1. Sankey Diagrams

2. Why are they called Sankey Diagrams? Captain Henry Sankey (1853 – 1925) Captain Matthew Henry Phineas Riall Sankey was an engineer. In 1898 he was the first person to publish a diagram that used the width of an arrow to show the size of the energy flow. The first ever Sankey diagram shows the energy flow in a real steam engine compared with a ‘perfect’ engine.first ever Sankey diagram

4. 10 J energy in 1 J useful energy out 9 J wasted energy out Sankey Diagram for a filament bulb

5. 10 J energy in 1 J useful energy out 9 J wasted energy out 10 J energy in 4 J useful energy out Sankey Diagram for a filament bulb Sankey Diagram for an energy efficient bulb 6 J wasted energy out