CFL is the winner

Researchers with Swizerland's Empa have investigated the ecobalances of various household light sources. In doing so not only did they take into account energy consumption, but also the manufacture and disposal processes. They also evaluated usage with different electrical power mixes. The clear winner is the compact fluorescent lamp.

In order to evaluate the total effect of a lamp on the environment over its entire life the researchers prepared a life cycle analysis for each kind. This takes into consideration the raw material and energy consumption of a lamp during its complete life cycle, from the production and usage to final disposal. The total point tally is a measure of the sum of all the damage the product in question inflicts on human health and the environment, as well as the usage of resources incurred during its manufacture.

For those wondering about the mercury aspect of CFLs, the environmental effects reduce by as much as 15 per cent when they are recycled instead of being incinerated. But even when they are incinerated in a waste disposal facility the much criticized mercury release is quantitatively insignificant.

This is because the overwhelming proportion of mercury in the environment is emitted by fossil fuel burning power stations. Depending on whether it uses brown or anthracite as fuel, a power station emits some 0.042 to 0.045 milligrams of mercury for every kilowatt-hour of energy it produces. A plant generating 1000 megawatts of power therefore releases 42 to 45 grams of mercury into the atmosphere every hour.

Any disagreements?