Hydroelectric Power Plant

What is Hydroelectric Power Plant?

What is hydroelectric energy? Hydroelectric energy and hydroelectric power plant are almost similar. Whereas kinetic energy of the water is used to generate electrical energy by special a plant which is called hydroelectric power plant. But where hydroelectric energy is generated it is called hydroelectric energy.  Water is one of the most crucial sources to generate electricity. Basically, the hydroelectric power plant is located in the hilly areas where we can create water heads by creating a dam. The main intention is to create a water force to rotate the water turbine. If the turbine rotates then the alternator will rotate thus alternator generates electrical energy. It is noted that the water turbine and alternator are connected with each other. We have shown here the hydroelectric generation process that can be sufficient to know the details of hydroelectric power plants.

Hydroelectric Power Generation Process

Hydroelectric power plants are the most essential for the low unit charge. We have discussed the hydroelectric power generation process. Whereas potential energy or kinetic energy of the water is used to generate electrical energy which is called a hydroelectric power station. The hydroelectric power plant is located in the hilly areas where huge water can be stored by using the dam. The dam is created between two hills so that dam can bind normal water flow.

The hydroelectric power plant working principle is very simple and low cost to generate bulk electrical energy. The hydro power plant is one of the easiest and cheapest power plants, and has a low running cost, for this reason, the hydroelectric power station is very familiar to some other electrical power plants. The hydroelectric power plant cannot easily create without hilly areas and this power plant has high efficiency and provides a reliable electricity supply.     


Many people think that what is hydroelectric energy, or what is hydro energy? Basically, hydro power or hydro energy is water energy. It is a renewable energy source in the world. The kinetic energy of the water is converted into electrical energy which is called hydroelectric energy or hydro energy.

On the other hand, a hydroelectric dam plays a crucial part to generate electrical energy from the kinetic energy of the water. A hydroelectric dam is a man-made barrier between two valleys. However, a water dam is created to stop the water flow in the river. It is also used to reserve the water so that we can use water flow to generate electrical energy.

What is the Type of Water Turbine?

A water turbine is one of the important parts of the hydroelectric power plant. The water turbine converts the kinetic energy of the water into mechanical energy. The water turbine is divided into two:

  • Impulse turbine
  • Reaction turbine

What is Impulse Turbine?

An impulse turbine is a type of hydraulic turbine that uses the kinetic energy of water flow to generate electricity. This turbine has been used in many different applications including hydropower plants, wastewater treatment plants, and others. The impulse turbine converts the potential energy of moving water into mechanical energy.

What is Reaction Turbine?

A Reaction Water Turbine (RWT) or reaction turbine is a type of hydropower generation system that uses the energy from the flow of water through a series of turbines to generate electricity. RWT can be used either as a stand-alone power generator or as the backup power supply for other renewable energy sources. A reaction turbine consists of two parts: a rotor and a stator. The rotor has blades that spin inside the stator. This spinning action turns the rotor and generates electricity.

Site Selection of Hydroelectric Power Plant

A hydroelectric power plant is a baseload power plant and it is located in hilly areas. Every hydro power plant designer must follow some instructions consciously. It is because every step of such kinds of a power plant is very important. There are some techniques to select the place or hydro power plant these are given below.

Availability of Water

Water is the main element of the hydroelectric power plant. Because kinetic energy of the water is converted into mechanical energy and mechanical energy of the water turbine converts into electrical energy. For this reason, the hydro power plant is built at a place (river, lake) where water is available.

Storage of Water

Water storage capacity is a very important part of the hydro power plant. The generation of electricity depends on the storage water or water flow of the river or canal. The storage water helps to flow water at the same speed to the water turbine to convert water energy into electrical energy.

Transmission Facilities

The hydroelectric power plant is located in a hilly area. For this reason, transportation of the crucial component of the hydro power plant becomes very difficult, and transmission cost becomes very high. It means that electrical transmission cost becomes very high because the hydro power plant is located far away from the locality.     

How does Hydroelectric Energy Work?

We will discuss here the hydroelectric power generation process which will be easy to learn about hydroelectric power generation process. The working procedure of a hydroelectric power plant working principle is very simple. First of all, the water flow of the river is stopped by the dam, generally, the dam is created between two hills. Reserve water is the main element of the hydro power plant. A water head is created by building a dam across the lake or river. The valve house consists of an automatic isolating valve and sluice valve.

The water flows from the reservoir to the powerhouse and the latter cuts off supply water when penstock bursts. Water flows to the turbine through the steel pipe which is called a penstock. The water turbine starts rotating and the kinetic energy of the water converts into mechanical energy. The water turbine is coupled with the alternator when the turbine rotates the alternator also rotates. It means that the turbine drives the alternator and the alternator converts the mechanical energy of the water turbine into electrical energy.

Advantages and Disadvantages of Hydroelectric Power Plant

The hydroelectric power plant is a baseload and reliable power plant. The hydropower plant is widely used as a baseload power plant there are a lot of advantages of hydropower plant such as

  • A hydro power plant requires no fuel but the water flow is used to generate electrical energy.
  • There is no smoke and fumes in the hydroelectric power plants.
  • Hydropower plant requires low running cost as compared to some other power plant.
  • It requires small construction and low maintenance cost.  
  • Hydro power plants use for two purposes, the generation of electrical energy and wasted water can be used for irrigation purposes.


The hydroelectric power plant has no more demerits due to its greater advantages. There are some disadvantages of the hydropower plant these are given below

  • Hydropower plants require high capital costs due to dam construction to create water head.
  • If the water becomes decreased in the river then electricity generation capacity can be decreased. It is because the electrical generation of the hydropower plant depends on water flow.

Constituents of Hydroelectric Power Plant

The entire component of the hydroelectric power plant is very essential. The constituents of the hydropower plant is divided into three types:

  • Hydroelectric structure
  • Water turbine
  • Electrical equipment

Hydroelectric Structure

There is a lot of equipment used in the electric power plants. There are some main components that are compulsory to construct a hydroelectric power plant. The hydropower plant structure components are given below.  

  • Dam
  • Spillways
  • Surge tank
  • Penstock


Dam plays an important for the hydroelectric power plant. A dam is one kind of barrier which is used to store the crate water head. Dams are made of concrete or stone, and earth or rock fill. Dams can be constructed in a narrow canyon, and a dam can be made between two valleys.


The spillway is made by the concrete and top of the dam. Whenever the river becomes over flooded, or whenever the water becomes exceeds the reserve water in the rainy season. In this case, a spillway is used to surplus water to the downstream side of the dam from the reservoir.   

Surge Tank

The surge tank is created at the starting point of the conduit. Moreover, the water turbine starts rotating at a steady load there is no surges flow of water through the conduit. It is noted that water flows to the turbine to meet the turbine requirement.


The penstock plays an important role in the hydro power plant. Penstock is a conduit that carries water to the turbine. Basically, penstock is made of reinforced concrete or steel. Concrete penstock is suitable to use for the small head or low head (water reservoir <30 m) power plant. Steel penstock can be used for any water pressure or any head. Most of the hydroelectric power plants used steel pipes to carry water to the turbine.

Why Transmission Cost is high in Hydroelectric Power Plants?

It is true that the transmission cost of the hydroelectric power plant is high than other power plants, such as nuclear power plants, steam power plants, diesel power plants, etc. There is a common reason to become higher the transmission cost. Basically, hydroelectric power plants are placed in a hilly area that is far away from the national grid or city. For this reason, hydropower transmission cost is very high.

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