The diagram below shows how electricity is generated in a hydroelectric power station.
Sample Response
The given diagram depicts the process of producing electricity in a hydropower plant.
Overall, there are various stages in the process of generating electricity, commencing with collecting river water and finalizing with the transmission of electricity to the national grid.
During the daytime, the river current is held back by a dam in order to accumulate water in a high-level reservoir. After that, the water flows downward through an intake pipe into the lower part of the power station. During this stage, under the pressure of water, the reversible turbines are rotated to power the connected generator. Electricity generated by this generator is then transmitted via power lines to the national grid system. After rotating the turbines, the water is released into a low-level reservoir for storage.
At nighttime, the water is directed back into the power station, which makes the reversible turbines start to rotate backward. As a result, the water will be pumped up back into the high-level reservoir again to get ready for the next cycle.
IELTS Writing Correction
- 1. Match task terminology Original: hydropower plant Suggested revision: hydroelectric power station Why it matters: This term matches the label in the diagram and the task prompt precisely.
- 2. Use natural process verb Original: finalizing Suggested revision: ending Why it matters: Finalize is transitive in this context, while ending with fits the process sequence.
- 3. Name stored material Original: current Suggested revision: water Why it matters: The dam holds back and stores water, not the current itself.
- 4. Clarify turbine action Original: are rotated to power Suggested revision: rotate and drive Why it matters: The water makes the turbines rotate, and the turbines then drive the generator.
- 5. Remove redundant wording Original: national grid system Suggested revision: national grid Why it matters: National grid is complete and matches the diagram label.
- 6. Use natural time phrase Original: nighttime Suggested revision: night Why it matters: At night is the standard concise expression for this stage.
- 7. Fix word order Original: will be pumped up back Suggested revision: is pumped back up Why it matters: Back must precede up, and the present simple describes a recurring process.
- 8. Use formal process wording Original: again to get ready Suggested revision: to prepare Why it matters: To prepare is more concise and appropriate for a formal process description.
- 9. Show the full cycle Suggested revision: State that water generates electricity by day and is pumped back to the high-level reservoir at night, forming a repeating cycle. Why it matters: The overview ends at transmission to the grid and omits the diagram's essential nighttime return stage.
- 10. Add nighttime intake state Suggested revision: Clarify that the intake is closed at night while the reversible turbines pump water from the low-level reservoir back to the high-level reservoir. Why it matters: The closed intake is a labelled feature that distinguishes nighttime operation from the daytime flow.
Suggested Rewrites
- hydropower plant hydroelectric power station
- finalizing ending
- current water
- are rotated to power rotate and drive
- national grid system national grid
- nighttime night
Why this response received Band 7.0
The response explains the daytime generation and nighttime pumping stages in a clear, logical sequence, and it accurately identifies the main components of the station. The overview is somewhat generic and does not foreground the cyclical day-night operation, while a few phrases are awkward or redundant. The highest-priority improvement is to state the cycle explicitly and clarify that the intake closes while water is pumped back at night.
IELTS Writing Criteria Scores
Task Achievement
The main daytime and nighttime stages are accurately covered, though the overview misses the central cyclical contrast and the closed nighttime intake is omitted.
Summarise the day-night cycle in the overview and mention that the intake is open by day but closed while water is pumped back at night.
Coherence and Cohesion
The process is organised logically into overview, daytime, and nighttime paragraphs, with clear sequencing and progression.
Strengthen the link between the final nighttime stage and the next daytime cycle to emphasise the continuous nature of the process.
Lexical Resource
A good range of process vocabulary is used accurately, although finalizing, rotate backward, and pumped up back are awkward choices.
Use more natural phrasing such as ending with transmission, operate in reverse, and pumped back up to the high-level reservoir.
Grammatical Range and Accuracy
Complex and passive structures are varied and mostly accurate, with only minor awkwardness and redundancy.
Edit redundant combinations such as back, up, and again in the same clause, and keep process descriptions consistently in the present simple.
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IELTS Academic Writing Task 1
The diagram below shows how electricity is generated in a hydroelectric power station.
Your response
Write the task yourself, then compare your choices with the annotated response.