Another example of a national energy flow Sankey diagram, this time from Spain for 2009. To be found on page 40 of the recently published ‘La Energía en España 2009’ (large 10 MB PDF!) downloadable from the Ministry of Industry, Tourism and Commerce (MITYC) website. This is somewhat more advanced than the one from Spain I showed in this post.

Flows are in ‘ktep’ (ktoe, ‘kilo tonnes of oil equivalent, in Spanish), and percentages given are in relation to the total primary energy (130.508 ktep primary energy in 2009).

Nice and colorful, indeed. But again a good example of how to make mistakes (i.e. violate the basic rules) in drawing Sankey diagrams. So, here is the Sankey didactics part….

a) Arrows should be (no: must be!) to scale. Example: See blue arrow ‘USO FINAL’ with 16.1 % in comparison to blue arrow ‘consumo transformación’ with 19.1%
b) The same arrow should not change its width …
… while it runs in the same direction. Example: light green arrow ‘USO FINAL’ gets narrower as it runs vertically before branching to the sectors ‘Transporte’ and ‘Indústria’. Very weird!
… when it changes the direction. Example: pink arrow from the petroleum arrow going to the sector ‘Residencial’ is much wider on the vertical segment than on the horizontal segment.
c) An arrow should not maintain its magnitude …
… as it splits into two different flows. Example: green arrow ‘USO FINAL’ splits into two flows of the same width leading to the sectors ‘Residencial’ and ‘Industria’.
… as other flows branch off. Example: blue arrow ‘USO FINAL’ continues with the same magnitude to the sector ‘Residencial’, even though a considerable portion branches off to ‘Industria’.
d) It would be nice to have labels on all flows. Many negative examples, especially on the right hand side of the Sankey diagram.

Anyone care to do a better version?

kulturometer.org presented a fantastic diagram that shows the municipality of Madrid’s spendings in cultural activities in 2009. By compiling data from numerous tables, tender calls, and administrative bulletins, they managed to stunningly visualize what one commenter called an ‘information overload’ (‘apagón informativo’). Click on the diagram to enlarge.

This is a breakdown diagram, or ‘diagrama de brazos’, that shows the distribution of the overall cultural budget (182 Mio Euros in 2009) by sectors, sub-sectors, and even into individual types of activities or projects.

It somewhat reminds me of Nicholas Rapp’s AIG bailout diagram, even though less colorful…

Each branch of the diagram is labeled with the relative weight in percent, as well as the absolute value in millions of Euros. The color scale indicates the reliability of the data, either non detailed estimate (light grey), published estimate (grey), or published budgeted data (black).

Here is the full diagram in large scale (PDF) with an additional breakdown of one particular section (Medialab) at another scale and full legend and annotations
Watch a slide show to learn more about the diagram (starting p 19)
– And finally, a blowup detail of a diagram section:

One type of Sankey diagram layout seems to get popular recently. A representation of national energy flows of a country with the energy carriers on the left side (source), and the consumption sectors on the right side (sink). The Sankey flows in between show how energy from these sources are consumed and in which sector. Wasted energy is shown, and the overall energy (in)efficient use of primary energy is made clear with such a Sankey diagram.

I just discovered the energy flow diagram for Spain for 2006 on Joan Vila’s blog.

Unfortunately I don’t speak Catalán (well, I learned that “blog” is “bloc” in Catalán!), and the image quality isn’t very good. You can see nuclear, natural gas, coal (“carbó”) and crude oil (“petroll”), as well as hydro an wind (the two green lines) on the left side. The top box on the right side that takes the big red Sankey arrow for losses from electricity generation (“pérdues”). The others are the use sectors transport, industry, and domestic / services / agriculture. Vila calculates an efficiency of 38,2% for the electric power generation.

Joan advocates Sankey diagrams for visualizing and being able to better understand the issue. He says, that you won’t understand many things about what’s going on, if you don’t study this [kind of] diagram (“No entendrem moltes coses sobre el que passa si no estudiem aquest diagrama.”).

Check out simiular diagrams for Japan, Scotland, Ireland, Canada, United States.