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  • Writer's pictureSolaready PH

How many solar panels do I need for my home?

Updated: Mar 21, 2022

How many solar panels do I need?

After making the decision to go solar, the next part of the process is to determine the size of your solar panel system. So, “how many solar panels do I need for my home?” Many homeowners want to produce enough energy to eliminate their electric bill. But, to work out the number of solar panels required on your roof, you need to figure out what your goals are. Ultimately, you will be calculating your home’s energy usage; your roof’s usable surface area; the climate and peak sunlight in your area; the wattage and relative efficiency of the solar panel system you’re considering; and

Determining the energy usage of your home The first rule of home solar power is the more energy your household uses, the more energy your home solar panel system needs to generate. However, how do you know how much energy your household is using? Start by looking at the number of kilowatt-hours (kWh) you’ve consumed in the year on your past utility bills. One way to find your annual energy consumption is to add the total number of kilowatt-hours provided from the last 12 months of your utility bill. Or, simply contact your utility company and they will provide you with your annual consumption. Your average daily energy usage needed to calculate the number of kilowatt-hours your solar panel system needs to produce if you want to cover 100% of your energy needs.

How many hours of sunlight do you need?

The peak demand hours for your location will have an impact on the energy your solar panel system is expected to produce. If you researched anything about solar energy, you’ve probably run into the term “solar insolation.” Solar insolation refers to the amount of solar radiation received over time by a given surface area. It’s an important factor when calculating the size of a solar photovoltaic (PV) system. For example, if you live in Phoenix you can expect to have a greater number of peak demand hours than if you lived in Seattle. However, this doesn’t mean that a Seattle homeowner can’t go solar, it just means the homeowner would need more solar panels.

Will your panels fit on your roof? Now that you understand how much energy you’re using and the number of kilowatt-hours your solar system needs to generate, it’s time to figure out how many panels can fit on your roof and the size of your system. The first thing to account for is that solar panels can only go on a roof that faces south(-ish). It could be southwest or southeast, but due south is best. Once you know which side of your roof is facing south, follow these steps below and do the math:

  1. Multiply the square footage of your sun-facing roof by 0.75.

  2. Then, divide the result by the square footage of one solar panel, which is 17.6.

For example, let’s say you have 600 square feet of roof: 600x0.75= 450 sq. ft. Now take your 450 sq. ft. and divide it by 17.6: 450/17.6 = 25. This means that 25 solar panels would fit on your roof, which is enough for the average 6kW system!

So, how many solar panels do I need for my home?

Knowing how many solar panels you need for your home isn’t a prerequisite to saving money on your electricity bill. If you leave the calculations to Solaready, you’ll save time, hassle and gain peace of mind knowing the size of your system will be optimized for maximum efficiency. Please contact us today for a free quote and find out if your home is a good fit for solar!



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