A standard incandescent bulb will use almost five times the energy of an LED bulb, a German study concludes. On its face this hardly seems significant since it’s well known that an LED is about five times as efficient as an incandescent bulb from a use standpoint. However this study, conducted by Osram, looks at energy efficiency from a life cycle standpoint. This is important since it refutes the notion that the efficiency of LED bulbs is compromised by an energy intensive production process. In fact, the study finds that the primary energy used in the manufacture in an LED is less than 2% of the total energy consumed over the life of the bulb. Compelling stuff. Even mainstream media such as the NYT has been quick to publish the results.
However a closer examination of the study is revealing. While 2% may sound impressive and further the study highlights how the energy consumed in manufacture is actually less than that of an incandescent, it’s important to understand the assumptions. While it may be true to say an LED is 35% more efficient to manufacture than an incandescent, this calculation is based upon a 25,000 hour versus a 1,000 hour expected life. That a factor of 25.
What the study doesn’t explicitly state, although simple math reveals, is that on a per unit basis an LED bulb is actually over 16 times more energy intensive to manufacture than an incandescent. On reflection this makes sense since the average LED is approximately 50 times more expensive than a regular incandescent bulb (the difference between 50 and 16 is explained by amortization costs associated with R&D and production).
So is this a dealbreaker for the LED? No, at least not as long as the 25,000 hour lifespan for the LED is bona fide and the technology can be effectively employed for all standard light bulbs (heat dissipation is currently an issue for a 100 watt LED replacement in a standard fixture for instance). Furthermore, consider the relative infancy of the mass production of LED bulb technology. Much of the production cost and energy for an LED is encompassed in the unit’s technology itself. LEDs are essentially solid state devices that use a circuit board. Advances in this area are brisk to say the least and will inevitably see energy consumption and attendant costs decline as adoption rates increase.
Will LEDs light the way of the future? Probably. While the incandescent won’t go down without a fight with talk of substantial recent increases in efficiency on its own, further advances in technology will likely yield another 100% increase in LED efficiency. Moreover it’s likely we’re fast approaching a tipping point as in 2007 Congress approved a phase-out of incandescent bulbs starting with the 40 watt bulb in 2012 and it’s hard to imagine demand for efficient lighting solutions waning in the face of uncertain energy prices.