In December 2007, Congress passed a bill and President Bush signed it into law that would ban conventional light bulbs by 2014, starting with 100W bulbs in 2012. In February 2009 the European Union’s Environment Committee voted to phase out conventional light bulbs, starting with 100W bulbs by September 2009. Australia and Canada have similar laws, which seek to encourage consumers to switch to more energy efficient compact fluorescent lights (CFLs) that also fit conventional fixtures, but use some 75% less electricity and last up to ten times longer.

Though CFLs are more expensive to buy (from about $3 compared to conventional light bulbs at 50 cents), they will actually pay for themselves via a lower electricity bill over only a couple of months. Also, because of the much shorter life span of conventional bulbs they would be more expensive to run even if electricity were free: At 10,000 hours per CFL and 1000 hours per light bulb, you’d end up buying 10 light bulbs that cost more than the single CFL that matches their total life span.

Nevertheless, there are other criticisms brought against a switch to CFLs. One of them is the fact that CFLs, like all types of fluorescent light, contain small amounts of mercury, a toxic heavy metal. They need to be handled carefully so as not to break them. Dead bulbs must not be thrown into the trash to go into landfills or garbage incinerators. Many electrical stores or recycling centres will take them back to dispose of them safely.

However, even if most consumers dumped old CFLs into the garbage bin, it is doubtful if this would cause more environmental problems than sticking with Edison’s old invention. In many countries, cheap coal provides a major portion of electricity. In the USA it’s about half. Unfortunately coal contains trace amounts of mercury, which goes up the chimney when the coal gets burnt. This makes for some interesting numbers:

• Annual mercury emissions from coal fired power plants in US (1999): 48 tons
• Electricity saved in US by switching all incandescent lamps to compact flourescents: 7%
• Equivalent mercury pollution reduction: 3.36 tons
• Typical amount of mercury in a CFL: 4 mg
• Number of improperly trashed CFLs per year it would take to match mercury pollution reduction from switching to CFLs: 1,000,000,000
• Number of CFLs sold per year: 330 million

Note that mercury content in CFLs is gradually being reduced. According to a July 2008 fact sheet by Energy Star, the average mercury content in CFLs dropped at least 20% during the previous year. Some models now contain as little as 1.4-2.5 mg of mercury, driving the break-even point up to 2 to 3 billion improperly trashed CFLs per year.

Better consumer education can avoid mercury pollution, whether it’s from lamps that should not be in the garbage or from coal that should not need to be burnt due to more efficient lights.

A recent New York Times article raised some questions about failure rates of cheap CFLs. Probably the bulbs I buy are not as cheap as those mentioned in the article (I used to pay about $10 a decade ago, maybe $5 now), but in all the years that I’ve been using CFLs I have yet to experience one failing in its first year.

Here in Japan regular fluorescents (non-CFL) have been very common in homes for decades, as people here like their homes brighter than in the west, which would have used a lot more electricity and put out much more heat with incandescent bulbs.

The average Japanese dining room, kitchen, living room or bed room uses either circular or straight fluorescent lights, but CFLs have become very common where incandescent bulbs were in use before.

When I moved to my current home 9 years ago and had to buy new lamp fixtures for all the main rooms, I installed CFLs or circular fluourescents throughout. The living room and the dining room table are only on their second set of CFLs during all these years.

Most of the first generation of bulbs in those rooms didn’t actually burn out before being replaced, but merely lost some brightness (the phosphor coating gradually wears out), so I swapped them for a new set and gradually reused the old set to replace less frequently used incandescents left in the house.

CFLs are big step forward from incandescent light bulbs, but eventually we will see them replaced with solid state lights and other new technologies that at the moment are still too expensive to compete for domestic lighting.