Home Energy: The Light Bulb Controversy

Home Energy 

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When it comes to light bulbs, which light bulb do you consider is the better choice?  Is it the incandescent light bulb or the compact flourescent light (CFL) bulb?  Well, before you automatically pick one or the other, there are quite a few factors to consider.  Energy savings is an obvious one, cost of purchase, longevity of the bulb, affect it has on the environment, etc.  But if you live in the Northern Hemisphere, such as Canada, Sweden, some parts of northern U.S., etc. you also have one more thing to factor in, heat…yes, heat.

Living in Southern California, heat is not something I would factor in when it came to choosing a light bulb.  I usually factor in cost, energy savings and what’s best for the environment.  But in chatting with a new Canadian friend on Twitter, he brought up the issue of “heat” when it comes to light bulbs.  Go figure!

So, I started looking around a little more and found this blog, “Compact Flourescent Lights Save Less Than Many Believe”.   His argument was that since a light bulb gives off heat, let’s say you replaced a 60-Watt incandescent light bulb (that you use 6 hrs/day) with a 15-Watt CFL bulb, you would lose 45 Watts of heat.  Yes, your energy consumption is less by 45 Watts during that 6 hrs, but if it is winter and you need to heat your home…then you’re going to have to make up (in heating costs) what you lost in “light bulb heat”.  Apparently the costs “wash”, so either bulb technically would suffice during winter months.  (NOTE: none of this factors in bulbs being close to the ceiling…with heat rising you’ll lose out on the heat anyway.)

Now, what about summer?  Aren’t you wasting those 45 Watts of heat during the summer when your home doesn’t need to be heated?  And spending more on A/C costs to cool the heat coming from those light bulbs?  Well, if you look at it one way, if you use CFL bulbs year-round at least you’d be saving for part of the year, right?  Some savings is better than no savings.

Additionally, according to GE the EPA recommends using CFL bulbs because they save energy (use about 2/3 less energy), save money (sometimes about $30 over the life of the bulb) and last up to 10 times longer.   Then for areas like Southern California, where we don’t rely on light bulbs for heat, the CFL bulbs will usually emit about 70% less heat.  That works.

However, there is one key issue I would be remiss not to mention…disposal.  How do you properly dispose of a CFL bulb?  Since CFL’s contain mercury you need to be careful – proper disposal is key.  Luckily there are stores like Ikea and Home Depot that take back used CFL bulbs, so you can bring your bulbs there for disposal.  Another “last-ditch” disposal idea mentioned by GE is to put your CFL in a plastic bag, seal it and then put it in the trash…of course only as long as your waste disposal company doesn’t incinerate its garbage.  Wait a second…what?  I’m sorry, I just don’t feel the idea of putting a light bulb with mercury into a plastic bag and then putting it in the trash to go to a land-fill is exactly environmentally-friendly.  Just take them to Ikea or Home Depot, hopefully they have a better disposal plan.

Anyway, a last little tidbit of information to help you in your home energy light bulb choice…according to GE “A coal-fired power plant will emit 13.6 milligrams of mercury to produce the electricity required to use an incandescent light bulb, compared to 3.3 milligrams for a CFL.”  Which do you think is the smarter choice?


  • David Leonhardt

    Disposal is a big issue, and hopefully companies that take back the bulbs dispose of them properly (can they be recycled in any way?). However, the heat issue really should be a non-starter, just because most heat generated at the ceiling level is wasted anyway, and even up here in Canada we don’t heat, even at night, for half the year.

  • Mostie Mitchell

    I bought the CFL bulbs for our house and within a week my wife made me replace them because they were so dang bright. I took them to work and we are using them there. Don’t know what I’m going to do when it’s time to dispose of them.

  • Amanda

    I agree, disposal and contamination is the serious issue.

    London isn’t well-known for its tropical temperatures, but we don’t have our heating on year-round, either.

    “with heat rising you’ll lose out on the heat anyway” by the way, heat doesn’t rise – warm air rises….

  • darcylars

    I agree, disposal of light is a serious issue.Compact fluorescent lighting is said to be the best alternative to the classic light bulb, because it consumes very little energy and is Eco friendly.

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