Band 9: The diagrams below show the amount of energy lost in 100 units when it is generated from black coal and when it is generated from brown coal. Summarise the information by selecting and reporting the main features, and make comparisons where relevant.

The diagrams illustrate the amount of energy lost from 100 units of fuel when electricity is generated from black coal and brown coal.

Overall, in both cases, the process consists of the power station and transportation and distribution. Most of the energy is lost at the power station, while only a small proportion is lost during transportation and distribution. In addition, electricity generated from black coal is slightly more efficient than that generated from brown coal.

In terms of brown coal, first, 100 units of fuel energy are transported to the power station, where the fuel is processed. After this stage, 70 units are lost and 30 units remain. The electricity is then transmitted and distributed. During this stage, a further 3 units are lost, leaving 27 units available to consumers.

Turning to black coal, initially, 100 units of fuel energy are fed into the power station. Energy is again lost during the generation process. This leaves 32 units, which is slightly more than the figure for brown coal. During transportation and distribution, the amount of energy lost is the same as that for brown coal, with a further 3 units lost, leaving 29 units for consumers.