Band 8.0 IELTS Writing Task 1 Model Answer

Overall Band Score: 8.0 · Cambridge IELTS 12 · 2026-10-01

IELTS Writing Task 1 question

The diagram below shows how geothermal energy is used to produce electricity.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

Student answer (Band 8.0)

The diagram illustrates the process by which geothermal energy is used to generate electricity in a geothermal power plant.

Overall, the process consists of five main stages, beginning with cold water being pumped 4.5 kilometres underground and ending with electricity being generated. The water is heated as it passes through a geothermal zone containing hot rocks, before being converted into steam and used to power a turbine and generator.

First, cold water is pumped down through an injection well to a depth of approximately 4.5 kilometres. It then passes horizontally through the geothermal zone, where hot rocks heat the water. The resulting hot water is subsequently pumped back to the surface through a separate production well.

Once above ground, the hot water enters a condenser, where it is converted into steam. The steam then flows towards a turbine and causes it to rotate. Finally, the rotating turbine powers a generator, which produces electricity that is transmitted to the power grid.

AI examiner evaluation

Task Achievement / Task Response: Band 7.5

The response covers all parts of the task well, providing a clear overview and highlighting the key features of the geothermal energy production process. The stages are accurately reported, from pumping cold water underground to generating electricity at the surface. For instance, the mention of the injection well depth '4.5 kilometres' and the geothermal zone containing hot rocks accurately reflects the visual data. The overview effectively summarises the main stages without unnecessary minor details. To reach the highest bands, the response could incorporate slightly more precise technical nuance from the diagram, such as mentioning the role of the condenser more fully or detailing the transmission loop.

Coherence and Cohesion: Band 8.0

Ideas are logically sequenced and follow the chronological order of the process seamlessly. The response demonstrates skilful paragraphing, with a clear introduction and overall summary in the first two paragraphs, followed by body paragraphs detailing the underground and surface stages respectively. Cohesive devices such as 'First', 'It then passes', 'Once above ground', and 'Finally' are managed naturally and appropriately without being overly mechanical. The progression of information is clear throughout, making the text very easy to follow.

Lexical Resource: Band 7.5

The student uses a sufficient and appropriate range of vocabulary relevant to the topic, such as 'geothermal zone', 'injection well', 'production well', 'condenser', and 'transmission'. Word choice and collocations are generally precise, for example, 'converted into steam' and 'causes it to rotate'. There are only occasional minor slips, but the vocabulary allows for good precision and demonstrates a strong awareness of academic style. To achieve an even higher band, the student could experiment with a wider variety of less common lexical items and more sophisticated paraphrasing.

Grammatical Range and Accuracy: Band 8.0

The response features a wide range of structures, employing both simple and complex sentences effectively. The majority of sentences are completely error-free, showcasing excellent control of passive voice constructions, such as 'cold water is being pumped' and 'is heated as it passes'. Subordinate clauses and participial phrases are integrated smoothly, as seen in 'before being converted into steam and used to power a turbine'. Punctuation and verb agreements are handled with a high degree of accuracy, leaving only very occasional minor inappropriacies.

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

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