Should I upgrade my light bulbs to LED

Posted on Feb 13, 2009 by Paul White

Before you read, please be aware that much of this information may be out of date due to the rapid advances in technology. I last updated the charts and info on 4/16/2012

The main reason I decided to do the math on these household upgrades, was because part of Obama's plan is to do things like replace light bulbs in government buildings to help save on energy costs. At first I was skeptical. But then I decided to research the options for myself. I was surprised with how much this upgrade can save me.

The upgrade I am talking about is replacing Incandescent light bulbs with the newer Fluorescent Bulbs or the LED Bulbs. The problem is like most Americans when I am Lowes or Home Depot getting replacement bulbs, I usually am focused on what this purchase is going to cost me today, rather than focusing on the long term savings. After all a light bulb only costs 80 cents or so.

The Lighting Options

Incandescent Bulbs

These bulbs have been around since the beginning. They provide plenty of light and are cheap to purchase. They work by running a current across a filament that emits light as it gets hot. They can be very bright, but they also generate lots of heat. Its estimated that 98 % of the energy they consume is converted into Heat. If you live in colder climates this heat might not be a bad thing, but during the summer months your Air Conditioner will be working over time to help remove the heat these bulbs generate.

Fluorescent Bulbs

These Bulbs used to be very expensive. We most frequently associate these to what is installed into office buildings and schools. The long 48" glass tubes, that use high voltage to excite gas within the tube to give off light. These are much more efficient than Incandescent bulbs, but they still create some heat, and until recently they have not been available in more compact forms that more closely resemble incadescent bulbs in their shape. Their cost is still higher than regular light bulbs ( about 3-5 times as much ), but they use about 1/4 the energy, and convert much less of that energy into heat.

LED Bulbs

LEDs have been around for a long time, but within the past decade or so, newer more powerful LEDs have been developed that are much brighter than the older ones. LEDs also run on lower voltages ( 5 Volts or less sometimes ), and they generate almost no heat. The downside to LEDs is their light is more directional, and they don't make very much light, with the exception of newer high output LEDs. In order to make a brighter LED you have to crame many LEDS into a single package. These packages sometimes have over 50 LEDs. Also since LEDs can't run on a home's 120 Volt AC. A transformer has to step the voltage down and convert it into DC rather than AC. These cost 10x as much as regular light bulbs, Though they burn 1/20 of the power.

Calculating the Cost Savings

Since most people in the USA have a Home Depot close by I will use them as the source for our bulbs. Pricing will come off their website. Also considering that the wattage rating of 60 watt LED bulbs are so close to that of the Incandescent bulbs we are going to use the 40 watt LED bulbs for our data. The thought behind this is we are going to buy the cheapest bulb that will fit our socket for each category.

Incandescent Bulb Properties

Philips 60 Watt Household Bulb ( 4 Pack ) from Home Depot
Life: 1000 hours
Price Per Pack: $1.47
Price per Bulb: $0.37
Power Consumption: 60 watts
Light Output: 860 Lumens

Flourescent Bulb Properties

EcoSmart 14 watt (60 watt equivalent ) Soft White CFL Light Bulb from Home Depot
Life: 10000 hours
Price Per Pack: $6.97
Price Per Bulb: $1.74
Power Consumption: 14 watts
Light Output: 900 Lumens

LED Bulb Properties

EcoSmart A19 8.6 Watt ( 40 Watt Equivalent ) LED Light Bulb From Home Depot
Life: 50000 hours
Price Per Pack: $9.97
Price Per Bulb: $9.97
Power Consumption: 8.6 watts
Light Output: 430 Lumens.

Our Light Bulbs Compared

For the following charts, I am going to use our household's electric rates, and usage habits. In my office I have a lamp that is used 8 hours per day. Our Electricity costs 8.7 cents per KWH.

Daily cost of use

The equation to calculate the daily cost for each bulb is
( Watts x Hours ) / 1000 = KWH x KWH rate = Daily Cost

Bulb Type	Watts	x Hours	KWH rate	Daily Cost
Incandescent	60	8	$0.087	$0.04176
Fluorescent	14	8	$0.087	$0.00974
LED	8.6	8	$0.087	$0.00598

We also want our chart to show when our bulbs go out ( assuming they last their advertised lifespan )
Incandescent bulbs replaced every 1000 hours ( 125 days )
Fluorescent bulbs replaced every 10000 hours ( 1250 days )
LED bulbs replaced every 50000 hours ( 6250 days )
On the chart below the blips represent the purchase of a new bulb.

Light Bulb Energy Costs Incandescent vs Fluorescent vs LED

Light Bulb Energy Costs Incandescent vs Fluorescent vs LED

As you can see the break even point of going from Incandescent Bulbs to Fluorescent Bulbs happens within the first month. Break even point of going from Incandescent to LED is about 250 days. But the biggest shocker is if you are already using Flourescent lighting there is little reason to upgrade to LED. It would take you 1726 days ( 4.7 years ) just to break even.

Light Bulb Energy Costs Incandescent vs Fluorescent vs LED

In the above graph you can see the break even points for upgrading from Incandescent to Fluorescent or LED

Please keep in mind these figure do not include cooling costs due to waste heat. Incandescent Bulbs actually have a much usage cost because of this heat, however we don't have the data on how many BTUs the bulbs generate to calculate the additional Air Conditioning costs. LED bulbs may also generate slightly less heat than fluorescent bulbs, which might shorten the number of days to hit the break even point.

Importance of calculating your KWH rates

Not everyone enjoys the cheap electric rates. Some states like California have much higher rates that are 2 - 3 x our rates. If you electric rate was 2x 8.7 cents / KWH, then this would cut the number of days to break even in half. So instead of 250 days to break even with a Incandescent to LED upgrade it would only take 125 days.

In my opinion LED bulbs still have a long ways to go before they will be cost effective for household lighting. I will definitely be upgrading all the bulbs in my house to the newer compact Fluorescents.

Another reason to upgrade from Incandescent bulbs is the fact that they convert 98% of their energy into heat. During the summer months, this means that your Air Conditioner will have to burn more electricity just to compensate for the heat your light bulbs make.

How much money will it save you in 1 year?

By upgrading a single Incandescent Bulb to a Compact Flourescent that you use for 8 hours per day, you will save about $11 in the first year.

How fast will upgrading a single Incandescent Bulb to a Compact Flourescent pay for itself?
This chart should help

Light Bulb Energy Costs Incandescent vs Fluorescent

Light Bulb Energy Costs Incandescent vs Fluorescent

The upgrade will pay for itself in about 43 days assuming the bulb is used for 8 / hours a day.

After a full year of running these bulbs for 8 hours / day. CFL are still the best value. What is even more shocking is that incandescents are still cheaper ( assuming they didn't burn out more than a few times during that year ). Keep in mind that these figures do not take into account the cost for additional cooling since 95% of the energy going into incandescent light bulbs is released in the form of heat.

So when does using LED bulbs or LED chips save money?

Specialty lighting used in commercial / industrial environments is one place where LED lights can save you a bundle. Traditional Halogen bulbs even though are cheap, consume 250 watts, and only last about 500 hours. Discharge bulbs might last 2000 hours but cost $100 per bulb. The new LED chips out are bright as a 250 watt halogen, last 50K hours, and only cost $40 / each. But before you run out and try to slap an LED bulb into you club lights, its important to realize that if your fixture was not designed to run on LEDs then you will have to heavily modify your fixtures to work with LEDs. This is often more expensive than buying new fixtures.

Summary
At this point CFL are still the best bargain for home owners.

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Discussion

frank | Feb 19, 2010 11:34 PM
I feel the rate of return for LED bulbs is much lower than youre calculation even against CFL fluorescents. I figure about two and half years . Savings at 8hrs a day based on .10 cent/kilowatt is about $ 10.50per year. Plus the fact that you will burn trough about 8 CFL in the life span of the LED. If you use them somewhere were they will be turned on/off often like closet, stairwells etc. they burn out in about 2 months. LEDs I bought havent died yet under same conditions, but jury still out.The bulbs I bought were from Menards $ 24.89 on sale. I also read if used in close proxcimitry like desk lamps the high U.V. from CFL's are not good for youre eyes.

James | Apr 13, 2011 9:37 PM
I know it has been a couple years since you wrote this, but the LED bulbs are about half what you said, contain no mercury, and SHOULD not generate heat. I bought one online just to see, and it's cool to the touch but a little pinkish for my flavor although I just randomly picked one. I JUST bought one at a well known housing store and it is white but for some reason, giving off as much heat as an incandescent. The pinkish one I bought online has been on for a month straight and is still cool to the touch as if it is off.

I would recommend buying one to test before throwing money at something that may not be what you expect for an entire re-lamp. I am still "real world" testing. I DO know we put LED's, 100 watts, for a tall structure at work for aircraft and the light emitted is extremely bright... I mean extremely.

(I am skipping the CFLs)

Jason | May 9, 2011 2:35 PM
I just bought 3 60 Watt equivalent LED bulbs straight from China on ebay for about $3 piece shipped, but they are more like 40 watt bulbs than 60 Watt, I will likely hold out for $5 LEDs from Phillips or GE...might be a few years, LEDs are one product where reviews, recommendations, and reputations will matter greatly, what I like to call the 3 Rs, actually I have never called it that but there are 3 R words....but I still have 20 new CFLs to go through (acquired at $0.80 / each) I might add that the non outdoor CFLs work great in negative 20 degree 50MPH blizzards of Chicago, in a light fixture, not fully enclosed..and they last for years.

Thom | Jun 24, 2011 8:36 PM
Very interesting and informative work, thank you.
I've been using CFLs for years inside and out and do like the fact they stay pretty bright for about a year. However, if used in a bathroom or other room where you are in and out they do not not get to full brightness which normally takes at least 1-3 minutes.
And if used indoors can give some people a headache after some time especially if reading, etc.

stefen | Sep 24, 2011 10:50 PM
thanks Paul for an excellent fact based analysis; agree CFL's are most cost/energy effective today; best price for a 7w LED is about $16 in midwest for a 25K hour average lift bulb; if heat is a factor, that life may be less [don't know]; if lumen output drops over life that make bulb less of an energy saver too [means replacement before failure]...and heat generated is significant in the A bulb LED [which believe shortens its life from 50K hrs to 25K hrs]; over the next few years the cost of electric generation may increase from 12c kwh to perhaps 14c kwh; and utilities have a base cost plus kwh cost sometimes graduated -- that is the first several 1000kwh may cost more than the next higher 1000kwh...all this increases cost of operation which may shorten the brake-even point for the LED; nevertheless, the very high first cost of an LED prevents the bulb from being economically affective, unless it is on 18 hrs a day or more -- commercial uses -- exit lights, hallway and stairwell lights and similar; I have two in outdoor open bottom being tested at 12hr/day use (cost $16/ea)...will see if they last for 5.6yrs...if less they failed before their advertised 25K aver. life span which happens and make the bulb a poor purchase

stefen | Sep 25, 2011 7:38 PM
thanks Paul for an excellent fact based analysis; agree CFL's are most cost/energy effective today; best price for a 7w LED is about $16 in midwest for a 25K hour average lift bulb; if heat is a factor, that life may be less [don't know]; if lumen output drops over life that make bulb less of an energy saver too [means replacement before failure]...and heat generated is significant in the A bulb LED [which believe shortens its life from 50K hrs to 25K hrs]; over the next few years the cost of electric generation may increase from 12c kwh to perhaps 14c kwh; and utilities have a base cost plus kwh cost sometimes graduated -- that is the first several 1000kwh may cost more than the next higher 1000kwh...all this increases cost of operation which may shorten the brake-even point for the LED; nevertheless, the very high first cost of an LED prevents the bulb from being economically affective, unless it is on 18 hrs a day or more -- commercial uses -- exit lights, hallway and stairwell lights and similar; I have two in outdoor open bottom being tested at 12hr/day use (cost $16/ea)...will see if they last for 5.6yrs...if less they failed before their advertised 25K aver. life span which happens and make the bulb a poor purchase

Jason | Nov 16, 2011 8:17 PM
I'm glad to see that you updated the article(it was a while back, but was just notified of another recent comment.) Not sure if homedepot.com at the time didn't have 60 Watt equivalent, but they do now. Your comparison looks a little strange using a 40 Watt equivalent LED, and the other bulbs are 60 Watt, or 60 watt equivalent. The 60W equiv bulbs are quite a bit more than the 40W equiv bulbs, in fact the 40W equiv bulb you used in your comparison is now under $10!, but the 60W equiv are over $23.97+ as of today.

Thom | Nov 16, 2011 11:21 PM
I've checked prices at Lowe's in southern California and the 60 watt equivalent retails for $49.99 + 8.75$ sales tax. The lumens are somewhat less than the 60 watt incandescent. I have 6 incandescent 60 watt floods in my entertainment room (pink tint) and at times could use a bit more light so going with the LED flood would have less light and probably lose some of the wall reflection due to the more direct light of the LED floods. When I ran the numbers it seems it woould take 7 years to recoup the price of the initial cost vs replacing the normal floods (6 per year). Granted the electric draw would be less but would not have any effect on my bill. I replaced all my outdoor lights (100 watt x 7) with the CFL and saw no decrease in my monthly bill. Albeit only have to replace the lights once per year vs three times a year. %

Jason | Nov 17, 2011 9:38 AM
I'm surprised at no decrease with CFL, that doesn't seem right, unless you just use a lot of energy overall and the difference is small, or maybe rates went up around the time you changed the lights, but you should be saving energy for sure, especially if they are on 8 hours a night or so. In general LED lights should be purchased by people with a lot of extra money, for the purpose of advancing technology and reducing costs for the masses, as well as so the rich can feel as though they are being green and have the best, for more common people, I would recommend waiting until they are at $5 / bulb for good ones, it will get there.

Paul | Nov 17, 2011 1:13 PM
I am still waiting for the prices of LED bulbs to come down. Though I will say after switching all bulbs in our house to CFL, so far we have had 3 bulbs go bad. This is after less than 3 years of being in use. These typical bulbs were not used very often, but the ones with the highest failure, seem to be the bathroom bulbs where the humidity gets really high from showers. I remember another person saying the transformers that are built into the CFL bulbs are very unlikely to last the full life. Starting to think they are right.

Paul | Apr 17, 2012 12:08 AM
I have updated the data above. Yes I kept the 40 watt equivalent LED bulb. I figure most people are going to buy the cheapest thing on the shelves at home depot, which for the LED bulbs is the 40 watt.

Anders Hoveland | Aug 8, 2012 9:43 AM
I also want to mention that many CFL's actually consume 20% more power than their rated wattage, because the little ballast in the base of the tube takes additional energy also. That 14 Watt CFL may actually be consuming 16.8 Watts of power, while still only giving off 14 Watts of fluorescent light.

Not only that but CFL's (like all fluorescent lights) become dimmer and less efficient over time. If low quality phosphors are used, like in most of the inexpensive CFL's that were made in China, this effect can become fairly noticeable after only 8 months. But even higher quality flourescent lights become 70% dimmer towards the end of their useful lives. In other words, that CFL (or the tube by itself at least) may initially have a 50 lumens/watt efficiency, but this can quickly go down to 35 lumens/watt over the course of time.

While LED's also dim over the course of their lives, it happens at a much slower rate, and more importantly does not effect the actual efficiency, as proportionally less power is consumed.

I really hate CFL's. I can't stand them. The plain truth is that the light given off by these three different types of bulbs (incandescent, CFL, and LED) is not the same. The spectrums of their light output are significantly different. In addition CFL's can flicker at high frequencies, which may not be conciously noticable to most people, but can be extremely irritating to certain segment of the population, especially migraine sufferers and those with autism.

pete | Mar 29, 2013 3:48 PM
Its now 2013 and I just ordered 800 lumin 8watt LED by Samsung at BestBuy for $10 each.

They are so bright I need a dimmer. My Cfl or gonna for good. LED is the future and the prices are here. Walmart has a 60w equivalent by Fiet lighting for $7. These are impressive to. I switched out my whole home while the wife was gone. She still doesn't see the difference.

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