Inhabitat » Solar Updraft Towers to Generate Food and Energy

September 10, 2008

Solar Updraft Towers to Generate Food and Energy

by Mike Chino

solar updraft tower, hahn & hahn, namibia, solar energy, alternative energy, solar power, desert greenhouse

A new breed of solar tower may soon be sprouting up in Namibia, providing the nation with a carbon-free source of electricity and food during the day and night. At one and a half kilometers tall and 280 meters wide, these massive solar updraft towers could potentially produce 400MW of energy each - enough to power Windhoek, the nation’s capital. Proposed by intellectual property company Hahn & Hahn, the towers generate energy by forcing heated air through a shaft lined with wind turbines. Additionally, the base of each tower will function as a 37 square km greenhouse where crops can be grown.

solar updraft tower, hahn & hahn, namibia, solar energy, alternative energy, solar power, desert greenhouse

Solar updraft towers are an oft-overlooked source of alternative energy, although they do require a great expanse of space and copious amounts of sunlight. Theo von Backström from the Department of Mechanical Engineering at South Africa’s Stellenbosch University states: “One of the main reasons why commercial solar chimney power plants have not been built that they have to be very large to be economically viable”. Fortunately Namibia’s arid desert region provides plenty of space for such a generator, and the country sees around 300 days of sunshine per year.

Solar updraft towers generate energy by using sunlight to heat the air within a vast transparent greenhouse situated at the base of the chimney. As the hot air rises, it is funneled into the reinforced concrete chimney, driving a series of wind turbines which in turn generate energy.

The structure’s greenhouse base provides the perfect environment for growing crops, which actually allow the plant to produce energy after the sun has set. The water used for crops is heated during the day and transfers this energy to the tower at night. Once the towers are constructed they require very little maintenance, and Namibia has agreed to finance half of the costs of the $780,000 pre-feasibility report.

We’d love to see the towers incorporate a Seawater Greenhouse and produce their own water as well!

+ Hahn & Hahn inc

Via Pruned and SciDev

Tip via Ryan Herbert

solar updraft tower, hahn & hahn, namibia, solar energy, alternative energy, solar power, desert greenhouse

7 Responses to “Solar Updraft Towers to Generate Food and Energy”

tomkington Says:

September 10th, 2008 at 1:04 pm

great idea - but at more than twice as high as the worlds tallest manmade structure i\’m not sure who and how this will get built??

Chublez Says:

September 10th, 2008 at 6:20 pm

http://www.youtube.com/watch?v=XCGVTYtJEFk

PhilW Says:

September 12th, 2008 at 2:02 pm

There’s other benefits as well. About 10-15 years ago, I saw this being proposed for the US Gulf Coast areas.

The day to day benefit of this would be to use brackis/salt water around the base and collect condensation from the cooling rising air to provide a fairly significant source of fresh water for the area.

The primary benefit of the proposal though was to defend the area from Hurricanes (such as TX/LA is looking at now. By reducing the amount of warm air trapped by inversion and harvesting the energy that is stored there, the high energy areas that Hurricanes feed on and trend toward would be minimized and thus reduce the chance of landfalls around these towers. And if landfalls did occur, they would be of lower power as the hurricanes would be less able to build in strength in the wamer water closer to the costline as that energy would already have been harvested/dissapted.

But yes, the primary problem is construction - these structures promise to be difficult and expensive to build.

lisasmyth Says:

September 12th, 2008 at 2:14 pm

What pray tell can one grow in a greenhouse in a the desert as a matter of interest, seems like it would be crazy hot?

bmagnanimous Says:

September 12th, 2008 at 8:17 pm

This is amazing, it’s the first time I’ve seen it, but it just makes sense to me. At a cost of about $1M USD you get an unmanned power plant producing 3000MW of power? Why wouldn’t you want to produce these? Well ok, tornadoes may be a problem, but I think it’s just too simple and cost effective of an idea to ignore. I’m all for it.

Brian
http://www.total-solar-solutions.com

acliss Says:

September 14th, 2008 at 10:32 pm

~1M is just for the pre-feasibility report, I only wish that was for the whole project. That video Chublez linked to laid out a solar tower built in Spain in 1982 as a pilot project to test the idea. It consistently generated between 30 and 50 MW. Currently there is a project in Australia to install a 200 MW solar tower, they plan to open in 2012. Really cool idea, if you have lots of extra desert space, it seems to make sense. There are, of course, going to be ecosystem consequences (diversion of wildlife, for example), but you get those kind of trade offs with most renewable energy. The alternative, however, is more coal, and we can\\\’t have that!

Aaron
fireignblog.com

yrag1 Says:

September 15th, 2008 at 2:29 am

I think this is completely unrealistic—not necessarily from a technological standpoint, but from basic economic reality. This would be a mega-project of enormous cost. For who? Namibia?
I’m not saying they don’t deserve it or need a reliable source of energy, They do. But what organization is in a financial position to fund something of this magnitude with absolutely no assurance or even prospect for a return? Just getting basic building materials to the area would be prohibitive. And then there’s the question of the electricity you would need just to do any sort of construction. Housing for workers, etc., etc. IF, something like this is going to be built, it’s going to be built in a very rich nation first. United Arab Emirates, I’m looking at you. Interested?

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