Class I area: the annual sunshine hours are 3200-3300 hours, and the annual radiation amount is 1860-2330 kWh/m2. It mainly includes: Qinghai-Tibet Plateau, northern Gansu, northern Ningxia and southern Xinjiang. Areas rich in solar energy resources.

Class II area: the annual sunshine hours are 3000-3200 hours, and the annual radiation amount is 1630- 1860 kWh/m2. It mainly includes northwestern Hebei, northwestern Shanxi, southern Inner Mongolia, southern Ningxia, central Gansu, eastern Qinghai, southeastern Tibet and southern Xinjiang. China is rich in solar energy resources.

Three types of areas: annual sunshine hours of 2200-3000 hours, annual radiation 1390- 1630 kWh/m2. It mainly includes Shandong, Henan, southeastern Hebei, southwestern Shanxi, northern Xinjiang, Jilin, Liaoning, Yunnan, northwestern Shaanxi, southeastern Gansu, southern Guangdong, southern Fujian, northern Jiangsu and northern Anhui.

Four types of areas: annual sunshine hours 1400-2200 hours, annual radiation amount 160- 1390 kWh/m2, mainly distributed in the middle and lower reaches of the Yangtze River, Fujian, Zhejiang and Guangdong, with rainy spring and summer and good solar energy resources in autumn and winter.

Five types of areas: the annual sunshine hours are about 1000- 1400 hours, and the annual radiation amount is 933- 1 160 kWh/m2, mainly including Sichuan and Guizhou provinces.