Folks-

Does anybody have any data on how the total cost of ownership for LED lights stacks up vs. CCFL or (gasp!) incandescent. I know the LEDS are more expensive to purchase, and I know they save energy and last forever, but what I haven't seen is how much $$$ you save over time.

D

Home depot actually has a nifty little CFL savings calculator, although it's hidden deep in a cluttered flash app:

http://www6.homedepot.com/ecooptions/index.html

Hit the "energy efficient" button, then the "light bulbs" tab

According to their estimations, swapping 10 incandescents for CFLs will save you about $34/year.

Yeah, but what about LED vs. CFL? I mean I know the CFLs save money, but I'm wondering if LEDs save even more money...

Cool app, though.

i too wonder the same thing.

on this group, cafemom, that i belong to, all the crunchy moms are up in arms about how spiral bulbs have mercury in them.

led's have no mercury and if they save just as much energy, or more, then it would be obvious to swith to those, right?

I found this info...

LED Light Bulb Savings
How much money will I save by switching to LED light bulbs? Life Span & Energy Saving Benefits of LED Light Bulbs vs. Incandescent Light Bulbs Incandescent 60 Watt Light Bulb Earthtech 2 Watt LED Light Bulb Life Span: How long will the light bulb last? 1,000 hours 60,000 hours How many bulbs used over 60,000 hour period 60 bulbs Only 1 bulb Bulb cost over 60,000 hours $40.20 (60 bulbs at .67 cents each) $39.99 Electricity Usage: kWh of electricity used over 60,000 hours 3600 kWh 120 kWh Cost of Electricity: 60,000 hours at 10¢ per kWh $360.00 $12.00 Total Cost After 60,000 hours $400.20 $51.99 Total Savings: Money saved by installing one Earthtech LED Light Bulb Total Savings $348.21 per bulb! Led Light Bulb Benefits

Organicgal - I think this is a perfect time for you to introduce yourself to the "Export to Wiki" button. A classic issue with discussion forums is that this type of fantastic information can get buried in a thread somewhere and is hard to find for more novice internet users. Take a stab at clicking "Export to Wiki" on your post, it will ask you for a name for your wiki article and move your post over there (it doesn't delete it here or anything.)

That way, if other Huddlers come across it and can add more details or anything, they can add their $.02 right to it. I'm happy to do this for you, but we'd like to have real users try it out so that we can make it better. Thanks for the great info!

For sure - the next step is to get the forum to leave a notification that says something like - "This post has been turned into a wiki called LED Savings Charts"

Great job - now if other folks have ideas or contributions to those wikis, they can add away...thanks again.

Thanks for putting that in the wiki, organicgal... I just updated and cleaned up the tables... hope you like it! See Led Savings Charts

A while back I developed a formula for computing the total (tangible) cost of ownership of light bulbs, it works for incandescent bulbs, CFLs, and LED lamps.

The formula gives dollars per megalumen-hours, given:

initial-dollars: the initial cost of the bulb in dollars

watts-consumed: how much power the bulb consumes in watts

average-lumens: how much light it produces at any given time, on average over its lifetime, in lumens

thousand-hours-lifetime: how long it lasts in thousands of hours

dollars-per-kilowatt-hour: the cost of electricity in dollars per kilowatt-hour

If you understand that a kilowatt-hour is the consumption of one thousand watts for one hour, or one hundred watts for ten hours, etc., then you'll understand the megalumen-hours concept too, it's the generation of one million lumens for one hour, or one thousand lumens for one thousand hours, etc.  In other words, its a way of measuring the total light output of the bulb over time, just as kilowatt-hours is a way of measuring the total energy consumed by the bulb over time.  I chose megalumens instead of just lumens because otherwise the numbers come out like 0.00000...

dollars-per-megalumen-hours = ( initial-dollars + watts-consumed * dollars-per-kilowatt-hour * thousand-hours-lifetime ) / ( average-lumens * thousand-hours-lifetime / 1000 )

I used "average-lumens" because both CFLs and LEDs slowly lose their brightness over their lifetime, and usually the end-of-life point is chosen to coincide with then the bulb has lost 30% of it's initial brightness (so it still has 70% left).  Thus, in the examples below, for CFLs and LED lamps, I use an average-lumens value of 85% of the so-called "initial-lumens" (how bright the bulb is at the beginning of its life).  This assumes a linear fallof of brightness over time, which I can't say is actually true, but it simplifies the formula greatly.

Here are some examples (all assuming $0.10/kilowatt-hour):

60-watt incandescent bulb, 800 lumens, 1,000 hours lifetime, $1.00 initial cost:

( $1.00 + 60 * $0.10 * 1 ) / ( 800 * 1 / 1000 ) = ( $1.00 + $6.00 ) / 0.8 = $8.75 / megalumen-hour

15-watt CFL bulb, 800 lumens (680 average), 6,000 hours lifetime, $5.00 initial cost:

( $5.00 + 15 * $0.10 * 6 ) / ( 680 * 6 / 1000 ) = ( $5.00 + $9.00 ) / 4.08 = $3.43 / megalumen-hour

7.5-watt LED lamp, 800 lumens (680 average), 50,000 hours lifetime, $100.00 initial cost:

( $100.00 + 7.5 * $0.10 * 50 ) / ( 680 * 50 / 1000 ) = ( $100.00 + $37.50 ) / 34 = $4.04 / megalumen-hour

Note that the CFL does come out a little better than the LED lamp in this case, but if the initial cost were dropped to more like $75.00, the LED lamp would start to have a better bottom line.

Note also that this formula does not consider less tangible factors like the cost of frequent changing of bulbs in difficult-to-access locations, or the cost to the environment of mercury escaping from improperly-disposed-of CFLs, or the additional CO2 that is put into the atmosphere to generate the extra electricity used by both incandescent bulbs and CFLs compared to LED lamps.

Edited by bobkart - Fri, 09 May 2008 08:56:38 GMT

Edited by bobkart - Sat, 10 May 2008 01:35:41 GMT

BOB - this is a really cool way to think about this! I love it.

It even makes it relatively straightforward to calculate the price-point at which the purchase of LEDs is a totally justifiable financial decision, not just an environmental one. This is definitely another candidate for a great wiki article.

I'd like to try to apply this formula to some of the other bulbs we have in the system and see how things shake out. Thanks again - awesome!

I went ahead and threw the info into a wiki - I'd love for you to take a look and make some edits Bobkart - thanks again!

It's called "Lifetime Costs of Light Bulbs"

Thanks Deej, I did take a look and made some minor edits.

I couldn't see how to do it but you must know, could you use this image for the LED lamp in the wiki page?

http://www.ccrane.com/images/medium/geobulb-led-light-bulb.jpg

Thanks for your help!

All set Bob - in the future, if you save an image to your computer, you can embed it in forums and wikis using the little mountain range looking button from the toolbar - if you mouse over it, it says "insert/upload image", then it will ask you to browse for the file on your computer and that's it. You can even re-size it within the window.

Hope that helps - PM me if you have any questions.

Thanks Deej.

I'll try the upload thing next time I get a chance.

EDIT: Actually I guess I did that when I changed my avatar.