|Fig. 1: In addition to its importance in agriculture, the carp has significance within Chinese culture as well, symbolizing life achievement that is gained through hard work. With this being true, it is important to consider China's achievements in energy in the context of what is being sacrificed. (Source: Wikimedia Commons)|
Hydroelectric power has strong energy potential in terms of its output and sustainability. As population's increase and economies grow, there is a clear increase in worldwide energy demand. According to BP's Statistical Review of World Energy, worldwide primary energy consumption has increased from 10,940 to 13,147 million tonnes of oil equivalent, while hydroelectricity consumption has increased from 661.4 to 892.9 million tonnes of oil equivalent from 2005 to 2015.  While the primary energy space is still dominated by fossil fuels, hydroelectric energy production and use is becoming more popular. As it further develops, there are concerns over its environmental and social effects on neighboring areas. Hydropower is one of the most important renewable energy sources in electricity generation. As water is found naturally moving in many locations, energy can be extracted from its velocity and positioning to power machinery and generate electricity. Hydropower provides a significant amount of energy in the world, contributing approximately 15% of the global electricity production.  Global growth has been primarily concentrated in several key countries, top of which is China. China had 15GW deployed in 2012 and has a 5-year plan to have 284GW through 2015, hypothetically using 71% of its available hydroelectric power. 
Given the prominence of China in the hydropower space, it is fitting to explore the Three Gorges Dam as a case of a large-scale hydropower project with wide reaching impact. The Three Gorges Dam is the largest hydroelectric dam in the world, providing energy production, flood control, and navigation to China's Yangtze River area. In its full completion with 26 turbines, it has a full power capacity that exceeds 22,000 MWe. Intended to help reduce China's energy reliance on burning coal, the energy from Three Gorges Dam is able to replace around 50 million tons of coal that otherwise would have been burned.  Additionally, the Three Gorges Dam has the added benefit of flood control, a major problem of the Yangtze River Basin. The Three Gorges Dam additionally is able to divert water resources to northern China, where rainfall is in a shortage.
However, the Three Gorges Dam has also had many negative implications on the local ecology and relocation of people. Ecosystems have been destroyed through the process of blocking a massive river. Additionally, the process of its construction offsets many of the immediate benefits it poses to reducing the negative externalities of fossil fuels. An estimated 2 million people downstream of the dam were relocated, without acknowledgement of their loss of livelihood. This project has also greatly affected the farming and fishing communities. The river is fished out, and the Yangtze's four major species of carp are dwindling, as referenced in the figure. This is a result of increased traffic, pollution from construction, and various industrial wastes. 
The Three Gorges Dam in China has proven to be a controversial project for its added pros and cons to the Yangtze River landscape. As China propels and continues to lead hydropower generation and leverage its hydropower potential, it is very important for planners to maintain careful planning and design to work around the challenges. In particular, lessons from the Three Gorges Dam must be taken when considering the development of new dams, such as the Nu River Dam. This 13-cascade would leverage China's last undammed river, have immense power generating potential, but also face many similar ecological and social consequences. 
© Kitty Kwan. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 "BP Statistical Review of World Energy 2015," British Petroleum, June 2016.
 C. S. Kaunda et al., "Hydropower in the Context of Sustainable Energy Supply: A Review of Technologies and Challenges," ISRN Renewable Energy 2012, 730631 (2012).
 "World Energy Resources," World Energy Council, 2013, Ch. 5.
 P. H. Gleick, "Three Gorges Dam Project, Yangtze River, China," in The World's Water, 2008-2009, ed. by P. H. Gleick (Island Press, 2008), p. 139.
 R. Stone, "Three Gorges Dam: Into the Unknown," Science 321, 628 (2008).
 P. H. Brown, D. Magee, and Y. Xu, "Socioeconomic Vulnerability in China's Hydropower Development," China Econ. Rev. 19, 614 (2008).