Light Emitting Diode (LEDs)

Frequently Asked Questions About LEDs

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• What are LEDs?

  • Light-emitting diode (LED) lighting is an exciting, rapidly evolving technology that produces light in a whole new way.
  • LEDs are small light sources that become illuminated by the movement of electrons through a semiconductor material, more akin to computer chips than to light bulbs.
  • The heat from an LED is conducted through the back of the fixture, rather than radiated in all directions as with other light sources. The proper dissipation of this heat is key to effective LED performance.
  • LEDs are the only light source that are inherently directional and do not require a reflector to direct light, offering increased energy savings in directional applications.
  • In select directional applications, LEDs can offer energy savings of more than 50% versus fluorescent, and more than 75% savings versus incandescent lighting.

• Are all LED lights highly efficient and long-lasting?

  Not all LED lighting is created equal. Look for the ENERGY STAR^® label, awarded to select LED fixture types that meet strict efficiency, quality, and lifetime criteria.

  While LEDs are already beginning to surpass the quality and efficiency of existing lighting technologies, such as fluorescent and incandescent, LED performance varies widely.

  • Testing by the U.S. Department of Energy has shown wide variability in performance of LED products, with some products not meeting the ratings listed by the manufacturer.
  • Only well-designed LED products using the latest in LED technology, and applied in the right applications, will provide the energy, lighting quality, and long-life benefits of LEDs.

• How are LED lighting products different from other lighting, like fluorescent or incandescent?

  LED lighting is more efficient, durable, versatile, and longer-lasting than incandescent and fluorescents lighting. LEDs emit light in a specific direction, whereas an incandescent or fluorescent bulb emits light—and heat—in all directions. LED lighting uses both light and energy more efficiently.

  For example, an incandescent or compact fluorescent (CFL) bulb inside of a recessed can will waste about half of the light that it produces, while a recessed downlight with LEDs only produces light where it’s needed—in the room below.

  

  Image source: www.energystar.gov

• Why aren't there more rebates and incentives available for LED residential light bulbs?

  The LED lighting industry is evolving at a rapid pace, but currently only a few products qualify for ENERGY STAR. Testing by the U.S. Department of Energy has shown widespread variation in products, with many products not meeting the ratings listed by the manufacturer which is why we are only incentivizing LEDs that pass ENERGY STAR testing. However, every day more and more products are passing and we continue to track this progress. Efficiency Vermont is excited about the development of screw-based LED light bulbs and soon, lamps for fixtures using PAR20, PAR30, PAR38, globes, candelabras and MR-16 lamps may be included in promotions. At this time, we have a few products that qualify but look forward to having many more included by the end of the 2011.