Only 39% of the energy the U.S. generates reaches users.
There's a big difference between U.S. fuel inputs (e.g. coal, natural gas, hydro, nuclear, solar, wind, etc.) and end-use energy consumption (e.g. residential, industrial, transportation). This wastage occurs because no process for generating and distributing energy is 100% efficient. But you probably would have guessed that more than 39% of energy made it to end-users.
This loss through inefficiency is known as 'rejected energy' -- and it's a ripe target for innovation
. Improving this percentage (even a little) would yield significant cost and environmental benefits. Remember: the energy is being produced -- it's just dissipating before we can use it..
Originally published in August, 2013, the article below references a 2012 chart that was just recently updated by +Lawrence Livermore National Laboratory
As you can see, the ratio of rejected to consumable energy hasn't budged in recent years (and actually increased in the last two years).