As you know, lightbulb technology is the subject of many financial blog posts. With the right lightbulb, you could see a reduction in your power bill, saving you money over time. Indeed, many of us, by now, wouldn’t even think of purchasing incandescent lightbulbs, now that the price of CFLs has come down, and you can buy them in bulk at your local warehouse club store.
But are CFLs really that much better than incandescent bulbs? And what about LED lightbulbs? How do those compare? Your lightbulb choices continue to expand, and it’s worth taking a few minutes to figure out what is your best option.
Obviously, incandescent lightbulbs are the cheapest available. You can buy a package of four 60W bulbs for anywhere between $1 and $3, depending on where you go, and how long the bulbs are supposed to last. The bulb pack I’m thinking of costs $1.49 for a four-pack, or about $0.37 apiece. However, these bulbs use more energy. Indeed, every hour, this bulb will use 60 watts — that equals 0.06 kilowatts (most power companies will charge by the kilowatt). Look on your power bill to see how much you pay. I pay about $0.09 per kilowatt. The cheaper bulbs are rated for right around 1,000 hours of light. So, I’ll be using 60 kilowatts over those 1,000 hours, at a cost of 60 x $0.09 = $5.40 per lightbulb.
Now, we get to the cost of the CFL lights. I can buy an eight pack of CFLs for $9.99, or about $1.25 for each. However, the energy use for the bulb is 13 watts per hour, rather than 60. With a rating of 8,000 hours, that means that each CFL bulb would use a total of 104,000 watts, or 104 kilowatts. That amounts to $9.36. Now, here’s where we have to make a fair comparison to the incandescent lightbulb. Sure, the lightbulb costs more in energy — but it lasts eight times longer than the incandescent bulb. You would have to buy eight incandescent bulbs for every single CFL, meaning that the energy cost for the incandescent bulbs, for the same time period, would actually be $43.20.
Clearly, over time, the CFL is going to cost you less in energy, easily overcoming the difference of $0.88 between the two bulbs. However, many people don’t feel that CFLs offer the same lighting benefits. Even if you prefer CFLs (I use them and like them), you do have to be aware that there are particular disposal concerns. And, there is a delay from when you flip the switch to when the light actually comes on.
The next incarnation of lightbulbs is the LED. Some feel that CFLs are really just placeholders. We used LED Christmas lights last year on our tree, and I noticed a a difference in the power cost. We spent $20 less (we use a lot of lights on our tree) in power for December 2010 than we did for December 2009. Of course, I don’t know how much of that was entirely due to the LED Christmas lights, since I wasn’t really keeping close track of what we were doing.
In any case, the you can buy LED lightbulbs rated for 30,000 hours for $19.95. That’s pretty hefty compared to CFLs and incandescent bulbs. However, LED bulbs only use 7.5 watts an hour. So, over 30,000 hours, it uses 225 kilowatts of power. The energy cost is $20.25. Now, since LEDs have such a long lifespan, I would have to buy 30 incandescent bulbs to match it, at an energy cost of $162 to match it. I’m going to say that you would need to buy four CFLs to get 30,000 hours, so the energy cost would be $37.44. While, over time, the energy savings would more than make up the difference between an incandescent bulb and the LED, the price on the LED would need to come down a little bit to make up its cost difference with the CFL.
LEDs, though, have advantages that CFLs don’t: They are easier to dispose of, and lighting is instant as you flip the switch. However, it’s important to note that LEDs are directional; they don’t yet light up an entire room the same way other bulbs do. However, there is likely to be some strides made in that direction, and as the price comes down, LEDs will probably become the new lightbulb of choice for long-term energy savings.
(Photo: Muffet )