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How to Find the Right Number of Solar Panels for Your Home

As energy prices go up, you’ve probably been thinking of moving to clean renewable energy. Solar panel systems are growing in popularity due to financial savings and increased home value. But one big question still stands: “how many solar panels do I need?” Before we can give you a straight answer, there are a few things to consider. These factors include your home’s total energy usage, roof or property surface area, and available sunlight related to your geographical location.   

Homes Total Average Energy Usage   

The U.S Energy Information Administration shows that in 2020, the average annual electricity consumption for residential consumers totaled 10,715 kilowatt-hours (kWh). This averages about 893 kWh per month.   

On average, a residential home in the U.S needs 19 –23 solar panels.   

To determine your total homes energy use, gather the total (in wattage) usage for the past 12 months. You can usually find this information on utility bills. Divide your total output for 12 months by 12 to estimate the average energy usage your solar panels will need to generate each month for your household.   

Available Sunlight   

It is essential to understand how many peak hours of sunlight your geographic location receives. A peak sun-hour is defined as an hour of sunlight that creates 1,000 watts of photovoltaic power per square meter. Sun-hours occur when the sun is highest in the sky and will increase with regions closer to the equator and during the summer season.   

Peak sun-hours should be at least 4 hours in a selected region for optimal solar panel use. On average, peak sun hours are 4.5 – 6 hours in Texas, and New Mexico averages 6 – 7 peak sun hours.   

Roof and Property Surface Area  

Usually, solar systems take up between 335 and 405 square feet of roof space. If your roof has a limited surface area, you may consider higher energy-efficient solar panels. These solar panels allow you to install fewer systems and generate enough energy for your household.   

Solar Panel Production Ratio   

The solar panel production ratio is defined as the estimated energy output of a system in kilowatt-hours to the size of the system in watts. Your ratio can also be affected by how much sunlight your system receives.  

This means if you have a 10 kW system that produces 15 kW of electricity in a year, then the production ratio is 1.5. (15/10 = 1.5) U.S production ratios average between 1.3 and 1.6.   


Let’s work out an example to understand the number of solar panels your home needs.   

Your family of 4, including you, live in a 1,600 sq ft house. On average, your energy consumption totals 1,100 kWh per month, making a yearly consumption of 13,200 kWh. You have a production ratio of 1.5 kWh/kW and have a 335 sq ft solar system.   

Equation: Total panel wattage/production ratio/system size in sq ft = Number of panels needed   

(13,200 kWh) / (1.5 kWh/kW) / (335 sq ft) = 20 – 25 solar panels   

This formula gives you a way to estimate the number of solar panels your home will need, but we still recommend that you rely on a qualified local solar company to give you a better estimate of what you need. J Ferg Solar is well equipped with a solar specialist who will provide upfront solar costs and have extensive knowledge of rebates, incentives, and tax credits you can qualify for in your area.   

The First Step Is To Connect With Us.

Give us a call or use the contact form here to get in touch with a member of our team. From there, we will figure out the best course of action to get your needs taken care of.