Fluorescent light bulbs (CFLs)

There are currently three choices when it comes to light bulbs in the home. Like anything else in life, they all have their pros and cons:

1. Incandescents including Halogen
2. Fluorescents (CFLs)
3. LEDs

First, though, we need to get used to thinking in lumens, not watts, since manufacturers have figured out a way to get the same amount of light with fewer watts. In other words, if you want the brightness of a 60-watt bulb, think 800 lumens. For a stronger bulb, try 1600 lumens.

Most people who are energy-conscious are replacing their incandescent light bulbs because they waste 90% of their power. They will have to be gone by 2014 unless they become more efficient. U.S. law does not ban them; it just requires that we use more energy-efficient lamps. Halogens (which are energy-efficient incandescents) are an alternative – they are said to consume 20-30% less power, give 20% more light and last 2-3 times as long.

CFLs (compact fluorescent lights), while more expensive, are the winner when it comes to efficiency and longevity. A problem though is that CFLs have tiny amounts of mercury so there's a disposal issue (more on this below) and while they can last a long time, the burn-out rate has been higher than expected, and that's certainly true in our house. If you object to the garish white or bluish light of CFLs, buy those with low kelvins. The k number measures color temperature and the lower numbers (say, under 3000) are warmer.

Also, if a CFL breaks, the EPA advises you to leave the room and let it air for 15 minutes then scoop up the glass pieces and powder using stiff paper or cardboard and place them in a glass jar with metal lid (such as a canning jar) or in a sealed plastic bag. Use sticky tape, such as duct tape, to pick up any remaining small glass fragments and powder. More here on their website: http://www.epa.gov/mercury/spills/index.htm#fluorescent. If you haven’t broken it, turn it in to Home Depot, which has a recycling program (here). Unfortunately, recent studies indicate only 2% of CFLs are being recycled by consumers (more here), so that mercury is being released into the atmosphere from landfills and storm water run-off.

The newest lamps are LEDs (light-emitting diodes) which last 5-10 times as long as CFLs, are very durable, contain no mercury and use far less energy. But they are also expensive ($35 but falling, last time I checked) and many complain they do not emit enough light (a problem known as droop, which kicks in just as the power levels get high enough for reading!). They do work for HDTVs and for street lights - the City Council is embarking on a project to replace them with LEDs - and, if you are into lavish displays of Christmas lights, LEDs may be a good idea. LEDs still have a way to go before they reach their potential and at the moment they are best suited to lighting cabinets, closets, drawers and so on. They don’t fill a room the way an incandescent does, but the first "warm" ones are now on sale so look for those.

All of the above options are dimmable, however dimmable CFLs are very hard to find. They should become increasingly available in the years ahead.