Article de Qi Wei Li (EnvIM 2019)

 

Introduction

Recently, thanks to global climate change strikes, there is more public attention to global warming and climate change worldwide. To deal with such dilemma, investing in renewable energy being one of the solutions, China is making effort to reduce carbon emission by adopting higher percentage of renewable energy. Therefore, for this blog, I would like to focus on the discussion of hydropower in China as related to its development and the challenges.

As part of the Paris Agreement, China has agreed with the target of controlling the temperature to below 2°C or even 1.5°C by the end of this century. Also, suggested by the Intergovernmental Panel of Climate Change (IPCC), renewables need to supply 70-85% of electricity in 2050 with the 1.5°C pathway scenario (IPCC, 2018). China agrees to put a peak on the CO2 emission and raise the fraction of non-fossil energy (primary energy consumption) to about 20% by 2030 (IPCC, 2018). So far, China has made great efforts to this end; at the end of 2017, the global installed capacity of renewable energy power generation reached 2,179 GW (including hydropower and ocean energy, solar energy, wind power, bioenergy, and geothermal energy), of which China accounted for 28.4%, making China a global leader (Li et al, 2018). Furthermore, the installed capacity of hydropower is about half of the total installed capacity of all renewable energy in China, making hydropower an important renewable energy of China (Li et al, 2018).

China’s hydropower resources are relatively abundant and large-scale development began in the modern times. The current level of technology and achievements of hydropower in China are already in the leading position in the world, but the degree of utilization is still low compared to the developed countries, which is 37% by the end of 2015 (National Energy Administration of China, 2017). The development of hydropower in various regions of the country is affected by factors including water resources reserves and economic development. At present, hydropower development in the Northwest is the most promising in the country (Li et al., 2018).

The basic principle of hydropower is to use the drop of the water level to generate electricity with hydroelectric generators and to convert water energy into mechanical energy and then to electric energy (Ye, 2002). Ranges of hydropower installed can be divided into large for 100 Megawatts or more, medium for 5 to 100 Megawatts and small hydropower stations for below 5 Megawatts (Ye, 2002).

As a renewable energy source, water has great natural advantages, because as long as the development is in place, water can be considered inexhaustible as long as water resources remain unchanged. Therefore, the efficiency of hydroelectric power generation is high, reducing the power generation cost. On top of generating power, the construction of hydropower stations can also be used as flood control, irrigation, aquaculture, and even as tourist sites (Li et al., 2018).

However, hydropower has some shortcomings, among which the main ones include the impact on the environment and local residents. Although hydropower has brought indispensable benefits to the environment, such as contributing to lower carbon emissions and atmospheric pollution, the construction of power stations has brought some disadvantages to the environment, especially large hydroelectric power stations (Botelho et al., 2017). These large projects will undoubtedly take up a lot of land area and bring a lot of pressure to the existing ecosystem (Botelho et al., 2017). The construction of the dam will change the flow of water and wildlife habitats, thereby destroying the life of animals and plants in the area, especially the aquatic animals upstream and downstream (Botelho et al., 2017). During the construction period, a lot of noise and dust will also affect the local environment. When the ecological environment is destroyed, natural disasters such as earthquakes and landslides may also be induced (Botelho et al., 2017). For example, field studies estimate that between 400 to 770 vascular plant species are at risk for flooding as for the consequence of the Three Gorges Dam, and two species could become extinct (Xie et al., 2006). Furthermore, the resettlement of local residents is also problematic. Some 10.2 million people were recognized as “reservoir settlers” in China in the late 1980s (World Commission on Dams, 2000). These people suffer economically and socially. They face impoverishment risks that include but not limited to landlessness, joblessness, homelessness, marginalization, food insecurity, increased morbidity, loss of common resources (World Commission on Dams, 2000).

 

Development of Hydropower in China

The development of hydropower in China can be generally divided into 4 phases from 1949 to today. The first phase is from the establishment of the first hydroelectric power station to the year of 1949, the establishment year of the People’s Republic of China. During this period, the main driving force for hydropower development was military and industrial production (Kang, 2014). Shilongba Hydropower Station is China’s first hydroelectric power station. It was built in Kunming, Yunnan Province in 1911 and is more than 30 years older than the world’s first hydroelectric power station (Kang, 2014). This hydroelectric power station initially had only two hydroelectric generating units with a capacity of 240 kW (Kang, 2014). Since then, China built a total of 22 large hydropower plants, but many of them were destroyed during the war (Kang, 2014). During this time, the public did not have enough knowledge of the idea of electricity, they were neutral about the establishment of power stations in China.

The second stage was up to the end of the Cultural Revolution after liberation to 1980. During this phase, hydropower did not develop much. More dams were used for irrigation and flood control. Therefore, most of the dams built during this period were small and medium-sized. Moreover, because the mining process has been developed, coal can provide a large amount of power support, and hydropower is neglected (Kang, 2014). The most famous dam constructed during this period was the Sanmenxia Yellow River Dam built in 1961 (Kang, 2014). This dam was initially opposed by many water conservancy experts, including Huang Wanli, a water conservancy expert at Tsinghua University. After the completion of the dam, it remained controversial for many years as soon after the completion, sediment was accumulating and caused severe flooding on the Wei River upstream causing many disasters to the local people (Kang, 2014).

The third phase is from 1980 to 2000, during which hydropower in China was developed relatively fast. During this period, through the massive investment of the World Bank, the Asian Development Bank and other foreign governments, dams that were previously impossible to construct for economic and technical reasons were built up (Kang, 2014). As early as 2000, China’s hydropower installed capacity reached 77 Gigawatts, becoming the world’s second largest hydropower development country (Kang, 2014). However, thermal power generation, especially coal burning, can solve the demand for electricity quickly, therefore its utilization rate has reached more than 70%, leaving much of the hydropower curtailed. The construction of the famous Three Gorges Dam was started during this phase, and this world’s largest hydropower project can have an installed capacity of 22.5 Gigawatts (Wilmsen, 2016). In addition to providing electricity, the additional objectives of the Three Gorges Dam are to provide flood storage space and increase the shipping capacity of the Yangtze River. Of course, this project has also received a lot of objections, including the transfer of archaeological and cultural sites, the transfer of millions of local residents, and the possibility of landslides (Lu, 2000).

The fourth stage started in 2000: hydropower development during this period has continued to rise. As China becomes more market-oriented and accepts more foreign investment, China’s economy has made significant progress while demand for electricity has also increased significantly (Kang, 2014). At the same time, the government has begun to control carbon emissions. At the beginning of this period, despite the hydropower capacity, only 25-30% were used due to curtailment (Kang, 2014). In 2009, 24% of electricity generation was provided by hydropower (Li et al., 2018). In 2010, China became the world’s largest hydropower producer. During this period, China no longer needs to use equipment and engineers from abroad, and private equity funds were allowed to invest in hydropower projects (Kang, 2014). The most controversial project during the period was the attempt to build a dam on the Nu River, which remains the only large river in China that did not have a dam today (Kang, 2014).

By the end of 2017, China’s hydropower installed capacity has reached 313 Gigawatts, accounting for 50.5% of China’s total installed renewable energy. It is estimated that, by 2020, the installed capacity of hydropower will reach 343 Gigawatts (Kang, 2014). In the past 100 years, the development of China’s hydropower has finally reached a new height (see Figure 1; especially in terms of technology, it can be said to be the world leader in terms of equipment, construction, operation and management, but some factors are still restricting the future of China’s hydropower if China ever wanted to further increase its proportion usage of hydropower.

 

Figure 1. Hydropower development in China (Ran & Lu, 2013)
Figure 1. Hydropower development in China (Ran & Lu, 2013)

 

 

Challenges for hydropower development in China

The major challenges of future hydropower development revolve around the problem of water curtailment. According to the definition of the Chinese National Energy Administration, the curtailment of water refers to the amount of water that the power station can use to generate electricity under the power generation capacity but is not actually used for power generation due to various reasons. There are many reasons for hydropower curtailment, including some natural factors, hydropower station’s own factors and social factors.

Natural factors are the most difficult to control. For example, rainfall in some areas is very irregular, and the dry season and the rainy season are completely different. For example, the water intake of the Jinanqiao Water Station during the flood season is about 7 or 8 times that of the regular intake (Liu et al., 2018). In addition, many rivers in China have a large slope, which leads to higher requirements of water storage capacity. However, at the same time, China is in tight in land, large storage capacity leads to additional relocation of people, which then leads to excessive costs and social issues of resettlement, therefore often the reservoir capacity is not sufficient. The combination of extreme weather situation and insufficient reservoir capacity will result in the water not passing through the turbine to generate electricity, but directly passing by the dam, leading to the curtailment of water directly (Liu et al., 2018).

The second factor is the hydropower station’s own factors. First of all, the general construction period is relatively long, especially for large hydropower stations. Therefore, when these power stations are built, they may encounter difficulties that have not been considered before (Zhang, 2016). For example, the construction of the power transmission line was not up to speed with the development of new dams (Zhang, 2016). In addition, In China, there is the concept of power transmission from west to east; because water resources are concentrated in the southwestern region, and there is a primary energy shortage in the east with relatively heavy electricity load (Zhang, 2016). Therefore, the problem of long-distance transmission of electricity has aggravated the problem of water curtailment caused by the unsynchronized construction of power lines (Wang, 2016). For example, the hydropower sent from Yunnan to Guangxi was originally planned to be transmitted by constructing a 500 kV UHV grid, but the Yunnan provincial government did not agree to the construction. As a result, the transmission of this West-East power transmission was completed through the provincial AC backbone line, but this line cannot accommodate such large amount of power, resulting in a lot of water and electricity curtailment until the establishment of the 500 kV UHV grid four years later (Wang, 2016).

The third major factor is social factor. First, market-oriented development has a negative impact on the construction of hydropower projects in China (Zhang, 2016). Unlike the United States, the central government of China is not directly responsible for the development of large-scale hydropower projects (Zhang, 2016). With harsh market competition, the social benefits of these large-scale hydropower become undermined (Zhang, 2016). Many state-owned power companies who are all capable of building large dams go into local competition for hydropower projects, which makes local governments view these projects as a channel for profit (Zhang, 2016). This kind of mentality of local governments has led to a raise of resettlement and environmental protection costs in hydropower development, resulting in the delay and even incompletion of some leading hydropower stations (Zhang, 2016). These leading hydropower stations are the most upstream control reservoirs in the cascade hydropower stations, and the scale is generally large, which plays a critical role in controlling and regulating the reservoirs downstream (Qian, 2017). Therefore, the lag of the construction of these leading reservoirs will lead to insufficient downstream capacity to adjust for dry and abundant seasons: large amount of water will then become discarded during the flood season, and the power generation become insufficient due to lack of water during the dry season (Zhang, 2016).

Recently, China’s energy structure is being forced to adjust slowly. Although the rate is slowing down, there are still new coal-fired power units constructed every year, which will lead to overcapacity in the entire power industry (Wang, 2016). The current slowdown of the increasing demand in electricity of the whole society has further worsened the problem of overcapacity, which has led to the squeeze of the market for clean energy, which has led to many problems of curtailing water electricity (Wang, 2016).

In fact, these factors also affect each other, making the problem of water curtailment more serious. Of course, there is also an economic factor. Due to the loss of water curtailment, investors will take a wait-and-see attitude, and even some projects that have obtained approvals have been postponed (Zhang, 2016). Because of the reduction in investment, the lag in the development of the leading water station mentioned above will further lead to the curtailment of water, which leads to a negative cycle.

 

Conclusion

In facing the dilemma of global warming and climate change, China is making efforts to employ more renewable energy. Hydropower is a mature renewable energy that has developed tremendously for the past 100 years. However, challenges in further development of hydropower exist, and thus opportunities also exist. Compared with China’s curtailment of wind and sunlight, the problem of water is less severe, but this problem is curbing the future of China’s hydropower and China’s realization of a high proportion of renewable energy. Resolving the curtailment of water has become part of the goal of ensuring non-fossil energy development in the 13th Five-Year Plan (National Energy Administration of China, 2017). In 2017, the Energy Bureau issued the “Implementation Plan for Solving the Problem of Water, Wind and Solar Curtailment”. In the case of serious water curtailment, the Energy Bureau will conduct monthly inspections, quarterly assessments, and annual warnings.

But to make things more complicated, in the context of climate change, changes in climate patterns not only affect precipitation and precipitation patterns, but also cause precipitation redistribution on both dimensions of time and space, and increase the possibility of extreme precipitation events, negatively effecting the development of hydropower (Liu et al., 2016). According to a recently published PhD thesis paper, most areas are predicted to face a significant reduction in power generation during 2020-2040 (Sun and Gu, 2019). Also, the power generation in the provinces such as Yunnan and Xinjiang, and the Haihe River and inland rivers will be significantly reduced, showing large regional vulnerability (Sun and Gu, 2019). Furthermore, the rise in temperature will require an increase in power demand for powering the use of cooling equipment such as air conditioners, and many extreme weather and climate events such as heavy rainfall, floods, hurricanes resulted from global warming can damage electrical infrastructure (Liu et al., 2016).

Therefore, on top of solving the difficult problem of hydropower curtailment, China needs to prepare for the future impact of climate change. But nevertheless, the next decades will be the golden period for China’s high-renewable energy transformation, and the development of hydropower is very crucial. However, the negative effects of dam construction such as biodiversity loss and social problems of resettlement should be taken more seriously when evaluating for future hydropower projects. By limiting these damages to minimum, China will take leadership in advancing hydropower and make an indispensable contribution to the control of global climate change.

 

References

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