Woah, here we are at the newest, yes the second ever edition of Cheapskate Analysis. Today we will be using the power of maths, after being confronted with a series of choices, to find the one that saves us the most money!
If you’re like me, monitoring the costs of everything, you’ve noticed that LED light bulb prices have really dropped since they were first introduced. It wasn’t that long ago that you’d have to spend $50 for one bulb. Now, you can get a bulb for one-tenth of that, or less!
But are they cost effective yet?
The Answer:
Yes… and No!
First, find your electricity cost
Our utility company does not make it easy to figure out the actual cost of the electricity we use. First they divide the bill up into Supply and Delivery. Then they break those down into a dozen constituent parts. I suppose this is good for transparency, but there also is no easy, total rate to look at. I had to add up fractions of a penny to get to the actual rate:
12 cents per kilowatt hour
Our easy to use electric bill!
Actually, it was 11.997534 cents per kWh, but who’s counting?
Next, find out how much electricity your bulbs are using.
All light bulbs are labeled with their wattage, the only important number. To convert the bulbs to “math-able” kilowatt hours, we just move the decimal point a little bit. I learned this conversion with our earlier entry comparing the air conditioner to the ceiling fan.
For example, a 60 watt bulb = 0.06 kilowatts. A 13 watt bulb is 0.013 kilowatts. Et cetera.
Multiply that kilowatt number by how many hours it is used in a day (or a month, or whatever), and then multiply that number by the cost of the electricity. So a 60 watt light bulb used 4 hours per day every day calculates like this…
0.06 kWh x 4 hours a day = .24 kWh per day or 87.6 kWh per year. Then 87.6 kWh per year x 12 cents per kWh = $10.51 per year.
Easy peasy! Now let’s take a tour around the house to find which bulbs should be replaced.
Frequently Used Rooms
I am most concerned about the rooms on the first floor. The dining room, living room and kitchen lights are turned on the most out of all the lightsin the house. Let’s start in the dining room.
We’ve got some nice recessed lighting, a chandelier… What kind of wattage are these fixtures sportin’?
The flood lights are 65 WHAAAATS??? This bulb was seriously hot to the touch when I took it out. And there are five of them in the room! There is some real wattage going on in this dining room.
To replace these, I would need dimmable LED flood light bulbs, daylight style. On our favorite name-redacted shopping website, these go for $6.25 each in a pack of four.
Light Bulb Tip #1: I just found out how to choose brightness. “Daylight” rated bulbs should be used in the ceiling. Anything used in a lamp or at eye level should be “soft white” or something, so it doesn’t burn your eyes out.
In the dining room, sometimes we use the chandelier, sometimes the flood lights, but usually not both, and only after work. So since we probably have these lights on 6 hours a day, each only half of the time, I’ll say these are used 3 hours per day every day.
| Old Bulb Wattage | 0.065 hWh |
| Hours Used Per Day | 3 hours |
| Kilowatt Hours Per Day | 0.195 kWh |
| Kilowatt Hours Per Year | 71.18 kWh |
| Cost Per Year | $8.54 |
| New Bulb Wattage | .009 hWh |
| Cost Per Year | $1.18 |
| Savings Per Year | $7.36 |
| Payoff Period | 0.68 Years, or 8 Months |
These flood lights are pretty clearly energy hogs. The LEDs would pay themselves off in only 8 months. Verdict: Replace 5 bulbs
Next, what about that chandelier?
This is also a dimmable light fixture. I remember trying to buy CFL bulbs, but they just didn’t work with the dimming function, so I put it in these old school incandescent bulbs! How much electricity are these using?
Yes, that is 53 watts! Do you remember the days when this was the norm? Weird!
We would have to buy more traditionally shaped LED bulbs to replace these, which are definitely cheaper than the flood lights. I can find the dimmable bulbs for $20.99 for a six pack, or $3.50 each. Again, we’ll assume we use these 3 hours per day, every day. These “warm” lights (3000K) take only 7 watts.
| Old Bulb Wattage | 0.053 hWh |
| Hours Used Per Day | 3 hours |
| Kilowatt Hours Per Day | 0.159 kWh |
| Kilowatt Hours Per Year | 58.035 kWh |
| Cost Per Year | $6.96 |
| New Bulb Wattage | .007 hWh |
| Cost Per Year | $0.92 |
| Savings Per Year | $6.04 |
| Payoff Period | 0.58 Years, or 7 Months |
The payback period on these is even sooner! And it costs less than a dollar to use each all year. Verdict: Replace 3 bulbs.
One more light in the dining room. It’s these two oddball smaller flood lights. These are halogens and tend to burn out much sooner than the other bulbs. But they only use 39 watts.
I had to find a similarly sized LED flood light here. These small ones are 12 watts each. At $24.95 for a four pack, they are $6.25 each, but I only need two!
We don’t use these extra flood lights all that often. They are on a separate switch and basically are made to highlight art on the walls. I’ll say we use them one hour per day.
| Old Bulb Wattage | 0.039 hWh |
| Hours Used Per Day | 1 hour |
| Kilowatt Hours Per Day | 0.039 kWh |
| Kilowatt Hours Per Year | 14.235 kWh |
| Cost Per Year | $1.71 |
| New Bulb Wattage | .012 hWh |
| Cost Per Year | $0.31 |
| Savings Per Year | $1.40 |
| Payoff Period | 2 Year, 6 Months |
Ouch. The payoff on these would be very slow since we don’t use them much, and the wattage of the original bulb isn’t as high as the others. Still, these halogen bulbs suck and I want to replace them with LEDs. The only problem is I need two bulbs, not four! Verdict: Replace 2 bulbs, if I can find them in a two or a one-pack.
Living Room
We’ve got four sconces in the living room. You can’t tell from the photo because it looks like a fireball, but the sconces are these really neat inverted cones. What kind of bulbs are in there?
Uh oh! We have 11 watt CFL bulbs in there. I would be replacing them with the 7 watt LED bulbs mentioned earlier. We do use these often, I’ll say 4 hours a day, but I don’t think this is going to be pretty…
| Old Bulb Wattage | 0.011 hWh |
| Hours Used Per Day | 4 hours |
| Kilowatt Hours Per Day | 0.044 kWh |
| Kilowatt Hours Per Year | 16.06 kWh |
| Cost Per Year | $1.93 |
| New Bulb Wattage | .007 hWh |
| Cost Per Year | $1.23 |
| Savings Per Year | $0.70 |
| Payoff Period | 5 Years |
That’s a long time! It’s hard to get much lower wattage than these CFL bulbs. When they do burn out, I will replace them with LEDs, but that might not be for a while. For now… Verdict: Do not replace
Let’s go upstairs!
The exercise room. It doesn’t get used as much as it should. Because it’s the summer, right? Right? And we all like to exercise outside?
Yet more 65 watt flood lights in the ceiling! Well, I’m just going to put these at 15 minutes per day for the year. Let’s be conservative. These are the same bulbs as in the dining room, and I would use the same $6.25 replacements, but let’s see how the math works out in a room that is not used as often.
| Old Bulb Wattage | 0.065 hWh |
| Hours Used Per Day | 15 minutes |
| Kilowatt Hours Per Day | 0.016 kWh |
| Kilowatt Hours Per Year | 5.93 kWh |
| Cost Per Year | $0.71 |
| New Bulb Wattage | .009 hWh |
| Cost Per Year | $0.10 |
| Savings Per Year | $0.61 |
| Payoff Period | 10 Years |
Well, unless we start using the exercise room a lot more often, these bulbs are not worth replacing! Verdict: Do not replace.
Well, I don’t want to drag you through the rest of our house. It has many, many rooms filled with many, many light bulbs. But now I feel like I have my bases covered as far as different types of bulbs here and the potential savings by switching them out
We’ve replaced many of the old incandescent bulbs with CFLs over the years. But there are a few energy-suckers straggling around. Some of them not worth replacing right away.
But in the end, I’ve found 11 bulbs worth replacing for an estimated total savings of…
$60.74 per year
Not a ton of money, but not bad. And what do you expect for a change that zero effort on your part? A medal? $60.74 is just over $5 a month, which is how much each of our cell phones costs, or how much our Ooma home phone costs. It’s almost as much as Hulu. So, you know, it’s something. And every little bit counts.