Friday, August 24, 2007

Energy Saving Tip: Yeah, the Lightbulbs

Wait, wait... I know you already know this: replacing incandescent bulbs (or especially halogen lights) with compact fluorescents will make a noticeable impact on your electric bill. Rather than beat a dead horse, I have what I hope are a few thoughts you may or may not have run across already.

First I want to address the two biggest complaints with compact fluorescent bulbs - light quality, and mercury content.

The simple answer to the light quality question is that you get used to it - just like you have at the grocery store, the doctor's office, the school, your workplace, and almost any other public building or place of business. The fact is that we're exposed to fluorescent lighting almost everywhere we go, and we don't even notice. Even many of our own kitchens have fluorescent lighting already. Why? So you can see what you're doing better.

Even so, you can get fluorescent bulbs that are "tuned" to a certain part of the light spectrum to simulate different tastes. You'll see them labeled as "warm", "cool" or "full spectrum". If it's been several years since you last bought one, you might be surprised. I've actually challenged visitors to guess which lights are incandescent and which are not, and they've not been able to figure it out.

As far as the mercury issue goes, keep in mind that a coal burning power plants emit mercury, and the mercury in the CF bulb is more than canceled out by the reduced electricity required (and thus the reduced mercury emissions). According to this article in Popular Mechanics:
In 2006, coal-fired power plants produced 1,971 billion kilowatt hours (kwh) of electricity, emitting 50.7 tons of mercury into the air—the equivalent amount of mercury contained in more than 9 billion CFLs (the bulbs emit zero mercury when in use or being handled).

[ ...
] Over the 7500-hour average range of one CFL, then, a plant will emit 13.16 mg of mercury to sustain a 75-watt incandescent bulb but only 3.51 mg of mercury to sustain a 20-watt CFL (the lightning equivalent of a 75-watt traditional bulb). Even if the mercury contained in a CFL was directly released into the atmosphere, an incandescent would still contribute 4.65 more milligrams of mercury into the environment over its lifetime.
Compact fluorescents have the additional advantage that the mercury is contained in an easily recycleable bulb, rather than released into the atmosphere. For information on CF bulb recycling, check this EPA web site. If you break one and need to clean it up, the EPA has this advice:
How should I clean up a broken fluorescent bulb?
The following steps can be performed by the general public:
  1. Open a window and leave the room for 15 minutes or more.

  2. Carefully scoop up the fragments and powder with stiff paper or cardboard and place them in a sealed plastic bag.
    • Use disposable rubber gloves, if available (i.e., do not use bare hands). Wipe the area clean with damp paper towels or disposable wet wipes and place them in the plastic bag.
    • Do not use a vacuum or broom to clean up the broken bulb on hard surfaces.

  3. Place all cleanup materials in a second sealed plastic bag.
    • Place the first bag in a second sealed plastic bag and put it in the outdoor trash container or in another outdoor protected area for the next normal trash disposal.
    • Note: some states prohibit such trash disposal and require that broken and unbroken lamps be taken to a local recycling center.
    • Wash your hands after disposing of the bag.
  4. If a fluorescent bulb breaks on a rug or carpet:
    • First, remove all materials you can without using a vacuum cleaner, following the steps above. Sticky tape (such as duct tape) can be used to pick up small pieces and powder.
    • If vacuuming is needed after all visible materials are removed, vacuum the area where the bulb was broken, remove the vacuum bag (or empty and wipe the canister) and put the bag or vacuum debris in two sealed plastic bags in the outdoor trash or protected outdoor location for normal disposal.
So now that that's out of the way, let me give you a few other thoughts. First, consider whether there are any areas that have too many light bulbs. Our bathroom light fixture had six 75-watt bulbs! After a bit of experimenting, we found that three was just about right, so the rest are partially unscrewed, acting as conveniently stored replacement bulbs. It seemed dark at first, but now if I screw them all back in, it seems uncomfortably bright. Instead of 450 watts in that room, we're down to 39 watts. If you're watching closely, you may have noticed that we also didn't replace 75-watt bulbs with 75-watt equivalents (18 watts). We stepped down even further to a 60-watt equivalent (13 watts), and did just fine. Buy some different kinds and see what works best for you.

The conventional wisdom seems to be that if you just replace the four or five most commonly used bulbs, you'll be saving a lot. But at least in our house, we continued to see savings even after a dozen or more bulbs were replaced. And if you accidentally leave a bare bulb on in the far reaches of your basement, better that it be a CF bulb too.

There are a lot of different styles of bulbs available now, so if you have any dimmable or exposed decorative bulbs, chances are you can find a good fluorescent fit. And if you feel like you've changed almost everything over, don't forget those stealth bulbs - the one over the stove, the desk lamp, in the closet, etc.

You certainly don't have to replace them all at once. I'd just buy a three-pack of whichever bulb type I needed whenever I happened to be in a store that was selling them. Once I'd used up a pack, I'd pick up another the next time I was out. That also helped spread out the cost. They're not always cheap, but they last 7 to 10 times longer than incandescents, so I promise you'll come out ahead.

It took several months before the last incandescents were out, but as far as I know, there are only three left in our house. One in the attic and one in a crawlspace - both are hard to get to and never used. And one in our ceiling fan because one of the two sockets consistently flickers with a CF bulb. I'm not sure why.

So how much will CF bulbs save? Depending on your usage, probably somewhere around 100 - 150 kWh per month, and about one ton of CO2 emmissions, and 20 pounds of sulfer oxides over the course of a year.

No more excuses. Get to it.



At 8/25/2007 12:06 PM, Blogger Wendy said...

100 to 150 kwh per MONTH?!?! I knew our electric bill had been dropping over the last year or so, but I thought it was due to using the clothesline. Deus Ex Machina said it was the bulbs. Drat! He was right :)!

Thanks for the tips. I hadn't considered partially unscrewing the bulbs in our "decorative" fixtures, but that makes incredible sense. I'll try it ;).

At 8/25/2007 8:23 PM, Blogger Suzer said...

It's funny, since I started changing over the light bulbs, I actually want the old ones to burn out so I can replace them! Good info, I never thought about possibly having to dispose of them differently.


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