|Serious environmental problems in China. Hydropower is possible solution.
China is country that is currently experiencing tremendous economic boost, its ever-increasing demand for energy requires constant development of energy sources and China is looking for other energy sources, besides dominant coal. This trend is not only the result of increased energy demand, but also because of serious environmental problems. China is world's number two emitter of carbon dioxide (CO2), and some analyses even showed that if China continues its current trend, it will already this year overtake United States becoming number one emitter of harmful carbon dioxide in the world, not to mention that China is also leading emitter of acid rain causing sulfur dioxide. Because of the global warming and tremendous air pollution China is practically forced to seek for an alternative in renewable energy sources, and this alternative looks to be hydropower.
China already has half of the world's largest dams, including the largest one Three Gorges dam, which is the world's biggest hydroelectric station with estimated total capacity of around 22,500 MW once being completely functional. China gains 15 percent of its energy from hydropower and plans to at least double this amount by building new large hydroelectric dams, especially in Southwest China because rivers located in this area are ideal to harvest hydropower since many of these rivers are 2000 m above sea level and rich with water. Hydropower potential of southwest China is estimated to be about 500 GW. China is well aware that hydropower is only renewable energy sector that can be used on large scale within its borders and is therefore making large investments in hydropower sector in order to reduce coal dominance, especially because coal has very negative impact on the environment causing acid rains and air pollution.
China's exploitable hydroelectric resources are around 378 GW which is equivalent to annual power supply of 1.92 trillion kWh, and China wants to take advantage of these hydroelectric resources, especially since because of large economic growth China’s energy needs have constant growth and massive hydroelectric dams should satisfy this ever-growing need for energy. Suo Lisheng, Chinese vice-minister of water resources recently said on international seminar on hydropower how “China’s exploitable hydropower is equivalent to 50.7 billion tons of standard coal. “ And the main location for hydropower exploitation is Southwest China where certain recent statistic shows that hydropower plants will be built over several rivers: Nujiang, Lancang, Jinsha, Dadu, Yalong and Minjiang. Dadu river area has especially large potential to exploit hydropower resources, according to some studies 50 percent higher potential than the largest Three Gorges dam.
While this all sounds to be good news for China in its fight against environmental and ecological problems, there are lots of ecologists and environmentalists that are worried about consequences these massive dams would have on environment and some of them even say this will worsen already serious global warming problem.
Positive and negative sides
|Changed Landscape of the Three Gorges Dam region. (NASA/Goddard Space Flight Center Scientific Visualization Studio). Some scientists says that China’s massive dam is even changing the local weather. Click on picture for full size.
Positive sides in massive building of hydroelectric dams is definitely the fact that this will decrease China’s dependence upon coal and it should also help decreasing China’s growing import of different energy fuels needed to follow country’s rapid economic growth. China is under great financial and diplomatic pressure caused by its dependence of overseas oil and gas, and this high potential of hydropower sector within China’s borders should cut down this dependence. However there is unfortunately lot more negative than positive sides.
First of all many people that live in southwest China and other locations with huge hydropower potential will be relocated and forced to abandon their households once these big installation projects take place. Good news is that Southwest China isn’t that heavily populated as some other parts of China, but still lots of people will have to abandon their homes and many of them are already worried about their future. For instance, Dadu River that has the biggest hydropower potential capable of having 22 power plants installed in near future will cause relocation of more than 100,000 people once and if this project starts. Some environmentalists and ecologists call this massive hydropower project as the second worst ecological disaster in China’s history comparable to terrific deforestation that was happening in period between the 50s and the 90s. Water ways are not the same as they used to be since hydroelectric power plants altered their way, and this has destroyed many different ecosystems, and this scenario should be expected in southwest China too.
China has many nature conservation areas but that isn’t preventing them from building new hydroelectric power plants in these areas, despite of laws and different other regulations and this trend is mainly the result increased energy demand. This problem has big, both economic and ecological impact, and China will have to choose whether to preserve this area as nature conservancies or to turn them into hydropower generator centers.
Man-made tunnels have also caused many rivers’ drying up and water scarcity problem has become serious problem in many areas in China and there are millions of people short of drinking water, since many of the last couple of years were poor with rains. Water shortage problem could be great problem for not only China’s future, but also for current hydropower projects since with the rise of global warming problem, drought and water scarcity became more often than they used to be. For example, water levels in country’s longest river Yangtze are the lowest in history of recording it, and climate change that is already affecting China will also put in jeopardy China’s massive hydroelectric projects. Hydropower if not supplied with enough water is worthless and if water scarcity continues China will again have to rely on coal or other fossil fuels to follow its rapid economic growth which would result in totally missed hydropower projects, and be meaning more imported fossil fuel and even higher expenses.
Besides these problems there is also the fear that hydropower projects would even worsen global warming effect, because of methane which is greenhouse gas even more powerful than the carbon dioxide because methane traps heat with significantly larger impact than carbon dioxide. Problem regarding methane lies in the fact that methane is produced by plants and animals that rot underwater and once water goes through hydropower turbines, methane is released into atmosphere. Considering China’s plan that includes doubling the amount of energy gained from hydropower this could mean significant increase in methane emissions, according to some experts of about 8 %. However certain methods allow capturing of this methane that could be later used for power generation, of course with proper design of dams which would stop methane reaching the atmosphere. Some estimations say 2.6 million tones could be collected from dams for additional power generation. It is also very important to prevent sewage from entering reservoirs and this is perhaps the biggest problem since China’s sewage system isn’t acceptable in many areas. Methane emissions are especially serious problem in shallow tropical reservoirs and luckily China’s dams are mostly deep enough and in temperate zones.
However scientists are still worried about future projects. Some people like Chinese writer Dai Quing have been issuing warnings about environmental damage and frequent landslides as the result of huge weight of water behind the dam and fluctuations in the water level that were caused by the largest Three Gorges dam and could continue in future projects as well. On the other hand Chinese government is refusing these claims by saying this has nothing to do with dams and reservoirs and is strictly the result of unstable area.
Three Gorges dam
Three Gorges dam is a massive Chinese hydroelectric river dam in making on Chinese largest river Yangtze with expected total capacity of 22,500 MW once fully functional. This project is the biggest project in China’s history since the Great Wall and Three Gorges dam should become fully functional in 2011. Three Gorges dam should significantly reduce coal consumption by more than 30 millions of tons per year and reduce emission of carbon dioxide that is result of this coal consumption.
|Three Gorges dam (NASA). Click on picture for full size.
The idea of building this massive dam had two simple premises that should make a dream conclusion: first - plenty of water in Yangtze and troubles with often flooding and second - China’s tremendous need for new source of energy. The solution seemed quite simple indeed - building large dam that will stop flooding and use the extra water to harness it for hydropower and so much needed energy. This really seemed like an ideal solution to solve the centuries long flooding problem and in addition to provide country with huge source of ecologically acceptable renewable energy. This dam was really a project of high pride for China throughout the 20th century and the new Chinese miracle with tremendous capacity potential, 20 times more than for instance Hoover dam in USA, with incredible 34 large generators once fully functional. Official costs of this gigantic project are around $25 billion, though some estimations say this amount will be significantly bigger, once this giant dam becomes fully functional. From economic point of view all looks good, especially since there are nine provinces and two cities consuming the power from it, including the largest city Shanghai and it also looks good from ecological point of view since it reduces coal consumption and reduces quantity of C02 emitted to atmosphere. So what is the problem then?
Problem is that this dam only looks to be ideal solution, while in reality this dam caused many problems, some expected and some most apparently not. About 1.5 million people had to be relocated and forced to live their homes because of building. But relocation of so many people is not the No.1 problem as there is one much bigger problem, problem of nearby environment. Many scientists issued warnings, describing this dam as new environmental catastrophe and even some Communist party members ordered preventive and urgent measures to stop disaster. Erosion and landslides on steep hills around the dam are becoming common thing, and many aquatic species are threatened with extinction.
After hailing this project as the new Great Wall, nobody of leading men in China wants to take the blame for its environmental consequences and even President Hu Jintao distanced himself as he stayed away from the completion ceremonies in 2006, showing with this act that he does not want to be associated with the Three Gorges project. Writer and environmental activist Dai Qing is the most notable person for constantly issuing warnings about this problem and by the looks of it, some of these warnings are finally coming to the ears of the right people. One official even said how the shore of the reservoir had collapsed in 91 places with total of 36 kilometers (22 miles) already caved in. Landslides are the biggest problems and they already created waves up to 50 meters high and there were already human casualties in 2007 when a mountain along a tributary collapsed, dragging 13 farmers to their deaths and drowning 11 fishermen. Chinese government still won’t publicly admit these environmental problems and there is still potential danger of tremendous methane emission into atmosphere which could even worsen global warming problem.
China indeed has enormous hydropower potential, especially in Southwest region, with many rivers high above sea level. Naturally China wants to exploit this potential and build new hydropower stations, mainly for two reasons: to satisfy need for energy with energy source within its borders and to reduce use of ecologically unacceptable coal that is dominant fuel in China’s big economic growth, but which use causes air pollution and global warming. With this great hydropower potential also comes the great responsibility and China has to think of the solution that would give them the opportunity to widely use its hydropower resource, but in correlation with preservation of the environment as to avoid the problems that showed up in their famous Three Gorges dam project.
Danger of methane emissions, erosions and landslides must be considered as the warning in all future hydropower projects in China as not to make the same mistake twice and first stop should be concern about possible environmental issues, before starting another massive hydroelectric dam that would cause more problem than real benefits. Hydropower is China’s only renewable energy source that can be used on large scale, but only under certain conditions if China wants to have benefits from its huge hydropower potential. It would be very hazardous to build new gigantic hydropower projects before solving the methane emissions problem and danger of erosions and landslides. Three Gorges Dam should be more than a worthy warning.
Hydropower - Basics