Tuesday, December 19, 2006

Discussion of LED Lights pt 3

Some Explanations and Clarifications

Item paying for itself.
At times I refer to a light paying for itself. I will admit to being quite a tightwad, and with this statement I am comparing the light either to getting a free standard flashlight, for which I would have to pay for batteries or in the case of electric lights, comparing to getting low cost standard bulbs at my local grocery store.

LED's in battery powered items vs electric items.
In time, LED's may be economical to use as household lights, but currently that is not really the case. They are still pretty much novelties, where the cost of the LED light will only barely be covered by the combined cost of replacing regular light bulbs cost of electricity saved.

In battery powered lights, on the other hand, LED's are well worth the small investment they require, and I suspect soon they will be on every hardware and department store shelf. In battery powered lights there is a twofold gain in economics. First, batteries cost more (by several orders of magnitude) for the electricity you get, and second, LED's used with batteries don't require a power supply to convert the relatively high voltage found in your walls to the couple of volts used by the LED's. (I will talk later about the failure of one of those power supplies)

In the gray area in between commercial electric costs and single use batteries are UPS power supplies and generators. Typically these sources of electricity seem to me to be about one order of magnitude more expensive than commercial electric power (I have studied generators and rechargable batteries, but not in depth).

Economists are already starting to talk about converting to LED's. If your favorite economist or home improvement expert isn't talking about them yet, check these references from Clark Howard.
clarkhoward shownotes 2006/11/23
3rd story is "LED lighting makes a spark"

and an older reference from his archives
clarkhoward.com shownotes-category 4/100/142
look at the Jan 12, 2004 story at the bottom of the page

What I would love to see is a discussion on having a secondary set of wires installed in homes to carry, maybe 4 volts, for LED lighting.

One last note:
Ideal low battery indicators.
I mentioned that my 5-LED headlamp would be better if it had a low battery indicator. Two problems I have seen with low battery indicators are they are either too subtle, or they take some energy to run - defeating a large part of the economy of the device. I would love to see a device like this designed so a couple of the LED's would quit when the batteries are down to about 20% charge left.

I expect to do maybe two more articles in this series on LED's - and maybe include discussion of compact fluorescent lights. I welcome any discussion, especially if you have any experience with household LED lighting or UPS or generators.



Aleksandr said...

Whooo! Economics and LED reviews, I am impressed. That’s why I read you.

Although, talking in pure economic terms, LED's aren't as financially good as you would think. Because in the real world the larger initial outlay for the LED would reduce your long term savings in LED’s due to present value of money.

Meaning that if a regular light costs ten bucks and the LED twenty, then the ten bucks you saved, would be worth more now then the savings you would make later.

Obviously, this is not a perfect economic world (no one actually invests the savings), so the LED's become economically advantageous.

TRex said...

Hmmmm, do I detect some sarcasm in the statement "That's why I read you" ?

I do thank you for pointing out about including inflation in the calculations for ROI - I had forgotten that. Do you think 4% is good?

I do respect your knowlege of many aspects of politics and economics, but technology and microeconomics is one of my favorites, and I will put myself against any layperson (and most professionals) in this field.