A Sankey diagram says more than 1000 pie charts
Bucknell University shows how it could reduce its GHG emissions significantly by switching over from a coal fired units to a cogeneration plant in 1998. The line-up is shown in a Sankey diagram.
Apart from the overall energy efficiency of 75% the Sankey diagram doesn’t show any figures. The shadow effects on the flows look funky, and add a spheric touch.
Environment Canada in 2001 published a Pollution Prevention Planning Handbook, a 153 page guidance manual on processes and techniques for pollution prevention. Update: The original handbook has been removed. Sucessor pages have been put online, and can be found here.
In appendix B of the handbook materials accounting and mass balances are presented as one technique. The text states that
materials accounting and materials mass balances can be presented in a tabular or diagrammatic format. A Sankey diagram provides one useful method for representing a picture of material flows and balances.
and a sample Sankey diagram is shown.
Although not all quantities of the individual flows are shown, and there is no reference to the unit used, I think this is a fine example of using Sankey diagrams. The mass imbalance at the first process “Presse” (at the very left) is clearly visible. From the neighboring downstream processes you can see that at least 2105 units (to “Trémie”) and 738 units (to “Évaporation”) leave the process, that has inputs of only 2616 units. The diagram was made with S.Draw.
Some of you might have noticed that I tend to get somewhat excited when I discover Sankey diagrams in other languages.
Here is one I dug out on this webpage of the Tsuji Labs at Osaka University in Japan, and it has the honor to be the first one presented on this blog in Japanese!
The diagram shows the “energy flows” (エネルギーフロー) as relative values for the year 1993 only. On the left side we can see that more than 80% of the energy consumed in Japan were produced from imported fuels (輸入), while only 17.8% came from domestic production (国内生産). The quantities are broken down into the different types of fuels, such as crude oil (原油, 46,1%) , natural gas (天然ガス, 10,5%) or hard coal (石炭, 16,4%). The right side of the diagram shows the consumption sectors, with industry (31%), residential (16,9%) and transport (15,6%).
Losses are at 29% which seems relatively low, if you compare to similar Sankey diagrams from the U.S. But then I am not sure if they accounted for the losses in the same way for this diagram.
There are these two other similar Sankey diagram thumbnails on that site, and my guess is that they represent different energy scenarios, considering renewable energy sources, as an option to reduce dependency from imports. Maybe someone who can read and understand more Japanese than I do wants to comment?