Information about Solar Energy

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Solar Energy and Technologies


Solar energy is generated deep in the interior of the sun by nuclear fusion reactions, is carried to its surface by high- energy radiation and then to Earth and down through the atmosphere by sunlight.

Solar technologies use solar radiation to produce heat and/or electricity.


1. Solar Heat and Solar Thermal Technologies

The solar thermal transformation inputs into heat production are estimated on the basis of 100% efficiency. The conversion of solar radiation in heat occurs through collectors. Generally two types of collectors exist:

  • Non- concentrating collectors

The global radiation can be fully utilized. They are mainly used in solar thermal systems for low- and medium temperature applications. Different types are available on the market. In Austria flat- plate collectors are common.

  • Concentrating collectors

We distinguish between parabolic and cylindrical collectors. Both can just use the direct beam of the radiation by optical installation for the generation of heat. They are preferable used in regions with more than 2500 annual hours of sunshine.

The choose of a collector- type depends from the application: Flat- plate collectors are used for temperatures up to 150°C, concentrating temperatures above 200°C, up to 1000°C for process heat and thermal electricity production.


2. Solar electricity and Solar electricity Technologies

Electricity can be generated by the conversion of sunlight in Photovoltaic (PV) systems. They use semiconductor materials and can be used separately or in hybrid form, in combination with other generating options such as other Renewables or fossil fuels. In the last years the market for PV systems grew rapidly and today several different variants exist such as single- and multicrystalline silicon, amorhous silicon or cadmium telluride. Efficiencies as well as costs of PV technologies increased, but there is still left a potential for further development and it is unknown which technology will dominate in the future.


Reference: Fanninger, G.: Renewable Energy Sources and Technologies in Austria, Wien 2006, online: http://www.nachhaltigwirtschaften.at


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