Pumped Storage Power Station

Introduction to Pumped Storage Power Stations 

Pumped storage power stations, also known as pumped hydroelectric energy storage, are one of the most efficient and cost-effective methods of storing energy. They are large-scale facilities that use electricity to pump water from a higher-elevation reservoir to a lower-elevation reservoir. When energy is needed, the water is then released from the upper reservoir, flowing down to the lower reservoir and producing electricity through the turbines. This process can be repeated over and over, allowing large amounts of energy to be stored and released on demand. It works by storing energy in the form of the gravitational potential energy of water, pumped from a lower-elevation reservoir to a higher elevation. If the upper lake is fed by a river or collects significant rainfall, then it can be a net energy producer like a traditional hydroelectric plant.

Definition of a Pumped Storage Power Station

A pumped storage power station is a large-scale facility that uses electricity to pump water from a lower-elevation reservoir to an upper-elevation reservoir. When energy is needed, the water is then released from the upper reservoir, flowing down to the lower reservoir and producing electricity through the turbines.

History of Pumped Storage Power Stations

Pumped-storage hydroelectricity has a long history. It was first used in 1907 in Switzerland at the Engeweiher pumped storage facility. The 1930s saw the introduction of reversible hydroelectric turbines that could operate as both turbine-generators and electric motor-driven pumps. 

In the United States, the first use of pumped storage was in 1930 by the Connecticut Electric and Power Company, which used a large reservoir to pump water from the Housatonic River to the storage reservoir 70 meters (230 ft) above. 

Today, PSH stations are used for a variety of purposes, such as providing ancillary services, grid stability, and peak load management.

Benefits of Pumped Storage Power Stations

Pumped storage power stations are beneficial for a number of reasons. They are extremely efficient, with some stations achieving up to 75% efficiency. They also have a relatively low environmental impact, which is important in an increasingly green world. In addition, they are cost-effective and reliable, making them an attractive option for energy storage.

PSH is the most widespread form of grid energy storage worldwide, with 181 GW of installed capacity as of 2020. The United States Department of Energy Global Energy Storage Database reports that PSH accounts for 95% of all active tracked storage installations, with 29 GW of that total in the United States alone.

How a Pumped Storage Power Station Works

Overview of the Process

The basic process of a pumped storage power station involves using electricity to pump water from a lower-elevation reservoir to an upper-elevation reservoir. When energy is needed, the water is then released from the upper reservoir, flowing down to the lower reservoir into penstock and producing electricity through the turbines.

This turbine can generate electricity when water is down from the mountain and then pump the water back up again to the upper reservoir.

Components of a Pumped Storage Power Station

Having a large head is a characteristic of this power station. A pumped storage power station consists of several components. These include a lower reservoir, an upper reservoir, a penstock, a Francis type Turbine, a pump or a generator, and a control system.  

Do you know why there use Francis-type Turbines?

When the head is too large, there used Francis type Turbine. The head range of Francis type Turbine is 100m (330ft)-300m(980ft). 

Source: ResearchGate & Energy.Gov

Types of Pumped Storage Power Stations

Pumped storage hydroelectric plants come in two varieties: open and closed loop. An open-loop system is directly connected to a natural water flowing source and is thus subject to potential aquatic life interaction and environmental impacts. Closed-loop systems, however, are used in two reservoirs and constructed independently of any natural body of water and thus reducing the potential for impacts and concerns.

Open-Loop Pumped Storage Power Station

Open-loop pumped storage projects are the most common type of project currently in operation. In open-loop systems, use the free flow of water from an upstream reservoir. 

The Okinawa Yanbaru Seawater Pumped Storage Power Station in Japan is an example of an open-loop plant where the sea is used as the lower reservoir. However, open-loop systems can bring about various issues such as water temperature, minimum water flow, drought, and fish passage.

Closed-Loop Pumped Storage Power Station

A closed-loop pumped storage power station uses two reservoirs. Water is pumped from the lower reservoir to the upper reservoir, and when energy is needed, the water is released from the upper reservoir and flows back down to the lower reservoir, producing electricity through the turbines.

Advantages and Disadvantages of Pumped Storage Power Stations

Advantages

Pumped storage power stations offer a number of advantages. They are extremely efficient, with some stations achieving up to 90% efficiency. They also have a low environmental impact, are cost-effective, and are reliable.

Disadvantages

The main disadvantage of pumped storage power stations is that they require large amounts of land and water. In addition, they are relatively expensive to build and maintain.

The Future of Pumped Storage Power Stations

New Technologies

New technologies are being developed that could make pumped storage power stations more efficient and cost-effective. These include systems that use air instead of water to store energy, as well as systems that use gravity instead of pumps.j

Potential Applications

Pumped storage power stations are used for a variety of purposes, including providing ancillary services, grid stability, and peak load management. They could also be used to store energy from renewable sources, such as wind and solar, making them an attractive option for green energy.

Conclusion

Pumped storage power stations are an efficient and cost-effective way to store energy. They are reliable and have a low environmental impact, making them an attractive option for energy storage. New technologies are being developed that could make them even more efficient, making them an even more attractive option for the future.