Sankey diagrams
A very useful way of showing the efficiency of a system is to use a Sankey diagram. An example of one of these for a nuclear power station is shown below and you can find further examples at: Sankey diagrams. The width of the arrows in the diagram is proportional to the magnitude of the energy flow. The primary energy provided has to match the energy consumed.
The efficiency of this power station is 42%.
Created with the Personal Edition of HelpNDoc: Benefits of a Help Authoring Tool