Hey Mr. Green,
I was at a bar the other night with a friend, and we came up with a question we thought you might be able to answer: How many households would need to exchange their incandescent bulbs for compact fluorescent ones to compensate for one Hollywood celebrity flying cross-country in a private jet to get a haircut by his or her favorite beautician?
--Nelson in San Francisco
Finally, a celebrity question more meaningful than "Is Angelina pregnant again?" or "Will Britney get her kids back?" Assuming that the star has a midsize charter jet and takes eight or nine groupies along for a 2,500-mile ride (roughly Los Angeles to New York), his or her share of jet fuel burned would be about 175 gallons, or 22.6 million British thermal units (Btus). Since it takes about 10,210 Btus to make a kilowatt of electricity, the flight would use up the equivalent of 2,214 kilowatt-hours of electricity.
Because a 25-watt fluorescent bulb is four times more efficient than an incandescent one yielding the same amount of light, the fluorescent will save 600 kilowatts in its 8,000-hour lifetime. Therefore, you'd only have to buy four fluorescents to save the energy required to fly the celebrity to the beautician. Amazing but true. Actually, let's make that five fluorescents because there's obviously a lot of energy squandered hauling his or her celebrity ass to and from the airports in a 15-mile-a-gallon limo. And that's not even counting the energy consumption of the paparazzi and media acolytes, which would change the equation considerably.
But time is also a big factor. The above calculation reveals the energy savings for the life of the bulb. If you want to know how many fluorescents you'd have to buy to compensate for the energy wasted for the duration of the celebrity's flight, the number changes dramatically. At a cruising speed of 540 miles per hour, your speculative celeb would be airborne for about five hours on the trip. In that time, a single fluorescent bulb would save only 0.375 kilowatts. So you'd need about 5,900 fluorescents to make up for the energy consumed on that particular flight. The beauty of this is that you can spin the argument either way, depending on how you want to package it!
And whether you buy four or 5,900 fluorescents to offset your favorite celebrity's flight, remember to recycle those bulbs when they die out. Since they do contain toxic mercury (albeit a small amount), that's the only way to truly lighten the burden of the environmental guilt he or she doesn't feel anyway.