How Many Solar Panels Do I Need?

Congratulations! You’re on your way to a world powered by clean, renewable energy. Now all that remains is determining the size of solar system that will generate enough electricity to fulfill your home’s energy consumption requirements.

To select the optimal size solar panel system for you, you must first establish the total number of solar panels required for your roof installation. This is how.

How Many Solar Panels Does The Average Home Need?

The average home in the United States will require between 21 and 34 solar panels to meet 100 percent of its power consumption. That’s at least 369 square feet of roof space required to accommodate the solar panels. This computation is based on the average monthly power usage of the US Energy Information Administration, which is 877 kilowatt hours (kWh), and assumes the system is composed of 280-watt solar panels.

While that range is typical for many houses, it is not always a number you can rely on for yours. That’s because the calculation takes a variety of things into account, including your location, the efficiency of the panels you’ve placed, and the amount of energy consumed by your home.

How Much Solar Power Do You Need?

The simplest approach to calculate how much energy you’ll require is to assess how much energy you already consume. Examine your previous utility invoices to determine your average energy use. The total kWh of power consumed is often listed at the bottom of most invoices. You’ll want to look for the phrase “kilowatt hours (kWh) consumed” or something similar, as well as the time period covered (usually a 30-day cycle).

If your statement does not include the number of kilowatt hours consumed, you may determine this by comparing the beginning and ending meter readings And then subtracting the prior value from the most recent one. Bear in mind that daily and hourly consumption is what you’re searching for here.

If your statement does not provide a daily average, divide the monthly or yearly average by 30 or 365 days. Divide that figure by 24 to obtain your average hourly electricity use. Your response will be expressed in kilowatt hours (kWh).

Once you get that number, you are nearly there. Are you ready to determine the number of solar panels you’ll require? Simply multiply the hourly energy use of your home by the peak solar hours in your location (we discuss this further below). Finally, divide by the wattage of the panel. To construct a range, you’ll want to utilize a low-wattage (150W) and a high-wattage (370W) estimate. If you have any questions about this, speaking with a solar professional will help you understand what to anticipate.

How Many Hours Of Sunlight Does Your Area Receive?

Solar panels require sunshine to function properly, which is why a home in wet Seattle vs one in sunny Austin will have very different solar requirements.

Calculating the number of solar panels you require involves knowledge about the peak sun hours in your location. The term “peak solar hours” does not just relate to the time period between dawn and sunset. Rather than that, it refers to the hours when the sun is most intense and your solar panels will be most productive. This is defined as the hour during which the sun’s intensity reaches an average of 1,000 watts per square meter.

The more peak sun hours a solar installation has, the more energy it can create. That is why a home in Austin, Texas, may generate the same amount of electricity with a smaller solar system than a home in Seattle, Washington.

Even if you live in a sunny country, the direction your roof faces and the amount of shadow you receive both impact the amount of sunshine you receive — and hence the quantity of solar panels you require. A trained solar installer can assist you in calculating these variables. For reference, the number of daily peak solar hours for each state may be seen here.

What Affects Solar Output Efficiency?

While several manufacturers of solar panels may appear to be identical, their performance and efficiency levels vary significantly. The grade of panel you select will also influence the number of solar panels required for your rooftop.

Solar panels come in a range of wattages from 150 to 370 kWh per panel. The wattage rating is determined by the panel’s size and the efficiency with which each type/brand of panel generates power, which is mostly dictated by the cell technology used.

For instance, unlike the majority of conventional panels, SunPower Maxeon cells are devoid of grid lines. This enables them to absorb more sunlight than other types of cells. Additionally, they are more durable, resisting corrosion and breaking in ways that others do not. While standard solar panels create around 250 watts per panel, SunPower panels yield 370 kWh per panel – making them the most efficient panels available in the United States.

As a result, the more effective your panels are, the more watts they can generate and the fewer panels you will need on your roof to produce the same amount of electricity. Consult your solar contractor to determine which you’ll require.