US Wastes 61–86% Of Its Energy
An updated analysis published last month by the Lawrence Livermore National Laboratory suggests that the USA is just 39% energy efficient.
Put another way, more than half (i.e. 61%) of the energy that flows through our economy is ultimately wasted.
The predominance of inefficiency is conveyed by the energy-flow diagram below: it shows the country’s energy fuel inputs (e.g. coal, natural gas) on the left side, and end-use energy consumption (e.g. residential, industrial, transportation) on the right side.
Of the 95.1 quadrillion British Thermal Units (known as “quads”) of raw energy inputs that flowed into the US economy in 2012, only 37.0 quads were constructively used at the end of the day (as “energy services”). The other 58.1 quads were, in essence, wasted. This waste, summarized in the top right of the diagram, is euphemistically classified as “rejected energy.”
As has been the case for decades, most of the economy’s energy waste stems from electricity generation (because most power plants are relatively inefficient) and the transportation sector (internal-combustion vehicles are also notoriously inefficient, but they are getting better).
One should not expect any economy, power plant, or car to be 100% efficient. Indeed, the Second Law of Thermodynamics tells us that achieving perfect thermal efficiency is as possible as unscrambling an egg. But 39% efficiency? It certainly leaves some major room for improvement.
And some experts argue that even 39% efficiency is painting a rosy picture: defining energy as the “capacity to do useful work” (rather than strictly as a commodity measured by its energy content), physicist Robert Ayres and his colleagues estimate that the true energy efficiency of the US economy is closer to 14%.
So how does Lawrence Livermore National Laboratory’s 2012 energy flow analysis compare to its analyses in recent years? Strikingly,