Architects Propose Fantastic Greenhouses Across the Sahara

By Eliza Strickland | September 2, 2008 6:01 pm

Sahara greenhousesA team of architects and environmental engineers has proposed covering swaths of the Sahara with vast “salt water greenhouses” powered by solar power arrays, in a plan they call the Sahara Forest Project. Charlie Paton, inventor of the salt water greenhouse, says the combined technologies could transform patches of the desert from arid wastelands into lush expanses that produce a bounty of fruits and vegetables for local people.

The plan is no doubt ambitious and unproved at this scale, but Paton says he has built demonstration greenhouses on the Spanish island Tenerife, as well as in Abu Dhabi and Oman; he says there is further interest in funding demonstration projects from across the Middle East, including UAE, Oman, Bahrain, Qatar and Kuwait. The cost is not as astronomical as one would think, and is estimated at approximately $118 million for a 20 hectare [50 acre] site of greenhouses and a 10MW concentrated solar power farm [Red Herring]. Paton is working with Exploration Architecture, a company that worked on the world’s largest greenhouse in England’s Eden Project.

The greenhouses work by using the solar farm to power seawater evaporators and then pump the damp, cool air through the greenhouse. This reduces the temperature by about 15C compared to that outside. At the other end of the greenhouse from the evaporators, the water vapour is condensed. Some of this fresh water is used to water the crops, while the rest can be used for the essential task of cleaning the solar mirrors. “So we’ve got conditions in the greenhouse of high humidity and lower temperature,” said Paton. “The crops sitting in this slightly steamy, humid condition can grow fantastically well” [The Guardian].

The project would use a concentrated solar power (CSP) system, in which huge mirrors focus the sun’s rays onto water heaters, which produces steam to power turbines. As the dreamers envision it, the Sahara Forest Project would be established near the north coast of Africa. The scheme has been designed as a ‘hedge’ of greenhouses providing a windbreak and shelter for the outdoor planting. CSP arrays will be placed at intervals along the greenhouse ‘hedge’. The greenhouses produce five time more fresh water than needed for the plants inside. This surplus will be used to irrigate the planted orchards and the Jatrophra [sic—the correct name is “Jatropha”] crop, which can be turned into bio-fuel for transportation and other needs [Treehugger].

Image: Exploration Architecture

Related Post: A Solar Power Plant in the Sahara Could Power All of Europe

CATEGORIZED UNDER: Environment
  • Mark

    Unfortunately the political will to develop this enough to offset a lot of hunger probably won’t come until lots of (mainly poor or nonwhite) people die. It’s a fabulous idea… (but following on its heels will likely be new resort towns, like, a neo Las Vegas filled with American fast food, American retail chains, and American (a k a Christian) gambling designed to make dimwit tourists feel at home and therefore feel slightly less stupid than usual.)

  • http://jrsjgd0818@yahoo.com jimmy

    this would be great! at least people living there can benefit from this.. to all you rich guys out there. this is the real avenue to help our brothers and sisters there..

  • http://www.earth-policy.org/Updates/2008/Update73.htm EnergyRevolution

    THIS IS THE FUTURE! ACCEPT IT LIVE IT …

    The Solar Millennium has eventually been unleashed, but not by Photovoltaics. The Future lies in the heat of the SUN.

    Nuclear Fusion, Baby!!! JUST FAR AWAY RISING EVERY DAY !!!

    Check Solar Millennium (S2M) I’m part of the Future ….

  • Jef

    Notice how they’re talking about doing this in the north. None of the northern countries are as poor or have food shortages on the scale of many of the Saharan and sub-Saharan countries. Using a line of these as a hedge is a great idea and Morocco as well as most of the other northern countries could easily finance this, but the Sahara is expanding to the south as well.

  • http://www.greenproduce.biz/ Thomas Bjelkeman-Pettersson

    There is plenty of deserts where this could be applied. The use of Seawater Greenhouse technology could help counter spreading deserts. Also growing vegetables this way can be made completely carbon neutral (i.e. use of locally grown biofuels to transport the food to the market).

    “Enough fertile land could turn into desert within the next generation to create an “environmental crisis of global proportions,” (1)

    ‘Ghana and Nigeria currently experience desertification; in the latter, desertification overtakes about 1,355 square miles (3,510 km2) of land per year.” (2)

    Taking into account what is happening in the next 25 years:

    Increased urbanisation (people stop growing their own food), 1.7 billion people more in 2030. (3)
    Climate change (more deserts). (4)
    Growing populations (more food needed), 2.5 billion more people in 2030 (5), and these populations are are all relatively close to areas where Seawater Greenhouse technology can be used successfully. (6).

    Seawater Greenhouse technology may be one of the least invasive ways of producing food when applied correctly. I think we should be clear on that we need this type of integrated thinking in the next 25 years.

    Disclosure: I work with Charlie Paton, Seawater Greenhouse.

    (1) http://www.nytimes.com/2007/06/28/world/28deserts.html
    (2) http://en.wikipedia.org/wiki/Desertification
    (3) http://en.wikipedia.org/wiki/Urbanisation
    (4) http://www.ipcc.ch/
    (5) http://www.census.gov/ipc/www/idb/worldpopinfo.html
    (6) http://www.seawatergreenhouse.com/regions.htm

  • http://blogs.discovermagazine.com/80beats/ Eliza Strickland

    Come to think of it, I’m surprised the Australians aren’t experimenting with this seawater greenhouse concept. They’re in the midst of a devastating drought.

  • David Bowman

    Mark, with an attitude like that, none of the good things that you take for granted would exist. We have to move forward optimistically while also accepting that anything we do has the potential to bring about negatives. It’s just the homeostatis of the world — you have to take the bad with the good. The potential for negatives doesn’t mean that we should sit at home, alone, writing nihilistic posts on science blogs.

  • Henry Ricks

    Anyone know where the salt from the sea water ends up? Just curious.

    Sounds like something that should be tested on a large scale.

  • Brian

    Interesting idea. It may have a future as an agricultural/industrial concept.

    However when they start talking about “… a ‘hedge’ of greenhouses providing a windbreak and shelter …” count me out. This sounds like terraforming on a regional level and it just won’t work. It’s high cost, high touch, high maintenance solution in an area of the world that has NONE of the resources required to even get this started.

    If you want to change the climate of an entire desert region, use plants. They are cheap, practical, and self-sustaining. Even when mankind is neglectful, underfunded, ignorant, unobservant, diverted, or whatever, plants can do the right thing automatically. They replenish themselves as needed. They spread into viable microenvironments and retreat from hostile areas.

    Plants, just plants, without all the high concept greenhouses, artificial water sources, shelters, power generation systems, mirrors that need cleaning (!), motors that need replacing, gears that need lubricating, the whole maintenance enchilada.

    Sure, the plants may need a little (or a lot) of help getting started. However that’s the only practical method available.

  • Eve

    I think this is a great idea.
    Friend of mine he has a patent about use green way to get both energy and pure water from the red sea ,to grow trees in Sahala.
    I would like to share it to everybody,contact me at evemiao2009@gmail.com

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