Quote:
Originally Posted by Ether
And they don't like being cycled, and they don't like cold temperatures (like outdoors), and they are toxic, and they are all made in China.
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Doing some quick calculations:
Approximately 0.0234 mg of mercury is released into the atmosphere per kilowatt hour of electricity generated in a coal power plant. Over a 7500 hour lifespan of a bulb, a 100 Watt incandescent bulb will use 750 kW of electricity. In the US, 44.9% of that electricity came from coal power sources in 2009. Assuming this is true for the energy used by the light bulb, that means 336.75 kW came from coal sources, which means ~7.88mg is mercury was released into the atmosphere.
The equivalent CFL bulb only uses 23 Watts of electricity but
contain between 1.5mg and 4mg of mercury (newer CFLs average between 1.5mg and 2.5mg, while the older ones have ~4mg. By comparison, older mercury thermometers contain about 500mg of mercury). Over the same 7500 hour life period, it would cause the release of ~1.81mg of mercury into the atmosphere via coal-powered electricity generation.
Even if the CFL bulb was not recycled and somehow had all of its mercury released into the atmosphere, it would have caused the release of ~5.81mg of mercury into the atmosphere, a ~26% reduction in mercury emissions when compared to incandescent bulbs.