FastCompany published a great article in its Sept. '06 edition about the energy-saving effects of Compact Fluorescent Lightbulbs (CFL's). You probably know what they are, but do you realize how far they've come and more importantly, how immense their impact can be?

"If every one of 110 million American households bought just one [CFL] and used it to replace an ordinary 60-watt bulb, the energy saved would be enough to power a city of 1.5 million people. One bulb swapped out, enough electricity saved to power all the homes in Delaware and Rhode Island. In terms of oil not burned, or greenhouse gases not exhausted into the atmosphere, one bulb is equivalent to taking 1.3 million cars off the roads."

And according to Chevron, this one bulb in every home would save 500 pounds of coal and over a 1/2 ton of CO2 emissions (per bulb, per home)!

Pass the word - Lead the pack of those you know - speak out about CFL's and other easy ways to save energy.

Second in our energy analysis series is TiVo (Series 2). According to BusinessWeek, Nielsen (the TV ratings company) says that 11% of U.S. households (or 1.2 million) have a DVR unit. The most popular DVR unit in use today is TiVo.

We put two DVR's - The TiVo Series 2 and the new DirecTV Plus DVR - to the test for 7 days, running continuously, recording and playing back shows under normal circumstances. The results of the Kill-A-Watt energy analysis test are shown below for the TiVo unit, because it is more widely in use. The DirecTV unit used exactly 10% less power over the duration of the test; its numbers are not included below.

Most people don't turn off their DVR, and that's fine because it only reduces power usage by 1 watt! Although the lights go out on the front of the box, the "computer" is still running and hard drive spinning. So you won't save any real power unless you unplug it.

So, some sellers on eBay are marketing these new 120v LED light bulbs (which are comprised of a cluster of dozens of individual LED's) for home use. Wow - bright light, only a couple watts, and a bulb that lasts virtually forever - what more could you want? Though expensive ($16-$25 per bulb), these sound so promising as to be the "next generation" of bulbs - surpassing even CFL's (Compact Fluorescent Light bulbs) in terms of bang for the buck.

Or so they say. We compared these fantastic-sounding new bulbs to both incandescent bulbs and CFL's in terms of light output and energy use, based on luminous intensity specifications (in lumens) of different types of bulbs from the EnergyStar.gov web site, and the LED manufacturer's light output and power consumption ratings. For example, the figures shown to the right were used to generate the graph below.

The three major problems of LED bulbs:

1. More expensive. As you can see above, the LED bulb is substantially cheaper to operate than the incandescent for the same amount of light (no surprise there) but about 3x the cost to operate vs. a fluorescent;
2. Odd color. The color produced by LED bulbs is not "warm" - many people describe it as "too blue." While white LEDs are becoming more natural in color temperature, they have a long way to go. CFL's are much easier to adjust to;
3. So many bulbs! LED bulbs produce (depending on type) from around 35 to 105 lumens per bulb. A 60w incandescent or 13w CFL produce over 800 lumens. That's a ratio of 10:1 on average. I don't know about you, but my closets and hallways have 1 or 2 light sockets, not 10 or 20. When you consider that you'd need to use 10 LED bulbs to replace each incan or CFL, the problems are, for most of us, insurmountable! I mean, where are you going to put all those bulbs?

So, to sum it up, don't expect these bulbs to outperform CFL's in terms of initial cost, light output, or efficiency. Perhaps someday, advances in LED technology will change this. But don't place a big order for replacement bulbs for your house just yet.