It might be somewhat surprising to know that in 2012 the US wasted 61% of all energy input into its economy, making it just 39% energy efficient.
Of the 95.1 quadrillion British Thermal Units (BTUs) of raw energy that entered the US economy, only 37.0 quadrillion BTUs were actually used, with the other 58.1 quadrillion BTUs being wasted. (Related article: US Energy Boom to Create 500,000 Additional Jobs by 2020)
In 1970, the US economy actually managed to use more energy than it wasted, using 31.1 quadrillion BTUs and only wasting 30.6 quadrillion BTUs, achieving an energy efficiency of higher than 50%. Since then the overall energy efficiency of the economy has steadily fallen as the use of electricity generation and transport has increased.
Power plants and internal combustion engines are notoriously inefficient, and as there use has increased, so the efficiency of the economy has fallen.
Some people even suggest that the 39% energy efficiency stated in the analysis is generous, with physicist Robert Ayres stating that the figure should be closer to 14%. (Related article: Canada's LNG Dream – Racing Ahead…at a Snail's Pace)
For the past ten years the National Laboratory has calculated the US energy waste to be in the region of 50%-58%, but in 2012 this figure jumped to one of the worst levels in decades.
AJ Simon, a senior researcher at the laboratory explained that the jump was mostly due to a change in the ways that they calculated the end use of the energy for vehicles and households. After separate studies into the efficiency of household energy use in areas such as heating, air conditioning and lighting, the figure was dropped from 80% to 65%. Likewise, the efficiency of the internal combustion engine was revised down to 21% from 25%.