Economics of a Lightbulb
Posted on December 2nd, 2008 by Bruce
Economics of a Lightbulb
Forget about saving the world for a moment and let’s just look at putting some money in your pocket.
Incandescent vs CFL
| DETAILS | Incandescent | CFL |
| Typical cost of bulb | $0.40 | $2.60 |
| Average life in hours | 1,000 | 10,000 |
| Cost of electricity $/kwh | $0.10 | $0.10 |
| Power of bulb in watts | 60 | 15 |
| Cost for 10,000 hours | $60.00 | $15.00 |
| Purchase + usage cost | $64.00 | $17.60 |
| SAVINGS per CFL | $46.40 |
EVERY incandescent lightbulb your replace with a compact fluorescent light (CFL), will save you $46.40 if you pay about 10 cents per kilowatt hour for electricity.
Replace 5 bulbs and you’ll save 5 x $46.40 = $ 232.00 !!!
Replace every bulb in your house with a CFL and save ?????
Don’t want for the incandescent bulbs to burn out before replacing them! Do it now and start saving money immediately.
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Filed under: conservation
This does not take into account the additional required user lifestyle behavioral changes needed to get the additional hours and efficiency from the CFL bulbs.
For example CFL bulbs require a warm up period before they reach their advertised illumination. In addition to this, they must REMAIN on for a short period of time before shutting them off (most suggest between 10 and 20 minutes) or you will drastically reduce the life hours of the bulb.
So where you would normally flip on the light in the closet, bathroom, kitchen, laundry room or bedroom for just a quick 30 seconds to get your keys, grab a class of juice, switch the clothes from the washer to the dryer, or a quick 3 minute a 2 a.m. bathroom break, remember to leave the light on for an additional 10 to 20 minutes longer than you need to.
As the above statistics indicate it costs 75% less to operate the CFL. What the statistics fail to incorporate into the equation is all of the excess time you much keep electricity flowing to the CFL bulb to accomplish this. In a true home reality this is simply not accurate since you would need to leave on the CFL bulbs at least 75% to 95% longer in any “just need light for a minute or two” situation. Not only does this On/Off cycling drastically cut into the 10,000 hrs life span of the CFLs it makes Incandescent bulbs much more efficient for these short time periods (under 5 minutes).
Then there is the mercury.
The mercury in compact fluorescent bulbs poses no threat while in the bulb, but if you break one:
- open a window and leave the room for 15 minutes or more
- use a wet rag to clean it up and put all of the pieces, and the rag, into a plastic bag
- place all materials in a second sealed plastic bag
- call your local recycling center to see if they accept this material, otherwise put it in your local trash. Wash your hands afterward
NEVER VACCUUM a CFL bulb break — vacuuming can make the mercury air born and breathing this stuff can be deadly.
It is this engineer’s belief that LED bulbs are the real answer to our bulb dilemma. They are even more efficient then CFLs, have no toxic chemicals, require no warm up period, work with dimmers, are cheaper and safer to produce, weigh much less, and are much easier and safer to dispose of.
All that said, please do not take my word on this, do a little research and put ALL the facts together yourself — statistics are easily manipulated simply by not showing all of them, as is the case here. CFLs definately have their place but the home is not really one of them.
While I prefer LED lights, until they are available at the local hardware store, CFL light bulbs are the way to go for your household. I presently have 5 LED light bulbs in my home, but they had to be ordered through the mail.
The above comparision does use the hours specified by the manufacturers. In real life, turning a CFL on for very short periods of time will reduce it’s lifespan, just as running an incandescent light at 130 volts rather than 120 volts, will cut it’s lifespan by more than half.
If you replace 90% of your incandesent light bulbs with CFL bulbs, and use these lights just the same as you always have, you’ll still save a lot of money. Even in extreme cases where a CFL light is on for only an average of five minutes, you’ll save both money and CARBON EMISSIONS over an incandescent light.
https://www.rmi.org/sitepages/pid173.php
I use CFL lights in my home office, kitchen, family room, dining room, bedrooms, bathrooms on the same floor as the bedrooms, etc. If you want, you can keep 10% of your incandescent light bulbs, for use in closets, where the lights may be on for a very short period of time (seconds not minutes)… or replace them with your mail order LEDs.
Mitchell, not sure why you think LEDs are cheaper to produce? If so, I hope they soon cost less that the $1.78 I routinely pay for CFLs. I’ll love to be able to pick them up at Home Depot, Rona, etc.
I have to say, I can not agree with you in 100%, but it’s just my opinion, which indeed could be very wrong.
p.s. You have a very good template for your blog. Where did you find it?
This Blog is a standard 3 column wordpress template, with our corporate logo added to the top. We host our own site, thus have full access to the code. I suspect that you are only allowed to pick from a limited set of templates when you have someone providing you will a free site such as yours on automotic jacks. If you follow the link above to greenterrafirma home page, you’ll find the rest of our site, which was created from scratch.
http://www.greenterrafirma.com/
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