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 brow coal Summarise the information by selecting and reporting the main features and make comparisons where relevant

The graphs show the volume of energy reduction during the generated process of the black coal and brow coal, when finally converted to products. It can be seen that black coal has a marginally more energy loss during the process than a brown one.
For a start, each kind of fuel was transported to the power station for 100 units respectively, and then through a procedure of electricity producing, everyone has a large proportion of loss. Black coal has more 2 units waste than brown coal by producing 32 units electricity, and this is the only reason why brown coal appears more productive in the final stage than black coal. In addition, in the further procedures, the electricity from each fuel has an equally lost. In the period of transportation and distribution, energy experiences a minor loss of 3 units, before turning into final usage.
In conclusion, brown coal seems to be more efficient in generation of electricity than black coal according the picture.