Understanding Kilowatts, Kilowatt Hours, and Your Solar Battery
December 20th, 2021 | By Chad McComas
December 20th, 2021 | By Chad McComas
When measuring the size of a home’s solar panel system, it is measured in kilowatts, which are units of power. That’s because homes typically need numerous solar panels to meet the homeowner’s energy goals. The amount of watts in one solar panel is typically somewhere between 300 and 400, so if you had 20 solar panels on your home, you’d have either a 6,000 watt or 8,000 watt system. Instead of saying that, we divide that number by 1,000 to get the kilowatt value. In this case, it would be a 6 kW or 8 kW system. Easier math, right?
But then you’ll see the term kWh (which stands for kilowatt-hours) on your power bill, and you may wonder what it means. This article will explain what a kilowatt-hour is, how many kilowatts of energy are stored in your battery system, and how long that battery can be expected to last during a power outage. Let’s get to it!
The difference between kilowatts (kW) and kilowatt-hours (kWh) can be easily understood in a single sentence. Kilowatts show the amount of electricity used by an appliance or generated by your solar panels, and kilowatt-hours show the amount of electricity you are using per hour. For example, if you have a 2-ton air conditioner that consumes about 2,000 watts per hour, or 2 kWh, and if your AC runs for 8 hours on a hot day, you’d be using 16 kWh alone on cooling your home. Utility companies charge consumers by kWh so they can fully charge for the energy used.
Now let’s look at this from a solar energy generation perspective. If you have a 6 kW system, and if you get an average of 4 hours of peak sunlight per day, you will generate approximately 24 kWh of energy each day. That would allow the average U.S. household to offset the majority of their monthly electric bill. Which leads us to our next question!
The average U.S. household uses about 10,715 kWh of energy annually. When you divide this number by the 12 months in a year, it averages to about 893 kWh per month. Then, dividing that monthly total by the 30 days in a month, you will see it works out to about 30 kWh as the daily amount of energy an average U.S. household consumes.
10,715 kWh a year / 12 months a year = 893 kWh per month
893 kWh per month / 30 days in a month = 29.76 kWh per day
Using the 6 kW system example above, your solar panels could offset about 80 percent of your home’s energy needs. That reduces your electric bill, and makes you more reliant on the energy your solar panels produce. What a win!
Now that we’ve covered solar panel production and grid usage as it relates to kilowatts and kWh, it’s time to figure out how a battery factors into the mix. Your battery is an essential addition to your home’s solar panel system. It keeps select loads in your home running at times when your solar panels are not producing energy. This can be in the instance of a power outage or at night when the sun is not shining. But do you know the amount of kilowatt-hours it takes to fully charge your battery cabinet?
Each battery cell can store up to three kilowatt-hours of energy. The standard battery system that Pink Energy installs for its customers comes with three cells, giving you a maximum of 9 kWh of energy storage. However, your battery cabinet can hold up to six cells, which would double the amount of energy storage at your disposal (18 kWh).
It’s important to note that having a battery does not back up every load in your home, meaning you won’t have power for all portions of your home during a power outage. However, it provides backup power to select loads that you choose to back up at the time of installation (such as a refrigerator, freezer, sump pump or outlets in a home office). The general rule of thumb is that you can back up one load for every one battery cell that you have.
Our top-selling SMARTPWR360°TM Package is an exclusive, energy-saving option for your solar panel system. The energy-efficient solutions in this package include items such as LED light bulbs, a Nest thermostat and a hot water heater blanket. The goal is to limit wasted energy, which in turn allows the solar energy produced by your solar panels to be used as efficiently as possible and potentially maximize your savings.
In sum, the terms kW and kWh may sound too scientific to understand, but not when you remember this sentence: Kilowatts show the amount of electricity used by an appliance or generated by your solar panels, and kilowatt-hours show the amount of electricity you are using per hour. Knowing the math involved will help you become a more conscious consumer of your energy, and perhaps give you a leg up on potentially saving even more money. If you want to get started on a solar energy future with us, call us today!