The concept of generating electricity with the help of flowing water has been around for centuries now. But with the inception of modern technology, hydropower plants were established. They took the effectiveness of electricity generation through the water to the next level. You can get the cleanest source of electricity through hydropower plants. In addition to that, the source of this energy is renewable, and the running cost is minimal.
Due to all the benefits mentioned above and many others, hydropower is amongst the most popular ways for electricity generation. All the major economies are relying on hydropower plants to fulfill their energy needs. In this blog, we will give you an insight into all the aspects of a hydropower plant.
- 1 The Mechanism of a Hydropower Plant:
- 2 Types of Hydro Power Plants:
- 3 Conclusion:
The Mechanism of a Hydropower Plant:
Hydropower plants use water to run turbines that produce electricity. A hydropower plant works on the principle of using the potential energy of water to generate electricity. The water is stored at height and then released onto a turbine that is connected with a generator. Different parts of a hydropower plant are given below:
The reservoir is the storage area of a hydropower plant that stores the water. A dam is built to give water the height for the required potential energy. The height of the reservoir is directly proportional to the amount of power generated by water.
The water reservoir has control gates that help manage the quantity of water to be released onto the turbine. If the gates are opened completely, more water will flow out of the reservoir and vice versa.
A penstock is a channel that is used for carrying water to the turbine. While the water flows through this pipe, its potential energy is converted into kinetic energy, which ultimately runs the turbine. The main objective of the penstock is to manage the direction of the flowing water to ensure that it falls on the turbine.
The turbine is one of the essential parts of a hydropower plant. The turbine rotates when the water falls on it and runs the generator attached to it which produces electricity. The number of turbines used in a hydropower plant depends on the power to be generated. Large-size head stations use multiple turbines for electricity generation.
The two types of turbines that are commonly used in hydropower plants are reaction turbines and impulse turbines. The reaction turbines are used with small to medium scaled heads, whereas impulse turbines are used with large scaled heads.
The turbine is attached to a generator that produces an electric voltage as a result of the turbine’s rotation. There are several transmission lines attached to the generator that carry the electricity generated to the consumers.
A surge tank is an important section of a hydropower plant that is connected to its safety. The level of water within the penstock rises and drops down according to the load on the turbine. The surge tank plays its role to keep the water level manageable within the penstock.
Usually, when the turbine load drops, its gates are closed that results in immense pressure within the penstock. In such a condition, the excessive amount of water in the penstock is released into the surge tank. The opposite reaction occurs when the turbine load increases.
Spillways are also an integral part of a hydropower plant. There are situations when the water level in the reservoirs increases, and there is a threat of overflow. In such a case, the spillway plays its role to keep the water in the reservoirs at a safe level. The spillway releases an excessive amount of water from the reservoir to prevent flooding.
A trash rack is a metallic structure that filters the dirt in the water, preventing it from entering the turbine. Different parts of the machinery, like globe valves, are vulnerable to blockage if debris gets stuck in it. The main purpose of a trash rack is to clean out all the unwanted material from the water to prevent clogging of the machinery.
Types of Hydro Power Plants:
There are following types of hydropower plants based on their working:
Storage Hydropower Plant:
The storage hydropower plant is also known as pumped storage that makes use of reusable water for generating electricity. In addition to the main reservoir, there is an additional reservoir built next to the turbine. It stores the water after running the turbine so that it can be used again. Whenever there is a need for more power generation, the lower reservoir pumps water into the upper reservoir to fulfill the demand.
Run-of-river Hydropower Plant:
The run-of-river hydropower plant, also known as diversion, does not need the construction of a dam or reservoir. It channelizes a river through a canal or a penstock to run the turbine. A run-of-river hydropower plant cannot store water to be used again. However, some run-of-river power plants have a limited capacity to store water according to their requirements.
The run-of-river hydropower plants are one of the most cost-efficient types of hydropower plants. Its reason is that they do not need the construction of a dam and reservoir which saves a lot of initial costs.
Impoundment Hydropower Plant:
An impoundment hydropower plant is the most popular type of hydropower plants. It uses a dam and reservoir for storing water at a certain height. The water is released from the reservoir to run the turbine to produce electricity. An impoundment hydropower plant stores the water after running the turbine to reuse it.
Offshore Hydropower Plant:
The offshore power plants are not the most commonly used, but their technology is gaining popularity around the globe. They use the tides of the sea for running the turbine to generate electricity.
Hydropower plants have a proven mechanism for generating electricity effectively. Hopefully, all the details mentioned above will help you understand more about the working of hydropower plants better.