And Let There Be Light!

Or I could’ve simply named the post ‘Saving money by selecting the right light bulb’!

Once upon a time, selecting a light bulb was as simple choosing a 60 watt or a 100 watt bulb, depending upon how bright you want the bulb to be. There was one popular size, you screw in the bulb and you were done!

But light bulbs have come a long way. In case you haven’t heard, incandescent bulbs (the one’s we are all familiar with!) are being phased out. There are a lot more choices now and and bulbs come in a variety of types, shapes and sizes.

There are three competing technologies when it comes to light bulbs.

The technology of the past: Incandescent bulbs
The technology of the present: CFL bulbs
The technology of the future: LED bulbs

Before we get into specifics, here’s a handy cost-benefits table to help you decide which one is the right bulb for you. I’ve used a standard A19 bulb for comparison.

Standard A19 'Household' Bulb INCANDESCENT BULB



Cost per bulb$1.66$3.77$14.50
Lifespan (at 3 hours a day)333 days4.56 years27.39 years
Pros & Cons Cheap, dimmable, instant start and highly inefficientIsn't entirely eco-friendly as it contains small amounts of mercury vapor, not dimmable, delayed startExpensive, highly efficient, eco-friendly, long lasting and heavy!
Energy cost per year (at 10c/kWh)$6.57$1.42$0.77
Replacements30 Incandescents = 1 LED
5 Incandescents = 1 CFL
6 CFLs=1 LED
Total Savings**If you replaced an Incandescent with a CFL, over the lifetime of the CFL (5000 hours), you'll save $31.35

If you replaced an Incandescent with an LED, over the lifetime of the LED (30000 hours), you'll save $214.01
If you replaced a CFL with an LED, over the lifetime of the LED (30000 hours), you'll save $25.88

*Includes energy and replacement costs.

One caveat about bulb lifetime. I’ve used total lifetime hours for calculation. In reality this will be much less as each time you turn on your bulb, there is an impact on the life of the bulb. Voltage fluctuations too play a role. Also, even the most expensive bulbs don’t carry lifetime warranties. So take in these figures with a little bit of skepticism!

The Technology Behind Light Bulbs

A lot of progress has been made with light bulbs and we are finally at a point where we can phase out incandescents. Let’s take look at the technology behind these bulbs.

Incandescent Bulb

incandescent bulb

This is the bulb that Thomas Edison invented. It hasn’t changed much in its working principle. When current passes through a metal filament (usually Tungsten), it gives out heat and the side effect of the heat is light. It is encased in a vacuum (or with an inert gas) glass bulb. Otherwise the filament would react with oxygen and burn out.

If you are wondering why Incandescent bulbs are being phased out, it has to do with its poor energy efficiency. There are better choices today.

In a nutshell:
Least expensive among bulbs

Consumes a lot of power compared to CFLs and LEDs

Very short life

Highly inefficient


All incandescents are dimmable

Start time
No warm-up time delay

Compact Fluorescent Lamp (CFL) Bulbs

CFL bulbCFL bulbs work on a different principle than incandescent bulbs. CFL bulbs have mercury vapor and coated with phosphor which is activated by a magnetic or an electronic ballast which produces light.

CFLs last 5 to 15 times longer and consumes only 20%-33% of the power that an incandescent bulb consumes. Though they are much more energy efficient, these bulbs are not eco-friendly due to the presence of Mercury. CFLs require special disposal and should not be discarded with regular trash.

CFLs are also more expensive than incandescent bulbs.

In a nutshell:
CFLs are cheaper than LED bulbs

CFLs consume much less power than incandescent bulbs

They last 5 to 15 times longer than an incandescent bulb

CFLs are more expensive than incandescent bulbs

CFLs are not eco-friendly due to the presence of mercury

The light output is determined by the surface area of the phosphor coating (that’s why CFLs are never transparent). Hence a larger output would mean a larger bulb

CFLs don’t do well with dimmer switches and require special circuitry to achieve that. Even with that, they don’t dim as gracefully as incandescent bulbs

Start time
CFLs have a start time delay and some may have an initial flicker. They also take a few seconds to warm up to their full potential.

Light Emitting Diode (LED) Bulbs

LED bulbLEDs are probably where the future of light bulbs are headed! They have all the advantages of an incandescent bulb and power efficiency of CFLs and last a lot longer! LEDs are called solid state devices (no filaments).

As you saw in the energy comparison table above, to emit equivalent light of a 60 watt incandescent bulb, an LED bulb only requires 7 watts! The higher the wattage, the bigger your electricity bill! And an LED bulb lasts 30 times longer than an incandescent bulb.

The first thing you’ll notice about an LED bulb is that it is heavy! The bulb has metal heat sinks to absorb heat which helps in extending the life of the bulb.

In a nutshell:

LEDs consume much less power than incandescent and CFL bulbs

They last 8 to 15 times longer than an incandescent bulb and 4 to 5 times longer than a CFL

Very eco-friendly

Looks futuristic due to metal heat sinks engulfing the bulb. Also heavy to hold

Technically LED bulbs are dimmable, but in reality, they don’t do well with traditional incandescent dimmers. Use dimmers marked specially for LED bulbs

Start time
Instant ons

Selecting a Light Bulb

With three different technologies with different energy requirements, you can no longer rely on just watts to select a light bulb. You have to deal with lumens and kelvins now!

Lumens measure the brightness of a bulb. The higher the lumen rating, the brighter the bulb.

A 60W incandescent bulb is approximately 800 lumens. Use that as a reference when purchasing LEDs or CFL bulbs

Color Temperature
Light bulbs: color temperature (kelvin)
You can also set the lighting ‘mood’ by choosing the color temperature, expressed in kelvins.

An Incandescent has a color range of 2700K to 3000K.

As the picture to the left shows, the phrases warm white, cool white, soft white etc., can actually be expressed as numbers.

This measures energy consumed. The higher the wattage, the more your electricity bill!

Common Bulb Shapes

One other thing you should know about light bulbs is that each shape has a code. Usually a letter or a series of letters followed by a number.

The letter is a hint to the shape of the bulb and the number is the diameter of the largest part of the bulb expressed as eighths of an inch

Here are some common bulb shapes and sizes and their codes:

A19 – Standard bulbs with a maximum diameter of 2.375 inches (stupid imperial system)

PAR30/PAR38 – Floodlights.

What is the difference between PAR 30 and PAR 38?

PAR stands for Parabolic Aluminized Reflector and a PAR30 has a maximum diameter of 3.75″, whereas a PAR38 has a maximum diameter of 4.75″. These bulbs are normally used in recessed light fixtures and knowing the diameter helps since if the bulb is larger than the fixture you won’t be able to change the bulb even though both bulbs have the same base.

Normally, PAR30 is used indoors and PAR38 bulbs can be used both indoor and outdoors. Normally, not always! Check the label. You also have dimmable and non-dimmable types in these configurations. Look for those as well as dimmable bulbs are more expensive.

A Note About Dimmers And LED/CFL Bulbs

One thing you can take for granted in an incandescent bulb is dimming. Not so with LEDs or CFLs. By default, LEDs and CFLs are not dimmable. If you are replacing incandescents that have a dimming switch, you need to buy special dimmable version of CFLs and LEDs.

It is better to also replace your old dimmer with dimmer switches that are specially made to work with LEDs and CFLs. I had varying luck with my old incandescent dimmer. It sort of dimmed my dimmable CFL bulbs and didn’t dim my dimmable LED bulbs at all! Once I changed the dimmer as well, they dimmed pretty well.

Incandescent Dimmer

LED/CFL Dimmer

Incandescent Bulb Phaseout

Incandescent bulbs are being phased out beginning Jan 2012. The bipartisan bill, EISA ( Energy Independence and Security Act ), was signed by President George W. Bush in 2007.

Here’s what you need to know:

  • Beginning 2012, 100 watt incandescent bulbs cannot be manufactured or imported into the US
  • The next to go will be 75 watt incandescent bulbs beginning 2013, and 40 and 60 watts beginning 2014
  • The stores will still be able to sell incandescent bulbs till their stocks run out
  • Technically, there is no ‘ban’ on incandescent bulbs. You are not required to throw away your existing bulbs and if you find incandescent bulbs in stores, you are free to buy them

My Thoughts

Even though newer technologies like CFLs and LEDs have been around for quite sometime now, it took a while to perfect them and make them affordable. A number of countries have already banned incandescent bulbs. It is sad, this has become a political issue here.

A wider adoption of CFLs and LEDs will bring down the price rapidly and this can only happen when cheaper alternatives like incandescents are phased out.

Did you know that a bulb installed in 1901 is burning even today at the Livermore fire station in California?

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50 thoughts on “And Let There Be Light!

  1. Sweet post. I always wonder about the “cross-over point” on one lightbulb vs. another. This clarified it. I have yet to buy an LED bulb. Is the light from an LED substantially different, like it is in XMas ornaments?

    If you weren’t such a good blogger, I’d tell you to go work at the Home Depot lighting department. You might not get rich, but you’d make guys like me with tons of lighting questions happy.

  2. I switched over to CFLs a couple of years ago. I think I save $5-10 per month. By now it has more than paid for itself.

  3. Wherever there’s a law, there’s a loophole. This guy is selling incandescent bulbs designed for ‘rough use’, which are given an exemption to the law:

  4. This is some really complete information on light bulbs. I’ve heard of LED bulbs in car running lights and TV’s but didn’t realize I could purchase them for my home lights. They do seem a bit pricey, but their life expectancy makes them much more affordable. Once my CFL’s die out, I’ll have to invest in the LEDs.

  5. Great info. I wonder about the life expectancy and dimmability (word?) of the LED. Are there improvements in the next several years that will make these dinosaurs?

    • That is a good point DIY! Since LEDs don’t have a filament, they don’t conk off like incandescents. The lose their brightness gradually. Hopefully as the price comes down, the technology improves as well.

  6. Great post MC. It was very advantageous to switch from incandescent light bulbs to CFL. We got so much more light, which was huge for us. To be honest, I am aware that it saves money but that wasn’t my main concern. I do like that it is greener though, just like you said. Also, thank you for pointing out the dimmer issue. I wasn’t previously aware of that. Good analysis @MC!

  7. Thanks so much for such an informative and educational post. It is very useful and hope many readers find it through web searches.

    We are currently using CFL’s because the LED technology still isnt’ where it needs to be. Plus they are really expensive. I am hoping this changes soon.

  8. I have heard that old light bulb story before, actually. Pretty amazing!

    I’m assuming your lifetime cost savings don’t account for inflation? Would make a difference over a 27-year lifespan of the LED bulb, but good savings are still there.

    I’ve already got 100% CFLs in my apartment, and I’m interested in LEDs but the cost is just too high. I hope the price comes down and fast!

  9. I just put some CFL’s in our cathedral ceiling recessed lht fixtures. I figure, even though it doesn’t look that great, they are so high up, I didn’t want to change them again for a long while.

  10. I would continue to use my incandescent and CFL bulbs for as long as they work and wait for the LED prices to come down from current level.

  11. I wish I could get my CFLs to last for four years. Some of them are OK, but others just don’t seem to go any more than about a year. I need to keep better track. So far, I am not all that impressed.

  12. I disagree with a government issued phase out. If the other bulbs are so great then regular bulbs will phase themselves out, it doesn’t take an act of congress to get a product off the shelves.

    Excuse me, I have to go I rewind the tape in my walkman.

    • Ashley, I think the first part of your comment is serious (right?)

      I’ll assume it is and say they’re not phasing incandescent bulbs out because the new bulbs are just “better” in terms of a product. They’re outlawing the bulbs that are more harmful to the environment (at least in terms of the energy they require to use them).

      I would liken it to the banning of leaded gasoline. Unleaded gasoline isn’t “better” as a product, it’s simply much, much less harmful in terms of the air we breathe (and airborne lead has dropped by 90% since the ban was enacted).

      • Invalid comparison. Leaded gasoline directly harmed others and either a ban or a surcharge was an appropriate response. Incandescents have no direct harmful impact on others. Sure they use electricity, but so do 1000 other things.

        It’s up to the consumer to make that choice and if there is a problem with the way that the electricity is generated, that’s a problem that should be addressed at the utility level. Attacking incandescents is the wrong scope and harms me as a consumer, as the light given off by CFLs makes me physically ill.

    • To add to Jeffrey’s comments, think about electric and hybrid cars today. There are incentives to buy clean fuel vehicles (like tax credits, use of car pool lanes, free parking at metered parking spots etc) which makes adoption of these technologies more widespread which makes companies put more resources on developing more efficient engines.

      The government plays an important role by offering these incentives and steering development.

      The first hybrid rolled out in 1917 by the way. By no means a recent invention! But since there was no incentive to develop this further it took almost 90 years for car companies to get back to this technology!

      If there are no incentives to further develop LEDs or CFLs, companies in China will continue dumping $0.99 bulbs in the US and people will continue buying them.

      The technology is there, for it to become more affordable, more people will have to adopt them and what the bill does is to hasten this adoption.

  13. I need to stock up on more 60W incandescent bulbs. I use two of them in reflector lamps to heat the water pipes in the well house, to keep them from freezing in cold temps. CFLs and LEDs are useless for this application.

    • Funny you should mention this 101C! Most traffic lights in major cities have been replaced with LED lights and the biggest complaint is that when it snows, the heat produced is not enough to melt the snow that accumulates! This wasn’t an issue with incandescents. I do not know if or how they solved this issue.

  14. Great post MC, the led bulbs are too expensive for my taste and the CFL ones need a few seconds before they produce maximum light. Will stock up on those Incandescent as I think Canada as well has a phase out plan. Right now 50% of my bulbs are CFL, until the technology improves I don’t think I will hit the 100% mark soon.

  15. Happy New Year MC! Oh wow I didn’t know they are actually phasing out Incandescents this month. I use CFLs in most places and measure the size of my current bulb before I go to the store now b/c I’ve had to return a few in the past because they were too big to fit. That’s cool that LED bulbs are coming out and that they don’t have the toxins that CFLs do. -Sydney

    • Size is a big issue with CFLs. The surface area of CFL is directly proportional to its power. Hopefully a solution will be found soon.

      Happy new year to you too Sydney!

  16. This is a great, comprehensive post, Money Cone! I personally hate CFLs and I’d only use them in a garage or a place like that, and I think that a ban on incandescents is retarded. Controversial viewpoint? Maybe, but consumers will switch when they decide that it’s worth it. Maybe I prefer the light quality of incandescents, and maybe I don’t mind the heat they throw off cause it’s cold where I live ;)

    • Technically there isn’t a ban on incandescents. In fact the bill does not even mention incandescents. The bill require bulbs of certain wattage to produce a certain amount of light measured in lumens.

      If some innovative company can manage to do that, incandescent will continue to live on!

  17. I have one LED desk lamp. We actually use it as a baby light and I like it a lot. Most of our other bulbs are CFL and I’m happy with them too.
    Hopefully the LED bulb will get cheaper soon.

  18. Your wealth of expertise never ceases to amaze me. Thanks for “enlightening” me. :) Happy New Year!

  19. I love innovation and competition to bring down the price. I’m not an “early” adopter, but a medium-term. I’m finally buying an iPad3 in the spring, and I’ll buy more efficient bulbs after they come down further in price. I’m not too worried about losing a few bucks over the next year in electrical costs vs paying an arm and a leg now to be the first one to have the hottest new bulbs.

  20. What a detailed post! I hadn’t realized the difference between the types of bulbs. Definitely a reference article – thanks!


  21. Great, comprehensive post. The numbers that jumped out at me were related to LED bulbs: 27.39 year lifespan? Wow! Buy one, and you might not have to get another until you have grandchildren…

  22. I’ve heard of LED tvs but I never knew that I could buy an LED lightbulb. I’m definitely all for paying up front for cheaper energy usage and lower longterm costs. Replacing those other bulbs could make the costs even out over time.

  23. I should go for the LED bulbs, but every time I need new bulbs, I reach for the mid-priced CFL. Oh well, I’m still getting some energy cost savings!

  24. I too am going to use my CFL’s until they die (in a few years). At this point, I may consider getting LED’s, especially if the price goes down a bit more.

  25. I appreciate your comprehensive presentation on the three bulbs. I have to confess that I’m an early adopter. Our house doesn’t have many IC’s, in fact the oven and fridge are the only two I can think of. I like the new bulb style LED’s that disperse the light better than the highly directional spots that were first available. I have a 4.5 watt LED out front above the garage, and I keep it on all night without stressing about the power bill…not that the CFL it replaced kept me awake. Sorry, rambling here.

  26. Interesting! We use the middle light bulb in most of our home lamps. I always wondered how much we are actually saving and if those bulbs are really that eco-friendly. Now I know! Great comparison and explanation. It made me thing that maybe we need to switch to the more expensive one.

  27. I am going to start hoarding incandescents. CFL bulbs are horrendous- I think many couples may break up when they see what their significant other really looks like in that horrible CFL lighting…

    I don’t know as much about the LED bulbs, but if the lighting is like the CFLs, then all the more reason for me to start raiding Home Depot and Lowe’s.

    • Loved this reply! I do believe that LEDs are much better than CFLs at color spectrum reproduction. There is a reason why the CFL lighting is horrible — the color spectrum is very unnatural and spiky. I go into more detail in a followup post I published today.

  28. As rising energy costs and environmental concerns become increasingly important factors in consumers’ and businesses’ purchasing selections, fluorescent lamps and CFLs are an ideal solution. CFLs emit approximately the same amount of visible light as incandescents, but they last 8 to 15 times as long and provide significant energy savings. The use of more efficient lighting options, such as CFLs, is one of easiest and lowest-cost ways for the nation to reduce electricity use and greenhouse gases. However, these lamps are fragile and, upon breaking, they release mercury vapor that can be detrimental to handlers’ health—from those involved with handling new bulbs to people involved with storing, packaging and shipping used lamps.

    Mercury-containing lamps need to be recycled properly. Fluorescent lamps should be taken to a recycling center or placed in one of a variety of containers that are marketed for transportation of fluorescent lamps and CFLs, however, many don’t provide sufficient protection against mercury vapor emitted from broken lamps. Using a proven packaging design is vital to ensuring the safety of people who handle these lamps, as well as maintaining their green benefits. Read about a recent study that tested several packaging configurations here:

  29. So the cost of LED’s has come down. I started getting CFL bulbs as early as 1991, when they were much bulkier and more expensive than they are now (and were better built). During most of the 1990s and 2000s, I was virtually 100% CFL. They did run cooler, and most of the time the bulbs did last longer.

    However, they were not perfect. As early as 2008, I started watching LEDs. Back then, I decided against them as they were still very expensive. Also, the light output was much lower. But that changed, as LED technology got better. So, just as the 100 watt incandescent bulbs were going out, I got my first LED.

    At that time, they were the snow cone style. Which worked fine with me, since the lamp was intended to put out light into the room from above. Less wasted lumens meant more usable light where I needed it. The only down side was the weight of the bulb. Later in 2012, I got several more LEDs, and placed a few in fixtures where they were mixed CFL and LED (more than one bulb). And that was the end of the CFL for me, as the light of the LED was much better.

    For those still holding out, technology has improved more. EcoSmart makes good LED’s–their bulbs now look something like a flying saucer when turned on, and work real good even if the plastic lens feels a bit cheap. Cree makes good LEDs, and their new bulb is low priced, yet looks like the old incandescent at only 9.5 watts for a 60-watt replacement. The Switch bulb works in enclosed fixtures but is very expensive.

    I do not regret moving to LED’s. Especially since I learned that CFL bulbs emit styrene, phenol, and naphthalene when working properly. I also learned that they emit dirty electricity that can ruin electronics and is bad for your health, their isolated blue is bad for your health, they cannot be turned on and off frequently for additional savings, they emit UV-C light (not the UV-A and B found in sunlight), and they often fail with a fire. I also do not miss the heat generated by incandescent lights, which makes extra work for the air conditioner and can ruin fixtures. Good riddance to both, especially those death bulbs (CFL).

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