Powering Your Future

How to Calculate How Many Solar Panels are Needed for Your Home

Apr 2, 2021 9:44:47 AM / by Elise Vue


The first step in calculating how many solar panels you will need for your home is to determine what your end-goal is in using these panels. People use them for different reasons, including reducing their carbon footprint, maximizing their  ROI (return on investment,) or saving money. For many people, it is a combination of these reasons. 

There are also some factors you need to know when calculating how many solar panels your home will need:

  • How much energy does your household use
  • How much of your roof will be usable for the panels
  • What is your climate and how much peak sunlight do you receive in your area
  • What is the relative efficiency and wattage of the PV (photovoltaic) panels you are considering
  • Is net metering available in your area
    • Net metering is a system that provides owners of solar panels to gain extra revenue when they sell excess power to the grid. If your system generates more power than your household uses, in some areas, you can get compensated for the excess amount

To get a true idea of how to calculate the number of solar panels your home will need, contact the professionals at Westhaven Power and answer these questions. 

How Much Solar Power Will it Take for Your Home's Needs?

Look at your past energy bills to learn what your energy requirements are on average for your household then:

  • Multiply energy requirements in your home by the hour by how many peak hours of sun falls on your roof
  • Divide that by the wattage of the panels you've selected to calculate how many panels you are going to need
  • It will make a significant impact on how many panels you need depending on the number of hours the sun hits your roof, the size of your roof, and battery storage

 The experts at Westhaven Power can help you with these calculations.

How Many Watts Does Your Home Currently Use?

Checking your energy bill, you can determine how many watts your home typically uses in an average month. It will be listed as 'kilowatt-hours,' kWh, or something similar. This amount is generally listed for 30 days or one month. 

You want to determine what the hourly and daily watts are for your calculation process of how many solar panels you are going to need. On average, a U.S. home uses roughly 900 kilowatts a month. Your average daily usage is the target number to calculate your solar needs. You will need this number to determine how many solar panels it will take to produce that number of kilowatt-hours and cover your energy needs. 

How Much Sunlight Does Your Area Receive?

The amount of sunlight that hits your roof where the solar panels will be installed has a direct impact on the energy you can expect them to produce. If your area has less sunlight, then you may require more solar panels to compensate. 

Solar Panels Efficiency and Output

Not all solar panels are the same. The PV (photovoltaic) solar panels are the most commonly used ones for residential installations. These panels will range from about 150 watts to 370 watts from each solar panel. This wattage will depend on the efficiency and size of the panels. 

Solar cells that do not have grid lines on the front can absorb more sunlight than the conventional types and will not peel as easily. The construction of the cells makes them more resistant to corrosion or cracking. 

Because there is a wide range of variations in solar panels between their quality and efficiency, it makes it difficult to exactly pinpoint how many solar panels you will need for your home. Answering these questions will help you get a general idea, but talking to the experts at Westhaven Power will help know more about your home's needs. 

Where to Learn More About Solar Panels

Westhaven Power has been in the solar panel industry for more than twenty years. We are a trusted, highly trained, and licensed team of professionals ready to help you with all your solar panel needs. If you are considering the installation of solar panels, with our advanced engineering, we can create an estimate of how many panels you will need and answer any other questions you have about solar power. 

Tags: solar panels, Rooftop solar, how much solar do I need, home solar

Elise Vue

Written by Elise Vue