Solar updraft tower
Sunshine heats the air beneath a very wide greenhouse-like roofed collector structure surrounding the central base of a very tall chimney tower.
They may also allow development of other applications, such as to agriculture or horticulture, to water extraction or distillation, or to remediate urban air pollution [citation needed].
A solar updraft tower power plant can generate electricity from the low temperature atmospheric heat gradient between ground or surface level and structurally reachable altitude.
An animal spitted above a fire or in an oven could be turned by a vertical axis turbine with four angled vanes in the chimney updraft.
In 1903, Isidoro Cabanyes, a colonel in the Spanish army, proposed a solar chimney power plant in the magazine La energía eléctrica.
[citation needed] In 1956, Edgard Nazare, after observing several dust devils in the southern Sahara, filed his first patent in Algiers on the artificial cyclone generator.
The solar tower was built of iron plating only 1.25 millimetres (0.049 in) thick under the direction of a German engineer, Jörg Schlaich.
[31] Critics have said that the 50m tall tower is too short to work properly and that it was a mistake to use glass in metal frames for the collector, as many of them cracked and shattered in the heat.
In December 2011, Hyperion Energy, controlled by Western Australians Tony Sage and Dallas Dempster, was reported to be planning to build a 1-km-tall solar updraft tower near Meekatharra to supply power to Mid-West mining projects.
[44][45] A second solar updraft tower using a transpired collector is operating at Trakya University in Edirne, Turkey, and is being used to test various innovations in SUT designs including the ability to recover heat from photovoltaic (PV) arrays.
[citation needed] A grade-school pupil's home do-it-yourself SUT demonstration for a school science fair was constructed and studied in 2012, in a suburban Connecticut setting.
This demonstration project was led by Cao Jun Ji, a chemist at the Chinese Academy of Sciences' Key Laboratory of Aerosol Chemistry and Physics.
[25][51][52] Model calculations estimate that a 100 MW plant would require a 1,000 m tower and a greenhouse of 20 square kilometres (7.7 sq mi).
[10] One 200 MW power station will provide enough electricity for around 200,000 typical households and will abate over 900,000 tons of greenhouse producing gases from entering the environment annually.
Concentrating thermal (CSP) or photovoltaic (CPV) solar power plants range between 20% and 31.25% efficiency (dish Stirling).
[53] Most of the projections of efficiency, costs and yields are calculated theoretically, rather than empirically derived from demonstrations, and are seen in comparison with other collector or solar heat transducing technologies.
The new hybrid design made the solar updraft tower feasible again, and proved it to be economical in saving much construction cost and time.
This concept also recaptures the heat of radiators that are thrown out into the atmosphere without efficient utilization, and prevents generation of excessive greenhouse gasses.
The performance of an updraft tower may be degraded by factors such as atmospheric winds,[56][57] by drag induced by the bracings used for supporting the chimney,[58] and by reflection off the top of the greenhouse canopy.
[59] A solar updraft power station would require a large initial capital outlay, but would have relatively low operating cost.
[81] The levelized cost of energy (LCOE) is approximately 3 Euro cents per KWh for a 100 MW wind or natural gas plant.
