chapters
Energy
Economy
Technology
Entities
Policy

sections
<< ^ >>
Technology
heat
Solar heating
electricity
Generation
Sunlight
Photovoltaics
PV types
CPV
CPV geometry
Solar thermal
Wind
Storage
Fuels
Electrolysis
Fuel cells

site
About
Glossary

Copyright 2008-10,
CaliforniaPHOTON.com
V 1.06
site last updated: 6/26/2010

C a l i f o r n i a   P H O T O N

CPV: Optical and Tracking Geometries

Concentrating photovoltaics (CPV) use optics to concentrate sunlight onto small receivers, and require the movement of the optics to keep the sunlight focused. Typically, CPV systems consist of sun-tracking modules, each incorporating an optical system and corresponding receivers. Most existing CPV systems can be classified according to the type of optics they use -- reflective or refractive, and line-focusing or point-focusing -- and the type of tracking they use -- one axis, and multi-axis. As the following table illustrates, the required type of tracking and practical concentration ratios are determined by the optics' focusing properties.

Type of concentration
Focal shape Line Point
Tracking motion One-axis Two- or multi-axis
optics Refractive typically, thin rectangular Fresnel lenses with optical planes (line-focusing), or optical axes (point-focusing)
Reflective typically, mirrors shaped as parabolic surfaces of translation (line-focusing), or of revolution (point-focusing)
Concentration ratio Moderate: 10-100 : 'MCPV' High: 100-10000 : 'HCPV'

Source: Sun Synchrony