Biomimicry in Design 1

"How to grow tomatoes in the desert"

by Fergal White

This is an ingenious piece of biomimetic design. This technique was invented in 1991 by a British inventor, Charlie Paton and developed by his company Light Works Ltd (now Seawater Greenhouse Ltd). What he invented was a greenhouse that facilitates mimicry of the hydrological cycle, (whereby seawater heated by the sun evaporates, cools down to form clouds, and returns to the earth as rain, fog or dew) to produce fresh water, high-quality crops and a restored landscape. The genius of the idea is that it can be used in dry, arid regions as long as they are near the sea.

SGdiagram

Fig1. http://www.seawatergreenhouse.com/process.html

The process is as follows:

1. The greenhouse is positioned so that it faces the prevailing breeze. It utilises fans to pull the air through the greenhouse.

2. The air enters the greenhouse through a lattice. Here it is first cooled and humidified by seawater which trickles down over the lattice. This cooled and humidified air then enters the planting area and provides good climate conditions for the crops.

3. This climate in the growing area is further improved by the roof which traps infrared heat, while allowing visible light through to promote photosynthesis. This roof plays a double role as it facilitates the solar heating of seawater which is piped through it to reach the evaporator unit on the exiting wall of the greenhouse.

4. As the air passes through this evaporator it becomes hotter and more humid. It then passes through a condenser consisting of vertical pipes through which cool seawater passes. As it passes through fresh water condenses as droplets that run down to the base of the pipes where it can be collected and used to irrigate the crops in the growing area.

5.  A seawater greenhouse evaporates much more water than it condenses back into freshwater. This higher humidity exhaust air facilitates the cultivation of more hardy crops downwind of the greenhouse itself. An example of this is the "before" and 2 years "after" shots from the Teneriffe project.

Seawater_Greenhouse_newly_installed_in_Tenerife

Fig2. http://en.wikipedia.org/wiki/Seawater_greenhouse

There have been three Seawater Greenhouse pilot projects to date in Tenerife, Abu Dhabi and Oman, which have enabled the accurate prediction and quantification of how the seawater greenhouse will perform in other parts of the world. In 2010, Seawater Greenhouse ltd built a new commercial installation in Port Augusta , South Australia (http://www.sundropfarms.com/) which is now independently operating as Sundrop Farms Pty Ltd. Here the process is perfected even further using Concentrated Solar Power (CSP) as the main source of energy to power the greenhouse. ABC Landline visited Sundrop Farm in in April 2012 (http://www.youtube.com/watch?v=KCup_B_RHM4) .

The most ambitious combination of CSP and Seawater Greenhouse technologies will be "The Sahara Forest Project". The object of "The Sahara Forest Project" is to ensure the long term survival of residents living in the Middle East's desert regions through the use of restorative agriculture. The aim is to turn inhospitable deserts into flourishing food and power producing habitats. This will see Seawater Greenhouses utilised on a massive scale, firstly in Jordan and then in Qatar.

Seawater Greenhouse_Sahara1

Fig3. The Sahara Forest project

The Board of the Sahara Forest Project includes an architect, Michael Pawlyn, author of the book "Biomimicry in Architecture". At first he worked in collaboration with Charlie Paton, the original inventor of the Seawater Greenhouse, but since then has teamed up with structural engineer Bill Watts and Norwegian environmental group the "Bellona Foundation".  Numerous large scale Concentrated Solar Power stations will provide all power necessary for the projects.

Final-image-Sahara-Forest-Project

Fig4. The Sahara Forest project

The most exciting part about this project is that it is actually going ahead. A 10,000 square meter man-made oasis will open in Qatar soon (Source: Blue Living Ideas (http://s.tt/1ciG6)) and the positive results of a comprehensive feasibility Study for Jordan were presented in April this year. This is a really good example of the of the deceptive simplicity of biomimicry as a means of solving problems, if you want to grow crops in an arid region, you just have to mimic the Hydrologic Cycle.

Ara, sure I could have told ye that........

Sources

http://en.wikipedia.org/wiki/Seawater_greenhouse

http://www.seawatergreenhouse.com/process.html

http://reneweconomy.com.au/2012/seawater-greenhouse-just-add-solar-13913

http://www.sundropfarms.com/

http://www.youtube.com/user/SundropFarmsTV

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