paraboloidal dish solar collectors; optical profile; short focal length; cavity designs
The basic geometrical optics equations for multifaceted paraboloidal dish solar collectors are presented in the form helpful for engineering design. Trade-off strategies are discussed to establish a balance between many constraining factors related to system cost, survival, reliability and lifetime properties. Performance data for experimental dish collectors of 5 m diameter, involving undemanding accuracy of optical profile and short focal length (1.8 m), are presented. In this situation modified cavity and the semicavity receivers tend to have a higher efficiency than cavity designs. Current research and application trends of dish collector systems are indicated.