Band 7.5 IELTS Writing Task 1 Model Answer

Overall Band Score: 7.5 · Cambridge IELTS 12 · 2026-09-17

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 shows how geothermal energy is used to produce electricity in a geothermal power plant.

Overview

Overall, there are five main stages in the process. Cold water is pumped underground, where it is heated by hot rocks. Then, the hot water is brought back to the surface and changed into steam, which powers a turbine and produces electricity.

Body Paragraph

First, cold water is stored on the surface and is pumped down through an injection well. The well goes about 4.5 km underground. The cold water then reaches the geothermal zone, where there are hot rocks. As the water passes through these rocks, it becomes hot.

Body Paragraph 2

Next, the hot water is pumped up through a production well. It reaches the surface and goes into a condenser, where it is changed into steam. The steam then moves towards a turbine and turns it. The turbine powers a generator, which produces electricity. Finally, the electricity is sent to the power lines.

AI examiner evaluation

Task Achievement / Task Response — Band 7.5

The student provides a clear overview of the process, identifying the main stages from pumping cold water underground to generating electricity. Key features such as the 4.5 km depth of the injection well and the role of the hot rocks, condenser, turbine, and generator are accurately reported. The information is fully grounded in the provided diagram without major omissions or invented data. Therefore, the response successfully satisfies all requirements for Task Achievement.

Coherence and Cohesion — Band 7.5

The response is logically sequenced and easy to follow. Progression is clear, moving naturally from the overview into the injection phase and subsequently to the production and generation phases. Paragraphing is used appropriately, separating the overview and body sections cleanly. Cohesive devices such as 'First', 'Next', 'As the water passes', and 'Finally' are deployed effectively to guide the reader through the continuous cycle of the geothermal power plant, ensuring smooth transitions between steps.

Lexical Resource — Band 6.5

The student demonstrates an adequate to good range of vocabulary appropriate for describing a scientific process, using correct technical terms such as 'injection well', 'geothermal zone', 'condenser', 'turbine', and 'generator'. Word choices are generally precise and natural (e.g., 'stored on the surface', 'pumped down'). While there is limited use of highly sophisticated or uncommon lexical items, the vocabulary used is functional, accurate, and fully sufficient to convey the mechanics of the process without any strain on the reader.

Grammatical Range and Accuracy — Band 7.5

The response contains a good mix of simple and complex sentence structures, such as 'where it is heated by hot rocks' and 'As the water passes through these rocks, it becomes hot.' Grammatical control is generally strong, with the majority of sentences being error-free. Punctuation and verb tenses (predominantly the present simple passive, which is standard for describing mechanical processes) are handled accurately throughout. Errors are virtually absent, demonstrating a high level of accuracy.

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

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