Update: See our latest post on LED Light Bulbs For The Home.
I recently had the chance to test two state-of-the-art LED light bulbs from EarthLED. LED bulbs have many advantages over incandescents and compact fluorescent: they use very little power, they last 10 years or more, and they contain no hazardous substances. They are also tough: they can be dropped and turned off and on repeated without damage, they can operate in very cold or warm temperatures.
LED bulbs can also save you money in the long term, because an incandescent bulb requires about $300 worth of electricity over ten years of use. The LED bulbs cost $40 (for the 60 watt equivalent Zetalux) and $50 (for the 100 watt equivalent Evolux), and their cost to run over ten years is about $38.
The first EarthLED bulb I tested was the ZetaLux LED (pictured above). This bulb produces a pleasing warm white light.
Until recently, LED bulbs were only capable of producing a stark, cool white light, so I was happy about the color temperature of this bulb (it’s rated at 3000K). The bulb didn’t need to warm up like a compact fluorescent, and there was no flickering at all.
The Zetalux uses a CREE LED engine and features a high CRI or Color Rendering Index (75 for cool white and 80 for warm white). The bulb is rated at 7 watts. However, when I tested it with a Kill-A-Watt meter it was drawing only 5 watts.
The warm white version of the Zetalux produces 350 lumens, and the cool white produces 450 lumens. Comparing LED bulbs and other bulb solely on lumens is tricky because LED bulbs tend to make better use of their lumens in recessed fixtures (see this page for more details). EarthLED says the bulbs are equivalent to a 50-60 watt incandescent bulb.
The Zetalux currently sells for $40. The bulb costs about $2 per year to run, assuming it’s left on 8 hours a day and the cost of electricity is $.10 per KWh.
The second bulb I tested was a cool white Evolux. This 13 watt bulb produces 1075 lumens, and according to EarthLED is equivalent to a 100 watt incandescent. This bulb is definitely bright — it illuminates my garage quite well.
EarthLED will be releasing a dimmable version of the ZetaLux, and a new version of the Evolux in early 2009.
These bulbs are available from GoGreenSolar