What is Hydropower Energy?
Hydropower energy is a renewable source of energy that is harnessed from the flow or movement of water from a higher elevation to a lower elevation. Hydropower, also known as Hydroelectric power, is used to generate electricity by deriving mechanical energy from water and converting it into electrical energy
Water possesses both gravitational potential energy and kinetic energy as it moves downstream from a higher elevation, and this is used to produce electricity with the help of a turbine and generator. This is the basic principle of hydropower energy, and it has been a proven, reliable and mature source of energy for electricity.
Hydropower has been utilized since more than a thousand years ago. For example, turbines were built by the ancient Romans which were used for grinding grains for making bread and flour. These turbines were turned by moving water to produce the energy required.
How hydropower energy works
Hydropower Energy is produced by the spinning of turbine blades with the help of the gravitational force of flowing water. This action generates electricity through a generator coupled to the turbine. A dam is usually utilized for altering the flow of water to achieve this electrical energy.
In hydroelectric power, the dam is used to create an artificial reservoir by holding back a river or large volume of water. The water is held at a higher elevation than the water at the lower side of the dam. When the gate at the elevated part of the dam is opened, water flows downstream through tunnels in the dam called penstocks to the turbines. As the water hits the turbine, its initial potential energy gets converted into kinetic energy as it spins the blades of the turbine. The spinning turbine, in turn, spins the generator which produces the electricity.
This hydropower electricity is channeled into an electrical grid to power businesses, industries, homes and electrical appliances. The electrical energy generated from the moving water is dependent on the volume of water flow and the change in elevation from higher to lower level. This means the higher the flow of water and the elevation change, the greater the electricity that will be produced.
The volume of water flow through the dam can be controlled by engineers through a process called an intake system. Therefore, whenever a larger amount of electrical energy is required, more turbine tunnels are opened, and a higher volume of water is allowed to flow through them. When a lesser amount of electrical energy is required, the intake system is slowed down by closing some of the turbine tunnels.
The Pros and Cons of Hydropower Energy
Advantages of hydroelectric power
- Renewable energy source: Hydropower energy is generated from natural water that can be replenished as it is used.
- Clean and environmentally friendly: The operation of hydropower does not emit greenhouse gases leading to a safer and non-polluted environment.
- Wide usage: Hydroelectric power plants are available and in use for generating electricity in various countries across the world.
- Large-scale electricity production: The versatility of hydropower plants makes it possible to produce electricity on a small scale and a large-scale capable of providing electricity for a whole country.
- Flexibility: The generation of electricity by hydropower plants can be controlled to meet the required electricity demand
- Durability and long-lasting: The types of equipment used in hydropower plants are durable and require little maintenance which makes it reliable and cost-effective
Disadvantages of hydroelectric power
- Loss of land and habitats: The flooding of lands for the building of hydropower reservoirs leads to the loss of wildlife habitats and fertile agricultural land.
- Risk of dam failure from natural disasters: Events like landslides, earthquakes and extreme weather conditions can lead to damage to the hydropower dams.
- Environmental impact: The creation of hydropower reservoirs and dams can lead to the disruption of natural ecosystems, habitats, communities, etc. Habitats like aquatic life are affected due to the alteration of water levels and river flow by the reservoirs.
- High cost of initial setup: Large-scale hydropower projects require a high cost for equipment, installation and labour expenses. This makes it less available for use than other renewable energy sources.