The radiant power emitted by the sun into space is 3.8x1023kW, of which one-billionth reaches the earth’s atmosphere. 30% of the solar energy that reaches the earth’s atmosphere is reflected by the atmosphere and 23% is absorbed by the atmosphere. 47% reaches the surface of the earth, and its power is 80 trillion kW, which means that the energy of the sun shining on the earth every second is equivalent to the heat released by burning 5 million tons of coal.
The total annual energy consumption of human beings worldwide is only equivalent to the energy of the sun shining on the surface of the earth in 40 minutes. According to the international solar thermal utilization regional classification, the regions with the best solar radiation intensity and sunshine time in the world include North Africa, the Middle East, southwestern United States and Mexico, southern Europe, Australia, South Africa, South America East, West Coast, and West China.
According to the recommendation of the German Aerospace Technology Center (DLR), the solar thermal power generation technology and economic potential data of different regions and their technical potential are based on the measured value of solar annual irradiance greater than 6480MJ/m2, and the economic potential based on the measured value of solar annual irradiance is greater than 7200MJ/m2. North Africa is one of the regions with the strongest solar radiation in the world.
Morocco, Algeria, Tunisia, Libya and Egypt have great potential for solar thermal power generation. The total annual solar irradiation in Algeria is 9720MJ/m2, and the annual technology development is about 169440TW·h. The total annual solar irradiation in Morocco is 9360MJ/m2, and the amount of technology development is about 20151TW·h per year.
The total annual solar irradiation in Egypt is 10080MJ/m2, and the amount of technology development is about 73656TW·h per year. Countries with total annual solar radiation greater than 8280MJ/m2 also include Tunisia and Libya.
Algeria has a land area of 2381.7km2. The total annual solar irradiation in coastal areas is 6120MJ/m2, and the total annual solar irradiation in highlands and Sahara is 6840-9540MJ/m2. 82% of the country’s total land is suitable for solar thermal power generation The construction of the station.
The total annual solar irradiation in southern Europe exceeds 7200MJ/m2. These countries include Portugal, Spain, Italy, Greece and Turkey. The total annual solar irradiation in Spain is 8100MJ/m2, and the annual technology development is about 1646TW·h. The total annual solar irradiation in Italy is 7200MJ/m2, and the technology development volume is about 88TW·h per year. The total annual solar irradiation in Greece is 6840MJ/m2, and the annual technology development is about 44TW·h. The total annual solar irradiation in Portugal is 7560MJ/m2, and the technology development volume is about 436TW·h per year. The technology development volume in Turkey is about 400TW·h per year. The southern region of Spain is one of the areas most suitable for the construction of solar thermal power stations. The country is also one of the countries with the highest technical level of solar thermal power generation and the most construction of solar thermal power stations.
Solar radiation energy in almost all regions of the Middle East is very high. Countries such as Israel, Jordan and Saudi Arabia have a total annual solar irradiation of 8640 MJ/m2. The total annual solar irradiation in the UAE is 7920MJ/m2, and the technology development volume is about 2708TW·h per year. The total annual solar irradiation in Israel is 8640 MJ/m2, and the technology development volume is about 318TW·h per year. The total annual solar irradiation in Iran is 7920MJ/m2, and the annual technology development is about 20PW·h. The total annual solar irradiation in Jordan is about 9720MJ/m2, and the amount of technology development is about 6434TW·h per year. The total land area of Israel is 20330km2; the Negev desert covers half of the country’s land and is also one of the best areas for solar energy utilization. Israel’s solar thermal technology is among the highest in the world. my country’s first 70KW solar tower thermal power plant was built using Israeli technology.
The United States is also one of the regions with the richest solar energy resources in the world. According to the statistical data of 239 observatories in the United States from 1961 to 1990, the total annual solar radiation in the first-class areas of the country is 9198 to 10512 MJ/m2. The first-class areas include all of Arizona and New Mexico, California, Nevada, Utah, Colorado and southern Texas account for 9.36% of the total area. The total annual solar radiation in the second-class area is 7884-9919MJ/m2. In addition to the rest of the states listed in the first-class area, it also includes Utah, Wyoming, Kansas, Oklahoma, Florida, Georgia and South Carolina. , Accounting for 35.67% of the total area. The total annual solar irradiation in the three types of areas is 6570～7884MJ/m2, including most of the northern and eastern United States, accounting for 41.81% of the total area. The total annual solar radiation in the four types of areas is 5256-6570 MJ/m2, including most areas of Alaska, accounting for 9.94% of the total area. The total annual solar irradiation in the five areas is 3942~5256MJ/m2, including only a few of the northernmost parts of Alaska, accounting for 3.22% of the total area.
The outer islands of the United States such as Hawaii belong to the second category. The southwestern United States has a high average temperature throughout the year and has a certain water source. There is no severe cold in winter. Although it is a hilly area, there are many flat areas. As long as it avoids strong winds, it is a very good solar thermal power generation area.
Australia’s solar energy resources are also very rich. The total annual solar radiation in the first-class areas of the country is 7621-8672MJ/m2, mainly in northern Australia, accounting for 54.18% of the total area. The total annual solar irradiation in the second-class area is 6570～7621MJ/m2, including central Australia, which accounts for 35.44% of the national area. The total annual solar irradiation of the three types of areas is 5389～6570MJ/m2, which accounts for 7.9% of the national area in the southern area of Australia. The four types of regions with total annual solar radiation below 6570 MJ/m2 account for only 2.48%. Recently, Australia also proposed a large-scale solar energy development and utilization investment plan to increase the utilization rate of renewable energy.
China has a total land area of 9.6 million square kilometers, which is 7% of the total land area of the world, and has very rich solar energy resources.
The total annual solar radiation throughout the country is 3340-8400MJ/m2, with a median value of 5852MJ/m2. From the perspective of the distribution of the total annual solar radiation in China, Tibet, Qinghai, Xinjiang, southern Ningxia, Gansu, southern Inner Mongolia, northwestern Shanxi, northern Shaanxi, Liaoning, southeastern Hebei, southeastern Shandong, southeastern Henan, western Jilin, Yunnan The central and southwestern regions, southeastern Guangdong, southeastern Fujian, the eastern and western parts of Hainan Island, and the southwestern region of Taiwan Province have large total solar radiation.
In particular, the Qinghai-Tibet Plateau is the largest, where the average altitude is above 4000m, the atmosphere is thin and clean, the transparency is good, the latitude is low, and the sunshine duration is long. For example, the city of Lhasa, known as “Sun City”, has an average of 1961-1970. The annual average sunshine time is 3005.7h, relative sunshine is 68%, the annual average sunny day is 108.5d, the cloudy day is 98.8d, the annual average cloud The amount is 4.8, and the annual total solar radiation is 8160MJ/m2, which is higher than other provinces and regions in the same latitude.
The total annual solar radiation in Sichuan and Guizhou provinces and Chongqing is the smallest in the country, especially in the Sichuan Basin, where there is much rain, fog and sunny days. For example, Chongqing, known as the “Fog City”, has an average annual sunshine duration of only 1152.2h, a relative sunshine of 26%, an average sunny day of 24.7 days, a cloudy day of 244.6 days, and an average annual cloud cover of 8.4. The total annual solar radiation in other regions is in the middle.
The main characteristics of the distribution of solar energy resources in China:
① The high-value center and low-value center of solar energy are located at 22°~35° north latitude. In this area, the Tibetan Plateau is the center of high value, and the Sichuan Basin is the center of low value;
②Total annual solar radiation, the western region is higher than the eastern region, and except for Tibet and Xinjiang, the southern region is basically lower than the northern region;
③Because most clouds in the south are rainy and rainy, they are 30°~40° north latitude. In regions, the distribution of solar energy is contrary to the general rule that solar energy changes with latitude. Solar energy does not decrease with increasing latitude, but increases with increasing latitude.
In order to make better use of solar energy according to different conditions in various regions, Chinese researchers in the 1980s divided the country into the following five categories according to the total amount of solar radiation received by various regions.
(1) Class 1 area
The annual sunshine hours are 3200~3300h. The total amount of solar radiation received in one year per square meter area is 6680~8400MJ, which is equivalent to the heat generated by the combustion of 225~285kg standard coal. It mainly includes northern Ningxia, northern Gansu, southeastern Xinjiang, western Qinghai and western Tibet. It is the region with the most abundant solar energy resources in China, which is comparable to the solar energy resources in India and northern Pakistan. Especially in western Tibet, solar energy resources are the most abundant. The annual sunshine hours reach 2900~3400h, and the total annual radiation is as high as 7000~8000MJ/m2, second only to the Sahara Desert, ranking second in the world.
(2) Type II area
The annual sunshine hours are 3000~3200h. The total amount of solar radiation received in one year per square meter area is 5852~6680MJ, which is equivalent to the heat emitted by 200~225kg standard coal combustion. It mainly includes northwestern Hebei, northwestern Shanxi, southern Inner Mongolia, southern Ningxia, central Gansu, eastern Qinghai, southeastern Tibet and southern Xinjiang. It is a region rich in solar energy resources in China. The equivalent of Jakarta in Indonesia.
(3) Three types of regions
The annual sunshine hours are 2200~3000h. The total amount of solar radiation received in one year per square meter area is 5016~5852MJ, which is equivalent to the heat emitted by 170~200kg standard coal combustion. Mainly include Southeast Shandong, Southeast Henan, Southeast Hebei, Southwest Shanxi, Northern Xinjiang, Jilin, Liaoning, Yunnan, Northern Shaanxi, Southeast Gansu, Southern Guangdong, Southern Fujian, Northern Jiangsu, Northern Anhui, Tianjin, Beijing and Taiwan Southwest and other places. It is a medium type area of China’s solar energy resources. Equivalent to the Washington area of the United States.
(4) Four types of regions
The annual sunshine hours are 1400~2200h. The total amount of solar radiation received in one year per square meter area is 4190~5016MJ, which is equivalent to the heat generated by the combustion of 140~170kg standard coal. It mainly includes Hunan, Hubei, Guangxi, Jiangxi, Zhejiang, northern Fujian, northern Guangdong, southern Shaanxi, southern Jiangsu, southern Anhui, and Heilongjiang and northeastern Taiwan. It is a region with poor solar energy resources in China. Equivalent to the Milan area of Italy.
(5) Five types of regions
The annual sunshine hours are 1000~1400h. The total amount of solar radiation received in one year per square meter area is 3344~4190MJ, which is equivalent to the heat emitted by 115~140kg standard coal combustion. It mainly includes Sichuan, Guizhou, Chongqing and other places. This area has the least solar energy resources in China. Equivalent to most parts of Europe.
Types I, II, and III regions have annual sunshine hours greater than 2200h and total annual solar radiation greater than 5016MJ/m2. They are regions with abundant or relatively rich solar energy resources in China. The area is relatively large, accounting for about 2/3 of the total area of the country. Above, there are good conditions for using solar energy. In the fourth and fifth areas, although the solar resource conditions are poor, they also have a certain utilization value, and some of them may be developed and utilized. In short, from a national perspective, China is a country with abundant solar energy resources, and has unique advantages for developing solar energy utilization. As long as we work hard and solidly, solar energy utilization has broad development prospects in my country.
Compared with other countries of the same latitude, China’s solar energy resources, except for the Sichuan Basin and its adjacent areas, are vastly rich in solar energy resources, similar to the United States, and much more favorable than Japan and Europe, especially the Tibetan Plateau The solar resources in the west and southeast of the country are particularly abundant, close to the world’s most famous Sahara desert.