2013-05-09
DoE Spells Out LED Energy Savings
LEDs saved two thirds of a billion dollars in energy costs in 2012, according to a new US Department of Energy report, and the potential savings are 50 times larger.
That's 71 trillion Btu of energy saved last year, and a potential savings of 3,873 trillion Btu if all older lighting technology in 10 major application areas were replaced with LEDs overnight.
The report breaks out 10 lighting application and for each covers the total size of that segment, LED penetration in 2012 vs. the other technologies in use, movement of this number from 2010 to 2012, the energy savings attributable to the use of LEDs, and the total potential energy savings.
For example, 3.3 billion A-type lamps are in service in the US. Fewer than 28 million were LEDs in 2012, according to the report, or comfortably less than 1 percent. (That number had been only 2 million in 2010.) Yet these replacement bulbs accounted for 31 percent of the energy saved by LED lighting in 2012.
In order to get to an estimate of the total potential energy savings in these lighting markets, the study asks the simplifying question, "What would savings be if LEDs replaced all older lighting technologies overnight?" The number thus arrived at clearly is going to be different than what the unfolding markets will reveal over the next decade. The simplification doesn't take into account the increasing efficacy of LEDs, nor indeed the increasing efficacy of the traditional lighting technologies being displaced.
Another effect not accounted for in this rough estimation is the replacement of the least efficient lighting by more efficient, but non-LED, alternatives, as for example when incandescents give way to CFLs. The energy savings will be less when LEDs replace these alternatives.
The low-hanging fruit
There are no surprises in the applications the report singles out as having the highest potential for saving energy and money: troffers and A-type bulbs. These are among the biggest areas of investment in the LED lighting business.
LEDs in troffers delivered just over 1 percent of energy savings in 2012, but have the potential for up to 30 percent of the total savings. This entire LED market has only developed since 2011, when LEDs became capable of competing with fluorescent sources on issues like visual appearance, glare, light distribution, and color quality. According to the CALiPER report we discussed last month, drop-in LED replacements for T-12, T-8, and T-5 fluorescent tubes don't fare as well currently in product comparisons as replacement troffer assemblies designed around their LED lamps.
Directional and A-type replacements made up the largest proportions of energy savings in 2012, at 34 and 31 percent of the total, respectively. This is because of the large absolute numbers of such replacements, and because in these applications LEDs are mostly replacing the least efficient means of generating light, namely incandescents. The A-type contribution to the theoretical savings possible with LEDs drops to second place at 21 percent, dwarfed by the scale of the troffer replacement and retrofit market.
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— Keith Dawson 
, Editor-in-Chief, All LED Lighting