China’s small hydropower resources are mainly distributed in mountainous areas far away from large power grids. They are not only an important part of rural energy, but also a powerful supplement to large power grids.
According to the “World Small Hydropower Development Report” (WSHPDR2013), the global potential small hydropower resources are about 17.3 billion kW, more than half of which are distributed in Asia, and China is a country with very rich small hydropower resources.
In 2009, the Ministry of Water Resources released the results of the national survey and evaluation of rural hydropower resources. This survey and evaluation of rural hydropower resources is a supplementary review of the national hydropower resources review work from 2000 to 2004. For the first time, the theoretical reserve of single river hydropower resources is 10MW. The following rivers were examined in detail. The investigation and evaluation work involves more than 16,500 rivers in China. The evaluation results show that the theoretical reserves of rivers with a single river’s theoretical reserves of hydropower resources below 10,000 kW are 266.2 billion kW h of annual electricity and 30.39 million kW of average power. It can be seen from this Small rivers in China are rich in water and energy. The country’s single-station technology can develop a rural hydropower installed capacity of 100kW (inclusive) to 50,000 kW (inclusive) of about 128 million kW, ranking first in the world. 62% of the resources are concentrated in the western region, and the annual power generation can reach 5,350. 100 million kW. As of the end of 2005, the country has developed a rural hydropower installed capacity of 690.86 million kW, with an annual power generation of 287.5 billion kW·h, accounting for 54.0% and 53.7% of the technically developable and annual power generation, respectively.
From the perspective of distribution area (Figure 1), the technically exploitable capacity of rural hydropower resources in China is 2,909MW in North China, accounting for 2.3% of the country; 555MW in Northeast China, accounting for 4.3% of the country; and 18,839MW in East China, accounting for 14.7% of the country %; the central and southern regions are 27057MW, accounting for 21.1% of the country; the southwest region is 56740MW, accounting for 44.3% of the country; the northwest region is 16937MW, accounting for 13.2% of the country. Figure 2 shows the distribution map of the technically exploitable watersheds of China’s rural hydropower resources. The technically exploitable capacity of the Yangtze River Basin is 55,317MW, accounting for 43.2% of the country’s total.
Specifically, the south of the Yangtze River in China has abundant rainfall and steep rivers, and is the main area for the distribution of small hydropower resources. The small hydropower resources between the Yellow River and the Yangtze River are mainly located in the Dabie Mountains, the Funiu Mountains, the north and south of the Qinling Mountains, the south of Gansu and parts of Qinghai Province. Xinjiang, Tibet’s Himalayas, Kunlun Mountains, the north and south of the Tianshan Mountains, and the southern foothills of the Altun Mountains are areas where small hydropower resources are relatively concentrated. Small hydropower resources in North China and Northeast China are mainly concentrated in the Taihang Mountains, Yanshan Mountains, Changbai Mountains and the Greater Khingan Mountains. The provinces where small hydropower is mainly distributed are Hunan, Hubei, Guangdong, Guangxi, Zhejiang, Fujian, Jiangxi, Yunnan, Guizhou, Sichuan, Xinjiang and Tibet, etc. The small hydropower resources that can be developed in these provinces and autonomous regions account for about 80% of the whole country.
The overall distribution of water resources in rural China is uneven in time. Most rivers have large differences in runoff in the wet and dry seasons, and the distribution is uneven in space. There are more in the west and less in the east, and there are large differences in resource conditions between regions. The resource investment scale is moderate, the development is convenient, the construction period is short, and the effect is quick, and it is suitable for the development of local and rural collective economic organizations and farmers.
A hydroelectric project was built in Cragside, Northumberland, England, to power single-arc lamps. In 1880 and 1881 small hydroelectric plants in Grand Rapids, Michigan and Niagara Falls, New York, USA began to generate (direct current) electricity for milling plants. On September 30, 1882, in Appleton, Wisconsin, the first Edison hydroelectric power station, the Vulcan Street Power Plant, began generating electricity with an output of 12.5kW, which was listed by some institutions as the world’s first hydroelectric power station.
Since the 1930s, due to the development of large and medium-sized hydropower stations and the power industry, many countries have closed small hydropower stations or reduced the number and installed capacity of small hydropower stations. The United States closed 300 small hydropower stations from 1930 to 1970, France reduced the power generation of small hydropower stations by 78% from 1903 to 1975, and the Soviet Union saw a decline in the number and installed capacity of small hydropower stations after 1960.
In the late 1970s, due to the rising oil price and the energy crisis, many western countries paid more attention to small hydropower and carried out a series of survey, design and scientific research work. The United States has investigated and registered 3,000 small hydropower stations that have been closed, and conducted research on nearly 50,000 dams without hydropower stations. Small hydropower in other countries has also developed to varying degrees. In 1977, France had 978 small hydropower stations with a capacity of less than 10MW, with a total installed capacity of 490,000 kW and an annual power generation of 1.8 billion kW·h. Sweden had 1,050 small hydropower stations with an installed capacity of 550,000 kW and an annual power generation of 2 billion kW·h; Japan has 1,350 small hydropower stations with an installed capacity of 7 million kW, accounting for 6% of the country’s total installed power capacity.
In 2005, the global renewable energy market grew rapidly. The newly installed capacity of small hydropower in the world is 5 million kW, with a total of 66 million kW, of which 38.5 million kW of installed capacity is distributed in China.
By the end of 2012, the installed capacity of small hydropower (less than 10MW) was about 75 million kW, distributed in 148 countries and regions.
China’s hydropower industry also started from small hydropower.
Before the 1950s, apart from a few medium-sized hydropower stations in the northeast that were left for reinforcement and reconstruction, there were only very few small hydropower stations in the west that were initially constructed. Since 1912, when the first small hydropower station was built in mainland China, the Shilongba Hydropower Station in Yunnan, by 1949, the total installed capacity of small hydropower stations in China was only 3.7MW.
The Best in China: The First Hydropower Station in Mainland China
The first hydropower station in mainland China was the Shilongba Hydropower Station built in Kunming in 1912. This hydropower station diverted water from Tanglang River at the exit of Dianchi Lake to generate electricity. The initial installed capacity was 2 × 240kW, and it was gradually rebuilt and expanded to 2 × 3000kW in 1958.
After the founding of the People’s Republic of China in 1949, small hydropower began to develop.
The wooden and iron-wood combined water turbine produced by the processing plant, the power station runs in a single station, low-voltage power transmission, and provides lighting for users nearby.
In the 1960s, the development of small hydropower gradually accelerated, with an average annual installed capacity of tens of thousands of kilowatts. Some small hydropower stations began to be connected to the grid or connected to the large power grid, mainly for lighting and some agricultural and sideline products processing. At the same time, more than a dozen professional manufacturers of small hydro turbines have been formed in the country, with an annual production capacity of 100,000 kW. The hydro turbines are mainly metal structures.
Since the 1970s, the country has formulated policies to protect small hydropower in a timely manner, supporting small hydropower in terms of capital, technology and key raw materials. There are more than 60 professional manufacturers of hydraulic turbines and supporting equipment, and they have completed the production of hydraulic turbines. Serialization has formed a series of products from 250kW to 1200W.
The rapid development stage of small hydropower is after the 1980s. During the “Seventh Five-Year Plan”, “Eighth Five-Year Plan” and “Ninth Five-Year Plan” period, the construction of three batches of rural hydropower primary electrification counties has brought about qualitative changes in small hydropower. Reservoirs have been built upstream of many cascade power stations, which has improved the adjustment capacity. More than 80% of the power stations are no longer single-station operation, but integrated into the county power grid for unified dispatch of small hydropower to solve rural energy supply, improve rural natural environment, poverty alleviation and rural promotion. The important role in economic development has made small hydropower develop greatly in China’s rural areas, and has attracted great attention from Chinese and foreign public opinion. In view of the achievements of China’s small hydropower development, in 1981, the Asia-Pacific Small Hydropower Research and Training Center was established in Hangzhou, China. In 1998, the United Nations Development Program (UNDP) officially established the International Small Hydropower Center in China.
After decades of construction, China has established a set of relatively comprehensive rules and regulations for the planning, design, construction, acceptance, economic evaluation, equipment manufacturing, and testing of small hydropower and its supporting power grids, and has formulated a set of rural primary The electrification standard system has strengthened the standardization and typology of electromechanical equipment, creating favorable conditions for the construction of small hydropower and electrification.
By the end of 2013, China had built 45,000 small hydropower units, with a total installed capacity of 65 million kW and an annual power generation capacity of 2,000.00 kW·h, accounting for 24.3% of China’s hydropower installed capacity and annual power generation capacity of 2,000.00 kWh. 22.3%, occupying an important position in hydropower generation. According to the Research on China’s Energy Medium and Long-Term (2030, 2050) Development Strategy, the development and utilization of China’s small hydropower resources will continue to maintain a strong momentum in the future. By 2050, the total installed capacity of small hydropower in China will reach 100 million kW.
The development and utilization of small hydropower resources has obvious economic and social benefits, and has played a huge role in solving the problem of power supply in vast rural areas and remote mountainous areas and improving the ecological environment in small hydropower supply areas. However, while achieving remarkable achievements, there are also some problems that need to be solved urgently.
(1) The on-grid electricity price is low and the development cost is rising. Due to China’s special power system, the rules, standards and supporting laws and regulations for the sustainable development of small hydropower are not perfect, and the electricity price for development needs to be further established and improved, resulting in the low on-grid price of small hydropower. The unreasonable on-grid tariff policy of “one station, one price”, “old price for old power station, new price for new power station”, “low price for small units and high price for large units”, coupled with rising prices and labor costs, make small hydropower operations difficult. The low feed-in tariff is considered to be a major constraint in the development of small hydropower.
(2) Insufficient national investment. Compared with the important role that small hydropower plays in the coordinated economic development between regions, the state’s investment in small hydropower is very limited. At present, the applicable policies of the “Renewable Energy Law” for hydropower generation are still unclear, and there is a lack of preferential policies for the development of small hydropower. stability.
(3) Disorderly development and serious waste of resources. In some areas, the concept of economic development is deviated, one-sided pursuit of economic benefits, violation of river basin planning, laissez-faire and disorderly development of hydropower resources, multi-level development of the same river or cross-basin water diversion of power stations for power generation, etc., which seriously waste the existing small hydropower resources.
(4) It is easy to cause environmental and social problems. In the process of developing rural hydropower resources, hydropower development enterprises in some areas have adopted one-time cheap compensation for the occupation of rural resources, which makes farmers seriously threatened by loss of land and unemployment; in the construction process, due to inadequate environmental protection measures, it has caused damage to the local environment In particular, the hydropower stations developed by diversion do not consider the discharge of ecological flow, resulting in water reduction or dehydration in some river sections during dry seasons, resulting in a shortage of water for living and production downstream.
In addition, after years of development, the small hydropower resources that can be developed in the eastern and central regions of China have been basically developed. During the “Twelfth Five-Year Plan” and the future, the main battlefield of small hydropower development in China will be the vast western regions, especially the high-altitude regions in the southwest. Transfer, its technical difficulty, ecological environmental protection and social impact, etc., have put forward new requirements for the development of small hydropower in the new era.