How Many Solar Panels Do I Need to Power My House?


Powering your home with solar energy offers many benefits. You’ll be able to shrink your utility bill, reduce your carbon footprint and have peace of mind knowing you’re contributing to the planet’s well-being. 

If you’re just diving into the world of solar energy, you may wonder, “how many solar panels do I need to power my house?” 

There’s no simple answer, as it requires looking at factors like your energy consumption, location, panel wattage, and more. 

Keep reading to learn how to calculate the number of solar panels you need for your home. 

3 Variables That Determine the Number of Solar Panels You Need

Three primary factors affect how many PV panels you need in your solar array. Let’s take a look at each in more detail. 

1. Annual Energy Usage

Your annual energy usage measures the amount of electricity consumed in your household in a year. You’ll need to pull out your past electricity bills and review your energy usage for the last 12 months to figure out this number. 

Electricity consumption tends to fluctuate dramatically over the course of a year — especially in areas that use electricity for heating or cooling. Just looking at a few monthly bills might lead you astray and leave you short of the capacity you need.

For reference, the average US household has an annual energy consumption of 11,000 kWh of electricity, which equates to 893 kWh monthly or 30kWh daily. 

2. Solar Panel Wattage

The panel’s rated wattage measures the electrical power output. The higher the rated wattage of the photovoltaic (PV) panel, the more energy it can produce. Panel wattage is one of the most crucial aspects you need to get right when putting together your solar power system. Overestimating the wattage you need can mean overspending, and underestimating the number will lead to insufficient power production. 

3. Solar System Production Ratio

The solar system production estimates the amount of energy an array will produce (in kWh) divided by the total wattage. While you may think there would be a 1:1 ratio, that’s not the case. A solar panel’s rated wattage indicates the maximum amount of power it can produce under ideal environmental conditions. Hours of peak sunlight, shade, tilt, temperature, and other factors will all impact how much energy your panels actually produce.

How to Calculate How Many Solar Panels Your Home Needs

Calculating how many solar panels are necessary for your home is the first step to planning your renewable energy system. 

1. Estimate Annual Electricity Usage

The more electricity you consume, the more panels are necessary to supply enough electricity. 

Check out your monthly energy usage to get the most accurate estimate. Since energy usage fluctuates depending on the season, reviewing a single monthly electricity bill may not be the best choice. It’s better to calculate all the bills for a year, if possible. 

2. Determine Solar Panel Wattage

The power rating determines how much energy the PV panels produce under ideal environmental conditions. The higher the wattage, the fewer panels are needed for your home. 

Most residential solar panel options, like the EcoFlow Rigid Solar Panels, range from 100 to 400 watts per panel.

3. Find the Solar Production Ratio for Your Area

Calculating the solar production ratio is quite complex and requires factoring in the shade, panel orientation, tilt, system size, and more.

Most production ratios are between 1.3 to 1.6. If you don’t know the solar production ratio because you haven’t yet decided how many panels you’ll purchase for the array, you can choose 1.6 as a safe estimate. 

4. Work Out How Many Solar Panels Are Needed

Once you’ve got your annual electricity usage, the panel wattage, and the solar production ratio, you’re ready to work out how many panels you need for your home. 

Here’s the formula:

Annual energy usage/solar production ratio/panel wattage = the number of solar panels needed 

Let’s put this into context by giving you an example calculation. As mentioned, the average household uses 11,000 kWh annually. For the other factors, we can stick with the 1.6 production ratio. We’ll use the 400W EcoFlow Rigid Solar Panel for this calculation:

11,000 kWh/1.6/400= 17 panels

With 17 panels, you can power the average American home that uses 11,000 kWh of electricity. Keep in mind that solar panels only capture the sun’s energy, they don’t operate as standalone systems. You’ll need a solar generator, modular power kit or other balance of system with sufficient capacity to store all that renewable energy the panels generate. 

A solar generator like EcoFlow DELTA Pro gives you a two-in-one, combining PV panels with a high-capacity power station to store the energy captured from your panels. A solar generator like the DELTA Pro can be key component to emergency home backup in case of blackouts.  

Average Number of Solar Panels Required Based on System Size

The system size is the number of solar panels in your array and their total wattage. The calculation for this is simple:

Number of solar panels X panel wattage = system size

Using the previous calculation, we could estimate the system size as the following:

17 panels x 400W = 6800W system size or 6.8kWh

Since solar installers don’t always know each household’s energy use, they will recommend arrays based on system size. Below is a table that illustrates the number of PV panels needed based on the system size. In addition, it also tells you the amount of roof space required and the estimated annual production you can expect. 

Keep in mind these are only ballpark figures. Therefore, it may be worth speaking to a solar design technician for an accurate estimate based on your home size. 

System SizeEstimated Annual ProductionNumber of Panels NeededRoof Space Required
4 kW480 – 600 kWh11193 sq. feet
6 kW720 – 900 kWh17281 sq. feet 
8 kW960 – 1200 kWh22386 sq. feet
10 kW1200 – 1500 kWh27474 sq. feet 
12 kW1440 – 1800 kWh32562 sq feet
14 kW1680 – 2100 kWh 38667 sq. feet 

If you prefer a self-contained system that doesn’t require wiring multiple components, you can opt for something like an EcoFlow Power Kit. With numerous system sizes ranging from 2kWh to 15kWh, it’s a convenient, space-saving backup and off-grid power solution. 

Frequently Asked Questions

How Does My Home Size Affect the Number of Solar Panels I Need?

Most home sizes range between 1,000 and 3,000 square feet. Over the years, technological advancement has allowed manufacturers to build more energy-efficient panels to generate greater output. Obviously, the bigger your home, the more appliances, and devices you have that fill up the space, like lights, refrigerators, TVs, washers, etc. 
Here’s a rough estimate of how many solar panels you’ll need based on your home size: 
• 1500 square feet – 14 panels 
• 2000 square feet – 19 panels 
• 2500 square feet – 24 panels 
• 3000 square feet – 28 panels 

Are Solar Panels the Right Solution for My Home?

Solar panels mean cheaper utility bills for you and your family and less reliance on the traditional grid. If your goal is to contribute to a greener planet and save some money, there’s never been a better time to make the jump. Implementing a solar system is getting more affordable and easier to set up than ever before. 

With so many benefits, the answer seems obvious. There’s a reason solar panels are increasingly popular. However, they’re not suitable for every home. 

The cost is usually a significant deciding factor for homeowners considering solar panel installation. Besides the panels, another factor to consider for cost is the balance of system. The solar array alone doesn’t make up the entire solar home system. You also need the solar battery, inverter, roof mounts, and other components. 

The good news is there are ways to offset costs. If you invest in a Smart Home Ecosystem, you can bundle and save on the solar panels, power station, and balance of system in one seamless package. It’s more cost-effective than buying separate components for your setup, and you don’t have to worry about compatibility.

Labor is another part of the overall cost. Traditional rooftop panels can be expensive to install because of the labor. 

Fortunately, EcoFlow Portable Panels are easy to mount anywhere and don’t require professional installation. You don’t even have to install them on your roof, making them a convenient option for RVs, camping, off-grid situations, and tiny homes with limited roof space.

Ultimately, only you can decide if solar panels are right for your home. To make an informed decision, look at the total picture, including your energy consumption, utility costs, and the system cost and installation. 

Final Thoughts

If you’ve made the decision to reduce energy bills and contribute to a greener planet, the solution starts at home with solar panels. EcoFlow is a reliable choice for solar panels that have exceptional efficiency, choice in design, and durability. Contact EcoFlow today to consult with our experts on how many solar panels are right for your home.

EcoFlow is a portable power and renewable energy solutions company. Since its founding in 2017, EcoFlow has provided peace-of-mind power to customers in over 85 markets through its DELTA and RIVER product lines of portable power stations and eco-friendly accessories.

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