Residential solar panels are a substantial investment for most homeowners. If you are considering going solar, you may have a number of questions about it, including how many solar panels you need to power your home.
Typically, the average solar system for a home consists of 20-25 panels, but the exact number you need depends on a variety of factors, including where you live, how much energy you typically use, and how much power generation your panels can provide.
It may seem like a lot to think about, but when you break it down it's pretty simple. Let's look at the three key factors that determine how many solar panels you need to power your house, along with an example of how to calculate system size.
Knowing how much electricity you use on an average year, month, and day is key to estimating the number of solar panels you need. Energy usage can vary widely depending on the number of people in your home, as well as the number of appliances you own and how often you use them.
Look at last year's energy bill to see how much electricity you used in all four seasons (hint: in kilowatt-hours or kilowatt-hours). Once you have that number, you'll know how much solar energy you need to generate to meet your needs.
Individual solar panels can produce a certain amount of energy, depending on the conditions of your home (including how much sunlight you receive and the amount of shade that covers the roof). This figure is called the power rating and is measured in watts, with typical panels producing between 250-400 watts. For example, you might buy solar panels with a nominal power output of 325W. You'll need to multiply the wattage of the panel by the number of hours of sunlight you get each day to get an idea of how much energy it will produce (more on that in the next section).
If you don't have much space, you may need to invest in solar panels with higher power ratings, as they are able to generate more energy for each panel.
Your physical location is a key factor in the efficiency of your home solar panel. With more sunlight, each of your solar panels will generate more electricity. For our calculations, we'll assume you get four hours of sunshine a day.
Of course, the location of your home is not something you can change, in short, when your panels are able to absorb as much sunlight as possible, they will operate at maximum capacity.
Taking these variables into account, we can make a rough estimate of the number of solar panels you'll need for your home. In this example, we'll use the average annual energy consumption, solar cell wattage, and hours of sunlight we mentioned earlier.
Suppose your property receives four hours of sunlight a day and you purchase 325W solar panels. In this case, each panel can produce 1,300 watt-hours (or 1.3 KWH) per day. Assuming your energy usage is in line with the average of 29 KWH per day, you would need 23 325-watt panels to provide enough electricity to power your home.