hydraulic energy

Content

• Advantages of hydropower
• Disadvantages of hydropower
• Examples of hydropower
• Other types of energy

The hydraulic energy (also called water energy or hydropower) is obtained thanks to the kinetic energy and potential energy of water currents (such as waterfalls or rivers) and tides.

Kinetic energy is the energy that any body possesses thanks to its movement. For example, if we lean a pencil against a paper and hold it immobile, the pencil does not transmit any energy to the paper (no kinetic energy).

On the other hand, if we hit the paper with the tip of the pencil, that is, we move it at high speed, the pencil breaks the paper thanks to its kinetic energy. For this reason, hydropower It does not come from lakes or ponds, but from moving bodies of water, such as rivers and seas.

Potential energy is that which is in an object due to its relative position within a system. For example, an apple on a tree has the potential energy of its fall, that is, the potential energy is greater if the apple is located higher.

Use the potential energy of water means that the difference in height between the place where the water comes from and the place where it will fall is used. The force with which it falls thanks to the acceleration of gravity is converted into kinetic energy.

See also: Examples of Energy in everyday life

Advantages of hydropower

• It is a renewable energy: In other words, it will not be exhausted by its use, thanks to the water cycle. Even if a huge amount of water comes out of a reservoir and passes through the hydroelectric power station, that water will return to the reservoir thanks to the water cycle, which will cause the water to evaporate and fall back as rain.
• High performance: Unlike other renewable energies (such as solar energy), little space is necessary to obtain large amounts of energy.
• Does not produce toxic emissions: Like those produced by other energy sources such as fossil fuels.
• Cheap: Its operation is independent of oil prices. Although the construction of a hydroelectric plant can be very expensive, its useful life can exceed 100 years.

Disadvantages of hydropower

• Although there are forms of hydraulic energy that do not affect the environment, most are hydroelectric plants, which form reservoirs, that is, the flooding of large areas of land around what was previously a river. This has a profound environmental impact, forcing the transfer of numerous species and dramatically modifying the landscape.
• The ecosystem is also modified downstream because the water that comes out of the dams has no sediment, which causes a more rapid erosion of the river banks. In addition, the flow of the river is drastically modified in a short time.

Examples of hydropower

HYDROELECTRIC STATIONS

They convert the energy in water into electrical energy. They use the potential energy of a large body of water (the reservoir or artificial lake) due to its unevenness with a river bed. The water is dropped through a turbine, in which its potential energy is converted into kinetic energy (motion) and the turbine converts it into electrical energy.

The first hydroelectric plant was built in 1879 at Niagara Falls. Currently, this is the cheapest form of energy, due to the low maintenance required by the facilities and the amount of energy obtained daily.

WATERMILLS

They use the kinetic energy of a watercourse. It is called a mill because in its first uses it was used to grind grains. The water moves the blades of a wheel that is located slightly submerged in the water course. Through a set of gears, the movement of the wheel in turn moves a pair of circular stones called grinding wheels that press the grains, turning them into flour.

Currently, water wheels can also be used to obtain electricity through a transformer, similar to the operation of the turbines of hydroelectric plants.

However, the amount of energy obtained is much less since the water moves at a higher speed due to the fact that the natural slope of the rivers is much less than that used in hydroelectric plants. The first water wheels were built in ancient Greece, in the 3rd century BC.

MARINE ENERGY

It is a specific way of using the energy of water. It is classified in:

• Energy from ocean currents: Ocean currents are surface movements of ocean waters. They are produced by multiple factors, such as the earth's rotation and winds. Rotors are used to take advantage of the kinetic energy of the currents.
• Osmotic energy: Sea water is salty, that is, it has a concentration of you go out. Rivers, on the other hand, have no salt. The difference in salt concentration between rivers and seas produces a delayed pressure osmosis, when the two types of water are separated by a membrane. The pressure difference on the two sides of the membrane can be used in a turbine.
• Thermal energy from the sea (tidal wave): The difference in temperature between deeper (colder) and shallow (warmer) ocean waters allows a thermal device to be moved to generate electricity.

Other types of energy