Understanding how electricity load works

If you pay an electric bill, then you have an electrical load. Understanding how to calculate electrical load helps to explain your monthly electric bill and provides actionable information that can help you reduce how much you spend on electricity each month. And in the age of innovative utility rate structures, such as demand charges and time-of-use rates, and increasing electrification of homes, with air source heat pumps and electric vehicles becoming more popular, knowing how to calculate your electrical load can you help you determine how much you could save from a solar or solar-plus-storage installation on your property.

At its core, an electrical load is anything that consumes electricity. In fact, from a technical perspective, electrical load has a very specific definition: it is the part of a circuit that consumes electricity.

Technically, a number of components of a circuit could act as an electrical load. However, as a homeowner, you only need to focus on your electrical appliances and applications: your electrical load is determined by any electrical applications in your house–from lights to toasters to washing machines to electric vehicles.

Importantly, electrical load is a measure of power: how much electrical output is required to actually run any appliances in your house. However, electrical load impacts the energy you consume, i.e., how many kilowatt-hours of electricity you use each month, a value that appears on and determines your electric bill.

Perhaps the best tool for calculating your electrical load is offered by the US Department of Energy. Their Energy Appliance Calculator allows you to enter individual appliances to see the average power requirement for that type of appliance, as well as to then see how much electricity you would consume–and how much it would impact your electricity bill–if you were to turn on that appliance for a certain number of hours. To calculate your electrical load, you can add the total Wattage for each appliance and see your household’s total cumulative electrical load.

The electrical load of your property can play two separate roles in your monthly utility bills:

First, if you are on a demand charge rate, your monthly bill is determined by the maximum amount of power you require from the grid during a single hour within a month. As such, calculating the electrical load of all of your appliances can help you determine how high the demand charge might be at the end of the month. What’s more, knowing how much power each appliance requires can help you reduce the magnitude of your demand charge by helping you determine which appliances to avoid turning on simultaneously. Planning carefully allows you to drop your maximum monthly power requirement and save money on a demand charge-based electric bill.

Second, and more importantly to most homeowners in the country, the amount of power an appliance needs to run is directly related to the amount of energy that appliance consumes, which ultimately impacts your electricity bill. For instance, turning on a television with an electrical load of 230 Watts for five hours would consume 1,150 Watt-hours, or just over one kilowatt-hour, the unit used to calculate your utility bill. Understanding the large role certain power-hungry appliances play in your monthly electricity consumption can also help you reduce your electricity bill.

Understanding your electrical load is essential to appropriately design a solar or solar-plus-storage system for your home. Knowing how much electricity you consume and why you consume that electricity allows you to size a solar panel system to cover 100 percent–or more!–of your present and future monthly electricity usage. Additionally, if you are considering adding storage to your solar panel installation, knowing how much power each appliance requires can help you determine which energy storage option can provide you with enough backup power to run all your important appliances for extended periods.

With EnergySage, it’s easy to directly compare your electricity bill to your possible savings from solar with our free Solar Calculator. Ready to take the next step and meet your property’s electrical load with solar energy? Register for the EnergySage Marketplace to receive up to seven free quotes from local solar companies today.