What Size Generator do you Need?

Posted in: Diesel Generators Engine & Drivetrain Power Outages

If you are planning to purchase a generator, you must first have an idea of how much electricity your home requires. This will help you choose the proper size. Every appliance or electronic device contributes something to your home’s total power consumption. By figuring out how much power each apparatus uses, you can get a more accurate picture of your needs.

Calculating power consumption is fairly easy as most devices indicate how many watts they use on the device itself or in the user’s manual.

The Wattage Level

If the device or the appliance does not indicate its wattage level, there are other options for determining it. You can buy a measuring device, such as the Kill A Watt. Simply plug the mechanism in question into the wattage-measuring tool and watch for the reading. 

Calculating Electrical Consumption

You can calculate your home’s electrical needs by adding up the consumption of yourindividual appliances or devices. For purposes of buying a backup generator, compute only the devices that you cannot do without. During power outages, you can disconnect those things that aren’t absolutely necessary for maintaining the health, comfort, and security of your family. By adding up the wattage consumption of essential machines, you will come up with a total number of watts.

The United States measures generator power with kilowatts (kW).  The rest of the world uses kilovolt-ampere (kVA) when they talk about generating power. You can calculate the kW consumption of your house by converting the total watts of usage you calculated earlier. There are 1,000 watts in a kW, so divide your wattage total by 1000 to arrive at your home’s kW consumption.As an example, if your devices and appliances consume a total of 350,000 watts, your consumption is 350 kW.

The kW rating of a generator is based on the horsepower of the engine. To determine kilowatts,multiply the horsepower rating of the generator’s engine by .746.  For example, a 500 horsepower generator engine has a kW rating of 373.If your house consumption is 350 kW of electricity, you will need at least a 500 horsepower generator with a kW rating of 373.