Band 8.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.0 · Cambridge IELTS 14 · 2026-10-02

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 8.0)

The diagram illustrates how electricity is generated in a hydroelectric power station using water stored in a high-level reservoir.

Overall, the process operates in two stages: during the day, water flows from the high-level reservoir through reversible turbines to generate electricity, while at night, the direction of water flow is reversed and the water is pumped back into the upper reservoir for reuse.

During the daytime, the intake is opened, allowing water from the high-level reservoir to flow downhill through a pipe towards the power station. As the water passes through the reversible turbines, they operate the generator, which produces electricity. The electricity is then transmitted through power lines to the national grid. After passing through the turbines, the water flows into the low-level reservoir.

At night, the intake is closed and the process is reversed. Water from the low-level reservoir flows back towards the reversible turbines. Instead of generating electricity, the turbines operate as pumps and send the water uphill through the pipes into the high-level reservoir. The water is therefore stored there until it is needed again during the daytime. This cycle allows the same water to be reused repeatedly for electricity generation.

AI examiner evaluation

Task Achievement / Task Response: Band 8.0

The response covers all parts of the task well, providing a clear overview and detailing the cyclical process of electricity generation and water pumping. The main features, such as the day and night operations, the intake valves, reversible turbines, and reservoirs, are accurately reported and well-developed. The writing successfully contrasts the daytime operations with the nighttime cycle, satisfying the requirements for reporting main features and making relevant comparisons. There are no notable omissions or inaccuracies in the data representation.

Coherence and Cohesion: Band 8.0

Ideas are logically sequenced, guiding the reader smoothly through the sequential stages of the diagram. The response utilizes appropriate cohesive devices naturally, such as 'Overall,' 'During the daytime,' 'After passing through,' and 'At night,' without any mechanical over-use. Paragraphing is used effectively, with a clear introduction and overview paragraph followed by distinct body paragraphs dedicated to the daytime and nighttime phases respectively. Referencing throughout the text is clear and precise.

Lexical Resource: Band 7.5

The candidate demonstrates a sufficient and flexible range of vocabulary suited to a process diagram, using terms such as 'transmitted,' 'reversible turbines,' 'subsequently,' and 'reused repeatedly.' There is good control over less common lexical items related to engineering and geography. Word choice and collocations are generally accurate, with only very occasional minor slips that do not impede communication. Spelling and word formation are handled correctly throughout the response.

Grammatical Range and Accuracy: Band 8.0

The text exhibits a wide range of complex sentence structures, including participial phrases and subordinate clauses, with the majority of sentences being entirely error-free. Grammatical control is strong, evident in accurate verb forms and tenses used to describe a continuous mechanical process (e.g., 'water flows,' 'is reversed'). Prepositions inside grammatical patterns and punctuation are managed with precision, contributing to the fluent and professional delivery of the report.

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