Customers often ask how to figure out how much solar power and batteries they need to do an off-grid solar system.
Kill A Watt Meter & Loads List
The first step to do is to create a loads list. We have a helpful load calculator tool on our site that you can use.
We’re here today to show you how to use a Kill A Watt meter to help you create that loads list. A Kill A Watt meter is a device that you would plug into the outlet and then you would plug the device that you’re trying to figure out how much power it uses into the Kill A Watt meter.
In our demo below, we show you how to use a Kill A Watt meter when you’ve got a device that uses a variable amount to power. Any device or appliance that you use in your house is going to be UL Listed. It will have a label on the back that shows you how many watts or how many volts and amps and, from that, you can calculate volts x amps = watts. So, you can tell from the label how much power it’s rated to use.
However, that label isn’t always accurate or it’s not always the same. For instance, a refrigerator will be turning on and off throughout the day, depending on if the fridge is cold enough. So, if you were to just say “alright, it’s rated a certain wattage, simply multiply that by 24 hours,” you would have probably doubled the amount of power that you actually are using.
Using a device like a Kill A Watt meter will help you get an accurate reading how many watt hours, or kilowatt hours, does this actually use in a day. From that, you can calculate out your off-grid solar system.