Renewable Hydroelectricity with Multiple Advantages
Hydroelectricity is generated by use of falling water from great height to turn turbines of a power generator. It is the most widely used form of renewable energy.
Worldwide, hydroelectricity supplied
an estimated 715 GWe in 2005.
This was approximately 19% of the world's electricity (up from 16%
in 2003), and accounted for over 63% of electricity from renewable
Negative Effects of Dam Construction
Dams can block fish passage to spawning grounds or to the ocean, although many plants now have measures in place to help reduce this impact.
Huge hydroelectric projects that
require the construction of dams are therefore increasingly becoming
unpopular and raise sensitive controversies.
Extensive deforestation is needed to make land for dam site. So, although there is no GHG emissions due to non-usage of fossil fuel. Prior to the construction of the dam, deforestation is needed to clear land for construction. With deforestation comes the emission of carbon dioxide and methane gases into the atmosphere.
Mini and micro hydroelectric stations are gaining popularity for meeting smaller and isolated electricity demands especially in remote areas. Minimum environmental impacts are caused.
Today, China is a leading producer in hydroelectricity
One of the most controversial hydropower dam
in the world is the
A large percentage of China's renewable energy is provided by this controversial Dam project. The Three Gorges Dam has been named among the world's top 10 renewable energy projects by the globally renowned science magazine Scientific American in July 2009.
China is also the world leader for small hydro with 38 GW in operation, out of 60 GW in global operations in 2006; and 145 GW in 2007. The utilizable hydropower of 2006 is equivalent to 50.7 billion tons of standard coal. Installed capacity is increasing at an annual rate of 17%. Implementation of rural energy development and provisions of incentives and funding is the main driver behind the 17% annual increase in installed capacity.
In the EU, compared to the wind power, market growth rates for mini hydropower are small with projected capacity reaching 13 GW in 2015.
China Dam Safety Under Pressure Ahead of Flood
Season: Sina.com May 05, 2009
China has the world's biggest number of reservoirs. Special purpose inspections on dams show many of them are not in good condition. Dam safety is in a severe situation.
From 1999 to 2008, a total of 59 dams had cracks, 30 of which were caused by torrential rain and 20 by quality defects. In 2008, 3 295 dams and hydropower plants were damaged during the May 12 earthquake in Szechuan but none was breached last year.
37,000 reservoirs, or more than 40% have potential dangers, of which 3,642 dams are undergoing strengthening, and another 7,611 need to be reinforced immediately.
A general lack of early warning systems poses yet another threat to dam safety. For instance, 19% of key medium-sized reservoirs and 25% of normal medium-sized reservoirs are not equipped with rain water monitor systems. Immediate plans including dam reinforcement and reducing water storage capacity are needed for emergencies and dam safety.
China's Energy Consumption and Utilization: Easy-carbon.com