Solar Updraft Tower - History

History

In 1903, Isidoro Cabanyes, a colonel in the Spanish army, proposed a solar chimney power plant in the magazine La energía eléctrica. Another early description was published in 1931 by German author Hanns Günther. Beginning in 1975, Robert E. Lucier applied for patents on a solar chimney electric power generator; between 1978 and 1981 patents (since expired) were granted in Australia, Canada, Israel, and the USA.

In 1982, a small-scale experimental model of a solar draft tower was built in Manzanares, Ciudad Real, 150 km south of Madrid, Spain at 39°02′34.45″N 3°15′12.21″W / 39.0429028°N 3.2533917°W / 39.0429028; -3.2533917 (Manzanares Solar Updraft Tower). The power plant operated for approximately eight years. The tower's guy-wires were not protected against corrosion and failed due to rust and storm winds. The tower blew over and was decommissioned in 1989.

Inexpensive materials were used in order to evaluate their performance. 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. The project was funded by the German government.

The chimney had a height of 195 metres (640 ft) and a diameter of 10 metres (33 ft) with a collection area (greenhouse) of 46 hectares (110 acres) and a diameter of 244 metres (801 ft), obtaining a maximum power output of about 50 kW. Various materials were used for testing, such as single or double glazing or plastic (which turned out not to be durable enough). One section was used as an actual greenhouse. During its operation, 180 sensors measured inside and outside temperature, humidity and wind speed data was collected on a second-by-second basis. This experiment setup did not sell energy.

In December 2010, a tower in Jinshawan in Inner Mongolia, China started operation, producing 200 kilowatts. The 1.38 billion RMB (USD 208 million) project was started in May 2009 and intends to cover 277 hectares (680 acres) and produce 27.5 MW by 2013. The greenhouse is expected to improve the climate by covering loose sand, restraining sandstorms.

A proposal to construct a solar updraft tower in Ciudad Real, Spain, entitled Ciudad Real Torre Solar would be the first of its kind in the European Union and would stand 750 metres (2,460 ft) tall – nearly twice as tall as the continent's tallest structure, the Belmont TV Mast – covering an area of 350 hectares (860 acres). It is expected to produce 40 MW.

In 2001, EnviroMission proposed to build a solar updraft tower power generating station known as Solar Tower Buronga near Buronga, New South Wales. The company did not complete the project and now plans a similar plant in Arizona.

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.

Based on the need for plans for long-term energy strategies, Botswana's Ministry of Science and Technology designed and built a small-scale research tower. This experiment ran from 7 October to 22 November 2005. It had an inside diameter of 2 metres (6.6 ft) and a height of 22 metres (72 ft), manufactured from glass-reinforced polyester, with an area of approximately 160 square metres (1,700 sq ft). The roof was made of a 5 mm thick clear glass supported by a steel framework.

In mid 2008, the Namibian government approved a proposal for the construction of a 400 MW solar chimney called the 'Greentower'. The tower is planned to be 1.5 kilometres (4,900 ft) tall and 280 metres (920 ft) in diameter, and the base will consist of a 37 square kilometres (14 sq mi) greenhouse in which cash crops can be grown.

A model solar updraft tower was constructed in Turkey as a civil engineering project. Functionality and outcomes are obscure.

In October 2010, EnviroMission announced further plans to build two 200 MW Solar Updraft Towers in Western Arizona. Southern California Public Power Authority (SCPPA) has agreed to negotiate a power-purchase agreement with EnviroMission. The project has been listed by the SCPPA. As of January 2011, the company had secured $29.8 million in financing from AGS Capital Group. In August 2011, United States construction services contractor, Hensel Phelps Construction Co. was engaged for delivery of a construction schedule and cost estimate of a 200 MW tower. A potential construction roadblock to is its potential environmental impact. Environmental concerns have arisen over desert solar panel arrays in the US Southwest.(registration required) The desert tortoise (Gopherus agassizii) is an endangered species in the area.

In 1926 Prof Engineer Bernard Dubos proposed to the French Academy of Sciences the construction of a Solar Aero-Electric Power Plant in North Africa with its solar chimney on the slope of a large mountain. A mountainside updraft tower can also function as a vertical greenhouse.

Locating a tower at high latitudes could produce up to 85 per cent of the output of a similar plant located closer to the equator, if the collection area is sloped significantly southward. The sloped collector field is built on suitable mountainsides, which also functions as a chimney. A short vertical chimney on the mountaintop to accommodate the vertical axis air turbine. The results showed that solar chimney power plants at high latitudes may have satisfactory thermal performance.