A presentation from 2005 on the French energy flows included the Sankey diagram below (I prefer not to name the author or the link to the original source, in order not to embarass anybody).
This Sankey diagram is pretty much messed up, and definitely a candidate for the “Worst Sankey Diagram Contest” that has already been called for. It took me a few seconds to understand that the flows dangling vertically below the blue arrow are actually a breakdown of the 177 mtep consommation finale. Vraiment … j’ai vu mieux que ça!
This is more or less how I would do it. Less colors, a breakdown of the blue flow into the five consumption sectors.