Environmental Impact of Hydropower
3 min read · Energy Atlas Editorial
The construction of a hydroelectric power plant affects a large area ecosystem and often leads to people's relocation. Then a new balance is established.
Hydroelectric Power Plants and the Environment
The construction of a hydroelectric power plant always has some impact on the environment. Large dams and reservoirs can flood vast areas, significantly altering or destroying existing ecosystems. Their construction may also require the relocation of large numbers of people and can endanger places and structures of great cultural value.
During the construction of the Aswan High Dam (map), many ancient temples had to be moved stone by stone. The filling of very large reservoirs can also induce seismic activity by changing stresses and water pressure in the underlying rock.
Once filled, a reservoir can provide additional benefits such as flood control, water supply, recreation and tourism. However, the operation of a hydroelectric power plant continues to affect the environment. Dams can obstruct fish migration and alter natural river flows, sediment transport, water temperature and aquatic habitats. Some reservoirs can also release greenhouse gases, particularly methane, as submerged organic matter decomposes.
One of the most serious risks associated with large hydroelectric power plants is dam failure or overtopping, whether due to extreme floods, structural failure or human error. Such accidents are extremely rare, but they can cause major material damage and loss of life.
Keep reading
Articles
The Physical Properties of Water
Water is a chemical compound made from one oxygen and two hydrogen atoms. At normal conditions, it is a colourless, clear, and odourless liquid.
3 min read
The Origin of Water Energy
The Sun warms surface water and evaporates it. After condensation, the water falls on the land with exploitable potential energy relative to ocean level.
3 min read
History of Water Energy Utilization
The energy of water was used since ancient times for grinding grain or irrigation. Later it powered mills or hammers, and finally a turbine was invented.
3 min read
Water Energy and Its Uses
The amount of available water energy, kinetic and potential, depends on hydrologic potential, mostly on hydraulic head and flow rate.
3 min read
Dams and Reservoirs
The dams create water reservoirs for hydro power plants, to prevent floods or to collect drinking water. Typical dams are gravity or concrete arch dams.
3 min read
The Highest Dams and Largest Reservoirs
The highest dam is the 305 m high, concrete arch-shaped Jinping-I dam in China. The largest reservoir is Lake Kariba in Zambezi, with a volume of 180 km3.
3 min read
The Segner Wheel
The Segner wheel was an important step on the way to modern turbines. Its principle is today used in rotating irrigation sprinkler systems.
3 min read
Francis Turbine
The Francis turbine has a radial-axial design, variable pitch guide vanes, and fixed runner blades. The largest one has a diameter of 10 m.
3 min read
Kaplan Turbine
The Kaplan reaction water turbine with adjustable blades, invented in 1918, is used in places with minimal heads and relatively high, variable flow rates.
3 min read
Pelton Turbine
The Pelton turbine is an isobaric impulse action turbine. The water jet is directed tangentially at the spoon-shaped buckets on the runner.
3 min read
Choosing a turbine (Turbine selection graph)
The turbine selection graph helps to select the best turbine type for the given hydraulic head and rate of flow.
3 min read
Hydroelectric Power Plant Operating Principles
In hydroelectric power plants, the water propels the turbine blades, and the generator transforms the energy of a rotating turbine shaft into electricity.
3 min read
Types of Hydroelectric Power Plants
The hydroelectric power plants can be divided into accumulation ones with a reservoir, run-of-the river without a dam, derivational, and pumped-storage.
3 min read
The Largest Hydroelectric Power Plants in the World
The largest hydroelectric dams in the world are the "Three Gorges Dam" in China, Itaipú Dam and Guri Dam in South America.
4 min read
Tidal Energy and Sea Wave Power
Tidal power plants use ebb-tide energy from turbines in the dam enclosing a tidal basin, while tidal stream generators are turbines anchored to the seabed.
3 min read
Marine Current Power and Ocean Thermal Energy
Energy contained in ocean currents can be exploited by various underwater turbines or by an OTEC system that uses ocean temperature differences.
3 min read