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Solar Photo voltaics (ref 127) electricity source of the future?
Solar Grid Parity (SGP) is when the lifetime cost of Photovoltaics meets the electricity house or industrial tariff.
Photovoltaic cells will be a significant green source of electricity in the future with obvious local application on buildings at the point of use. Power storage would require batteries and diversification obtained from the grid(s.) However massive arrays of cells are needed to provide power on a large scale.
Photons (sunlight) absorbed by semiconductor material (eg silicon p-n semiconductor junctions) cause electrons to be emitted producing direct current (DC). Voltaic cells consist of a thin film of crystalline semiconductor attached to glass. The glass faces the sun to provide protection from the elements.
The original single junction devices were only 33% efficient. These are being superceded by thin film materials on glass or ceramics. Cells can be made wafer thin and printed on aluminum foil. Use of low cost materials and production techniques will pull costs down and increase efficiency eg by manipulating materials on a nano scale to keep sunlight bouncing around inside to boost the amount of electricity produced.
The world production of electricity by Photovoltaics is projected to be 0.4% by 2010. There are several installations of 10 to 20 MW in Europe and a 130 MW installation planned in Spain. A 154 MW installation of photovoltaic panel heliostats, which track the sun in both axes, is planned in Victoria Australia by 2013. Light is also being magnified onto the cells eg using Fresnel lenses (light weight lens with wide aperture as used in lighthouses.)
AbuDhabi is building a 6 sq km city for 50,000 residents and 1500 businesses entirely powered by the solar photovoltaics, which should be complete by 2012. Thin film polysilicon rubber will be applied to the surface of buildings and on canopies to generate electricity. A feature will be travel by bike and light rail with no cars. Design by Foster and partners. See Masda project .
550 MW Topaz Solar Farm project will use thin film PV panels by OptiSolar, producing electricity direct. These swivel in 2 dimensions to track sun. These installations could soon be competitive with CSP and wind but in future may be several times as effective which could enable them to be a major contribution to zero carbon homes, including older dwellings, in addition to large scale arrays / power plants. (ref 187.)
