Band 6.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 6.5 · Cambridge IELTS 14 · 2026-09-24

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 how hydroelectric power station generates electricity during the day, and how the process is reversed at night.

Overall, water flow from upper reservoir to the lower reservoir during the day to generate electricity. At night, the direction of water flow reversed, as water is pumped back to upper reservoir to reuse.

During the day, water from the river is stored in high-level reservoir behind the dam. When the intake gates are opened, water flows through a pipe toward turbines.The force of the flowing water causes the turbines to rotate, which in turns drives a generate to produce electricity. This electricity is then transmitted to power lines to the national grid. Finally, the water is discharged into the low-level reservoir.

At night, when electricity demand is lower, the intake gates are closed and the process operates reverse. Water from the lower reservoir is pumped through same pipe in reversible turbines that functions as pumps. The water is then returned in the upper reservoir, where it is stored until electricity is needed again during the day.

AI examiner evaluation

Task Achievement / Task Response: Band 7.0

The student successfully covers all main stages of the hydroelectric power station process, clearly distinguishing between daytime electricity generation and nighttime water pumping. An effective overview is provided in the second paragraph, capturing the dual cycle of the system. Key features such as the high-level and low-level reservoirs, the intake gates, reversible turbines, and the national grid are all accurately reported and positioned in the correct sequence. The response is fully grounded in the visual data with no major omissions or misinterpretations. This fulfills the Band 7 and Band 8 descriptors well for task achievement, as all parts of the prompt are addressed with a clear overarching summary.

Coherence and Cohesion: Band 6.5

The response exhibits clear logical organization and progression throughout. The information is divided into sensible paragraphs: an introduction, an overview, the daytime generation process, and the nighttime pumping process. Cohesive devices such as 'Overall', 'During the day', and 'At night' are used effectively to guide the reader through the cycle. However, referencing and cohesive links occasionally feel slightly mechanical, and minor mechanical errors in cohesion prevent it from reaching the highest bands. Overall, the paragraphing is used appropriately and the flow of information remains logical.

Lexical Resource: Band 6.0

The student demonstrates a sufficient range of vocabulary appropriate for an academic process description, incorporating terms like 'generate electricity', 'discharged', 'reversible turbines', and 'transmitted'. There are, however, some minor lexical and grammatical word-choice errors, such as 'generates electricity' missing an article ('a hydroelectric power station'), 'flow reversed' instead of 'flows are reversed', and 'returned in the upper reservoir' instead of 'returned to'. Less common items are attempted with decent awareness of style, but occasional inaccuracies keep the score at a solid Band 6.5.

Grammatical Range and Accuracy: Band 6.0

The writing contains a good mix of simple and complex sentence forms, demonstrating control over relative clauses and time markers (e.g., 'When the intake gates are opened, water flows...'). There are, nevertheless, some noticeable grammatical errors and missing articles throughout the text, including 'how hydroelectric power station generates', 'upper reservoir' lacking an article, 'which in turns drives a generate', and 'operates reverse'. While these errors do not impede communication, their frequency prevents the grammar score from reaching Band 7.

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

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