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Did you know that in early 2019, the total number of solar energy system installations in the United States exceeded 2 million?

When people contemplate going solar for the first time, one of the first things they ask is, “How many solar panels do I require to power my home?”

While this may seem to be an easy question to ask, it is really one of the final responses you will get when determining what kind of solar power system to place on your property. The first thing you’ll need to figure out is how much energy your house is presently using.

Are you thinking of installing solar panels but don’t know how many you would need? Here is how to calculate the number of solar panels needed for your home.

Calculate How Many Solar Panels You Need

It is pointless to put a single solar panel in your home! In addition, the financial advantages of a solar panel installation will need more than just that first panel.

Calculating how many solar panels you’ll need to power your house is based on three main factors: 

Annual Usage of Electricity

To get the answer to this million-dollar question, you’ll need a copy of your last electricity bill. 

Your annual energy consumption is the total quantity of power used in your house over the course of a calendar year. This figure, expressed in kilowatt-hours (kWh), is affected by the items in your house that consume energy and the frequency with which they are used. 

Some of the appliances that consume high amounts of electricity are:

  • Refrigerators
  • Air conditioning units
  • Small kitchen appliances
  • Lights
  • Chargers

The US Energy Information Administration (EIA) reports that the typical American home consumes 10,649 kWh of power per year. Therefore, it makes sense to use that number to determine the solar panel system size needed for an average home.

The Wattage of a Solar Panel

The wattage of a solar panel is also known as a solar panel’s rating power. Panel wattage refers to the amount of energy generated by a particular solar panel under ideal circumstances.

Wattage is expressed in watts (W), and the majority of solar panels produce between 250 and 400 watts of electricity. Therefore, to get a decent average, use 320 watts in these calculations.

Production Distribution

A solar panel system’s production distribution is the ratio of the estimated energy output of a system over time to the actual system size. Energy output is measured in kWh and actual system size in Watts. 

Hardly ever are these numbers exactly on a ratio of 1 to 1.  That ratio depends on how much sunlight your system gets and the change in production ratio. 

Production ratios in the United States are typically between 1.3 and 1.6. Accordingly, using those two values as a high and a low for our computation makes perfect sense!

What Are Your Power Saving Goals?

Are you thinking of offsetting, neutralizing, or receiving a quarterly credit from your utility company?

Your anticipated savings directly influence the number of solar panels you should put on your house. But, of course, there are other variables to consider, such as site and installation considerations. 

Solar panels need sunlight. Thus, places with more daylight hours, such as California, will need fewer panels to get the same effect as those with fewer daylight hours.

Additionally, certain factors can affect solar panel energy output, such as: 

  • Solar panel shading
  • The direction they face
  • The changing of seasons
  • Weather conditions

Your solar power distributor can add a little buffer to your average daily output. That buffer will compensate for these variables.

Determining the Best System for Your Requirements

You’ll need to calculate some numbers to figure out what size system you should install. For example, either 3 kW, 5 kW, 7 kW, etc.

Each kilowatt-hour of solar energy you install will generate an average of 4 to 4.5 kWh each day. So to determine the size of the system you require, divide your daily usage by 4.5 kWh.

For example, if you need 14.3 kWh per day, divide it by 4.5 kWh. This will give you 3.1, which means you will need a 3 kW system.

Your solar dealer can assist you in calculating these numbers. They can also provide you with an estimate of your planned system’s average daily kWh output. 

How Many Solar Panels Do You Need?

After deciding on the solar panel model to install, divide the total kW need by the output production of each panel. That answer will give you how many panels you will need for your home’s power.

Bear in mind that not all panels are of a similar size, both physically and in terms of output power. For example, in solar panels with a typical output of 250 W to 265 W, a 3 kW system would require 12 panels.

Solar Panel Benefits

As we know, while the sun is shining, solar panels will generate energy. What you don’t use of that power, you can sell back to your retailer. Factor this saving into your solar financial benefits.

Also, please take into consideration when your power usage is at its highest. You could do load shifting depending on where your solar panels are facing. If they face west, this increases power during the afternoon.

In this case, it would make sense for the home to concentrate usage of appliances in the late afternoon, while your power production is at its highest.

A Brighter Solar Power Future! 

Thomas Edison once said, “I’d put my money on the sun and solar energy. What a source of power!” What a forward-thinking man!

As shown above, the most precise and trustworthy method of sizing solar panels for your home is based on your own energy use. Unfortunately, however, not everyone has access to that information. 

We hope this article has helped those who are just getting started with solar research by offering reference system sizing depending on a few key factors.

If you are looking at changing to solar power, contact us, and we will help you with your solar installation.