Solar Energy Collection

Since the power density of solar radiation is quite lower, a certain level of technology and device (solar collector) must be applied to collecting the solar energy in order to obtain enough energy or to raise the temperature. The solar collector can be divided into 2 types, which are concentrating collector and non-concentrating collector according to whether it can concentrate or focus the sunlight. The non-concentrating collector (flat plate collector and evacuated tubular collector) can take benefits of the direct irradiation and scattered irradiation among the solar irradiation with the lower temperature of heat collecting. The concentrating collector can allow the sunlight converge on a small heat absorbing area, thus higher temperature can be obtained. But it only can utilize the direct irradiation and must follow the sun¡¯s path.