Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 12 · 2026-09-22

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 7.5)

The diagram illustrates the process by which geothermal energy is converted into electricity in a geothermal power plant.

Overall, the process is cyclical and involves five main stages: cold water is pumped underground, heated by geothermal rocks, and the resulting steam drives a turbine and generator before being condensed and reused.

The process begins when cold water is pumped down an injection well to a depth of 4.5 kilometres (stage 1). This water travels through the injection well until it reaches the geothermal zone, an area of hot rocks located deep underground (stage 2). As the cold water passes through this zone, it is heated and rises back to the surface as hot water through a separate channel known as the production well (stage 3).

Once the hot water reaches the surface, it is converted into steam (stage 4). This steam is used to power a turbine, which in turn drives a generator to produce electricity (stage 5). The electricity generated is then transported via power lines, represented by an electricity pylon, for distribution.

After passing through the turbine, the steam is directed into a condenser, where it is cooled and converted back into water. This water is then recycled into the system as cold water, completing the cycle and allowing the process to be repeated continuously.

In summary, geothermal power generation relies on a continuous loop in which water is heated underground, converted to steam to generate electricity, and then condensed and reused.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The student provides a clear and well-developed overview of the process by which geothermal energy is converted into electricity. All key stages of the diagram—from cold water injection at a depth of 4.5 kilometres to the geothermal zone, production well, condenser, steam turbine, and generator—are accurately identified and described in a logical sequence. The summary successfully captures the main features of the process without omitting any critical steps, and the inclusion of the cyclical nature of the loop satisfies the requirement to report main features and relationships. The response fully satisfies the requirements of Task 1.

Coherence and Cohesion — Band 7.5

The response is exceptionally well-organized, with a clear introduction, body paragraphs detailing the sequential steps, and a concluding overview. Cohesive devices such as 'The process begins when', 'Once the hot water reaches the surface', and 'After passing through the turbine' are used naturally and effectively to guide the reader through the linear and cyclical aspects of the process. Paragraphing is logical, ensuring that each phase of the diagram receives appropriate focus.

Lexical Resource — Band 7.5

The vocabulary used is accurate and appropriate for an academic process description. Terms such as 'cyclical', 'injection well', 'geothermal zone', 'condenser', and 'recycled into the system' demonstrate a strong control of subject-specific terminology. The student also successfully employs a range of general academic vocabulary with good precision. Word choice and collocations are natural throughout, reflecting a flexible lexical resource.

Grammatical Range and Accuracy — Band 8.0

The response exhibits a wide range of complex sentence structures, such as participial phrases ('represented by an electricity pylon') and multi-clause sentences ('As the cold water passes through this zone, it is heated and rises back to the surface...'). Grammatical accuracy is very high, with the vast majority of sentences being error-free. Control over punctuation and tense consistency (primarily present simple for describing a permanent process) is well maintained.

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.