Learn more physics!
Much has been said here in Australia about energy efficient light globes. In fact the old incandescent globe will be banned by 2010 due to their low energy efficiency. My question is: when you look at the components of an incadescent globe, ie, small amount of glass, some filament, a drop of lead and a little steel; will the energy efficient globes actuially contribute more to energy use due to their complex construction, use of a higher amount of glass and the creation of other components, eg. circuitry. Also, in terms of land-fill and waste pollution the "greener" globes would appear to contribute more.
- Chris (age 53)
That's an excellent question. I'm sure the answer will end up favoring the new fluorescent bulbs, but you're right that it's important to consider all these factors. One important thing to consider is that the new bulbs last many times as long as the old incandescents, so you have to compare the construction and waste costs of one fluorescent with not one incandescent but several. As far as the net energy expense goes, that's easy to compare. Say that all
the $3 cost of a fluorescent was for energy used in production. (Of course that's an overestimate.) Compare that with the typical lifetime energy savings of over $30/bulb. So there's no doubt that the new bulbs are major energy savers. For the most part, disposing of one fluorescent would not be worse than disposing of several incandescents with the same net lifetime. The exception is that the fluorescents have traces of mercury, a toxin. Now you can return them for recycling at some big stores. Even when it was hard to recycle, if much of your electricity came from burning coal, the excess mercury released by the larger electrical use of an incandescent exceeded the mercury waste of a fluorescent bulb.
(published on 04/08/2008)
Follow-up on this answer.