LED Versus Incandescent Bulbs (An Update)

In the post, LED vs. Incandescent Bulbs, I made the following case: that for high-usage incandescent bulbs, it makes sense to replace those bulbs with LED bulbs, because the cost of the bulb (the “fixed cost”) is more than covered by the savings in electricity (the “variable cost”). I also stated my intent to start replacing the BR-30 incandescent bulbs in my kitchen with LED equivalents once they started burning out.

That event happened two weeks ago. I had a BR-30 incandescent bulb burn out in the kitchen.  I also noted as part of Halloween preparation that I had two burned-out BR-30 incandescent bulbs on the front porch. Therefore, I decided to replace all five bulbs in the kitchen with LED bulbs, and use two of the four remaining incandescent bulbs from the kitchen to replace the two burned-out bulbs on the front porch, with two spares. However, when I visited amazon.com to purchase the Philips BR-30 bulbs I found earlier this year for 19.95 each, I couldn’t find them listed. Bummer.

Later that week, on a separate errand to Home Depot, I looked through the lighting section to see what was available. Here is what I found:

Philips SlimStyle 65W-equivalent BR-30 soft white bulb, 9.5 W, 650 lumens, 2700 K

http://www.homedepot.com/p/Philips-SlimStyle-65W-Equivalent-Soft-White-2700K-BR30-Dimmable-LED-Light-Bulb-452383/205337959

It was listed for $14.97 – a better price than the bulb I found earlier this year on amazon.com, and one whose brightness (650 lumens) and color spectrum (2700 K) are even closer to those of the incandescent bulbs I have. Because the fixed price of the Home Depot bulb is $5 less than the earlier LED bulb and the power draw is 1 W less, these shift the economics even more favorably for the LEB bulb versus an incandescent bulb. Here’s how.

At 12 cents per kilowatt-hour, the breakeven for the earlier LED bulb versus an incandescent bulb occurs at 2692 hours of operation, as I mentioned in the earlier post. At the same price for electricity, the breakeven for the LED bulb from Home Depot occurs even sooner – at 1892 hours of operation. Beyond that point, the LED bulb is more cost effective than an incandescent bulb.

LED Update 1

The improvement of the Home Depot LED bulb versus the earlier LED bulb is due to two factors: (1) the lower fixed price – $19.95 for the earlier LED bulb versus $14.95 for the LED bulb from Home Depot, which lowers the “starting point” for the total cost line; and (2) the lower variable cost – the bulb from Home Depot draws 9.5 W versus 10.5 W for the earlier bulb, which lowers the slope slightly versus the equivalent line for the earlier bulb. (The earlier bulb results are not shown, but you can see them in the earlier post.) These two factors combine to reduce the number of hours necessary to reach the breakeven point.

Just as a reminder, the longer-term trend is again in favor of the LED bulb. Something I mentioned in the original post, but failed to highlight sufficiently, is that the longer-term trend of the incandescent bulb is far dominated by the cost of electricity and not in the replacement cost of the bulb. What this means is that in the longer trend it doesn’t matter if you are unlucky and your incandescent bulb burns out after 100 hours, or if you are extremely lucky and your incandescent bulb never burns out – the cost is dominated by the cost of electricity. You can tell this by the plot, where the upward “zag,” indicating a new incandescent bulb purchase, is so small c the upward slope of the line, representing the cost of electricity.

LED Update 2

From an economic standpoint, the fundamental question remains this:  Will I operate my BR30 incandescent bulb long enough to where I’ll exceed 1892 hours of lifetime operation? If the answer is yes, buy an equivalent LED bulb.

If the earlier post caught your interest, hopefully this updated analysis will inspire you even further.

By the way, I replaced the bulbs in the kitchen last week.  After a solid week of operation, I notice no difference in brightness and light quality of the LED bulbs versus the incandescent bulbs they replaced. And I didn’t expect a difference – the color spectrum is the same (2700 K, the soft white lighting I prefer) and the brightness is essentially the same (650 lumens). I’m very pleased, and I’m sure my wallet will be pleased with the decreased cost in electricity I will start seeing.

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LED Versus Incandescent Bulbs (An Update)