IELTS graph 320 - How electricity is generated in a hydroelectric power station
- Last Updated: Tuesday, 25 August 2020 23:49
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IELTS Academic Writing Task 1/ Graph Writing - Pie Charts:
You should spend about 20 minutes on this task.
The diagram below shows how electricity is generated in a hydroelectric power station. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.
Summarize the information by selecting and reporting the main features, and make comparisons where relevant.
You should write at least 150 words.
The diagram outlines the process of electricity production in a hydroelectric power station. The process begins when the water flows from the river into a high-level reservoir and ends with the transmission of electricity to the national grid.
In general, the process is broadly distributed into day and night stages with the daylight stages involving electricity production from a river and storage of water in a reservoir. At night, the water flows back in the opposite direction towards an initial reservoir and the river.
The day stage of the process involves channelling the river water into a high-level reservoir backed up by a dam. There is an intake area leading to the power station that opens during the day and closes at night. Water flows during the day to generate electricity through the power station turbines. The generated electricity is then sent to a national grid through power lines while the excess water runs to a low-level reservoir.
During the night stage, the water stored in the low-level reservoir is reverted to the power station and the turbines of the generator pump it back into the high-level reservoir which is closed during the night. The river water is stored at the upper level and later it flows down, starting the cycle again.
In general, this hydrostatic power station consists of 3 main units, namely- the high-level reservoir, the power station, and the low-level reservoir. As can be seen in the diagram, during the daytime, intake at the bottom of the dam of the high-level reservoir is kept open to allow water to flow down to the power station and pass through the turbines to the lower reservoir. A power generator coupled to the turbine generates electricity and then it is transmitted to the national grid via power lines. The water is stored in another reservoir next to the power station. The produced electricity is then sent to a national grid through power lines while the excess water runs to a low-level reservoir.
During the nighttime, the stored water is pumped back to the high-level reservoir with the help of the reversible turbine that acts as a water pump. We can see that the intake valve is closed in the nighttime while water is being pumped back.
Electricity production from a hydroelectric power station consists of 6 stages, and electricity production is done in two shifts - day and night.
In the day shift, the water is collected into the upper reservoir through the river channel which is strengthened by the dam wall. The intake valve remains open during the day time and water flows into a turbine to create enough energy to generate electricity. This electricity is then transferred to the National grid through power lines. The remaining water is transferred to the lower reservoir for later use.
At night time, the lower reservoir water is transferred to the high-level reservoir with the help of a pump. It pumps water upwards by a reversible turbine and repeats the same cycle to generate electricity. Through power generators in a power station, the electricity is supplied to the national grip of power.
Overall, the electricity generation in this station involves a sophisticated procedure of 6 stages. Moreover, it requires a few instruments such as a reservoir for storing water, reversible turbine, generator, power lines and so on.
The process begins with storing water from the river in the high-level reservoir, which is situated behind a dam. During the day, the dam allows the flow of water via pipes to the turbine that is connected to a generator. The extreme flow of water rotates the turbine, and thus produces electricity in the generator, which is supplied via power lines to the National grid. The used water, on the other hand, is transferred to the low-level reservoir for storage.
When the night comes, the stored water is shifted by means of reversible turbines that help to pump the water uphill to the high-level reservoir which is closed during the night. The river water, on the contrary, is stored at the upper level and starts the process anew when it flows down.