efficiency – Page 2 – Building Earth

CFL or compact fluorescent lamp light bulbs are pretty typical these days. A CFL bulb is made up of a ballast and a tube containing gas. The ballast turns the current from the wall outlet into high frequency current, which it sends into the gas tube. The high frequency current knocks excites electrons in the gas, causing them to produce ultraviolet (UV) light. When the UV light hits the fluorescent coating on the glass tube it produces visible light.

“Light Bulb” by Pedro Lozano CCBY

Let’s compare CFL light bulbs directly to the pro and con list I put together last week about incandescent bulbs:

Light Quality: Mixed Reviews. The light quality can be all over the board with different brands of CFL light bulbs. We’ve grown accustomed to the warm, soft light produced by incandescent bulbs, and in comparison, some brands of CFL bulbs can produce cold, harsh light. However, many brands have improved their designs to provide warm light just like incandescent bulbs. You may have to shop around a couple brands to find the light quality that meets your expectations.
Price per bulb: Pro. While more expensive than filament bulbs, you can pick up CFL bulbs for around $2 per bulb.
Availability: Pro. You can get basic CFL bulbs pretty much everywhere you can get filament bulbs these days.
Style: Con. While CFLs fit pretty much any standard light bulb socket, you’ll have trouble finding specialty shaped bulbs of the CFL variety.
Energy use: Pro. A CFL bulb that produces a comparable amount of lumens as a 60 watt filament bulb requires only 14 watts.
Lifetime: Pro. 8000 hours! Which translates into about 7 years of burning for 3 hours a day.

And one more important point to consider when using CFL bulbs:

Toxicity and Disposal: Con. The gas inside the CFL tube contains mercury which is hazardous to come in contact with. This means you have to be careful not to break open the tube, and you really should not just be disposing of a CFL bulb in the trash. Used CFL bulbs should be disposed of by bringing them to an appropriate drop site for safe disposal.

If you’re looking for a disposal site near you, you can check out search.Earth911.com

So the tally when comparing CFLs to Incandescents is 4 pros, 2 cons, and 1 mixed review. Now let’s look at the long term cost.

10 year cost for burning filament bulbs in one lamp: (3 hours a day, $0.12/kwh cost of electricity, $2.00/bulb, 2 bulbs) = $22.40.

Pretty cheap when compared to the $96.84 it would cost to run the same light with a incandescent bulb.

Shortly after we moved one of our lamps burnt out. The light bulb was the last of an old 6 pack of filament lights that we finally used up. For a while now, one of the items on our green living to-do list has been to upgrade to LED light bulbs, but since I already had that old pack of filament bulbs, we had to use those up first. Because one of our rules is use what you already have first.

So I ordered a 6 pack of LED lights. Maybe overkill considering we only have 2 lamps and these things have a 10 year guaranteed life. Real talk: sometimes I let the discount for buying in bulk counteract our desire to have less stuff. I need to work on that.

Anyhow, today I’m going to do a compare and contrast on the three most common types of light bulbs, so that next time you need to replace one, you can make the best choice.

Incandescent Light Bulbs

I mean, let’s hand it to Thomas Edison, this design for an electric light bulb has been around since 1878. Edison wasn’t the first to make a bulb that used a filament – about 20 others had done so with varying degrees of success starting in 1802 – but Edison’s design using a carbon filament had a long life and was the one that took off commercially. Filament lights work by passing an electric current through a material known as the filament. Today, filaments are typically made of tungsten.

Pros:

Light Quality: Incandescent light bulbs produce the warm, soft light we’ve come to expect from our lamps.
Price per bulb: Incandescent light bulbs typically cost about $1 – $2 per bulb
Availability and style: You can easily pick up a filament light bulb at a grocery store, convenience store or hardware store. And you can get a wide variety of sizes and styles. If you have a chandelier that takes specially shaped bulbs, they are most likely going to be Incandescent light bulbs.

Cons:

Energy use: A standard 60 watt incandescnet light bulb produces anywhere from 600-800 lumens. Lumens are the unit that the amount of visible light is measured in. As suggested, to do this it takes 60 watts of electricity flowing through the filament. Newer, more efficient filament bulbs claim to produce the same amount of lumens using about 45 watts, but that is still significantly more energy than other light bulbs require.
Fragility: Filaments are rather delicate things. If jostled too strongly, the filament can get dislodged or break without even being lit.
Lifetime: A 60 watt bulb will burn for about 985 hours. This translates to around 11 months of use if lit for 3 hours each day.

10 year cost for burning incandescent light bulbs in one lamp: (3 hours a day, $0.12/kwh cost of electricity, $1.50/bulb, 12 bulbs) = $96.84

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You can find my report of the pros and cons of CFL light bulbs here, and LED light bulbs here to see how Incandescent light bulbs measure up.