I stumbled across these intriguing charts at the Lawrence Livermore National Laboratory's website:
These are not "flow charts." Instead they are "energy flow" diagrams. They tell a rich story regarding how much energy the USA uses; in what form; and for what purpose. I don't particularly like their super saturated colors, but the information is great. From what I understand, the lab puts an enormous number of resources into gathering the data and producing these charts.
I decided to replicate the chart in Excel 2007. Here's an image of out it turned out:
This was seriously tedious work, as Excel has no native chart type to do what is required automatically. Each flow pipe is proportional in it's thickness to how much energy it represents. The thickness of a line can be easily adjusted in a chart dialog, but not by formula. Another difficulty is that a number of flow pipes need to stack on top of each other to serve as a proportionately sized aggregate input to an energy category.
I lightened the colors on the input boxes (had to do it), but otherwise I think my rendition is faithful to the original. I may have stayed too true to flow pipe proportionality. Some of them are so thin they do not print well. This should be addressed. While my pipes are seemingly lined up, they will not survive the chart being resized vertically without some small errors, either gaps in a pipe stack, or overlap.
From this chart I learned a great deal about our country's energy budget. I had no idea that electrical production and transmission was so wasteful (as in 69% waste!), nor did I realize that natural gas was so versatile. Likewise I did not realize that coal produced such a large percentage of our electricity while oil produced virtually none.
So how much is 99.2 Quads of energy? A Quad is a quadrillion BTUs, or 1,000 trillion BTU. So basically, the US uses a hundred million billion BTUs of energy each year! And 57% of that is wasted! I think we can do better.
I'm not an environmentalist, but all of this world's energy comes from the sun at some point, save nuclear, so it's amazing that more of our energy is not directly solar. Solar is currently less than 1/10 of 1 percent! If I were in charge of energy policy, I would move our focus to solar power generated on as many homes and buildings as possible to eliminate the transmission waste and fill the gaps with natural gas for all other energy requirements.
An interesting project would be to create an Excel addin that would allow you to specify category box locations and have VBA do all of the grunt work in lining up the flow pipes, automatically creating the chart.
However, in it's current form, dissecting the chart may prove instructive, as quite a few advanced techniques are used to create it. In it's current form no VBA was used. But it's definitely a chart. You can move the location of everything on it by just altering the data.
Here is the chart: