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Small hydro plant power: What is it and how it works?

Small hydro plant power: What is it and how it works?

Small hydro plants are becoming popular for those looking to reduce their energy costs and conserve the environment. They generate clean energy and can be used to power homes, businesses, and public facilities. But what is a small hydro plant power, and how does it work?

This article will explore the basics of small hydro plant power to produce electrical energy, including how it works and its advantages over other renewable energy sources. We’ll also examine some of the challenges associated with small hydro plants and discuss potential solutions. So if you’re curious about this renewable energy source, read more!

What is a small hydro plant?

A small hydro plant is a power station that uses the energy of falling water to generate electricity. The waterfalls may be created by dams or by natural features such as hillsides, rivers, and lakes.

The power generated by a small hydro plant can be used to supply electricity to homes and businesses, or it can be fed into the grid. These energy systems are often used in remote and rural areas where it is not economically viable to connect to the grid.

Small hydro plants typically have a capacity of less than 10 MW. The largest small hydro plant in the world is the 99 MW La Grande-2-Power Station in Canada.

Differences between a hydraulic power plant and a small hydro plant

A small hydro project has some peculiarities compared to sizeable hydroelectric power plants and the advantages of using renewable energy.

  • Limited investments: the construction of such a system generally takes place in running waters that do not require the construction of costly works (such as large dams). This allows for a quick return on investment.

  • It allows an improvement of the hydrogeological conditions of the territory;

  • This hydropower system contributes to reducing the greenhouse effect and therefore benefits from green certificates for producing energy from renewable sources.

How does a mini-hydro power plant work?

The objective of a small hydroelectric plant is to take advantage of hydraulic energy, transform the potential energy of a waterfall into mechanical energy using water wheels, and then, in electricity, through an electric generator.

The installed power of the plant is a function of the head and flow of the turbinated water; therefore, the height of the water fall.

Small river hydroelectric power stations are built on the riverbed and equipped with Kaplan jet turbines.

The single power of each turbine can reach up to 50 MW.

Jet turbines work efficiently with amounts of water that vary over a vast range. This property makes them suitable for rivers and canals with constant water runoff.

Another variant of Kaplan turbines widely used in small-scale hydropower plants is Bulb turbines. These turbines are double-regulated Kaplan turbines, in which the turbine and the generator are integrated into a single casing called a "Bulb."

This design increases the efficiency of the plant. In addition, the technology for constructing a canal-type hydroelectric power station with the "moving bulb turbine" is also innovative.

Types of turbines in a small hydro power plant

A Francis turbine is the most common type in a small hydropower plant. Other turbines that may be used in a small hydro plant include Pelton wheels, Kaplan turbines, and cross-flow turbines. Each type of turbine has its advantages and disadvantages.

Francis turbine

The Francis turbine is the most common type used in small hydro plants. It is a reaction turbine that uses water flowing through blades to rotate the shaft. Francis turbines are usually horizontal and have an internal or external draft tube.

The advantages of Francis turbines include their high efficiency and ability to operate at a wide range of head levels. Disadvantages of Francis turbines include their large size and the fact that they require a high level of maintenance.

Pelton Wheel

A Pelton wheel is a reaction turbine that uses water flowing through nozzles to strike buckets attached to the periphery of the wheel. Pelton wheels are usually vertical and have an internal or external draft tube.

The benefits of Pelton wheels include their high efficiency and ability to operate at a wide range of head levels. Disadvantages of Pelton wheels include their large size and the fact that they require a high level of maintenance.

Kaplan Turbine

A Kaplan turbine is a reaction turbine that uses water flowing over blades to rotate the shaft. Kaplan turbines are usually horizontal and have an internal or external draft tube.

Advantages of Kaplan turbines include their good efficiency at low head levels and their ability to operate at a wide range of head levels. Disadvantages of Kaplan turbines include their large size and the fact that they require a high level of maintenance.

Cross-Flow Turbine

A cross-flow turbine is an impulse turbine that uses water flowing over blades to rotate the shaft. Cross-flow turbines are usually vertical and have an internal or external draft tube.

Pros of cross-flow turbines include their relatively small size and low cost compared to other types of turbines. However, the cons of this type of turbine have their lower efficiency than different types of turbines, as well as their limited range of operation due to their inability to operate at high head levels.

Micro hydro power plant with vortices

This type of hydraulic power plant was developed in Austria. It has immense potential, requires little technique, and doesn't require a steep slope. A water supply channel from a river to a basin allows the production of 80 to 130 MWh per year. The production depends on the amount of water and the depth of the basin.

The rotor works by the force of current and gravity, driving a generator that will produce electricity.

A hydraulic vortex hydraulic power plant can operate from a drop height of 0.7 meters and an average amount of water of 1000 liters per second.

This technology is virtually safe for fish because they can safely pass upstream and downstream through the small hydroelectric plant.

Conclusion

Small hydro plant power is an environmentally friendly and efficient way to generate electricity. Using the natural water flow can produce a significant amount of clean energy without causing any environmental damage or pollution. The amount of electrical energy produced depends on the flow rate and the head.

Not only that, but its construction and maintenance costs are relatively low compared to other renewable energy sources. With the increasing demand for sustainable energy sources, this type of technology is becoming more and more popular worldwide.

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Publication Date: March 26, 2018
Last Revision: January 23, 2023