Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 14 · 2026-08-14

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 the process by which electricity is generated in a hydroelectric power station.

Overall, the process involves the movement of water from a high-level reservoir through a dam and a series of mechanical components before electricity is generated. The water is then released into the lower reservoir and can be pumped back to the upper reservoir for reuse.

Initially, water is stored in the high-level reservoir behind a dam. When electricity is required, the intake gate is opened, allowing water to flow down through the tunnel. As the water moves through the tunnel, it passes through a reversible turbine, causing the turbine to rotate.

The rotating turbine powers a generator, which converts the mechanical energy into electricity. The electricity is then transmitted through power lines to the national grid. After passing through the turbine, the water flows into the low-level reservoir.

During periods when electricity demand is low, the process can be reversed. The turbine operates in the opposite direction and acts as a pump, moving water from the lower reservoir back through the tunnel to the upper reservoir. In this way, the water can be stored again and reused to generate electricity when demand increases.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The response effectively covers all stages of the hydroelectric power generation process. You have clearly identified the main features, including the movement of water between reservoirs and the dual-function nature of the turbine. The overview provides a concise summary of the entire cycle, and the body paragraphs logically detail the generation phase and the reversible pumping phase. The information is accurate and well-selected, meeting all requirements for a Task 1 response by reporting the key stages without unnecessary detail.

Coherence and Cohesion — Band 7.5

The essay is logically organized, with a clear progression from the initial state to the generation phase and finally the reversible cycle. Paragraphing is used effectively to separate the different stages of the process. Cohesive devices such as 'Initially', 'As the water moves', 'After passing through', and 'During periods when' are used naturally to guide the reader through the sequence. The referencing is clear, and the flow of information is smooth throughout the response.

Lexical Resource — Band 7.5

You have demonstrated a good range of vocabulary appropriate for a technical process description. Terms such as 'mechanical components', 'reversible turbine', 'mechanical energy', and 'national grid' are used accurately. The language is precise and fits the formal tone required for an Academic Task 1 report. There are no noticeable errors in word choice or spelling, and the vocabulary is sufficient to convey the process clearly and fluently.

Grammatical Range and Accuracy — Band 7.5

The response displays a high level of grammatical control. You have used a variety of complex sentence structures, such as participial phrases ('causing the turbine to rotate') and subordinate clauses ('When electricity is required', 'During periods when electricity demand is low'). The majority of sentences are error-free, and the punctuation is used correctly to manage the flow of information. The control over verb tenses and passive voice constructions is consistent and appropriate for describing a mechanical process.

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