By Hongbing Zhu, Jun Chen, and Xueyuan Cheng
China is constructing more than 90,000 mw of new hydro. Much of this development is guided by the concept of multi-purpose utilization of water resources. Development of the resources in the Yangtze River Basin serves as an example.
Operating hydro plants in China represent a total capacity of about 117,000 mw. This accounts for about 25 percent of the country’s total installed generating capacity. Opportunities for additional hydro development are abundant. A recent study, “Comprehensive Utilization Plan of the Yangtze River Basin,” indicates hydro potential of about 694,000 mw. Of this, about 58 percent is economically feasible to develop.
Most of the hydro potential is in the southwestern area of China. However, most of the population centers are in the eastern part of the country. In 1993, the government developed a “Scheme of Electricity Transfer from West to East.” This involves developing hydro plants in the west, then transmitting the electricity through high-voltage lines to eastern China. As part of both this scheme and the 11th National Master Plan, China’s goal is to have installed hydro capacity of 388,000 mw by 2020. To build this capacity, China plans to spend more than 1 trillion renminbi (RMB) (US$132.5 billion) on large hydro projects. And the country also is increasing its small hydro portfolio of projects, as described in the box on page 26.
More than 170 hydro projects, totaling more than 90,000 mw, are now under construction. These projects include 6,300-mw Longtan on the Hongshui River, 4,200-mw Laxiwa on the Yellow River, and 12,600-mw Xiluodu on the Jinsha River. Xiluodu is to be the second largest hydro project in China, behind 18,200-mw Three Gorges (which is being expanded to 22,400 mw with the addition of six units in an underground powerhouse). Eventually, Xiluodu is to be expanded to 14,480 mw.
Beyond the projects under construction, more than 250 hydro projects are proposed for development in China, with a total capacity of more than 180,000 mw. These projects include 12,000-mw Baihetan on the Jinsha River, to be the third largest hydro project in the country; 5,850-mw Nuozhadu on the Lancang River; and 8,400-mw Hutiaoxia on the Jinsha River.
Why focus on hydro?
Hydroelectric power is a valuable resource for China for two primary reasons. First, because of the significant potential, it can be developed on a large scale. Second, hydropower is a clean energy source that does not pollute the atmosphere or cause ecological damage through discharge into the water.
Thermal plants discharge pollutants, causing environmental damage due to burning of large amounts of coal and ecological damage due to release of industrial residue and wastewater.
In 1980, China’s thermal power capacity was 45,550 mw, and these plants generated 37.6 million tons of soot, sulfur dioxide, and ash. Just 15 years later, thermal capacity had grown to 162,940 mw, with generation of 109.3 million tons of pollutants.
Over the past 16 years, development of hydro facilities has allowed China to cease generation from some thermal plants. This has reduced emissions (including industrial waste) in the country by about 27 percent.
In addition, by developing hydro projects, the country can reduce the pressures related to shortages of coal or oil, as well as the issues surrounding transportation of these resources. At present, the major energy resource in the country is coal. However, proven reserves of coal can only meet 20 to 30 years worth of energy demand. According to recent energy production and consumption figures in China, hydropower provides 5.5 percent of the total. But the government plans to increase this portion to 30 percent.
More than 170 hydroelectric projects are under construction in China. As part of the government’s new strategy, hydro project development is guided by multi-purpose utilization of water resources. Click here to enlarge image
Hydropower is also a valuable source of peaking power and transmission-related services, such as frequency adjustment for load following, load backup, and as a backup in the event another resource experiences an outage. The economic efficiency of hydro plants in China is four to ten times that of thermal power.
Developing multi-purpose projects
As China proceeds with developing its hydro potential, a prominent trend is to make comprehensive use of a water resource for multiple purposes, not just for power generation. These purposes include: flood control, irrigation, navigation, water supply, aquaculture, control of ice during the spring thaw, recreation, and ecology.
Since the 1990s, China has attached more importance to multi-purpose, comprehensive use of water resources to achieve harmony between people and nature and to provide for sustainable development. This allows comprehensive considerations of social, economic, and cultural factors, as well as coordination to benefit the different sectors.
For example, the primary purpose of the 22,400-mw Three Gorges project is flood control. More than half of the reservoir capacity at this facility can be used to control floods. Hydroelectric generation is a secondary but vital purpose because it supplies direct economic benefits through the sale of electricity. The third purpose is river navigation.
Multi-purpose projects have several advantages. They attract wider support and face less opposition than single-purpose projects. They also can be easier to finance because of the prospect of attracting money from multiple sources, based on the non-power benefits they create.
Benefits of multi-purpose development
In China, one of the main benefits of multi-purpose dam development is flood control. This is particularly true for the Yangtze River Basin area. As China focuses on implementing a sustainable development strategy for this river basin, the population will increase, more land will be used in the area, and industrial and agricultural development will increase. This will make flood control for this area even more vital.
Development of hydro project reservoirs allows better flood control downstream. Some reservoirs of hydropower stations will be the key structures in the country’s flood control system. By restricting the amount of water that can be impounded behind the dam during the flood control season, generating capacity at the facilities will be less. However, the resulting social benefits from flood control are worth the tradeoff. In fact, the country’s “Water Act” and “Flood Prevention Law” both place an obligation on hydropower development to provide flood control.
At present, the system of dams on the middle and lower reaches of the Yangtze River can only control under-ten-year floods. When the Three Gorges project is completed, the system will be able to control 100-year floods. This will protect 15 million people and 1.5 million hectares of farmland from the threat of floods.
A second benefit of multi-purpose dams is waterway navigation. To foster modern transportation, ship locks are being constructed as part of dam development. In addition to allowing passage of boats to various stretches of the river, dam construction improves navigable conditions both upstream and downstream due to control and regulation of flow. As part of the development of the Three Gorges project, the large reservoir is greatly improving the 660-kilometer navigation channel running from Yichang to Chongqing. A 10,000-ton barge fleet can arrive directly in Chongqing Harbor. Annual one-way navigation capacity is increasing to 50 million tons from 10 million tons.
Poverty reduction is a third benefit of multi-purpose dam development in China. Hydropower development has a significant effect on regional economic development. To determine the effects of the development of multi-purpose projects, the government of China investigated 21 representative large and medium-sized hydropower stations. Results showed great economic and social benefits.
For example, five power plants have been built on the Yellow River from 1968 to 2000 — 272-mw Qingtongxia, 1,160-mw Liujiaxia, 1,280-mw Longyangxia, 2,000-mw Lijiaxia, and 1,080-mw Wanjiazhai. Since these plants were put into operation, gross national product in the area increased tenfold. In addition, several cities with a population of 20 million to 30 million each were formed in the area.
Flooding in cities in China causes significant economic losses and loss of human life. Development of multi-purpose hydro projects that control floods, among other factors, is important to the well-being of the country’s residents. Click here to enlarge image
When the 900-mw Danjiangkou station on the Han River was completed in 1958, Danjiangkou grew from a small trading town into a city with a population of more than 100,000. Hydro project construction provided employment for local farmers. The plant attracted industrial investment, including construction of the China Second Automobile Factory in Shiyan, with a guaranteed power supply via a short transmission line. This greatly improved the socio-economic situation in the northwest region of Hubei Province by providing jobs and industrial development.
Construction of the 500-mw Dongjiang project on the Laishui River, completed in 1992, resulted in inundation of 57,000 acres of farmland in Zixing City. However, in 1994, the city’s industrial output value and local fiscal revenues were 6.1-fold and 7.9-fold greater, respectively, than the situation before construction.
Once the 663-mw Xin’anjiang project on the Xinan River was put into production, new cities like Chun’an and Jiande were created. The industrial output of these cities, together with the surrounding six counties, represented an increase of 5.1 to 7.1 times the situation before construction.
The study also indicated that, on average, production of 1 kw of hydropower can relieve the loss of 5.2 acres of farmland inundated by flooding each year, increase the irrigation area by 2.1 acres, add 2.9 kilograms of aquatic products in the reservoir, provide 393 cubic meters of water for industrial and agricultural production and domestic consumption, and allow for new development of 0.2 acre of farmland and woodland. At the time of the study, the total comprehensive conversion value efficiency of these gains was computed at 354 RMB (US$47) per kw.
Multi-purpose development in action
Development of the Yangtze River Basin provides an example of the concept of multi-purpose dam development in China. Planning for development in this basin involved formulating a long-term plan for the comprehensive development, use, harnessing, and protection of the water resources in the river. Uses studied included flood control, water-logging control, training of the river channel in the middle and lower reaches, hydropower development on the upper reaches, navigation of the main reach, water and soil conservation, irrigation, and water protection.
The main reach of the Yangtze River, from Yibin to Yichang, is 1,036 kilometers long. The drainage area above Yichang covers about 1 million square kilometers and generates an average annual runoff of 451 billion cubic meters and an annual sediment discharge of 530 million tons. During the flood season, this water accounts for 90 percent of the flood volume at Zhijiang and 60 percent at Hankou. Because of this, the main purposes of development in the upper reaches of the mainstream Yangtze River are, in order, flood control, power generation, and navigation. Development also considers aquaculture and recreation.
The river reach above Chongqing is characterized by flat terrain on both banks. Thus, only low-head projects are appropriate to develop to avoid excessive losses due to inundation. In this area, the main purpose of development is navigation, followed by power generation.
During formulation of the development plan for this stretch of the Yangtze River, a five-step scheme was recommended for the reach from Yibin to Yichang. Projects to be developed were 2,715-mw Gezhouba and Three Gorges (both now operating), as well as 1,000-mw Xiaonanhai, 1,900-mw Zhuyangxi, and 2,130-mw Shipeng, all still to be developed. When these five projects are completed, the river will have 16.8 billion cubic meters of active storage capacity, 22.1 billion cubic meters of flood control storage capacity, and 25,400 mw of power generation capacity. In addition, navigation conditions in the river will be greatly improved, and flooding in the middle and lower river, particular the Jingjiang Reach, will be alleviated.
From Yushu in Qinghai to Yibin in Sichuan, the Yangtze River is called the Jinsha River. This 2,290-kilometer-long stretch of the river has superior conditions for the development of hydro projects. The comprehensive utilization plan for the basin, revised in 1990, proposed nine plants in a cascade from Yushu to Shigu with total installed capacity of more than 15,000 mw. When completed, these plants will provide annual energy of about 80,000 gigawatt-hours (gwh). One of these projects, 161-mw Dongjiula, is being developed. The other eight, not yet under construction, are 150-mw Baili, 2,800-mw Baimian, 2,500-mw Batang, 900-mw Enan, 3,200-mw Jiangquhekou, 177-mw Chaila, 2,500-mw Tuoding, and 2,800-mw Wangdalong.
From Shigu to Panzhihua, the government proposed six plants in a cascade with total installed capacity of 19,000 mw to 20,900 mw. The plants are 4,000-mw Hutiaoxia Upper Reach, 4,400-mw Hutiaoxia Lower Reach, 5,000-mw Hongmenkou, 2,500-mw Zili, 2,500-mw Pichang, and 2,500-mw Guanyinyan. And on the lowest reach, from Panzhihua to Yibin, four plants in a cascade are proposed. This would include 7,400-mw Wudongde and 12,000-mw Baihetan, as well as Xiluodu and 6,000-mw Xiangjiaba, both under construction.
In total, the 19 power stations on the main reach of the Yangtze River would have total installed capacity of 78,000 mw to 80,000 mw. With an expected annual output of 374,000 to 380,500 gwh, this equals about 17.8 percent of the developable power generation in the entire country. After completion of all the plants, China can use the annual output of the hydro plants to reduce coal consumption by 200 million tons at thermal plants.
In addition, these 19 reservoirs will have a total gross storage capacity of about 130 billion cubic meters and total active storage capacity of 50 billion cubic meters. The dams also will provide significant benefits related to sediment interception, irrigation, timber floating, soil conservation, and navigation.
The concept of integrated multi-purpose hydropower projects guides the development of China’s water resources. It is vital that hydro project development includes comprehensive consideration of social, economic, and cultural factors, allowing development to provide adequate benefits for all. By carefully implementing the concept of responsible sustainable development, China is building projects that boost local economies, harmonize with the environment, and benefit local communities.
Dr. Zhu may be reached at the Sci-technology and Environmental Protection Department and Mr. Chen and Ms. Cheng may be reached at the International Cooperation Department, China Three Gorges Project Corporation, 1 Jianshe Road, Yichang, Hubei 443002 China; (86) 717-6767450 (Zhu), (86) 717-6767257 (Chen), or (86) 717-6762290 (Cheng); E-mail: email@example.com, firstname.lastname@example.org, or chengxy@ ctgpc.com.cn.
Hongbing Zhu is senior engineer in the sci-technology and environmental department, Jun Chen is deputy division chief of the international cooperation department, and Xueyuan Cheng is project coordinator in the international cooperation department of China Three Gorges Project Corporation.
© Developing Small Hydropower in China
China has abundant hydropower resources, of which a large part is small hydropower (SHP) resources. In China, small hydro is defined as having a capacity from 501 kw to 25 mw. The economically developable potential of these resources amounts to 100,000 mw. The central government always has recognized the possibilities offered by development of SHP resources, and today these facilities serve more than 300 million people in rural areas of China.
The country’s program to develop SHP resources began in the 1960s. Development continues at a fast pace today. About 3,000 SHP plants are under construction, for a total capacity of about 8,000 mw.
Two recent developments have led to an increase in SHP development in China. First, hydro project development has evolved into a market-driven process, based on profit and cost-effectiveness. Traditionally, hydro projects were managed by decentralized state-owned entities, in order to carry out social equity principles. However, the economic policy in China changed from a planned economy to a market economy. This revitalized the power market, allowing private companies to develop many construction projects, including SHP. While state-owned enterprises do develop economically viable projects, they now primarily develop economically unsustainable projects that are required to resolve the electricity shortage.
Second, the development of very rigorous licensing requirements for power projects can pose barriers to traditional large hydropower development. Because of strict environmental requirements in the power industry, hydropower development has become a highly contentious issue. Both large and small hydro projects have obligations regarding the environment. However, SHP has a lower environmental cost because they submerge less land and do not displace as many people. Consequently, the government more readily approves SHP development, making it more attractive.
Two significant events enhance the outlook for SHP development in China. First, the Kyoto Protocol, which entered into full force in February 2005, created new opportunities for financing SHP projects. The Kyoto Protocol stipulates actions to be taken by the signatory nations to combat global climate change. Its main goal, to be achieved in 2012, is to reduce greenhouse gas emissions by an average of 5.2 percent of the values recorded in 1990 for industrialized countries (called Annex I countries). Receiving funding for carbon credits generated by SHP activity under the Clean Development Mechanism fosters the development of new projects.
Second, the country’s leaders recently decided to integrate sustainable development principles into the constitution of the Communist Party, in order to develop better management of environmental issues. This decision was intended to give a sense of responsibility. It will allow implementation of new policies to realize energy savings and to reduce emissions.
— By Tong Jiandong, director general, and Aurélien Baudoin, assistant program officer, International Network on Small Hydropower, 136 Nanshan Road, Hangzhou, Ahejiang 310002 People’s Republic of China; (86) 571-87132792 (Jiandong) or (86) 571-87132790 (Baudoin); E-mail: email@example.com or firstname.lastname@example.org.