Photovoltaic Systems

Recent development in solar systems involves the use of a concentrator technology where the solar energy over a large area is concentrated onto a small area of solar cells. Concentration of sunlight using a freznel lens or reflective surface can increase energy density several hundred times. This allows the use of more exotic solar cell technology that has greater efficiency. The cells used in concentrator modules are more expensive, but fewer cells are required, resulting in an overall cost per watt that is competitive with flat plate technologies.

Concentrator efficiency levels above 30% have been demonstrated in the laboratory and 20% or better efficiency units are becoming commercially available. Concentrator technologies work best in regions where sunlight is not scattered by haze or air-pollution. Concentrator technologies currently represent a small fraction of the photovoltaic market.