the original, high-resolution, version is readable anyway. There are a few basic things to notice here. Along the left hand side there is a column of colored boxes.These are our significant sources of energy. Notice there are no boxes labeled 'people' or 'oxen'.
Along the right hand side there are two boxes. These are our 'sinks'. This is where our energy goes. The lower dark gray box is labeled Energy Services. This is where we have gotten energy to do something useful for us, like propel our cars, heat our homes, or light our lights. The upper, light gray box is Rejected Energy. This is wasted energy, energy that escaped because our machines are inefficient. Typically it gets turned into heat which is dissipated into the environment. That is what the radiators on our cars and the cooling towers on our nuclear power plants do, they pump that waste heat out of the machinery and into the outdoors.
Note that Rejected Energy is almost twice as large of Energy Services. That shows that our machines are about 38.4% efficient in turning energy into something useful. The general rule of thumb for heat engines, like steam turbines and internal combustion engines, is only about one-third, or 33.3%. I suspect the difference is because some of our energy is used to heat our living spaces, and using energy directly for heating is quite a bit more efficient than using it produce mechanical motion.
At the top center is a yellow-ish box labeled Electricity Generation. Notice that the waste (Rejected) energy here (25.8) is more than twice the useful energy (Services) produced (12.4). I blame the missing one percent on transmission line losses.
Notice the column of four pink boxes on the right. Those are the categories where our energy gets used. Notice the big, fat one at the bottom: Transportation. Those are our cars and trucks and they run on oil (the fat green line across the bottom of the chart). Other forms of transportation also use oil, but their consumption pales into insignificance under the tsunami of commuter-mobiles.
Coal is still the big source of power for generating electricity. Powder River is where all the 'good' electrical companies get their coal, never mind that it first has to be hauled clear across the continent by train.
Now that we have covered the basics and understand what the general situation is, we can notice a couple of small items that probably weren't there ten years ago. Biomass is providing almost 4.5% of our supply (fermenting corn to make ethanol and then distilling it), Wind power is over one percent, but Solar is still virtually zero.
2 hours ago