What is hydraulic energy? Advantages and disadvantages

The hydraulic power or water power is obtained from the use of kinetic energy and potential stream of water or natural waterfalls.

In the process, the potential energy, during the fall of the water, becomes kinetic and moves a turbine to take advantage of that energy.

This resource can be obtained by taking advantage of resources as they arise in nature , for example a natural gorge or waterfall, or by building dams .

For centuries there are small farms in which the current of a river moves a rotor of blades and generates a movement applied, for example, in rural mills.

However, the most common use today is the hydroelectric plants of the dams.

With the Industrial Revolution, and especially since the 19th century, it began to gain importance with the appearance of hydraulic wheels for the production of electrical energy .

Gradually the demand for electricity was increasing. The first modern hydroelectric power station was built in 1880 in Northumberland, Great Britain. However, the new system was expensive and the power plant ended up closing after only two and a half years.

The revival of hydraulic energy was caused by the development of the electric generator , followed by the improvement of the hydraulic turbine and due to the increase in the demand for electricity in the early twentieth century by industrial development.

Already in 1920 hydroelectric plants generated an important part of total electricity production.

Discover how hydroelectric power stations are a great opportunity to create clean energy.

How do hydroelectric plants work?

Two factors influence the use of hydraulic energy : the flow and the height of the jump . To make better use of water, dams are built to regulate the flow depending on the time of year. The dam also serves to increase the jump.

Another way to increase the height of the jump is by deriving the water through a small slope channel (smaller than that of the riverbed), achieving a greater slope between the channel and the riverbed.

When you want to produce energy , part of the stored water is let out of the dam so that it moves a geared turbine with an electric power generator . Thus, its potential energy is converted into kinetic energy reaching the engine rooms.

The water passes through the turbines at high speed, causing a rotational movement finally converted into electrical energy through the generators.

In many countries small plants have been installed, with powers below 10Mw. In several regions of China, for example, these small dams are the main source of electricity.

The small hydro power is considered environmentally friendly because the impacts generated are small and easily minimizable.

Hydropower offers great potential for many developing countries that are using this system with good results.

Advantages of Hydraulic Energy

Currently, renewable energy generates more than ten million jobs . This, already in itself, is an advantage that entails any of the renewable energies currently available, in addition to caring for the environment.

Each of these energies has its advantages and disadvantages, in the case of hydraulic energy its advantages are:
  • It is a clean energy, as it does not generate pollution through waste.
  • It is one of the most used renewable energies worldwide.
  • Your source of supply is stable.
  • It is used many times to complete the necessary electricity provided by other energy sources.
  • By adjusting the water flow, it can be adapted to the electricity demand.
  • Reservoirs allow control of the river, reducing risks in case of floods.
  • It is not subject to the ups and downs of non-renewable energy prices.
  • Reservoirs and swamps that are created to store water allow other uses, such as water supply in necessary cases or aquatic activities.
  • It is possible to generate it in remote places where there is a river with a flow that has enough power.

Disadvantages of hydraulic power

  • Dams cannot be built anywhere, it is necessary that the appropriate flow and height conditions be met.
  • Alters the life of the river fish , which need their flows.
  • A large space is necessary to build the dam and the hydroelectric power station.
  • In case of drought , the productivity of a hydroelectric plant will be affected.

Hydraulic Energy is renewable

Renewable energies are those whose source for creating electricity and other energy is given by Nature.

It is renewable because that source of resources does not end, although it can be obtained in greater or lesser quantity or intensity, such as energy from the sun or wind.

In the case of hydraulic energy , large droughts can seriously damage its production.

But there are other ways to get energy using the movement of water without obtaining affected by drought, these are the tidal energy , the wave energy and Ocean thermal energy conversion .

Tidal Power

It is obtained through a generator with blades that is introduced into the sea; It can be on the bottom of the sea floor or anchored. With this method, the movement of water and the currents that cause tides to rise and fall are used.

Wave Energy

Take advantage of the movement of the waves . Although to create this type of energy also depends on the weather, companies that generate wave energy choose seas in which waves are more or less common.

To create electricity, buoys are installed on the surface of the sea, these are attached to machinery that is located at the bottom of the sea.

Thus, the buoys transmit the movement of the waves to the turbines and they generate electricity.

Other methods to produce wave energy is through "the sea snake", or Pelamis . It consists of generators that are on the surface of the sea, receiving the force of the waves directly.

Tidal Energy

The Ocean thermal energy conversion takes advantage of the different temperatures of ocean water. Ocean water, especially in the tropics, has three thermal layers.

Between the first 100 and 200 meters the temperature is about 25 to 30 °, between 200 and 400 meters the temperature varies and acts as a thermal barrier before reaching the deepest layers.

At 1,000 meters the water temperature is 4 ° and 5,000 meters 2 °.

The water of the first 100 and 200 meters is used to, with the help of a heat exchanger, heat a liquid that achieves a boiling point, which is transformed into steam that moves a turbine, thus generating electricity.

Once generated, the steam is cooled on contact with the cold water of the deeper ocean water layers using another heat exchanger, and the cycle is restarted.

Mini Hydraulic Energy

The operation of mini-hydraulic energy is the same as that of hydraulic energy, but in this case the energy is usually obtained thanks to river flows.

This way of obtaining energy has been used for more than a century, being used in the most remote areas,  it is a form of self-supply.

At present, when it is possible to inhabit almost empty villages or even buy them, many of them in the north, it could be a great saving to use mini-hydraulic energy in those places where rivers flow with an adequate amount of water and power for it. .

In this way, it is possible to supply a home or a small town, and surpluses of electricity that can be produced can also be sold to electricity companies.

The mini-hydraulic dams measure less than 15 meters and have a power of less than 10 MW.

Kinetic Energy

The kinetic energy is the amount of energy needed to move a body at rest. In the case of renewable energy , kinetic energy is essential to produce heat or electricity. In hydraulic energy, kinetic energy is linked to potential energy.

The amount of kinetic energy that water contains depends on the volume of water and its speed as it falls through the dam.

In this way, the potential energy is that which is in the water and becomes kinetic energy as it flows through the dam.

The amount of potential energy that water has depends on the height at which it is located, the more height more potential energy, so it will create a greater amount of kinetic energy.

Both energies together will create mechanical energy , which will move the turbines to generate electricity or heat.