Academic Writing Task 1 · process diagram

A diagram illustrating a potential future method for home energy production

The diagram below shows a possible future means of home energy production.

Summarise the information by selecting and reporting the main features, and make comparisons where relevant. Write at least 150 words.

Home energy production process
  1. 1.Compost fermentation in a steel tank
  2. 2.Methane gas storage
  3. 3.Compression of gas
  4. 4.Combustion engine usage
  5. 5.Generator power production
  6. 6.Battery storage and home electricity supply

Chart redrawn by BandLadder from the data in the original IELTS practice task. Many IELTS practice tasks come from the Cambridge IELTS series (Cambridge University Press & Assessment); all rights in the original tasks remain with their owners.

Band 8 sample answer

The provided diagram illustrates a potential future method for generating electricity at home using organic waste. The process is a sequential system that transforms compost into usable electrical energy through several distinct stages.

In the initial phase, a steel tank is filled with a mixture of water and compost, such as food scraps and leaves. This material undergoes fermentation to produce methane gas, which is then directed into a storage unit. Following this, the methane is passed through a compressor, resulting in compressed gas that is transported to a combustion engine. This engine generates mechanical energy, which is subsequently fed into a generator to produce electrical energy.

Finally, the generated electricity is either directed for immediate home use or stored in a battery for later consumption. The entire system creates a closed-loop cycle, allowing households to become self-sufficient by converting everyday waste into a reliable power source. Overall, the diagram highlights a sustainable approach to energy production, demonstrating how organic materials can be effectively repurposed to meet domestic electricity requirements without relying on external utility providers.

176 words. Every figure in the answer comes from the chart above.

How to write about process diagrams

sequential
following a logical order or a set sequence
subsequently
happening after something else in a process
repurposed
adapted for a different use or purpose
self-sufficient
needing no outside help in satisfying needs
distinct
clearly different or separate from each other
illustrates
explains or makes something clear using images

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Frequently asked questions

What should the overview say?

The process describes a multi-stage system that converts organic waste into electricity through methane fermentation, mechanical combustion, and electrical generation.

How long should an IELTS Task 1 answer be?

At least 150 words; 170 to 200 is the safe range. Spend about 20 minutes on it and leave 40 for Task 2, which carries twice the marks.

How do I describe process diagrams?

Say how many stages there are and where the process starts and ends. Use the passive and sequencers: first, after this, once, finally. Keep every stage; a missing step costs task achievement.

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