An report on American energy use updated in July by the Lawrence Livermore National Laboratory showed that 61 percent of the energy generated in the United States is ultimately wasted, making 2012 the worst year for energy wastage in more than a decade. Electrical power generation and transportation account for almost all of the waste, but the amount of energy wasted by residences and businesses rose compared to 2011.
According to LLNL, which has released updated "Energy Flow Charts" for the United States since the 1970s, the U.S. economy wasted about 58.1 quadrillion BTUs (quads) of energy in 2012. That energy is displayed in the chart below labeled as "rejected energy":
58.1 quads is equivalent to more than 17 billion megawatt hours of electrical power. For a bit of perspective, the energy the U.S. wasted in 2012 is about 3,500 coal plants the size of soon-to-be-closed Nevada's Reid-Gardner, or for those knee-deep in the business, roughly 10,000 copies of the Ivanpah Solar Electric Generating System would be expected to produce per year.
Of that 58.1 quads of wasted energy, about four-fifths is wasted by the transportation and power generating sectors. Much of that loss is due to inefficiencies in the process of burning fuel to convert to mechanical energy, and some of those inefficiencies are inescapable due to pesky physical constraints such as the Second Law of Thermodynamics, which says that every exchange of energy ends up with some of that energy being lost as unusable heat.
But as OPower's Barry Fischer points out, even though the United States cannot violate the laws of physics, there's still a lot of improvement that could be reasonably made in our profligate waste of the energy we feed into our economic engines. For one thing, moving toward energy sources that don't involve burning fuel couldn't hurt.
That 61 percent wastage figure for 2012 is up by a few percentage points over 2011's, and part of the reason for that is likely a combination of a recovering economy and streamlining of environmental laws. But as Fischer relates, some of the increase also stems from more realistic (and pessimistic) models of how efficient we actually are at using energy. LLNL tweaked its assumptions about both transportation and household energy efficiency in last year's study, making the outlook bleaker and probably closer to the truth. Previous estimates of energy efficiency for lighting and climate control in homes had run around 80 percent; 2012's figures adjusted that to a still probably optimistic 65 percent. Fischer notes that even that lower efficiency figure doesn't account for people leaving lights on and running the AC with the screen door open.
Reducing the U.S.'s energy waste from two-thirds to one third, likely a goal that is both technically and economically feasible, is quite likely the easiest and cheapest way to cut our greenhouse gas emissions drastically. And we don't need to displace any desert tortoises to turn those lights off in the closet.