How Many Solar Panels Do I Need To Install? |

Please enter a valid zipcode.

How Many Solar Panels Do I Need To Install?

The number of solar panels installed on your home’s roof is determined by how much electricity you consumed over the past year – not the size of your roof which is a common misconception. A target goal for a solar panel energy system is to offset 100 percent of the cost of electricity you purchased from your utility company. To achieve this, a few different factors will need to be evaluated to determine the number of panels you will need:

  • Electricity Consumption
  • Environment
  • Size of Roof
  • Orientation of Roof

Size of Home Does Play a Role When Installing Solar Panels

The size of your home does indirectly play a role in determining how many solar panels need to be installed on your home’s roof for a 100% electric bill offset. A large house typically uses more energy than does a small one – but this is not the steadfast rule in every project. Our experts will design the size of your home’s new solar energy system by determining how much kilowatt-hours (kWh) of electricity you consumed in the past year. Check this video to find more about kilowatt-hour (kWh)


If you are contemplating building an addition onto your home or purchasing an electric vehicle in the future,’s energy experts will build these factors into the design specifications of your solar panel system. The major objective of determining how many solar panels need to be installed is ensuring a system is designed and built to offset your electricity bill by 100 percent.

Simulator for Determining How Many Solar Panels

Once your electricity consumption has been determined, our solar energy engineers will design a system specific to your home through a simulator. This simulator will take into account several variables specific to your home and locale.our-solar-engineers-at-work

  • Roof pitch
  • Roof orientation
  • Roof irradiance

Roof irradiance takes into account the latitude and weather patterns local to your area’s geography.

Based on these three variables, the simulator will determine the size of your solar panel energy system. The number of solar panels arrived at through the simulator will 100 percent offset your home’s electricity bill.

Selecting the Module Size

When the size of your solar panel system has been determined through the simulator, you will then be able to select the module best suited for your roof. If there is limited space on your roof, you would likely want to install a high-efficiency panel with high wattage, allowing you to maximize the watts per square foot on your roof. If space isn’t an issue, which for most houses it’s not, then a standard efficiency panel should be fine and will cost a bit less than a high-efficiency panel. Panels for residential solar energy systems typically range between 250 and 365 watts.

Formula to Determine How Many Solar Panels You Need

If a 5kW system is recommended by our solar energy experts, divide 5,000 by the size of the panel module. This formula will determine how many solar panels need to be installed to reach a 5kW system. Every solar panel is rated to produce a set amount of electricity – nominal power. Electricity is measured in watts and the average solar panels have a nominal power rating of 270 watts.

Our solar energy engineers utilize state-of-the-art software and satellite imagery to build a 3D model of your house. Then, they use this technology to design a customized solar panel energy system for your home.

Here is what you can expect:

  • An online simulation on production
  • Technology determining the size of your system
  • No on-site visit during the solar system design

Discover How Many Solar Panels You Need to Install On Your Home is your one-stop shop for solar energy. We will find you the most trusted and best qualified solar panel installers in your area. All fees for our remarkable online solar marketplace are paid by installers. Compare competitive solar panel quotes online and save money.

Our energy experts are available for one-on-one consultation Monday through Friday – 7:30 a.m. to 7 p.m. Call 888.454.9979 and chat with one of our solar experts for only 15 minutes – or – click the button below to find out how many solar panels you will need to install on your home.

Return to

Solar Panel Installation Process

⇠ Return