Adoption of Compact Fluorescent Light bulbs

Compact Florescent Light bulbs offer a significant opportunity to save electricity over standard incandescent lights through increased electrical conversation efficiency.  While the excess heat they generate might be welcome in colder climates, it is generally an added load in southern climates.  In fact, a standard 100W bulb requires a total of 451 W of power (317 W to generate electricity & 134 W to generate electricity for the AC) to produce 5W of useful light-an overall efficiency of 1.1% (Source: Energy Technology & Policy Lecture 3 – Thermo and Efficiency, page 25).

Most people know CFLs save energy and they are installing them in their homes.  As of June 2009, 91% of all homes in covered by Investor-owned utilities in California have CFLs and the average home has more than 10 CFLs.  However, CFLs only occupy 21% of the sockets in California and 11% of the sockets nationwideWith an average financial payback of 6 months, 10 times longer life and net lifetime savings of $40, why don’t more sockets have CFLs?

“Higher potential” sockets

Assuming you use CFLs, which of your lights sockets have CFLs?  Most likely the ones you use a lot.  Does it really make sense to install one in your pantry, above the washing machine or in a bedroom closet when you frequently turn that light on & off and it is only on a few hours a month?

Dimmer switches

Many existing light sockets have dimmers.  Utilities recommend avoiding placing non-dimmable CFLs in dimmable light sockets, however the DOE’s Energy Star program claims if you never dim the light, a non-dimmable CFL should work fine in a dimmer.  Personally, I have tried to put non-dimmable CFLs into dimmable light sockets and not use the dimmer switch, however they haven’t lasted nearly as long as advertised.  Several times I’ve noticed the light flickering, which is a tell-tale sign the CDL is not receiving full power.  Dimmable CFLs are now on the market, however how many users are willing to pay $13.99 for a 100W blub?

Light quality/color

I think the biggest problem with CFLs is light quality.  The basic rule is to buy a light bulb whose color matches your desired use.  However, consumers are not used to having to think about light quality when they purchase light bulbs-we are used to incandescent light bulbs providing a high-quality light.  In their attempts to make reduce their energy consumption, many people have bought a bunch of CFLs only to find they don’t work in their circumstance, ending up with a collection of unusable CFLs .  Personally, I have a box of 15-20 unused CFLs, mostly due to light quality.  Magazines like Popular Mechanics and Consumer Reports along with the DOE Energy Star program provide guidance for choosing CFLs, however I think a lighting demo area in a home improvement store (Home Depot, Lowes, etc) would be the most useful tool.  In addition to providing consumers a direct indication of lighting color, it would force manufacturers to produce higher-quality lights people will buy and actually use.  After all, what use is a CFL if no one uses it?


CFLs contain mercury and no substitute exists for mercury in CFLs.  Each light bulb contains roughly 5 mg, whereas old manual thermostats contain up to 3000 mg.  CFLs don’t emit any mercury directly under direct use, only when they break.  The EPA mercury cleanup guidelines recommend airing out the room, scooping up broken bulb shards, sealing them in plastic bags and disposing them properly.  Depending on state regulations, a dead CFL bulb might need special recycling.  Many stores that sell CFLs will also recycle unbroken CFLs.

Given the special precautions needed to handle CFLs, do they reduce the amount of mercury in the atmosphere?  Recent research shows that regions with coal-burning utilities can significantly reduce their mercury consumption by switching to CFLs.  For the U.S. as a whole, switching all incandescent light bulbs to CFLs would reduce mercury emissions by 25,000 tons annually.  However, I think the mercury issue is really a personal perception problem.  Mercury emitted from coal-fired power plants is spread across many square miles, however a broken CFL only directly affects a single house.  When even a small mercury emission would directly affect you, I know many people who don’t want to take that risk.

LED Lights

Finally, should we really worry about CFL penetration when LED lights can save even more energy?  LEDs are available for Christmas lights, night lights and traffic lights.  I also recently bought an LED flood light from Costco for $13.99.  It is supposed to be 90% more efficient than an incandescent light & last 30,000 hours.  However, its light quality is worse than any of my CFLs.  I think it will be quite some time before LEDs really take-off in the marketplace.

In the meantime, is 11% CFL penetration good?  Maybe the better metric would be total hours of CFL as a percent of hours of light useage.  I suspect this would be higher than 11%.  While the economic incentives for more efficient lights are clear and consumers do recognize the benefit, I think any more significant CFL penetration will require marketable improvements in light quality and a reduction in the risk of mercury contamination or technological advancements that eliminate mercury outright.


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