Engineering Students Tackle Solar Tower
by Jeff McIntire-Strasburg, St. Louis, MO on 05.24.06
While Australians may begin construction on a solar tower as early as this year, engineering students at the University of Arizona are already at work on a project to discover the optimum specifications for one of these large-scale power production facilities. So far, the students have built a 12-foot tall scale model that will allow them to test some of their theories concerning the relationship between the size of such structures and the amount of power they can produce:
The students’ tower has a circular collector constructed from a surplus trampoline frame covered with transparent Mylar. The chimney is a length of ABS pipe and their generator is a tiny cell phone motor modified to run in reverse. The motor originally powered a vibration alert mechanism in the phone.A cone at the base of he tower helps to direct the airflow so it doesn’t meet a 90-degree bend at the junction of the horizontal collector surface and vertical tower. "We tried to keep the flow as efficient as possible," [senior engineering student Andy] Lovelace said.
While experiments at this point haven't produced the expected wind speed of 6 mph within the tower, the students already have opinions on what changes will be needed to reach maximum efficiency. This model represents only the first effort by a student team, and Professor Hermann Fasel plans to sponsor another team next Fall to build an even larger scale model and continue the work. :: innovations report via Hugg
Looks like yet another reason for an American to visit down under. I have this sneaking suspicion that the a/c needed to keep you comfortable in those little trains to get to the base of the tower will suck up all the electricity produced.
Anyone think that solar energy will a meaningful impact on US energy production in the next 2-3 years. Please post your thoughts on http://boards.cutoilimports.org/groupee/forums
I thought I had read somewhere (Wired?) that these kinds of things would also be covered with solar collectors to maximize the structure. I suppose too many collectors would then result in a lower temperature inside the tower.
I seem to recall also that they were talking about 1Km tall towers, or taller.
Anyway, neat stuff. I love to see this kind of ingenuity and research.
I suppose some PV panels could be placed on the ground under the big circular collector, but they'd have to be able to handle the heat and probably wouldn't be as efficient as panels exposed directly to the sun...
Still, it could be a way to maximize the use of that surface that probably can't be used for anything else.
I'd imagine some kind of secondary heat exchanger will be under the panels
The structure should be made of the new type of passive concentrating PV panel glass. I think this would allow for the infrared heat energy to pass through into the interior of the structure while still allowing the photons within the sun's rays to power the PV panels. I suspect that this combination would result in the most cost-effective method of producing electricity with a solar tower.
There is also a student project in Turkey where they built a small and successful version in 2005
The University of Florida has their own solar chimney project. I'm not sure of the current status as I've been having problems accessing the website.
some pictures:
http://www.flickr.com/photos/cbdvs/sets/72157594144351833/
project website: (google has a cached version if this link doesn't work)
http://seecl.mae.ufl.edu/solar/chimney.html