Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 14 · 2026-09-12

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 illustrates how electricity is generated in a hydroelectric power station during the day and how water is pumped back into the high-level reservoir at night.

Overall, the process operates in two stages. During the day, water flows from the high-level reservoir through the power station, generating electricity, while at night the direction is reversed and water is pumped back to the upper reservoir.

During the daytime, the intake is opened, allowing water from the high-level reservoir to flow downhill through a pipe towards the power station. The water passes through reversible turbines, which operate a generator. The electricity produced is then transmitted through power lines to the national grid. At the same time, the water is collected in the low-level reservoir.

At night, the intake is closed and the turbines work in reverse. Water from the low-level reservoir is pumped back up through the same pipes into the high-level reservoir. This allows the water to be reused for electricity generation the following day.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The student has successfully addressed all parts of the task by providing a clear and comprehensive summary of the process of electricity generation in a hydroelectric power station, including both daytime and night-time operations. The main features are accurately reported and well selected, such as the flow of water from the high-level reservoir, the functioning of the reversible turbines and generator, transmission to the national grid, and the subsequent pumping back of water at night. Comparisons and contrasts between the day and night cycles are effectively integrated. There are no significant omissions, and the information is fully supported by the diagram, corresponding well to the Band 8 descriptor for Task Achievement.

Coherence and Cohesion — Band 7.5

The response is logically sequenced and easy to follow, moving smoothly from a clear introduction and overview to detailed paragraphs describing the daytime operation and night-time cycle respectively. Paragraphing is used sufficiently and appropriately, with each paragraph focusing on a distinct phase of the process. Cohesive devices such as 'Overall', 'During the daytime', 'At the same time', and 'At night' are managed well to guide the reader through the sequence of events without mechanical overuse. Referencing is clear throughout, reflecting the characteristics of a Band 8 performance in Coherence and Cohesion.

Lexical Resource — Band 6.5

The candidate demonstrates an adequate and appropriate range of vocabulary suitable for describing a technical process. Terms such as 'high-level reservoir', 'reversible turbines', 'national grid', and 'direction is reversed' are used accurately. While there is an attempt at less common vocabulary, the range is somewhat standard for this topic rather than exceptionally wide or flexible. However, word choices and collocations are generally precise, and there are no spelling or word-formation errors that impede communication, firmly supporting a Band 7 score.

Grammatical Range and Accuracy — Band 7.5

The student displays a good variety of sentence structures, successfully incorporating both simple and complex forms, such as participle clauses ('allowing water from the high-level reservoir to flow downhill') and relative clauses. The majority of sentences are error-free, and the grammar and punctuation are controlled very well throughout the text. Minor inaccuracies or awkward phrasings are absent, and the control over complex structures allows for smooth flow and precise communication, aligning closely with the Band 8 criteria.

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

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