Thursday, July 9, 2009

The "promise" of LED Lighting

The DOE has invested vast amounts of money to support the development of Solid State Lighting (SSL) = Light Emitting Diode (LED) technology. The good news is that the LED is not creating a "pending environmental disaster" as some have said about CFL technology and the "mercury problem". The bad news is that LEDs are coming up far short of delivering on their promise of being the perfect, long term solution to all of our energy efficient lighting needs. In a recent Webinar hosted by LEDs Magazine the following information on the residential usage of LEDs "came to light".

Creating viable (affordable and well performing) residential solutions will be hard work for the LED industry. Why?

  • They have to get to acceptable light quality, - good color rendering and good color temperature
  • They have to provide reasonable brightness with good energy efficiency. Lumens of 50+ lm/w. That means delivered not the claimed lab bench lumens.
  • They will need good light dissipation (not easy for a point light source)
  • They have look nice – not like shower heads
  • They have to do something about the huge amounts of heat sinking required
  • Many will need to work in their worst scenario environment – heat retaining recessed cans
  • They have to dodge the bad press that is going to occur from cheap, low quality, poorly performing products.
  • Their 10 year Total Cost of Ownership has to be at least as good as CFLs. Today they don’t even come close (they are 3x more costly). A Cree LR6 sells for $100+ a bulb. The GeoBulb sells for $120. The Philips E27 sells for $70. The inexpensive bulbs being sold for $12-15 give a hideous, blinding, blue/white laser type light that is very directional that cannot be dimmed. We call them "Corpse Lights". They give everyone that "morgue glow".
We are always surprised when we see an announcement that a new LED lamp bulb is a "replacement for a 40 watt incandescent". Philips just released their $70 E27 lamp bulb and makes this claim. The IEC 60064 standard for the illumination of a 40W bulb is 450 lumens. The Philips E27 is rated at 155 lumens. Is it accurate to state that a 155 lumen bulb is a 450 lumen bulb "equivalent"?

By the way, we believe that LEDs will be very successful in many applications such as automotive, street lighting, retail and specialty applications. Over time in homes we will see new lighting architectures emerging that will feature surface mounted LED lighting that will be able to function without the heat controlling issues that are most concerning to the LED industry. The LED industry is beginning to admit that they may only be successful in residential lighting if they can convince consumers to move to new LED "fixtures". Retrofitting into the 800 million recessed can fixtures in the U.S. (growing at over 20 million a year) is not going to be a market they will want to aggressively address. We are hoping that Vu1 ESL technology will be complimentary to LED technology. If we can provide an energy efficient soluton to the world of recessed can downlights then LEDs will be able to focus on more LED friendly enviornments.