Some Patterns of Energy Use

Overview of US Energy Use:

The overall scale of our energy usage is much larger than the common person knows or even understands. This is one of the reasons why its so difficult to move away from fossil fuels as their very high energy content has allowed the US to build a hugely wasteful energy economy and relatively modest cost. But those days are over but because the scale is so large, replacing fossil fuels is really a multi decadel effort. Yes we can, well maybe, for it will take 30-50 years and we really haven't started yet.

This situation is clearly summarized in the graphic below were for the last 50 years or so the US per capita energy consumption is at least twice as high as Europe or Russias and roughly 6 times higher than the world. Note however, the rate at which China is growing in this regard. We will revisit this issue later. Also note that this graph only goes to 2010 but the situation over the last 6 years has essentially remained the same with China continuing to grow.

Total Energy consists of 3 main uses:

• electricity generation (usually via fossil fuel heating of water to make steam)
• transportation (using fossil fuels for transport)
• heating (burning natural gas to give off heat)

For now we simply state that the use of Fossil Fuels is so prevalent in these three areas because of fossil fuels have much larger energy content per kilogram of material than anything else. For instance, tne energy content of gasoline, on a per mass basis, is 350 times higher than lead-acid batteries and is about 100 times higher than the best Li-Ion batteries currently in use.