Fig. 3

Parabolic dish layout. a Dish of 25 kW Stirling solar power unit installed at Solarversal Hangzhou site. To allow free tracking, a notch is made to the parabolic dish to avoid intervening between dish and the supporting pedestal. b Its net reflecting area can be model by a sector ring, which is described by Eq. 3. c, d Depending the sun positions, shades will be casted to the dish by its neighbors, reducing the effective reflecting area (light blue area)