Sunday, February 26, 2012

Life in Post-Lightbulb efficiency standard America

Today for the first time in 2012, I bought a new light bulb. Now, this may not seem significant, but it is the first time I had to select a bulb without the option of the standard 100W incandescent, which are no longer sold because they don't meet the minimum efficiency standards of the 2007 light bulb law. There has been some political posturing about this law and government interference in the free market. There have been some dubious 'facts' and scare tactics in the media as well (see: Right-Wing Media Continue To Mislead On Nonexistent Light Bulb "Ban") so I thought I would relate how it affected my life as a light bulb consumer today.

In this particular case, I was looking for a bulb for my laundry room, which has been lit by two 100W incandescent bulbs in simple 'bare bulb' fixtures on the ceiling. They are controlled by a motion sensor which I installed a few years ago, and which is only compatible with incandescent style bulbs. This limits the 'on time' to only when someone is in the room, and provides hands-free operation which is nice when you are carrying baskets full of clothes. Because of this, CFL bulbs were not an option. I also don't recommend them for applications where they are on only briefly, due to warm up time issues. Basically, you are finished with the laundry task by the time the bulb fully warms up. CFL lifetime is also known to be shortened by repeated on-off cycles. CFL's also contain a tiny bit of mercury which bothers some people, as it can be released if the bulb breaks. It also means you have to recycle CFL bulbs, which means taking them to Home Depot or other retailers that support recycling.

This left LED or halogen. LED bulbs are wonderful devices, I highly recommend them for uses such as recessed lighting in areas like kitchens which are used a lot. However in this case the 'on time' is so brief that an LED would probably take longer than my expected life time to pay back its cost. Also Giant doesn't stock a lot of LED bulbs yet. So I chose a 72W halogen bulb by Sylvania. These are also "Made in USA" according to the package, which appeals to me. Halogens have no mercury or special disposal requirements.

I replaced both bulbs with the 72W bulbs and can't tell any difference in the lighting, although according to the package they produce slightly less light (1490 vs 1690 lumens). The halogen bulbs do cost more than the old style bulbs, $2.50 each vs. $0.50 for the old bulbs. But since they use 28W less power, will they pay back that up front cost? Here are the calculations for total lifetime bulb cost for my laundry room:

First up, incandescent.
Incandescent:  $0.50 cost per bulb with a 750 hr lifetime.
So for 1000 hrs of on-time I need to buy (1000/750)*2 = 2.66 bulbs
Bulb cost: 2.66 * $0.50 = $1.33
Electricity cost: My power costs roughly $0.12 per KWh
Power used over 1000 hr lifetime: 100W * 1000hrs * 2 bulbs = 200,000 watt/hrs = 200KWh
Lifetime power cost: 200 * $0.12 = $24

Total lifetime costs for incandescent bulbs: $1.33 + $24 = $25.33

Now let's see how well the 'more expensive' halogen bulbs do:
Halogen: $2.50 cost per bulb with a 1000 lifetime
So for 1000 hrs of on-time I need to buy (1000/1000)*2 = 2 bulbs
Bulb cost: 2 * $2.50 = $5.00 (uh oh, looks higher)
Electricity cost: As previously stated, $0.12 per KWh
Power used over 1000 hr lifetime: 72W * 1000hrs * 2 bulbs = 144,000 watt/hrs = 144KWh
Lifetime power cost: 144 * $0.12 = $17.28

Total lifetime costs for halogen bulbs: $5.00 + $17.28 = $22.28

So, halogen comes out slightly less ($3.05) in total lifetime costs! Okay, so this is not going to change my life in any appreciable way, but that is kind of the idea behind the law. I get the same light for less money. The real value is considering things like if we replaced all incandescent bulbs the country could save $18 billion per year and reduce power usage by the equivalent of 80 coal plants. I fully expect that by the time these halogen bulbs burn out LED bulbs will be cheap enough to make sense as a replacement.

So don't fret but embrace your new choices in lighting options, and enjoy all the money you'll be saving!