Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 14 · 2026-09-27

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 given diagram highlights the sequential process of electricity generation in a hydroelectric power station.

Overall, the process is based on three main stages, which begin with the intake of water from a river and concludes with the supply of energy to the national grid station, while reversible turbines act as an intermediate stage. In addition, they are bifunctional in terms of the direction of pumping water.

During the day, gates of the dam are opened to allow the maximum intake of water, which flows downward to rotate reversible turbines, which are present in the bottom of the power station. Additionally, these turbines power the generator, located at the top of the power station to produce electricity, which is transmitted through various power lines to the national grid station.

In contrast, during the night, the water moves from the low-level reservoir to the high-level reservoir, then to the river, with the help of reversible turbines that play the essential role of pumps to push the water in an upward direction from the low-level reservoir to the high-level reservoir.

AI examiner evaluation

Task Achievement / Task Response: Band 6.5

The student successfully addresses all parts of the task by presenting a clear and accurate overview of the hydroelectric power station process. The response correctly identifies the main stages, distinguishing between daytime electricity generation and nighttime water pumping. Key features such as the high-level and low-level reservoirs, the intake gates, the reversible turbines, and the national grid are all accurately reported. The comparison between day and night operations is well-developed and grounded in the visual data. The overview effectively captures the cyclical nature of the process without any major omissions or misinterpretations. This performance meets the criteria for Band 7.0.

Coherence and Cohesion: Band 6.5

The response demonstrates a clear logical organization and progression throughout. Information is grouped coherently into introduction, overview, day operation, and night operation paragraphs, which aids readability. Cohesive devices such as 'Overall', 'In addition', 'During the day', and 'In contrast' are used effectively to guide the reader through the sequential and contrasting aspects of the diagram. Referencing is generally clear, and paragraphing is managed appropriately. Although cohesion is sometimes slightly mechanical, the overall structure supports a smooth flow of ideas, earning a Band 7.0.

Lexical Resource: Band 6.0

The student uses an adequate and generally appropriate range of vocabulary for the task, incorporating process-specific terms such as 'sequential process', 'reversible turbines', 'bifunctional', 'intake', and 'transmitted'. There are occasional slight inaccuracies in word choice or phrasing, such as stating that turbines are 'present in the bottom of the power station' rather than housed within it, or using 'gates of the dam' where the diagram indicates an intake. However, the vocabulary is flexible enough to describe the mechanisms and operations clearly without impeding communication. This aligns well with the descriptors for Band 6.5.

Grammatical Range and Accuracy: Band 6.5

The response features a good mix of simple and complex sentence structures, utilizing relative clauses and subordinate clauses effectively (e.g., 'water, which flows downward to rotate reversible turbines...'). Grammatical control is generally strong, with many error-free sentences. Minor lapses occur, such as the awkward phrasing in 'concludes with the supply of energy to the national grid station, while reversible turbines act as an intermediate stage', where punctuation or conjunction choice could be smoother. However, these errors do not impede communication and punctuation is mostly accurate. This warrants a Band 7.0.

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