Band 7.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.0 · Cambridge IELTS 14 · 2026-10-12

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 7.0)

The given diagram illustrates the production of electricity in a hydroelectric power station.

Overall, the generation of electricity takes place during the day when the water flows from high-level reservoir to low-level reservoir through reversible turbines. At night, the process is reversed when the water flows back to high-level reservoir through turbines.

During the daytime, water stored in high-level reservoir flows through an intake which is open at this time. The water passes through a large pipe and reaches power station, where reversible turbines rotate when water places pressure on it and operate generator. Consequently, electricity is produced which is transmitted through power lines to the national grid. The water flows from turbines to low-level reservoir.

At night, the turbines pump water from low-level reservoir back into high-level reservoir, making water available for reuse again. The generation of electricity does not take place at night due to closure of intake.

AI examiner evaluation

Task Achievement / Task Response: Band 7.0

You cover the main stages and give a clear overview of the day–night cycle: water moves from the high-level reservoir through the turbines to the low-level reservoir by day, then returns at night. The intake’s daytime opening and nighttime closure, electricity transmission to the national grid, and the turbines’ pumping role are also included. This is a well-focused account of the diagram. To make the description more fully precise, avoid adding unsupported mechanical detail such as water “places pressure” on the turbines, and clarify that the turbines are reversible: they generate electricity during the day and pump water back uphill at night. The claim that generation does not occur at night is consistent with the diagram, but could be linked more directly to the pumping cycle.

Coherence and Cohesion: Band 7.5

The response is organised effectively into an introduction, an overview, and separate descriptions of the daytime and nighttime stages. This gives the reader a clear progression through the process, and time markers such as “During the daytime” and “At night” make the contrast easy to follow. Linking expressions including “Consequently” also help show cause and result. The organisation is strong, though some connections between stages could be made more smoothly: for example, the transition from the generator and power lines to the water’s movement into the low-level reservoir is abrupt. You could use a clearer sequence marker or combine these related outcomes in a sentence. Overall, the paragraphing and progression are clear, with only minor opportunities to make cohesion more seamless.

Lexical Resource: Band 7.0

You use a suitable range of process vocabulary, including “intake,” “reversible turbines,” “transmitted,” “power lines,” and “national grid.” These terms are relevant and generally precise, and the contrast between “flows” and “pump[s]” helps explain the two operating modes. Some collocations and phrasing are less natural, however: “water places pressure on it” is awkward, and “making water available for reuse again” is repetitive. “Large pipe” is understandable but less precise than “conduit” or “channel,” depending on the part shown. Aim for concise, conventional process language and avoid adding descriptive wording that is not needed. The vocabulary is sufficiently varied for the task, but more consistent collocational control would make the account more polished.

Grammatical Range and Accuracy: Band 6.5

You use a mix of simple and complex structures, including the overview sentence beginning “when the water flows” and the result clause “Consequently, electricity is produced.” Most sentences communicate the process clearly, and the present simple is generally appropriate for describing a diagram. Some grammatical errors remain. Articles are missing in phrases such as “from high-level reservoir” and “reaches power station”; these should be “from the high-level reservoir” and “reaches the power station.” In “when water places pressure on it,” the pronoun reference is unclear, and the clause would benefit from a clearer grammatical construction. The sentence “At night, the turbines pump water…” is clear, but the final explanation could be integrated more smoothly. Greater accuracy with articles and clause construction would strengthen an otherwise understandable range.

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

Browse more IELTS Writing model answers or get your own writing scored by the same AI examiner.