Band 9: You should spend about 20 minutes on this task. The diagram below shows how one type of coal is used to produce electricity. Summarise the information by selecting and reporting the main features, and make comparisons where relevant. You should write at least 150 words.

The diagram illustrates how one type of coal is used to produce electricity through a series of stages.

Overall, the process involves converting coal into gas, which is then cleaned and used in a gas power plant to generate electricity. During several stages, waste heat is produced as a by-product.

At the beginning of the process, raw coal is crushed into smaller pieces using a crusher. The crushed coal is then transported to a gasifier, where it is heated and converted into gas. This gas is directed upwards to a cooling stage. As a result of cooling, some waste heat is released.

Next, the cooled gas goes through a cleaning process to remove impurities. After being cleaned, the gas is transferred to a gas power plant. In this plant, the gas is used to generate electricity. Similar to earlier stages, additional waste heat is produced during this step.

Finally, the electricity generated is supplied to factories and transmitted through power lines for wider distribution. Thus, coal is transformed into usable electrical energy through several carefully controlled stages.