This “spaghetti diagram” (aka Sankey diagram, or Energy Flow Chart officially) is the 2008 version. Lawrence Livermore National Lab (LLNL) has been making these things since the 1970s. It’s more detailed than a simpler national energy flow diagram because it includes “rejected energy.” It’s also more complex — it actually includes within itself the electricity flow diagram. It’s a pretty cool visualization.
The main thing I dislike is that it doesn’t split up transportation or electricity generation “rejected energy” by sector. Since these are really the two biggest sources of “rejected energy,” you can’t see which group is the biggest “rejector.”
Below, in an undated but funkier design, they’ve not only split up transportation into light duty vehicles, freight/other, and aircraft, they’ve also added domestic and net imports to petroleum and natural gas. They still haven’t split up “Electricity Generation, Transmission & Distribution Losses,” so we don’t know who “loses” the most energy.
LLNL has used flow charts to show possible future scenarios, such as the example below for 2050 where we use 145.5 Quads of energy (4.86TW power) but have “a) 50% efficient electricity generation, and b) 318 million “80 mpg” H2 fuel cell vehicles.” (Taken from this 7.8MB PDF.) It’s a nice depiction of how hydrogen is just a way of making energy more convenient, similar to electricity. Hydrogen is not itself an energy source (there are no hydrogen mines); hydrogen is a way of storing energy, and it takes energy to produce hydrogen.
LLNL has also made diagrams showing the carbon emissions from our energy sources. There’s no separation of “Useful CO2 Emissions” and “Rejected CO2 Emissions” — it’s all rejected. Alternative energy sources are shown with zero emissions, but that ignores the not-insignificant CO2 emissions that would result from the manufacturing massive quantities of those alternatives.
There’s another type of diagram that might be tied in to these spaghetti diagrams. More about that in part 2.