via EcoGeek
Incandescent light bulbs are really little space heaters with a side benefit of producing some light. They are an old technology that is being phased out for many applications by more efficient alternatives. Now, in addition to the LEDs and CFLs, we can add ESL bulbs, which have started to reach the market, to the available technologies.
We’ve been watching for Electron Stimulated Luminescence (ESL) lighting technology for a few years. It is now commercially available with the introduction of the Vu1 bulb. ESL lighting uses an electron gun to stimulate a phosphor coated surface for illumination, much like an old CRT or television tube. The bulb is actually a vacuum, with no mercury (or anything else) inside it, so disposal and recycling is easier.
The Vu1 bulb has an expected lifespan of 11,000 hours, which can be 5 times that of an incandescent and close to that of a good CFL. It uses 19.5 watts to produce 500 lumens, so it falls in between CFL and incandescent in efficacy. The color-rendering index (CRI) of the ESL bulb is 90+, again falling between an average CFL with a CRI of 80 and an incandescent with a CRI of 100.
Street pricing for the Vu1 is about $15*. That’s more expensive than a CFL these days, but that’s in the range of what CFLs were a decade ago, and LEDs with this color quality aren’t at this price level, either. For further information and a more subjective review of the light, you can read a longer review about the Vu1 light on my personal blog.
[Disclaimer: Vu1 provided the sample bulb to me at no charge for my review.]
[* Edited to add: After posting this yesterday, I got a call from William Smith, the chairman of Vu1. One thing he wanted to emphasize is that the company expects the price for this bulb to be less than $10 within 18 months, as production ramps up which is in the range of other dimmable bulbs.]
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