by Flack » Thu Dec 10, 2020 6:36 pm
While cleaning out my desk drawers I found my old Kill-o-Watt. The Kill-o-Watt is a device that you can plug into the wall, plug another device into, and get information on how much electricity the device is using. The Kill-o-Watt costs around $30, give or take.
By pressing the different buttons on the front of the device, the Kill-o-Watt will tell you how many amps or volts a device is using, but the reason I bought it was because it'll also tell you how many watts something draws. Divide the watts by 1,000 and you get kilowatts, which is how we get billed by the electric company. Take a device's watt usage, divide by 1,000 (to get kilowatts) multiple by 24 (hours), and finally multiply that number by your kWh (kilowatt per hour) rate to calculate how much a device costs to leave it on all day. Multiply that number by 30 and you can estimate how much it would take to run all month.
As a kid, my parents were always telling me to turn off the light in my room when I walked out. I checked my electricity bill and I currently pay $0.074 (almost seven and a half cents) per kWh. Using my formula, I determined it costs 18 cents a day to leave a light on ($5.33/month).
To expediate all that math, I created a Google Sheet with the formula built in. All I have to do is copy the formula to a new line and enter the watts of another device.
I have multiple Raspberry Pi 3s that I leave running pretty much 24/7. I plugged one of those into the Kill-o-Watt and was surprised that it was only pulling 2.2 watts. That's less than a penny per day, and only about 12 cents a month. On the other hand, the 21" monitors they're plugged into pull 50 watts each, which figures out to 9 cents a day and $2.66/month. The three monitors I leave running 24/7 are costing me close to $8/month. Not the end of the world, but interesting to know.
I also remember my dad telling me to turn the TV off when I wasn't watching it. I have an old Visio 46" in my office that I decided to test. The rating on the back says 200 watts, but Kill-o-Watt rated it at 220, which is 39 cents a day or $11.72/month. Perhaps more interesting was the fact that with the television turned off, it still draws 1.2 watts. That's only 6 cents a month and it would take a lot of those devices to affect your bill, but I still found it interesting. The PS3 I have hooked up to the TV draws another 1.1 watts while turned off. I guess these things could add up.
The last thing I tested was the portable electric heater I have out in my workshop. It's one of those 3' tall ceramic heaters. I have always heard that it takes a lot of electricity to generate heat, and that was the case here. The heater pulls a whopping 1,375 watts. That's $2.44/day or $73.26/month. I know a lot of people who sneak these things under their desks at work and leave them on year round.
One other feature the Kill-o-Watt has is average usage based on a period of time. This is good for things like refrigerators that use a lot of electricity when the motor is on, and not as much when it's off. Using the average button, it'll monitor watts over a period of time and give you the average.
I have the three monitors on my main computer set to never go to sleep and I've decided to change that based on the Kill-o-Watt's findings. Between that and the other three monitors I've been leaving on 24/7, the Kill-o-Watt will pay for itself in about two months. A lot of these things are just common sense, but I find the numbers interesting. Also, I found it interesting that my old C64 power supply used 22 watts, but a Raspberry Pi running a C64 emulator only uses 2 (and the new THEC64 only uses 4), which in theory is an argument for moving to modern technology.
While cleaning out my desk drawers I found my old Kill-o-Watt. The Kill-o-Watt is a device that you can plug into the wall, plug another device into, and get information on how much electricity the device is using. The Kill-o-Watt costs around $30, give or take.
By pressing the different buttons on the front of the device, the Kill-o-Watt will tell you how many amps or volts a device is using, but the reason I bought it was because it'll also tell you how many watts something draws. Divide the watts by 1,000 and you get kilowatts, which is how we get billed by the electric company. Take a device's watt usage, divide by 1,000 (to get kilowatts) multiple by 24 (hours), and finally multiply that number by your kWh (kilowatt per hour) rate to calculate how much a device costs to leave it on all day. Multiply that number by 30 and you can estimate how much it would take to run all month.
As a kid, my parents were always telling me to turn off the light in my room when I walked out. I checked my electricity bill and I currently pay $0.074 (almost seven and a half cents) per kWh. Using my formula, I determined it costs 18 cents a day to leave a light on ($5.33/month).
To expediate all that math, I created a Google Sheet with the formula built in. All I have to do is copy the formula to a new line and enter the watts of another device.
I have multiple Raspberry Pi 3s that I leave running pretty much 24/7. I plugged one of those into the Kill-o-Watt and was surprised that it was only pulling 2.2 watts. That's less than a penny per day, and only about 12 cents a month. On the other hand, the 21" monitors they're plugged into pull 50 watts each, which figures out to 9 cents a day and $2.66/month. The three monitors I leave running 24/7 are costing me close to $8/month. Not the end of the world, but interesting to know.
I also remember my dad telling me to turn the TV off when I wasn't watching it. I have an old Visio 46" in my office that I decided to test. The rating on the back says 200 watts, but Kill-o-Watt rated it at 220, which is 39 cents a day or $11.72/month. Perhaps more interesting was the fact that with the television turned off, it still draws 1.2 watts. That's only 6 cents a month and it would take a lot of those devices to affect your bill, but I still found it interesting. The PS3 I have hooked up to the TV draws another 1.1 watts while turned off. I guess these things could add up.
The last thing I tested was the portable electric heater I have out in my workshop. It's one of those 3' tall ceramic heaters. I have always heard that it takes a lot of electricity to generate heat, and that was the case here. The heater pulls a whopping 1,375 watts. That's $2.44/day or $73.26/month. I know a lot of people who sneak these things under their desks at work and leave them on year round.
One other feature the Kill-o-Watt has is average usage based on a period of time. This is good for things like refrigerators that use a lot of electricity when the motor is on, and not as much when it's off. Using the average button, it'll monitor watts over a period of time and give you the average.
I have the three monitors on my main computer set to never go to sleep and I've decided to change that based on the Kill-o-Watt's findings. Between that and the other three monitors I've been leaving on 24/7, the Kill-o-Watt will pay for itself in about two months. A lot of these things are just common sense, but I find the numbers interesting. Also, I found it interesting that my old C64 power supply used 22 watts, but a Raspberry Pi running a C64 emulator only uses 2 (and the new THEC64 only uses 4), which in theory is an argument for moving to modern technology.