Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 14 · 2026-09-20

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 6.5)

The diagram illustrates the process of how electricity is generated and managed in a hydroelectric power station using a two-stage daily cycle.

Overall, it is clear that the system operates in two distinct phases: energy is produced during the day using downward water flow, while water is pumped back up at night.

During the day, the intake from the high-level reservoir is kept open. Water flows downward through the dam, rushing towards the power station. This heavy flow spins the reversible turbines, which drives the generator to create electricity. Finally, this power is transmitted to the national grid via power lines.

In contrast, at night, the intake is closed. Water that was collected in the low-level reservoir is pumped back up into the main reservoir. During this phase, the turbines run in reverse, using electricity to push the water uphill, readying the system for the next day.

AI examiner evaluation

Task Achievement / Task Response — Band 5.5

The student provides a clear and accurate summary of the hydroelectric power station diagram, correctly identifying the core components, the two-stage daily cycle, and the contrasting mechanisms between day and night operations. The overview successfully highlights the cyclical nature of the system. However, it must be noted that the word count is 147 words, which falls slightly short of the 150-word minimum requirement specified in the instructions. Consequently, this minor length penalty prevents the response from achieving a higher band score despite its strong content and accurate reporting of the visual data.

Coherence and Cohesion — Band 6.5

The response demonstrates a clear and logical overall progression, moving smoothly from an introduction and overview to the daytime phase and finally the nighttime phase. Paragraphing is used appropriately to separate these distinct operational stages. Cohesive devices are handled effectively, with linking phrases such as 'Overall', 'During the day', and 'In contrast' guiding the reader through the process effortlessly. Referencing throughout the text is clear, ensuring that the relationships between the reservoirs, turbines, and the national grid remain easy to follow.

Lexical Resource — Band 6.5

The student displays a sufficient and appropriate range of vocabulary for an Academic Task 1 response, successfully employing subject-specific terminology such as 'reversible turbines', 'intake', 'national grid', and 'conduit' (implied via water flow descriptions). Less common lexical items are used with reasonable awareness of style and collocation, as seen in phrases like 'two-stage daily cycle' and 'turbines run in reverse'. Word choice is generally precise, and there are no noticeable spelling or word-choice errors that impede communication.

Grammatical Range and Accuracy — Band 7.0

The writing features a good mix of simple and complex sentence structures, including participial phrases ('rushing towards the power station') and subordinate clauses ('Water that was collected in the low-level reservoir...'). The majority of sentences are error-free, demonstrating a firm command of tense usage, particularly in the present simple tense required for describing processes. Punctuation is accurate, and grammatical control remains strong throughout, facilitating an effortless read for the examiner.

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

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