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How to Calculate the Savings of Using LED Lights in Your Home

Posted July 27, 2013 12:00 AM by Dereklangley32
Pathfinder Tags: calculator LEDs lighting

LEDs have been sold for decades now, but even today it is rare to find households running completely on LED lighting fixtures. However, they are getting more accessible, cheaper, and more commonplace, and for good reason.

The first and most important reason for the growing popularity of LEDs is their reduced energy usage. LEDs produce light in a way that uses far less energy than other lighting technologies, like CFL. The increase in efficiency is quite high, especially when compared to old and still commonplace lights like incandescent bulbs. It could even be as high as 85 percent, and at least 5 percent more efficient than the plasma tube approach.

For instance, a single 60-watt incandescent bulb in one fixture can take up 525 kWh every year. On the other hand, an LED lamp in the same fixture and wiring setup can take up around 65 kWh per year. The reduction in carbon dioxide production is also quite high, and this is just for one bulb.

Energy efficiency apart, LEDs are also long-lasting light solutions for a household. A good LED light bulb can last for as long as 20 years without changing.

LEDs are solid state lights, which is very different from fluorescent and incandescent lights. This seemingly small difference makes LED lights last as long as 30,000 hours while incandescent lights last only 750 hours.

This extra time does come at a cost though. LED lights are generally costlier by incandescent and fluorescent bulbs by a huge margin. The average 60-watt LED light generally costs around $100, and the ones with lower outputs can cost around $60-80. In comparison, a regular incandescent or fluorescent bulb only costs a few dollars.

Does this ultimately balance out the savings you get in energy bills? Amazingly, the answer is no. even at $100 per bulb, LED lighting still saves a significant amount of money in the long run because of their long lives. Replacements are only needed every decade or so, whereas incandescent and florescent bulbs often need to be replace within a year or two. Still, the upfront costs needed for a complete switch is extremely prohibitive; not everyone can shell out thousands of dollars for a lighting change.

How much savings

There are several online LED Savings calculators that help you estimate the cost savings with full LED lighting. In general, the annual energy bill at a home can come up to more than $2,000. Out of this, around 12 percent goes for lighting online. This amounts to around $240. If you use incandescent or fluorescent bulbs, you can expect around 95 percent of the energy consumed to be wasted.

A switch to LED lights completely can cut this average lighting bill by 75 percent, bringing it down from $240 to $60. The more expensive LEDs last longer and are even more efficient (as much as 90 percent more). This can bring down the average annual lighting cost to $24.

Editor's Note: Amy is a guest blogger interested in writing energy saving related article. She mostly prefers to write LED and other energy saving electronic products.

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#1

Re: How to Calculate the Savings of Using LED Lights in Your Home

07/27/2013 7:50 AM

So, Dereklangley32 = Amy?

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#2

Re: How to Calculate the Savings of Using LED Lights in Your Home

07/27/2013 9:24 AM

Well, I have some pushback.

1. A 60 Watt LED bulb does not cost $100. The last one I bought was a Phillips at Home Depot and was under $30.

2. The published lifespan maybe a bit of a misrepresentation. The 20-year lifespan might be the time until catastrophic failure (i.e., dead bulb syndrome). It depends on the manufacture and how they rate them.

I am not clear how the latest batch of LED bulbs fare, but a few years ago I found some of the no-name Chinese bulbs are not exhibiting the same lumen output as when new. The light falloff can render a bulb useless for the task a lot earlier than the published lifespan.

As the LED lamp ages the lumen output dims, but the current draw remains the same. So you get less light for the same hourly operational cost.

3. We use a lot of LED lamps in our house, but not so much for their operational cost or long life.

Heat is the primary concern for us, as we live in Florida. My home office is small, but using incandescent lamps generates a lot of heat, which requires more air-conditioning to counter and a more sophisticated A/C zoning system to manage that heat.

Converting to LED drastically cuts down the heat in the room. We also did this in our kitchen.

4. Lastly, we also use LEDs for lamps that we just do not want to replace due to their location. For instance, our outside house lights either require a very long extension ladder or tend to burn out fast. The lamp by our garage uses candelabra bulbs and for whatever reason they always seem to burn out in a month or two. We are switching those to LEDs to see if that resolves the maintenance issues.

Commercially, the longer time between replacement for LED is something that is big business. LEDs have penetrated aircraft lighting (both interior and exterior) and drastically cut maintenance costs. For new aircraft this also cuts down on wiring weight.

The same goes for obstruction lighting on towers. Not only is a burned out light a safety issue, it is expensive to call a tower climber to replace the lamp and they usually need to be replaced at off-hours.

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#8
In reply to #2

Re: How to Calculate the Savings of Using LED Lights in Your Home

07/29/2013 9:08 AM

The loss of Lumen output is a well-known phenomenon called "droop", and is caused by overheating of the emitter. That, in turn, is a function of poor design, since a long-lived LED light will require some good heat-sinking in it's design. And the design engineering is still what drives up the cost, since the numbers currently being sold are not sufficient to bring the prices down to true volume-manufacturing driven price points.

All that said, I don't think we are far away (note my other post here, I find them at Home Depot, from Phillips and other well-credentialed manufacturers, in the Washington, DC, area, for 12$-15$) from the rock bottom price (I think it will settle around $8-$10 for all "normal" light output ranges), or much wider availability. And that will be driven by a wider acceptance, and understanding, of the value they present.

The color-temperatures are getting very close to what we expect from incandescent lamps. The longevity, with good design and heat-sinking, beats anything else available. The efficiency, as you noted, is much better than anything else on the market. They don't produce a notable heat-load on your environment, so that is an added "green" benefit.

I think they are on the way, and soon to be at very much affordable prices, given how long they last, and how little power they use.

And CFSs will go away. Boo and Good Riddance!

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/29/2013 9:11 AM

CFL. CFL. CFL!! I HATE it when I miss a spelling error like that!

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/28/2013 4:29 PM

It was reported that fluorescent light has the highest conversion rates of watts into lumens. For fluorescent tubes, it is 80-100 lumens per watt. For incandescent it is 12-18, For halogen it is 16-19, For compact FL it is 60-70, For LED white, it is 20-50. Thus we don't get extra light by using LEDs. However, the life of LEDs could be as high as 1,00,000hours as against a maximum of 20,000 hours with fluorescent lamps. Presently, LEDs are very much costlier than other luminaries, and unless the price comes down drastically, there cannot be that much future. Another problem with LED is the light coming out from almost point source, which could be a cause of concern, unless the point light is diffused effectively. If one just glances at an LED, the persistence of vision will last for some considerable time. Anyway, there should be development and tht is fraught with some risk.

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#4
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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/28/2013 4:36 PM

I think you are mistaken.

LED is more efficient than CFL. Or this Popular Mechanics link that states, "LED delivers 112 lumens per watt compared to a CFL's 50 to 70 lumens per watt."

I would like to see the source for your data that LEDs are only 20-50 lumens.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/28/2013 5:10 PM

In the plethora of info available thanks to Internet, it is becoming increasingly difficult to check the veracity . I did note the info, but the source , I cannot recollect. However Precision-paragon www.p-2.com/helpful gave some info that the output lumens per watt are almost the same for CFLs and LEDs, while the cost difference is quite high.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/29/2013 7:33 AM

"The average 60-watt LED light generally costs around $100, and the ones with lower outputs can cost around $60-80."

????????

Not in the USA. I have bought several from Home Depot, made with CREE emitters, and from very reputable supplier/designer companies, for USD12 to USD14.

So far we stick with the "60 Watt" versions (which, for reasons having to do with what a "WATT" is, and our silliness in measuring how much power something USES as a means of defining how much light it produces, is VERY inaccurate. Lumens is one correct measurement for comparison purposes.), and have been very satisfied with the light quality, apparent temperature of the light (definitive of both the warmth of the "feel" of the emitted light, and the color spectrum emitted), and the longevity of the lamps.

And our electric bill has been reduced, despite our trying to use the LED lamps in as close to the same way as we have always used the incandescent lamps they replaced.

I don't have good numbers on the usage yet, since our usage varies so widely for other reasons from month to month. But when we've replaced all the incandescent lamps in the house with LEDs (year's end, probably. Our budget is stretched thin now.), we should be able to generate some better comparison numbers.

If so, I'll report back. Certainly the LED lamp over the front door (normally replaced the incandescent about every two months due to environment, vibration, etc.) has now been running for over 8 months without a hitch. And my wife insists that any light left on in the living room overnight must be one of the LED lights. In addition, she has had me replace the ceiling fan lights with LEDs so that the vibration won't "kill" them, and she likes the light from them better than from the incandescent or CFL lamps we've tried before.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/29/2013 9:07 AM

I agree. LED has a number of advantages.

However, the title of this article, "How to Calculate the Savings of Using LED Lights in Your Home" is an absolute myth. There is no financial savings except for the next buyer of your house.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/30/2013 12:36 AM

Personally I am becoming a rather solid fan of induction lighting myself.

Granted the smaller lower wattage home use bulbs don't run at the peak efficiencies of their bigger counterparts but they have a far more natural and pleasing light output to my eyes!

http://cr4.globalspec.com/thread/84306

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 12:05 AM

I make my own LED light bars for about 5 dollars per 10 foot section using 3.2 volt LEDs producing about 18 to 27 Candela for each LED. I wire four LEDs in series adding as many branches as I deem needed for the application and power them from a 12 volt output SMT or common solar charged battery (no voltage conversion losses or related thermal losses). I also self assemble point-able assemblies using 1/2 inch end caps, elbows, and T's. I have also made a pretty nice looking lamp from an antique Native American fishing basket (without altering the physical integrity) and made very effective bench lights for soldering, reading, etc. The lights work great and provide adequate lighting. Each branch uses about 1/4 of a watt of power.

I originally designed this method for use in the third world but given the very high efficiency and low light pollution have adapted them in lighting applications for myself, my neighbors, and am currently installing a test system in the basement shop area at a remote US Forest Service Station I am currently volunteering at.

The thermal handling challenge in LED lighting is due to the voltage conversion not the LED thermal losses. When operating at a low safe voltage this is not an issue.

I have several systems that have been operating on home made dusk to dawn switches for over two years without a single failure.

Also - total luminosity per watt is a poor metric to be using for effective lighting unless the idea is to just throw light everywhere. A better measure is Candela on target. Light pollution sucks.

Tomorrow I go back up the mountain after having three days back in civilization.

I have gone about two months now without the continual bombardment of modern minutiae - I think I'm getting used to it.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 7:41 AM

"The thermal handling challenge in LED lighting is due to the voltage conversion not the LED thermal losses."

After reading all the "droop" reports, I wondered about this, as the LEDs I've used in control panels, switches, etc., never seemed to have this problem. Glad to know what makes the difference.

And "going back up the mountain" sounds great. Can I come along? I live in Northern Virginia (if you've ever been here, you don't NEED to look up "crowded" in the dictionary) and have for 33 years. My coworkers look at me like I'm nuts when I tell them the happiest week of my life each year is spent on the backside of a mountain, with my rifle over my knees, and no humans (except my wife, whom I go home to every night, and love it).

A guy in my van pool (130 mile round trip to go to work every day, another "benefit" of living here) was commenting on how weird it is to willing live where you can't just call 911 and get an answer anytime, day or night. When I told him how much of America lives at least 60 miles from WalMart he asked why they don't just get a WalMart. I like WalMart, but I don't want to live where there are enough people to support having their own. He is clueless about self-reliance, and not having Central AC.

I want to come live on your mountain. I won't bring anyone else besides my wife, I promise. Can I farm there, too?

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 10:24 AM

While not directly involved with the project, aircraft and obstruction lighting requires careful attention to heat sinking the actual LED, not the power supply (which were remotely mounted).

In situations where you have indicator lights or low lumen output it is not as critical, but as your lumen output requirements goes up it becomes mandatory to wick heat away from the LED.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 10:44 AM

Yep. Knew that. But didn't know the source of the heat was not the LED being driven, but the power conversion process.

I should have guessed, having done a bit of power supply (AC to DC regulation) design and construction, but somehow it never occurred to me that the reason LED's running off "native" <5 VDC systems didn't droop, no matter how bright they are, but "incandescent bulb replacement LEDs" did, must have to do with the onboard power control processing for the replacements, since that is the only thing added.

And LEDs, by the very nature of the emitter, don't produce heat in the emission process. So it makes sense for it to be on the other end of the "power to the light-emitter" process.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 10:55 AM

No, the high intensity LED gets hot.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 11:28 AM

Quoting Gavilan, 11

"The thermal handling challenge in LED lighting is due to the voltage conversion not the LED thermal losses. When operating at a low safe voltage this is not an issue."

I don't wish to get into an argument about this, but I wonder if I, or someone else, misunderstood this statement? Or was otherwise in error.

I truly would like to get to the bottom of this, because I am a strong proponent of LED use as replacements for all incandescent lights in my home, as is my wife. But we would both like as much understanding of the "droop" factor as we can get, including root cause.

Perhaps you and Gavilan could both help me understand this? I think we would all benefit from the clarity, regardless of the final agreed upon answer.

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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 1:39 PM

I can't speak for these home replacement LED bulbs, but when I was working for a company that specialized in lighting, LEDs required careful design and heat sinks.

One of the reasons is simply density versus lumen output. Some of these LEDs were used as strobes on wings and towers and were quite bright. Basically, they were pushing the LED technology to its limits to get high output out of a small package. They got hot, too.

I do have some 200 lumen flashlights made by Coleman that use two AA batteries. The head where the lamp resides gets pretty warm after a minute or two.

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#18
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Re: How to Calculate the Savings of Using LED Lights in Your Home

07/31/2013 2:18 PM

I have some with CREE emitters that get warm to the touch. But not warm enough to cause droop. I can see how the emitter density in an ultrabright lamp like tower lighting could cause serious problems, but what I'm trying to get a handle on is the ~850 Lumen lamps that are replacing the old standard incandescent lamps that burned 60-75 watts for the same output. I guess we'll be looking at 1100-1200 for replacing the 100 watt burners and the issue will be bigger. And I'm not in the business of engineering fix for it. I just want to isolate for myself what components are causing the problem in that specific output range.

Overdriving them is the issue, I know. That much has been determined, as has the heating that overdriving causes. But the question now is, just which components heat up the most, and thus require the best heat-sinking.

And, concomitantly, how does that link up with the fact that "singleton" LEDs, used in everything from switches and control panels to very powerful pocket flashes don't reach droop-inducing heat levels?

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