Saving Pennies or Dollars? Light Bulbs

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saving pennies or dollarsSaving Pennies or Dollars is a new semi-regular series on The Simple Dollar, inspired by a great discussion on The Simple Dollar’s Facebook page concerning frugal tactics that might not really save that much money. I’m going to take some of the scenarios described by the readers there and try to break down the numbers to see if the savings is really worth the time invested.

Greg writes in: I was thinking of changing my light bulbs to the new energy efficient CFL bulbs. I counted quantity 14 60watt bulbs in my house. For $25 to buy an 18 pack of 60watt equivalent, each bulb uses 13watts. If I estimate that roughly everyday 4 bulbs are turned on for 5 hours. Saving me 188 Watts of power per hour, giving me 940 watts saving a day. Is it worth it?

It absolutely is.

Let’s do a price comparison of normal incandescent bulbs, CFL bulbs, and the new LED bulbs that are starting to emerge onto the scene, using Greg’s scenario.

Greg can buy a 24 pack of 60 watt incandescent bulbs for $11.87, or $0.49 a bulb. He would have to buy twelve bulbs to replace the ones in his home, costing him $5.94 in bulbs. These bulbs have an average lifetime of 1,000 hours, so to cover 10,000 hours of use, it will cost him $54.90 to use incandescent bulbs.

Greg can also buy an 8 pack of 13 watt CFL bulbs for $8.75 (which replace 60 watt incandescents), or $1.09 a bulb. He would have to buy twelve bulbs to replace the ones in his home, costing him $13.08 for a round of bulbs. These bulbs have a stated average lifetime of 8,000 hours, but my experience with CFLs has shown me that you should roughly halve that, so to cover 10,000 hours of use, it will cost him $32.70.

Yes, even without the energy savings, CFLs are cheaper due to the longer lifespan.

Greg could also buy a single 7 watt warm white LED bulb for $14.99 (this replaces a 60 watt incandescent). I’ve used these and they actually do a really good job of matching incandescent light. He would have to buy twelve bulbs to replace the ones in his home, costing him $179.88. These bulbs have a stated average lifetime of 25,000 hours, so to cover 10,000 hours of use, it will cost him $71.95.

So, for 10,000 hours of light out of twelve light sockets, you’ll have to pay $54.90 for 60 watt incandescent bulbs, $32.70 for equivalent CFLs, and $71.95 for equivalent LEDs.

Now, what about energy use?

Over 120,000 hours of use (10,000 hours per socket), a 60 watt incandescent will use 7,200 kWh of energy. At an average price per kilowatt hour nationwide of about $0.12 per kWh, it would cost him $864 over that span.

Over that same timeframe, a 13 watt CFL will use 1,560 kWh of energy. At a price of $0.12 per kWh, it would cost him $187.20 over that span.

Over that timeframe, a 7 watt CFL will use 840 kWh of energy. At a price of $0.12 per kWh, it would cost him $100.80 over that span.

So, what’s the total cost?

For 12 light sockets over 10,000 hours of use per socket, the total cost of using 60 watt incandescent bulbs is $918.90.

For 12 light sockets over 10,000 hours of use per socket, the total cost of using 13 watt CFLs (which produce light similar to the 60 watt incandescents) is $219.90.

For 12 light sockets over 10,000 hours of use per socket, the total cost of using 7 watt LEDs (which produce light similar to the 60 watt incandescents) is $172.75.

Yes, LEDs are the cheapest option now. The startup cost for such bulbs is very high, but their long lifespans and incredibly low energy use end up making up the difference and more.

On the other hand, even though they’re the cheapest initially, the short lifespan and high energy cost of incandescent bulbs make them incredibly expensive over the long haul.

My suggestion? Try a CFL and a good LED like the one I linked to above. Make sure the lighting is up to the standard you want. If it is, you should absolutely jump ship to the one that provides the light you want, even if the bulb costs more. You’ll save dollars, not pennies, over the long run.

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36 thoughts on “Saving Pennies or Dollars? Light Bulbs

  1. Wow, that is a really confusing way to answer a direct question. It would have be easier to say Greg would shave around $3.30 off his monthly electric bill by converting from incandescent to CFLs. And incandescent replacements will cost five times more than CFLs over time.

  2. This post is incredibly insightful. I’ve been slowly converting my bulbs to CFLs as they incandescents go out, and have been wondering how much I was saving.

    Thank you! These are the posts I enjoy the most!

  3. The first month after changing all my incandescents to CLF, we saved $15 on our electricity bill. We haven’t look back since. The longer life is also good since you do not have to change them out as often.

  4. I enjoy when conspiracy theorists/haters diss CFLs. I tell them this:

    All the CFLs I bought 5 years ago are still running… and they survived a move from an apartment to a house. My “standard” bulbs that were left were mostly killed during the move when the filaments rattled apart in transit.

    Money. Saved.

  5. I cannot figure out how the initial bulb costs of $54.90, $32.70, and $71.95 are being calculated. I must be missing something obvious. I have tried calculations with a few different assumptions (and get extra confused as Trent seems to be making his own assumptions such as using 12 bulbs instead of 14).

  6. Does anyone have a brand or type of CFL or LED bulb that they like or that seems comparable to a soft white or full-spectrum daylight incandescent bulb? They all seem incredibly dim to me and when I bought a “daylight” bulb it was very yellow. I can’t stand them, even with cost savings and reduced environmental impact.

  7. My husband and I have just not experienced the longer life on our CFL bulbs that other people have written about. Very disappointing given the price!

  8. It’s not always that straightforward.

    I live in Winnipeg, where it’s cold for 6 months of the year. If I move to a CFL bulb, I save money on reduced lighting costs, but my furnace has to run longer as I have less heat generated inside the house.

    Once I factored into the costs of heating my house, my spreadsheet that showed that while CFL’s were still cheaper in the long run, it was only barely.

    It also seems that about 90% of the light fixtures in my house are NOT CFL compatible. (The bulb is enclosed, or it hangs upside down, or it’s on a dimmer, or it requires a specialty bulb.)

    As a result, my house is a mix of all types of bulbs, and to save money, we just do the old fashioned “turn the lights off” trick.

  9. We use one lightbulb going through the basement to our cars. Quick on and off multiple times a day.

    CFL’s don’t work for that.

  10. CFLs wear out much faster the more you turn them on and off. There is a rule of thumb, I forget it now, maybe someone else remembers… like if you are coming back in five minutes don’t turn your CFL off.

    So CFLs are not ideal for lights you might flick on momentarily, such as you might do to go to the bathroom in the night. To resolve some of this, we installed night lights in a two strategic places on the house, so we do not have to turn CFLs on and off nearly as much. They throw off enough light so i do not need to turn on a light to get myself a snack in the kitchen.

    I have previously read what Ray has said about CFLs throwing off less heat, which offsets the heating bill in colder climates.

  11. I am not at all a fan of CFLs due to the generally garish color and primarily for the time it takes them to get to full intensity (a very major factor, especially when you walk from sunlight into the house – it’s like the lights aren’t even on for several minutes). Plus, I have had them burn out very quickly on many occasions. I have never used LEDs, but I assume they don’t have any warm-up time? That would be a major benefit to me.

  12. We found that our CFLs die very quickly in our ceiling fan fixtures (not enclosed). Also, our bathrooms have enclosed light fixtures and our dining room is on a dimmer. So, in our home, that leaves less than half of the lights that could use a CFL. And until the past year or so, CFLs were about $5 per bulb. Only recently have they come down significantly in price. I got a pack of 3 at Menard’s yesterday for $.97, which was phenomenal.

    And don’t forget, CFLs require hazardous waste disposal because they contain mercury. Incandescent bulbs are recyclable as they are glass and metal.

  13. I’ve replaced a bunch of incandescents with CFLs and have to say I’m not a big fan. CFLs do not work well in cold weather; There is a big variation in the light colour and often they do not last much longer than incandescents. On top of that they are not particularly environmentally friendly given their manufacturing processes. LEDs do sound promising, but I have not yet tried any.

  14. Can anyone recommend a high quality LED that is a 100 watt incandescent equivalent? The one Trent linked to was a 60 watt equivalent and Amazon suggested a 75 watt equivalent but nothing else. Neither is bright enough to sew by or to read an old paperback.

    I’d feel much better with an LED in the kids’ rooms than the CFLs which I have taught them are “poisonous” light bulbs – leave the room immediately and get a grownup if one breaks (so far no breakages). On the other hand, CFLs (and LEDs) will not cause a rubber snake to start smoking if it is thrown into the floor lamp – so incandescents have their own safety hazards.

  15. re: CFL lifespans. While CFLs give off less heat to produce the same amount of light, they still give off a noticable amount. If you are using them in an enclosure that traps the heat in with the CFL bulb, the buildup of heat can significantly reduce the lifespan of the bulb.

    #13 Jessica: You mentioned that the bulbs you tried were in a ceiling fan, but they were not enclosed. Was the design such that the bulbs were vented at the top? Since heat rises, if the a CFL bulb is surrounded by a glass fixture that opens downward, but is not vented at the top, the bulb can still overheat.

    I actually had an electrician recommend I replace a fixture outside for this very reason (the fixture opened downward, but did not have ventilation at the top) if I wanted to use CFL bulbs in it. He told me if I used CFL bulbs in the fixture, they would probably burn out much faster than normal, despite the fact that it was open on the bottom.

  16. I converted all the bulbs in my apartment to CFLs, and I’ve already had about 5 burn out. It’s been maybe a year now. I think I’ll replace them with the LEDs because I don’t like the idea of having to deal with proper disposal of the CFLs.

    Sometimes it’s hard to do the right thing.

  17. This analysis shows that –

    1 – Incandescent bulbs that are not used much should never be replaced with CFLs or LEDs until they burn out. If a lightbulb has an expected life of 1,000 hours, but is only on 2-3 hours a week, it will last for about 10 years. That it burns more electricity during those few hours than another variety is not a good reason to replace it.

    2. – The real value is in replacing the bulbs that are on long and often. I replaced my reading lamp and my kitchen floods with CFLs, since those are on for hours every day, but closet, laundry, basement, bedroom, and others will be replaced only when they burn out, which may be years.

    My understanding is that incandescents are NOT wasteful indoors in cold climates during the winter. The “extra” energy they use is heat energy that simply reduces the need for other heating. If I had enought extra incandescents on hand, I’d swap them out in the cold months even in the high-use fixtures where I use CFLs usually.

  18. I can’t read using CFLs. I have also found they last no longer than incandescent bulbs in fixtures that hold the bulb in a horizontal orientation (like the kitchen) or in a fixture that does not allow the heat they generate to escape quickly. Halogens work better in such aplications but only last 6 months rather than the advertised 2 years. For reading nothing I have tried beats GE Reveal 100 watt incandescent bulbs. I hate CFLs. I have not tried LEDs due to the cost.

  19. We just had a power surge through a rental house, all the expensive CFL bulbs burned out immediately, leaving all that toxic waste to go into the landfill. The regular incandescens are still shugging along. I think very few people realize how toxic CFLs are, you really ought to call the Hazmat team to clean up when they break. I’d rather use the safe, tried and true incandescents, and when they burn out or break, the glass bits are intert and eventually break down to sand, and the metal parts get tossed into mixed metal recycling and there is no pollution. The same can’t be said for toxic CFLs. When your children and grandchildren start getting more cancers from this stuff leaching into the water supply, you’ll express outrage that “the government” let this happen. I’m stockpiling incandescent bulbs so I’m not part of the pollution problem for the forseeable future.

  20. Knock on wood but I’ve always had great experiences with CFLs, enclosed or not, whether I’m flipping them on or off frequently, whatever. I have an incandescent in my laundry room that has lasted a surprisingly long time as well. I have noticed that people with spotty electricity delivery (surges) tend to go through the CFLs faster.

    There’s a limited number of places they don’t work (my garage door opener is one), but I even recently replaced the light in my refrigerator with one. The “quality of lighting” difference to me is not worth the 4x energy cost, and humans quickly adapt to different environments. I honestly could not identify the type of lighting if you put me in identical rooms with CFL vs Incandescent bulbs but didn’t let me see the lighting fixtures.
    (Deruiter – mercury, while not particularly healthy, is not a carcinogen)

  21. Have an energy audit, which most electric companies will subsidize. The auditor will replace most of your lights with CFLs as part of the program. Check your states website and electric company website, as they will have rebates. When you buy, try to buy in bulk. If you don’t like the harsh light of CFLs, look at the color temp spec. That will determine how ‘natural’ the light is (ie warm). I think in the long run, LED is the best choice. Some people have asked for a good supplier of LEDs. Try TekSupply. Google them and do a search for LED on their site. Last tip, get one of those device electrical measuring devices. You can connect your lamp to it and see exactly how much you would save with a CFL vs reg. light.

  22. Oh and regarding heat from incandescent bulbs, the heat generated by 4 bulbs at 60 watts for 5 hours (the reader example) is less than 1000 BTU per hour. It’s helpful, but probably negligible to your heating cost, and let’s consider that they’re probably off for the coldest time of day: overnight.
    Actually if you run the numbers, you pay 14.4 cents in electricity to save 5 cents in gas:
    5000 BTU is about 1/20 of a therm, $1 per therm divided by 20 is 5 cents. 1.2kWh times 12 cents per kWh is 14.4 cents.
    So per 30 days, you’ll spend $4.32 in electricty for lighting, saving $1.23 in Natural gas with conventional lightbulbs. Net, you spend $3.09 per month in utilities. With CFLs, you’ll spend $0.94 for lighting, and save $0.27 in gas. Or, to think of it another way, you’ll need to burn an extra 0.96 Therms/month due to less heat generated from your CFLs. Good thing therms are cheap, the sum being $1.63 spent for an equivalent amount of energy used.
    CFLs win. They win even more in the summer months, where all that captured heat is not so good for your AC.

  23. I HATE CFLs. It is depressing to go to my parents house, where the lighting is always dim and takes them forever to warm up and they still never quite get as bright as incandescent. Plus my dad is a freak about turning them off at every opportunity so he’s not really saving anything and ruining the ambiance of his house.

  24. I agree that CFL’s aren’t a perfect solution, but they do help a lot. I’ve noticed that the acquisition costs have gone way down. I regularly see a variety of styles at the dollar stores and last week saw single bulbs for 25 cents each at WinCo. In both cases, the bulbs were Energy Star rated and approved by our local energy provider. The catch? The packages contained expired rebate info. Big deal. With prices like this, it certainly tips the numbers in their favor.
    Re: #10 Gretchen – I use one in the same location and it works just fine.
    Does anyone know anything about using CFL’s for specialized applications such as refrigerators and range hoods?

  25. Is there anyone else who actually likes the light from CFL’s? They seem brighter to me and you can use a brighter watt equivalency where you need it because the actual wattage is much lower than the maximum for most fixtures. I even have them in our enclosed fixtures and they’ve lasted several years already. But I think they look best uncovered, because I like the curly look of the bare bulbs. And, we saved $15 a month immediately by replacing all 28 incandescent bulbs around the house with CFL’s about five years ago. Also, since we’re in Texas, I really appreciate that they don’t give off the heat that the incandescents did. Is anyone else an all-around fan of these bulbs? (And no, I don’t work for a bulb company.)

  26. This sounds good in theory, except they seem to burn out quickly at my house. I thought these were supposed to last for years…not months. Maybe the house is wired badly, but for us I’m really questioning if this is a saver…

  27. I’m always surprised how many CFL haters there are. I use CFL’s in my whole house and have no problems. They save money and work as promised.

    CFL’s are not full of toxic waste requiring hazmat teams. You should handle them property if they break and dispose of them properly but they’re really no worse or inconvenient then any of the numerous batteries in your home or the bottle of bleach in your laundry room. If you’re actually worried about toxins and the environment then you should be more concerned with the mercury that coal plants pump into our atmosphere. You get more mercury emissions from coal plants when using incandescents than you do with CFLs.

    CFL’s are not a good way to heat your home. In the winter the energy wasted in heat isn’t really wasted since it offsets your heating bill. This is true. However electricity used in light bulbs is a pretty inefficient way to heat your home. Thats why most homes in colder climates don’t rely on electric heat. Plus any incandescent bulb worsens the situation in any warm climate area where you use AC during the summer. Nationally we spend about as much cooling our homes as heating them. Most people living in cold climates don’t heat their homes all year so that impact is generally only in the winter months. You’re still wasting the energy in the summer, autumn and spring. But this is still a valid point and if you live in northern Canada then CFLs will save you much less than if you live in Arizona.

    I agree the light from flourescents can be harsher than an incandescent. THe light from CFL’s varies. You can get CFLs with different lights. Some are more yellow and some are more bluish. If you get the better CFL then their light is almost indistinguishable from an incandescent. If you get a crappy CFL then the light looks awful. THe light spectrum has gotten a lot better in the past 10 years. So if you’re used to old flourescents then things have changed. Theres a picture on the wiki page for CFL’s that shows side by side of several bulbs and illustrates how a good looking CFL light compares to incandescent.

    CFL’s do really last many years. Of course theres exceptions. If you bought cheap crappy CFLs of low quality manufacture then they may burn out fast. If you use CFL’s in a room whre you frequently turn the light on and off then it will die quicker. Theres always a ‘bad apple’ in any bunch and random CFLs will die faster than normal. I replaced my whole home with CFL lights over 10 years ago and the vast majority of them are still working. I’m sure you remember buying an incandescent bulb to only replace the same bulb a couple months later. I’m sure you know if you buy the cheapest incandescent bulb then they will be lower quality. I’m sure you know that turning incandescent bulbs on and off regularly will result in more frequent failures.

  28. Above I said : “Nationally we spend about as much cooling our homes as heating them.” That is not right. I said that off the cuff. I looked it up and nationally we spend much more heating our homes than cooling.

  29. I wanted to add a second comment:

    I went to Cuba in 2008 (I’m from Canada, remember, so it’s ok) and one thing I noticed down there was that EVERYTHING was a CFL.

    In a country that has issues delivering enough power to all citizens, and is nice and warm, mass conversion to CFL’s probably saved them from having to build a new power plant and/or having rolling blackouts.

  30. I have been very happy with CFL bulbs. We have been using them for about 5 years with good results. We have had a few burn out, but the energy savings easily offsets the cost. Several complaints have been made about CFL bulbs, which I’d like to address, at least from my perspective.

    Mercury – As was mentioned previously, CFL bulbs contain only a small amount of mercury; comparable to that in a watch battery. They are certainly nothing to be feared. I’m sure they do break from time to time, but I’ve yet to see it happen. I’m not sure what it takes to break one, but I know they are much harder to break than an incandescent bulb.

    Brightness – Its so strange that we think of the brightness of a bulb in terms of watts or incandescent watt equivalent. Its important to understand what the ratings on a bulb mean when purchasing it. If you try a bulb that isn’t bright enough for a particular use just move it to another area and replace it with a higher output bulb. A 100 watt incandescent bulb has an output of 1750 lumens, while a 23 watt CFL bulb has an output of around 1500 lumens (depending on the bulb). The 23 watt CFL is often marketed as a 100 watt replacement, but that isn’t really accurate. The 23 watt CFL is not going to be as bright, because the output is approximately 15% less. The solution, buy a 27 watt CFL with an output of 1800+ lumens.

    Color – The color of the light is another of these issues that can be solved by understanding the color (temperature) of light and buying bulbs that match the color you prefer.

    Dimming – We have a lamp that has 3 settings and use a 3-way CFL bulb in it with no problems. We also used a regular CFL bulb in a fixture that had a dimmer. We never noticed any problems there either.

    Heating – I wonder if a study has been done regarding the effectiveness of using incandescent bulbs in the winter instead of more energy efficient bulbs because of their ability to produce heat. While a bulb that generates heat is certainly going to have a small impact on heating bills, is it enough to offset the additional energy used by the bulb? As mentioned earlier, lights may not be on when you need the heat the most. Also, for ceiling mounted lights you’re putting the excess heat where its least needed in most cases.

    Having said all of that, there are certainly situations where CFL bulbs are not a good solution. That was always true for incandescent bulbs as well. I’m hoping that, if nothing else, the CFL discussion raises awareness about choosing appropriate lighting for each task.

  31. In case anyone wants to do more math on incandescent vs CFLs…

    where I live, electricity is 6.3 cents/kwh
    natural gas (what I heat my house with) is 50.51 cents/cubic meter

    1kwh=3413btw
    1cubic meter of natural gas is 35375 btu

    I get $1.84 for 100kbtu electricty and $1.43 for 100kbtu of natural gas.

    I then did the math on energy consumption for 1440 hours of 13w cfl electricity + 47w of natural gas vs 60w incandescent.

    at 30 cents for a regular bulb and $1.25 for a cfl, it worked out to $5.74 total cost for incandescent and $5.72 for cfl.

    This is winter only, this would obviously be WAY the other way if I lived in Arizona.

    Also, for TCO purposes, you have to factor in replacing light fixtures if your house is like mine, where every fixture hangs the bulb upside down – CFL’s don’t like those, or it’s fully enclosed (CFL’s also don’t like those.)

    My house is about 1/3 CFL, 1/3 regular, and 1/3 “specialty” bulbs – my wife likes her fancy light fixtures that take all special bulbs. I just roll my eyes and install them.

  32. Ray,

    Your electricity is far below US average and your gas is well above average compared to US national. So for you the CFL’s aren’t as great in the winter since your electricity is so cheap and your gas is pricey.

    But what about summer? You don’t live above the Arctic circle right? In the summer you’d have no heat benefit from the incandescent so for those months you’d be looking at just 13W versus 60W of electricity.

    Electricity is 11¢ average and gas would be $11.21 / 1000 cubic feet ~= 32¢ cubic meter

    Plus you seem to be using a cost of 30¢ for an incandescent and $1.25 for CFL and assuming 1440 hours. Incandescents last half that long and CFL’s last about 5 times as long. So for 1440 yours you’d be looking at 60¢ for incandescent and 25¢ for CFL.

    BTW, your gas furnace isn’t 100% efficient so you’d have to take that into account too, which would actually raise the cost for the CFLs. I’d assume an 80% efficient gas furnace.

    Using national averages and assuming you heat with 80% efficient gas half the time then it would be like $3.63 for the CFL and $10.10 for the incandescent over 1440 hours total use.

  33. Why do people think you can’t use CFL’s upside down? I’ve not heard that and I don’t think its generally true. I have CFLs operating in every position.

    GE’s website says:
    “Can I use a CFL in any position?
    Yes, GE screwbase CFL bulbs can be used in any operating position unless there is text printed on the lamp or packaging that indicates a required operating position.

    Enclosed fixtures are usually fine too with certain exceptions.

    “Can I use a compact fluorescent light bulb in an enclosed light fixture?
    Compact fluorescent light bulbs may generally be used in enclosed fixtures as long as the enclosed fixture is not recessed. Totally enclosed recessed fixtures (for example, a ceiling can light with a cover over the bulb) create temperatures that are too high to allow the use of a compact fluorescent bulb.”

  34. @Jim, in the summer, we open the windows at night. It barely gets hot enough for the AC to kick in most days. (I love the heat, I wish it was hotter.) We’ve gone mostly CFL on the second story where possible. We also have some long life incandescent bulbs – homedepot.ca has a 4 pack of philips 60W long life (1550hours) for $1.49.

    My furnace is a high-efficiency, it’s 92%.

    My spreadsheet is old – that was the prices I was paying for bulbs 3-4 years ago when I did it.

    MY experience in MY house is that on average, CFL lifespan is no greater than the cheapest incandescent bulb. Some fixtures seem to eat bulbs, others have gone almost 10 years on the “original” bulbs.

    You CAN put a CFL in an enclosed fixture and upside down, but doing so reduces the lifespan because the base (where the electronics are) overheats. The big draw of CFL’s is that the high initial purchase price is offset by the reduced electricity costs over a longer lifespan, so if you reduce the hours down to 500 or less (I have had cfl’s that made it less than 500h in enclosed fixtures hanging upside down) then the CFL cost savings goes totally out the window.)

    My house is about 50% incandescent, 50% fluorescent (CFL and plain old tubes.) We were higher, but some fixtures aren’t compatible – dimmers, enclosures, or just plain goofy looking when converted to CFL.

    I don’t hate CFL (I use them too) I just find that they’re no magic bullet for saving (me) money – especially in the house I own. As I said in my initial post, I just do what my Dad used to nag me to do when I was a kid – I shut the darn lights off when I leave the room. :)

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