This 3D Sankey diagram for a compressed air system from a Mechanical Engineering blog post is taking it somewhat over the top…

It shows energy efficiency of a compressor. Only a fraction of the energy (electricity) to power the compressor is converted and delivered in compressed air, while the largest chunk is wasted as off-heat.

Yes, the 3D-look is fancy (see other samples of the 3D species here). The elliptic orange backdrop makes it look more dramatic, but doesn’t really contribute to conveying the information. No units are given.

The green arrows represent “simple, cost-effective measures” that could probably increase efficiency of the compressed air system if implemented. The blue arrow that stands for the energy delivered as compressed air is supposedly “approximately 10%” of the energy input, but he height is much less than 1/10th of the stacked arrows.

Craig Meskell from Trinity College, Dublin submitted the Sankey diagram below for publication on the blog.

Craig writes:

“here’s a Sankey diagram of the energy balance in an industrial compressed air system. The factory is situated in Ireland (not too far from Co. Tipperary!) [Note from Phineas: this is where Cpt. Sankey was born]. The work is detailed in: Eret, P., C. Harris, G. O’Donnell & C. Meskell, A practical approach to investigating energy consumption of industrial compressed air systems. Proceedings of the Institution of Mechanical Engineers, Part A (Journal of Power and Energy), 2011. DOI: 10.1177/0957650911423173″

A nice, simple, clear diagram. Thank you. If other readers have Sankey diagrams to share, please send them to