The biggest concern for people interested in going solar is usually the cost of installation. And when they inquire about it, the typical answer is it depends on the number of photovoltaic (PV) panels that the solar company will set up in your home.
But how many solar panels will you need? Ten? Twenty?
You know you need multiple PV panels, but you’re looking for a precise number.
Does the size of your home factor in the calculation? How about the number of appliances or people living in the house? If you thought of these questions, you’re on the right track.
The answer is contingent on your home’s average energy usage. With more people and appliances, that number goes up. But it also depends on other factors like geographical location.
Here’s how to calculate the number of solar panels required for your home.
First, Review Your Home’s Average Energy Usage
Look at recent electricity bills and note the number of “Kilowatt-hours (kWh) used” or something similar. Also, check the length of time represented (usually thirty days). Because your electricity usage may vary from month to month, it’s best to get the readings for several months or up to a year if possible.
Get your home’s average monthly kWh usage. For reference, the average electricity consumption of an American home is 893 kWh per month. But what you want is the daily electricity usage, so divide the monthly average by thirty (or whatever timeframe the bill uses).
Research Your Area’s Peak Sunlight Hours
During peak sunlight hours is when you can expect the PV panels to generate most of their electricity for the day. That’s why geographical location is a crucial factor. If you live in an area with fewer peak sun hours, it doesn’t mean you can’t go solar, but you’d likely need more panels.
You’re interested in knowing the amount of electricity the panels would have to produce during peak hours to meet your daily needs. To solve that, divide your home’s daily kWh usage (the number from the first step) by the peak sunlight hours.
For example, let’s assume you use 900 kWh in thirty days like the average homeowner, and the peak sunlight hours in your area is 5 hours. Your average daily electricity consumption is 30 kWh (900 divided by 30), which your panels would have to produce in a 5-hour period. That means that your panels would have to generate 6 kWh per hour for 5 hours to get to 30 kWh.
“How Many Solar Panels Do I Need?”
For the final calculation, you need to look at the solar panel output efficiency, which depends on the quality of the PV panels. Most are rated at 250 to 400 watts per panel per hour. The higher the efficiency, the more expensive they get, but you can reduce the costs thanks to various local and state solar incentives.
To calculate the number of panels, divide your home’s hourly wattage requirement by the solar panels’ watts. In our example, it’s 6 kWh or 6000 watts. If the power rating of the panels is 300 watts, you’ll need 20 panels (6000 divided by 300).
Ready to Go Solar?
Not knowing how many solar panels are needed is a common stumbling block for homeowners. But once you know the steps, it becomes easy to figure out.
Coming up with a precise number will help you determine if you have the budget for solar installation and if it’s the right time to go solar.
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