Last Updated: August 3rd, 2020 at 11:11 am
Read Time: 4 Minutes
When thinking about adding solar panels at your home, the first question you may ask yourself is: How many solar panels will I need to power my home? The answer has many layers to it. It’s not as easy as looking at your roof and saying, “I can fit 20 panels up there, that’s how many I need!” And it’s not entirely based on the square footage of your home either. But we have a pretty easy calculation to give you an estimate.
Before we get to that calculation, the first thing to know is that solar cannot take you off the grid. The exception is if you live in an area where there’s no grid service available. But for nearly all of us, we live in neighborhoods or areas where grid power is available.
You may wonder, why go solar if I can’t go completely off the grid? Well guess what – you still can aim to lower the amount you pay the power company as much as possible. But with the grid as a backup, you have the flexibility to choose a smaller percentage offset, or reduction, depending on your goals.
The amount of solar panels you need will depend on how much of your electric bill you want to offset. Your electric bill should show how much energy your house is using per year, allowing solar companies such as POWERHOME SOLAR to calculate how much solar energy you need.
Factors that determine how many solar panels you need
Solar is not a one-size-fits-all concept. Beyond current power usage, several factors influence the number of panels you need, including geographical location, how much sun your state gets, and how much money you want to save. Also, remember that the most amount of solar energy comes from the panels being placed on the south side of your house. But if solar panels cannot be placed there because of shading or lack of usable roof space, it is fine to place the panels on the east or west sections of your roof.
Calculating the number of solar panels to fit your home
Now that we’ve laid that groundwork, we’re on to the fun stuff! Keep in mind that even when following this formula, it’s still just an estimate. When one of our POWERHOME SOLAR representatives visits your home, their proposals give you more precise information. But this is how you can calculate your home achieving a 100 percent offset of your current electric bill.
Step 1: Review your power bill and find your monthly kilowatt-hour usage. The average monthly kilowatt-hour usage is 914, so we’ll use that for this example.
Step 2: Find the average of daily peak sunlight in your state. Because each state varies, the production and number of panels needed will fluctuate based off this number. We used North Carolina for our example, because that’s where POWERHOME SOLAR is based.
Step 3: Follow the formula below:
kWh per month / (daily sunlight average in your state * 30) = kW solar system you need
Our formula for this example will look like this:
914 / (4.71 x 30) = 6.5 kW solar system
We’ve taken the average monthly kilowatt-hour use (914) and divided by the average of sunlight received monthly (4.71 x 30) = 141.3. This gives us a 6.5 kW solar system.
However, we’re not done. Our next step is to multiply our kilowatt number by 1000, because 1kW = 1,000 watts.
Step 4: 6.5 kW * 1,000 watts = 6,500 watts.
Our last step is dividing the number of watts of the system by the number of watts one solar panel generates. POWERHOME SOLAR uses high quality 320-watt panels, so we’ll use that as an example.
Step 5: 6,500 / 320 = 20.3 Solar Panels
Ready to move forward with solar panels? Final tips
The number of solar panels you need for your North Carolina home using 914 kilowatt hours per month is approximately 20. But remember, the number of solar panels you’ll need will vary by state because of the varying amounts of sunshine. And as we mentioned before, that’s not the only factor we need to consider when calculating how many solar panels you need. The other factors (your power usage, shading, etc.) are just as important.
So have fun playing with this formula to see how many solar panels you need for your home. But remember, this is just an estimate. When you have your free in-person consultation with a POWERHOME SOLAR energy consultant, every detail of your house will be considered and over 25 years’ worth of weather patterns will be analyzed. You’ll know exactly what you can get. The fun starts when you say yes to solar.