Benefits of Using LED Replacement Bulbs in a Nightlight
This past Christmas my son got this nightlight for his room. Can you tell he's a soccer player? It was a basic light that came with a traditional incandescent bulb. He used it most nights and after the last few months, it burned out.
After doing a bit of research I discovered that the bulb type was a C7 Night Light Bulb with an E12 Base (Candelabra Base). Be careful when you are shopping as it looks very similar to the old school Holiday Light base, but it's not.
Benefits of LED Replacement
There were a few reasons that I really wanted to replace the burnt out bulb with a new LED. First, being that this is a night light this bulb is on all night long. That's quite a few hours to be on every day. Maybe a light bulb isn't the huge energy hog compared to appliances, but every penny counts. Also, since it is on so long and in my son's room, I worry about it getting hot and fire risk. Typical LED bulbs don't create nearly the heat that incandescent bulbs do, and keep my nerves at ease.
After shopping around a little online I found these . They offer 50 lumens of light, and use only 0.7 watts. I've not seen the yellow looking part of the filament before in the actual bulb. I was curious how this would affect the light output, but it really seems to be doing a great job and my son loves having his light back. LED bulbs
Calculating Energy Cost
These small LED bulbs really are amazingly cheap to run. In the picture above you'll see they print an estimate for the annual cost to run this bulb. They put it at $0.07 cents a year. That is cheap, but since I'm using it in a nightlight my figures will vary.
First you have to know how many watts the bulb is using. In this case we know that is 0.7 watts. The key concept to understand is that watts are a measure of how much electricity is being used at a moment in time.
When it comes to your electricity bill the power company needs to know whether you have used the 0.7 watts for a minute or an hour. This is measured in hours. So if I leave this night light on for an hour, I have used 0.7 watt/hours. Further because a watt is a very small amount of electricity, your power company will bill you in Kilowatt/Hours. A Kilowatt is simply 1,000 watts. If you use 1,000 watts constantly for an hour, you have used a Kilowatt/Hour of electricity.
So if I figure that my son goes to bed about 9am every night and wakes up around 6am that would be 9 hours. Although I would say he NEVER remember to turn it off, so I usually do it at some point before I leave for work. Let's call that another hour. So this light is on every day for 10 hours. 365 days a year for 10 hours per day is 3,650 hours a year (Notice this is much more then the 3 hours per day estimate printed on the package).
So this means I can plan to use 2,555 Watt/Hours of electricity each years running this bulb 10 hours a day (3,650 hours X 0.7 watts = 2,555 Watt/Hours). I then need to state this is Kilowatts because that is how the power company charges me. That means I will use 2.555 Kilowatt/Hours for the year (2,555 Watt/Hours / 1,000 = 2.555 Kilowatt/Hours).
That last part of the equation is how much a kilowatt hour costs. On the package they use $0.11 per Kilowatt/Hour. I took a look at my last few bills and it looks like my average is about $0.18 per Kilowatt/Hour. That is simply taking the total amount of my final bill for the month divided by the number of Kilowatt hours I used that month. It will fluctuate from month to month, so I averaged my last three months.
So this means my final bill for running this new LED night light bulb for the year is going to be $0.46 (2.555 Kilowatt/Hours X $0.18 per Kilowatt/Hour = $0.46). Small price to pay to bring some light and joy to my son's room.