Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 14 · 2026-09-09

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 7.5)

The diagram shows how electricity is generated in a hydroelectric power station.

Overall, the process involves storing water in a high-level reservoir and using it to generate electricity during the day. At night, the water is pumped back to the upper reservoir so that it can be used again.

At the beginning of the process, a river flows into a high-level reservoir, which is separated from the lower reservoir by a dam. During the daytime, the intake is opened and water flows from the high-level reservoir down through a pipe towards the power station. As the water passes through reversible turbines, they operate a generator. The generator then produces electricity, which is transmitted through power lines to the national grid.

After passing through the turbines, the water flows into a low-level reservoir. This water is not wasted because it is used again at night. When the intake is closed at night, the reversible turbines work in the opposite direction. They pump water from the low-level reservoir back up towards the high-level reservoir. As a result, the water is stored at a higher level and the same process can be repeated the following day.

Thus, the hydroelectric power station generates electricity during the day and recycles the water at night.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The response effectively addresses all parts of the task. You have clearly identified the main features of the hydroelectric power station, including the cyclical nature of the process (daytime generation and nighttime pumping). The description is accurate and follows the logical flow of the diagram. You have successfully highlighted the key components such as the reservoirs, dam, turbines, and generator. The overview provided in the second paragraph is concise and sets the stage well for the detailed description that follows. No significant information is omitted, and the comparison between the daytime and nighttime operations is well-integrated into the narrative, demonstrating a clear understanding of the process.

Coherence and Cohesion — Band 7.5

The response is logically organized, with a clear progression from the general overview to the specific stages of the process. Paragraphing is used effectively to separate the daytime generation phase from the nighttime recycling phase. Cohesive devices such as 'At the beginning of the process', 'During the daytime', 'After passing through', and 'As a result' are used naturally to guide the reader through the sequence of events. The referencing is clear, and the flow between sentences is smooth, ensuring that the reader can easily follow the technical process described without confusion.

Lexical Resource — Band 7.0

You have used a sufficient range of vocabulary to describe the process accurately. Terms such as 'high-level reservoir', 'reversible turbines', 'national grid', and 'transmitted' are appropriate for this technical task. The language is precise and fits the context of a process description well. While the vocabulary is functional and accurate, it could be slightly more sophisticated to reach the highest band; for instance, using more varied verbs or descriptive nouns to characterize the flow or the mechanical actions would enhance the lexical variety. However, the current range is more than adequate for a clear and professional explanation.

Grammatical Range and Accuracy — Band 8.0

The response demonstrates a high level of grammatical control. You have used a good mix of simple and complex sentence structures, such as 'At night, the water is pumped back to the upper reservoir so that it can be used again.' The use of passive voice is appropriate for describing a technical process, and the punctuation is accurate throughout. There are no noticeable grammatical errors, and the sentence construction is consistently clear and fluent. The control over complex structures is consistent, and the writing is error-free, which supports a high band score for this criterion.

See this exact question answered at other band scores — the same prompt compared across bands.

Browse more IELTS Writing model answers or get your own writing scored by the same AI examiner.