A hydroelectric plant is one that uses water power to generate electricity. They are the current result of the evolution of the old mills exploiting the flow of rivers to move a wheel.
The production of electricity is one of the most important in Spain. Large hydroelectric plants are located in the Pyrenees, in the reservoirs that dot the rivers, although the biggest plant is located in the reservoir Mequinenza in the Ebro.


How does it work?
Its objective is to convert the potential energy, contained in the form of water, into electrical energy using turbines coupled to generators.
The large amount of water that is retained is through a dam, forming an artificial lake or reservoir will generate a waterfall, to effectively release the potential energy and then transform it into electrical energy.
Water management is to carry water from the dam by a gallery with just drop driving up to a reservoir called the chimney of expansion. From this chimney started a pipe that carries the water to the engine room of the plant. After that the water is returned to the river, using a water channel below.
In the plant there are electrical equipment composed of turbine-generator groups. The forced water that is coming through the gallery is conducted to the turbine blades, which connected by an axe to the alternator rotor make it turn, inducing in the stator a high intensity electric current and medium voltage. This means a transformer will be of low intensity and high voltage, therefore suitable for transport and distribution to consume centres.

Main disadvantages.
– The construction and operation of the dam and the reservoir are the main source of the environmental impacts. The powerful projects dams can cause irreversible environmental changes, in a very large geographical area.
– The flooding of the earth to form the reservoir, and the alteration of water flow downstream. These effects exert direct impacts on soils, vegetation, wildlife, fisheries, climate and human population of the area.

 Main advantages.
The obvious benefit of the hydroelectric project is the electric energy, it can support economic development and improve the quality of life in the service area. Hydroelectric projects are very labor-intensive and provide employment opportunities. The roads and other infrastructure can give people greater access to markets for their products, schools for their children, health care and other social services.
– Moreover, the generation of hydroelectric power provides an alternative to burning fossil fuels or nuclear energy, which can meet energy demand without producing hot water, air emissions, ash, radioactive waste and emissions of CO2.