Band 7.5 IELTS Writing Task 1 Model Answer
Overall Band Score: 7.5 · Cambridge IELTS 12 · 2026-09-20
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 electricity is generated using geothermal energy.
Overall, the production of electricity involves five main stages. The process begins with cold water being pumped deep underground, where it is heated by hot rocks, and ends with electricity being generated after steam powers a turbine.
Initially, cold water is pumped from the surface to a depth of approximately 4.5 kilometres through an injection well. Once underground, the water passes through the geothermal zone, where it flows between layers of hot rocks. As a result, the water absorbs heat and becomes hot before being forced back to the surface through a separate production well.
In the next stage, the hot water enters a condenser, where it is converted into steam. This steam is then directed towards a turbine, causing its blades to rotate at high speed. The rotating turbine is connected to a generator, which converts the mechanical energy into electrical energy. Finally, the electricity produced is supplied for use, completing the geothermal power generation process.
AI examiner evaluation
| Criterion | Band |
|---|---|
| Task Achievement / Task Response | 7.5 |
| Coherence and Cohesion | 7.5 |
| Lexical Resource | 7.5 |
| Grammatical Range and Accuracy | 7.5 |
| Overall | 7.5 |
Task Achievement / Task Response — Band 7.5
The response fully satisfies the requirements of Academic Task 1 by providing a clear, accurate, and comprehensive summary of the geothermal energy production process. The student successfully identifies all main features, including the initial cold water pumping, the depth of 4.5 kilometres, heating via hot rocks in the geothermal zone, the production well, the condenser converting water into steam, the turbine, and the final generation of electricity. An effective overview is provided at the beginning, outlining the five main stages. The data is accurately reported without any notable misinterpretations or omissions, demonstrating a strong command of visual data interpretation.
Coherence and Cohesion — Band 7.5
The response is logically sequenced and easy to follow, with a clear progression from the beginning of the cycle to the end. Paragraphing is used appropriately, separating the introduction/overview, the initial subterranean stage, and the final surface generation stage. Cohesive devices such as 'Initially', 'Once underground', 'As a result', 'In the next stage', and 'Finally' are deployed naturally and effectively to guide the reader through the process without being obtrusive or repetitive. Referencing between sentences and clauses is smooth and precise, ensuring an unbroken flow of information.
Lexical Resource — Band 7.5
The vocabulary used is precise and well-suited to describing a scientific or industrial process. The student successfully incorporates subject-specific terminology from the diagram, such as 'injection well', 'geothermal zone', 'production well', 'condenser', 'turbine', and 'generator'. Furthermore, they demonstrate a good range of functional vocabulary with accurate collocations and lexical chunks, such as 'pumped deep underground', 'absorbs heat', 'forced back to the surface', and 'mechanical energy into electrical energy'. Word choice and spelling are entirely accurate throughout, showing a high level of control.
Grammatical Range and Accuracy — Band 7.5
The response displays a wide range of complex grammatical structures used with a high degree of accuracy. The student employs participial phrases ('causing its blades to rotate at high speed', 'completing the geothermal power generation process'), relative clauses, and passive constructions ('cold water is pumped', 'is heated by hot rocks', 'is directed towards a turbine') which are entirely appropriate for a process description. The majority of sentences are error-free, and punctuation is handled with precision. Minor errors are absent, and overall syntactic control easily meets the criteria for a high band score.
See this exact question answered at other band scores — the same prompt compared across bands.
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