standalone greenhouse would be able to use solar- generated electricity to produce irrigating water and to regulate the temperature, humidity and air velocity of the plants’ environment, while allowing in sunlight needed for the plants’ photosynthesis process. The recovered thermal and electrical energy would be used to desalinate seawater or brackish groundwater using membrane technology, as well as collecting water from the air humidity through a humidification/ dehumidification system.

The system we are designing can easily produce enough water to irrigate a greenhouse. Excess water can be stored on site for days where either the sky is cloudy (and so less water is produced) or the temperature is hotter than usual (and so more irrigation water is used).

Through this system the greenhouse can sustainably cool, shelter, and hydrate plants. It can be set up anywhere reasonably close to ground or seawater, without requiring any other infrastructure.

Such greenhouses are ideal for high quality plants that require precisely controlled conditions. This could be organic foods for the UAE’s domestic market, or pharmaceutical plants for export. And the greenhouse can also be modified for livestock, providing cattle or poultry with a comfortable climate while not draining natural resources.

It could even be used as self-sufficient housing for people, providing air conditioning and water from renewable resources. Discussions are currently on with the Abu Dhabi Food Control Authority for the construction and testing of a prototype of this sustainable greenhouse.

It is hoped that with the completion of this research project in two years’ time, we will be able to show a new source of food, security, wealth and development for the UAE.

Prof Dr. Hassan El-Banna Fath is a professor of practice of water and environmental engineering at the Masdar Institute of Science and Technology.