Steered collector pointed at sun 1000 Slanted stationary surface 500 Horizontal surface 0 8 A M 12 noon 4 P. M Time Solar power incident on three types of collectors for a typical winter day at 40. N latitude. The energy collected each day is proportional to the area under each curve 复旦大学环境科学与工程系 Department of Environmental Science and Engineering, Fudan UniversitySolar power incident on three types of collectors for a typical winter day at 40。N latitude. The energy collected each day is proportional to the area under each curve