Band 5.5 IELTS Writing Task 1 Model Answer
Overall Band Score: 5.5 · Cambridge IELTS 14 · 2026-08-05
IELTS Writing Task 1 question
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.
Student answer (Band 5.5)
The diagram illustrates the process of electricity generation in a hydroelectric power station.
Water from the river in a high-level reservoir behind a dam. During the day, intake is open, and water flows down through a channel to the power station. As the water passes through reversible turbines, it drives the generator to produce electricity, which is then transmitted to the national grid via power lines. The used water then enters low-level reservoir.
At night, when electricity demand in lower, the intake is closed. The reversible turbines switch function and fact as pumps. They take water in the water in the low-level reservoir and pump is back up to the high-level reservoir, ready for the next day electricity generation.
This system effectively utilizes the gravitational potential energy of water to generate electricity, and the reversible turbines paly a crucial role in both electricity production during the day and water recycling at night, making a sustainable and efficient power generation method.
AI examiner evaluation
| Criterion | Band |
|---|---|
| Task Achievement / Task Response | 5.5 |
| Coherence and Cohesion | 5.5 |
| Lexical Resource | 5.5 |
| Grammatical Range and Accuracy | 5.5 |
| Overall | 5.5 |
Task Achievement / Task Response — Band 5.5
The response successfully identifies the main features of the hydroelectric power station process, including the day-time generation and night-time water recycling phases. The overview is clear, and the comparison between the two operational modes is well-handled. However, the first sentence of the second paragraph is a fragment ('Water from the river in a high-level reservoir behind a dam'), which lacks a main verb and hinders the clarity of the initial description. While the key stages are covered, the response could be improved by providing a more precise description of the transition between the reservoirs and the turbines. Overall, the response addresses the requirements of the task effectively.
Coherence and Cohesion — Band 5.5
The essay is logically organized into three distinct paragraphs, which helps the reader follow the process. Cohesive devices such as 'During the day', 'At night', and 'This system' are used appropriately to guide the reader through the stages. However, there are some minor issues with referencing and flow, such as the repetitive phrasing in the second paragraph ('take water in the water in the low-level reservoir'). While the paragraphing is effective, the mechanical nature of some transitions and the occasional lack of clarity in sentence structure prevent a higher score.
Lexical Resource — Band 5.5
The vocabulary is generally adequate for the task, with relevant technical terms like 'hydroelectric power station', 'reversible turbines', 'gravitational potential energy', and 'national grid'. There are some noticeable errors in word choice and collocation, such as 'fact as pumps' (should be 'act as pumps') and 'pump is back up' (should be 'pump it back up'). These errors do not impede communication, but they demonstrate a lack of precision. To reach a higher band, the student should focus on more accurate verb-noun collocations and avoid repetitive phrasing.
Grammatical Range and Accuracy — Band 5.5
The response uses a mix of simple and complex sentence structures, but there are several grammatical inaccuracies. The first paragraph contains a sentence fragment, and the second paragraph has errors in subject-verb agreement and pronoun usage ('pump is back up', 'demand in lower'). Additionally, there is a typo ('paly' instead of 'play'). While the meaning remains clear, the frequency of these errors suggests that the student has not yet achieved full control over complex structures. More attention to proofreading for basic grammatical slips would improve the score.
See this exact question answered at other band scores — the same prompt compared across bands.
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