The volume of water on planet earth is extremely important. We have about seventy per cent water composed of oceans, seas, lakes, waterfalls and dams. Therefore, humans have used this natural power for decades. Whether they utilized it for water supply or irrigation, water still an indispensable source of life for human beings since their first civilizations. However, only in modern times the world humans utilized water to generate electricity.
In 30th of September in 1882 was the date of implementation of the first hydroelectric plant in the world. The plant initiated its operation and the world witnessed the first electrical energy generated from water. The hydro power plant was in Fox River in Appleton, Wisconsin USA.
How is hydroelectricity produced?
The common rule says that hydro power plants are using dams to generate electricity. Well this is true but not always the case. For instance, in the United States of America there is more than 80.000 dam. Only 2400 of them generates electricity the others are used for irrigation and water supplies and other usages.
There are multiple sizes of hydroelectric plants. Their array of size is from large plants to small ones, which are only responsible for domestic supply of energy. There are three major categories of technologies, which help to generate electricity from water. These three major types are impoundment, diversion, and pumped storage.
The Impoundment technique in hydro-electric generation:
The most conventional way of hydro electrical generation is indeed, impoundment. During the impoundment process, the hydro energy company in charge employs a dam as the source of energy. How is hydroelectricity produced through a dam? Well the answer is that they utilize dams to store the water of rains or rivers.
These dams play the role of reservoir in that case. Then, when they release water, flooding creates a strong flow.
Actually, this flow of water is the most important part of the process. By definition, a flow is the water’s strength of streaming. The measurement of the water’s volume is in cubic meter per second in a definite marge of time of course. Thus, the flow of water in our case should be strong enough to move the turbines. When the strong flow is outpouring through the turbines, they spin continuously. This movement will trigger the generator and produce electricity at the end. The level of water in the reservoir is very important in this process.
The Diversion technique in hydro-electric generation:
This technique is perfectly sustainable and environment-friendly. Another synonym of diversion is run-of-river (ROR). There is no requirement of water reservoirs. That is why it is considered more sustainable than other techniques. The operation starts when the hydro energy company responsible for the project chooses a river with a strong flow.
Then they create like a channel where a part of the river streaming direction is diverted to the turbines. Then as in the first process, a turbine spinning engenders the suitable power to trigger the generator.
During this process, it might happen that the project engineers create a penstock. A penstock is a kind of small reservoir in case the water level decreases. ROR projects have less environmental effects. Their disadvantage is that the lack of storage system might cause a shortage of electricity.
The Pumped storage technique in hydro-electric generation
This technique depends on the electricity demand. This process requires two reservoirs. Most importantly, during this process these reservoirs have two main roles. The roles are storage, and electrical generation. A reservoir is placed in a high position the other is in a lower position. When the demand of electricity is high, the project engineers release water from the higher reservoir to the lower one. The fact that creates water flow and spins the turbines. Consequently, the spinning causes the activation of the generator. At the end, the production of electricity happens.
In case of energy storage – the second role- the movement of energy pumping is reversed. Therefore, the water will move from the lower reservoir to the higher reservoir. This operation functions like a battery of hydroelectric power.
How efficient is hydroelectric power?
Through hydroelectric power, societies can obtain the electrical power they need in addition to clean environment. Water floods are not renewable energy but they are more sustainable and ecological than many other resources. However, many would argue that the creation of these dams-reservoirs is harmful on the environment.
More precisely, it has disastrous effect for the superficial aquifers and groundwater aquifers.
These could be accurate facts but they do not reflect the entire image. The reality of the issue lays on a very important theory of sustainability. For instance, the American governmental orientation considers hydropower among the main sources of energy. More specifically 95 per cent of the nation electrical storage is provided by pumped storage hydropower.
For investors the value market of such an energy source is growing since its initiation. Hydropower companies are among the most successful businesses in the industry of renewable energies.
To know more about the sustainability of this energy sources, there is a protocol of assessment that is called The Hydropower Sustainability Assessment Protocol. This protocol has numerous criteria to determine whether a project is sustainable or not. The operation starts with an audit of performance and ends up with a full assessment of the situation. During the assessment, there are different aspects.
For instance, the assessment touches upon how much the project (and the reservoir level) will affect the environment (the aquifers). Besides, the experts will study cultural aspects, such indigenous people situation and cultural heritage.
Despite its benefits, the hydropower is always discussed with cautiousness. However, this did not hinder 20 per cent of the world population to generate power from water. This is thanks to its clean nature. By clean we mean that the use of hydropower each year avoids the burning of 20 billion gallons of oil. In addition, it prevents the burning of 120 million tons of coal. By clean we also mean the prevention of greenhouse effect and other forms of polluted air. Moreover, hydropower does not have any chemical wastes whatsoever.