Hydroelectric Power Plant: Definition, Working Diagram or Layout [with PDF]

In 2019, hydroelectric power plants contributed about 18-20% of the total electricity generation in the world. Hydroelectricity is the most widely used form of renewable energy. It is a much flexible source of electricity and the cost of electricity generation is relatively low. 

Today In this paper we will try to understand How does Hydro Power Plant Works? and also we will try to understand it's layout, Advantages, Disadvantages and Application.

Hydroelectric Power Plant Parts or Layout:

The Hydro Power Plants consists of mainly six parts:

1. Dam and Reservoir
2. Control Gate
3. Penstock
4. Water Turbine
5. Generator
6. Surge tank

1. Dam and Reservoir: 

When we hearing the word Dam that means sufficient water storage at some height (Because when the water from some height release so the velocity increase and which is further used for the generation of electricity with the use of turbine).

The dam forms a large reservoir behind it. The height of the water level (called a water head) in the reservoir determines how much potential energy is stored in it.

2. Control Gate: 

In simple words, this is like controlling the flow of water (first Water from the reservoir is allowed to flow through the penstock and to the turbine).

The amount of water that is to be released in the penstock can be controlled by a control gate. When the control gate is fully opened, the maximum amount of water is released through the Penstock.

3. Penstock: 

The potential energy of the water is converted into kinetic energy as it flows down through the Penstock due to gravity.

4. Water Turbine or Hydraulic Turbine: 

The flow of water from the Penstock is taken into the water turbine. The turbine is mechanically coupled to an electric generator.

The kinetic energy of the water drives the turbine and consequently, the generator gets driven.

5. Generator:

A generator is mounted in the powerhouse and it is mechanically coupled to the turbine shaft.

When the turbine blades are rotated, it drives the generator, The electricity is generated which is then stepped up with the help of a transformer for the transmission purpose.

6. Surge Tank:

The Surge tanks are usually provided in high or medium head power plants when considerably long Penstock is required.

A surge tank is a small reservoir or tank which is open at the top. It is fitted between the reservoir and the powerhouse.

The water level in the surge tank rises or falls to reduce the pressure swings in the Penstock.

Hydro Power Plant Working:

A large amount of water available in the reservoir before the dam. In the dam there is fitted penstock which works is to flow of water to the turbine and at the tailrace, there is turbine situated when water strikes to the turbine blade it starts rotating therefor hydraulic energy is converted into the mechanical energy and then use of generator the mechanical energy is converted into electrical energy.

Advantages of Hydroelectric power plant:

The following advantages of Hydro Plants are:

1. This power plant is a renewable energy source. The water-energy can be used again and again.
2. This is having high efficiency.
3. The running cost of the Hydraulic turbine is less as compared to other turbines.
4. The environmental pollution system is negligible here.
5. The main advantages of the Hydraulic turbine are that at the turbine place, the people can visit and come across all the main parts in detail. This is like an open system.

Disadvantages of Hydroelectric power plant:

The following disadvantages of Hydro Power Plant are:

1. This power plant Installation or Initial cost is very high.
2. This plant takes several decades to produces the profit.
3. The main disadvantages are that It can develop at only a few sites or place where a good amount of water is available. 

Application of Hydroelectric power plant:

1. Hydro Plants are the most widely used (18-20 percent global electricity consumption) form of renewable sources of energy according to a survey.
2. The obviously large amount of electricity has been produced by this Hydroelectric power plant with the use of Hydraulic turbines.