Andrew M., a new but loyal reader, didn't like the flow charts used by the EPA to illustrate cleantech. We had some lively discussion on flow charts before. The bottom line seems to be that they are difficult beasts to tame, especially when the relationships are complex. The example shown by Andrew (below) is not particularly horrid in this scheme of things. It's the abundance of annotations and colors that cause dizziness.
Here's a view of the same data, using a partitioning approach. The inputs are fixed at 100 units, which I find easier to comprehend, while the original fixed output at 30 units of electricity and 45 units of heat. And of course, it is a tremendous service to readers not to have to work out the efficiencies. Tacitness is a vice, not a virtue, in graph-making.
Reference: "Catalog of CHP Technologies", US EPA Combined Heat and Power Partnership.