Hydropower: what it is, how it works and examples

The hydropower is part of one of the oldest energy, that with the advancement of technology has progressed to become more efficient. It is part of renewable energies and is the one that generates the most electricity in the world. Here we explain much more about whether hydraulic energy is really renewable or not?

To generate this energy, the movement of water that flows through rivers and other bodies of water is used. In general, this movement, which is what is known as the kinetic energy of the water , occurs with the fall of the water, that is why the areas to locate the power plants have to present unevenness. The falling water makes a turbine move that generates electrical energy that will be injected directly into the electrical network.

The operation will depend on the model of the hydroelectric plant and these vary according to the place where they are located. Taking this into account, we find that there are three types of hydroelectric plants and this is the operation of hydraulic energy in these:

Flowing water plants

They are located on land that is not very uneven, and does not have a reservoir. The river flow must be stable to ensure the power required for the entire year. In times of abundant rainfall the maximum power is generated and in drier times, the power is lower, sometimes nil due to a complete drought of some rivers.

Reservoir plants

These plants have more than one dam to store the water. They are power plants that need greater economic investment, but have the advantage that, by being able to accumulate water, in times of drought despite the river being completely dry, it can use stored water and continue generating energy.

Pumping or reversible stations

In these found two reservoirs that are located at different levels and rationalize the water resources since, depending on the time of day, the demand for energy is higher or lower. When the demand is high, the water falls from the reservoir that is in the upper level causing the rotation of the turbines, and this water is stored in the lower reservoir. However, when the demand is lower there is a pumping towards the upper reservoir so that the cycle of power generation occurs again.

After knowing all this, we think it is interesting to also discover what mini-hydraulic energy is and how it works with this other post.

We will mention some of the hydroelectric plants that are located all over the world as examples of hydraulic energy :

• Robert Moses Niagara Power Plant hydroelectric plant: it is located in Niagara Falls, taking advantage of the large waterfall in these, this plant was the first to be built in the world.
• Salime Reservoir: This reservoir is located in Spain, exactly in the city and Asturias. It is supplied by the Navia River and it is true that the river bed had to be changed. It produces 350 GWh per year for the population.
• Three Gorges Dam: surely the name of this dam you have ever heard, as it is the largest hydroelectric plant in the world that produces a great power of 24000MW. It is found in China and is fed by the Yangtze River. Construction was completed in 2012, although 19 cities and some towns were flooded with the problem of having to evacuate all their inhabitants.
• Itaipú Dam: this project is led by Brazil and Paraguay as it is located on the border where the Paraná River passes. It generates up to 14000MW and it was in 1984 when it started operating.
• Xilodu Dam: this is also located in China, on the Jinsha River, it has the capacity to produce up to 13,860 Mw of electricity, but it also controls the channel to prevent floods from occurring, as well as to make navigation easier.
• Yacyretá-Apipé Dam: it is located in an area that belongs to Argentina and Paraguay, on the Paraná River as well as the Xilodu dam. Of all the energy that Argentina demands, 22% comes from this dam with a power of 3,100MW. This dam brought with its construction too many controversies, as it had a great impact on the biodeversity of the area, causing the extinction of endemic species.

Although it is true that hydroelectric plants have great advantages, there are still some disadvantages such as the impact on biodiversity that belongs to the territory where they are built, or that can cause the flooding of nearby towns. It makes producing this energy not entirely sustainable, even if it comes from a renewable resource. In this other AgroCorrn article you can learn about the advantages and disadvantages of hydropower .