Solar Updraft Tower

Abstract

Solar Updraft Towers will have a share already in the near future in solving one of today’s dominant challenges: The global, sustainable, inexhaustible and affordable supply of energy. The principle of this technology is rather simple: under a large glass roof the sun warms up the air (greenhouse effect) which is sucked in by the central vertical cylindrical tube (chimney effect). The updraft wind, thus created, drives turbines/gen erators and so generates electricity. Due to the soil under the collector working as a natural heat storage system, Solar Updraft Towers can operate 24 h on pure solar energy, at reduced output at night time. Simple water tubes, placed on the ground, increase the storage ca pacity and can yield a uniform 24 h electricity generation, if desired. Solar Updraft Towers, mainly suitable for large-scale energy production in units of 100 MW or more, can be erected by local labor force and to a high degree with locally available materials. Solar Updraft Towers can be built in desert countries either to cover regional demand resp. to save oil reserves, or to contribute to the energy supply of e.g. Europe, since the electricity produced by Solar Updraft Towers in the sunny countries can be transported and sold to any place either by transmission lines or – as liquid hydrogen – by ships without substantial losses. Solar Updraft Towers are particularly reliable. Turbines and generators are the plant’s only moving parts. This simple and robust structure guarantees operation that needs little main tenance and of course no combustible fuel. Unlike conventional oil / gas fred and also other solar-ther mal power plants, Solar Updraft Towers do not need cooling water. This is a key advantage in many sunny countries that already have major problems with water supply. Electricity from Solar Updraft Towers is the cheapest when compared with other solar power plants. Nevertheless its



 



energy production costs are still somewhat higher than those of “conventional” coal or gas-fred power plants. However, the approaching shortfall of fuel reserves in combination with dramatically increasing demand will soon balance the cost difference of today and later even reverse it. We expect this “break-even-point” already at a value of 60 to 80 $/barrel of crude oil. Therefore it is time now to build large-scale solar power plants and also large-scale Solar Updraft Towers.