How Many Solar Panels to Power a House (For Every Size, Type, Location)

Although the number of solar panels you’ll need is impacted by your energy use, it’s also impacted by how your house is situated and the average number of sunlight hours in your location.

There are general guidelines for each factor involved, but it can seem confusing at first. This calculator can help estimate the number instantly:

However, there are several other factors that will determine whether your  specific home and location falls into the nationwide average of 17 to 21 solar panels.

If you live in a smaller home or have lots of mature trees blocking the sun, you may need more or less than that.

This complete guide explains how many solar panels to power a house based on the basic formulas, and provides estimates for various sizes and types of home in every state.

Can Solar Panels Power a Whole House?

It can be a homeowner’s dream to completely disconnect from the local electricity grid and live 100% from energy from the sun.

And, it is possible to complete power your home using solar panels.

To determine how many solar panels to power a house completely are needed, these are the 5 variables that have to be considered.

• The yearly average of your utility bill
• The number of hours of peak sunshine that falls onto your roof
• Your location
• The size and pitch of your roof
• The wattage of the solar panels

All of these variables play their role in the efficient conversion of the sun’s energy into sufficient usable electrical energy to power your home into the next century.

But even if you’re not in the sunniest state and feel like your house is constantly sitting under a giant cloud, you can still take advantage of this clean energy option.

How Many Solar Panels To Power a House: By Size

About 900 kWh of energy consumption per month has been estimated as the average usage for an average home in the United States of America based on residential utility bills across the country.¹

The figure of between 17 – 21 solar panels is not exactly an arbitrary number, but it is based on the average house, and yours may not be average.

To calculate how many solar panels to power a house, full-time, let’s look at the square footage of a house under a microscope.

Type of house	Square feet	Average monthly electricity usage
1 bedroom	550 sq ft	400 kWh
1 bedroom	670 sq ft	532 kWh
2 bedrooms	800 sq ft	700 kWh
2 bedrooms	1,000 sq ft	894 kWh
3 bedrooms	2,000 sq ft	1,325 kWh
3 bedrooms	2,500 sq ft	1,573 kWh
4 bedrooms	3,000 sq ft	1,840 kWh
4 bedrooms	4,000 sq ft	2,200 kWh

The formula used to calculate how many solar panels to power a 1000 square foot house, is either to add up 12 months’ worth of the kWh on the electric utility bills or multiply an average number by 12.

If this can be done for 2 years it would increase the accuracy of the kWh readings to enable the correct number of solar panels to be bought.

The average yearly consumption across the United States of America currently stands at 10,632 kWh.

That can vary significantly from many factors apart from the square footage, and those factors will all influence the types of solar panels to be ultimately selected.

Home Appliance	Average Monthly Electricity Usage	Average Yearly Electricity Usage
Microwave	4 – 8 kWh per month	48 – 96 kWh per year
Oven	25 – 60 kWh per month	300 – 720 kWh per year
Refrigerator	34.5 – 60 kWh per month	414 – 720 kWh per year
Air Conditioning	150 – 900 kWh per month	1800 – 10,800 kWh per year
Washing Machine	3.9 – 11.7 kWh per month	46.8 – 140.4 kWh per year
Central Heating	77 – 111 kWh per month	924 – 1,332 kWh per year
Dryer	13 – 39 kWh per month	468 kWh per year
Television	9 – 13.65 kWh per month	163.8 kWh per year
Lighting	3.65 – 5.48 kWh per month	65.7 kWh per year
Electric Water Heater	380–500 kWh per month	4,460 – 6,000 kWh per year

Being aware of the accumulation of kWh from household appliances in your home will point to why your house is not average,² and why the yearly electricity utility bill may well be double the national average of 10,632 kWh, or way below it.

How Many Solar Panels To Power a House: By Bedrooms

It may even help you to cut back on your monthly expenditure by making some small energy adjustments. So once the yearly kWh has been calculated accurately, that figure needs to be divided by the wattage output of the solar panel.

For example, if the wattage of the solar panel was 500, the number of solar panels required for a 1-bed, 2-bed, 3-bed, and 4-bedroom would be

• An average household
  10,632 kWh ÷ 500 = 21 panels
• 1 Bedroom
  4,800 kWh ÷ 500 = 10 panels
• 2 Bedroom
  8,400 kWh ÷ 500 = 17 panels
• 3 Bedroom
  15,900 kWh ÷ 500 = 32 panels
• 4 Bedrooms
  22,080 kWh ÷ 500 = 44 panels

These calculations are based on the manufacturer’s optimum rating on a solar panel at 500 watts. That may be lower in a real-world environment, and will definitely be affected by the hours of peak sunshine in the local area.

Another factor is the size of the solar panel itself. A solar panel rated at 600W or 700W would greatly decrease the number of panels required, and if it is the same size of standard solar panel at 3.25 feet by 5.5 feet, then you can get more power for your buck while not needing additional square footage for installation.

How Big of Solar System Do I Need for Where I Live?

Statistics, and very good weathermen, have ascertained that the average daily peak sun hours across the country is between 3 to 5 hours.

How many solar panels do I need for 1000 kWh per month, will depend on these sun hours.

If based on the national average of 5 hours and a 500 W solar panel, then the number of panels required can be calculated by using this monthly formula

Monthly:

• Electricity usage in kWh
• Amount of peak sun hours for your area
• The rating of the solar panel
• Divide the monthly kWh usage by the monthly peak hours
  1,000 ÷ 150 = 6.7
• Multiply by the monthly kWh Usage
  6.7 x 1,000 = 6,700
• Divide by the solar panel power rating of 500
  6,700 ÷ 500 = 14 solar panels

Adding at least another 2 panels to account for a loss of real-world output efficiency is always advisable as how much power does a solar panel produce in a factory setting is not always reflected in less-than-ideal conditions on your roof.

If the power ratings on the solar panels were lower,³ and the peak sun hours were shorter, that would mean an increase in costs, and consequently the number of panels needed.

How Many Sun Peak Hours in Your State and What Is the Average kWh Usage?

The variation of peak sun hours across all the states can be quite significant.

Knowing what those hours are in your area would help in choosing the power rating and how many solar panels to power a house.

Referring to the table below with the sun hours and the monthly average electricity usage, will give an accurate idea of how many solar panels to run a house off-grid, and enable you to contribute towards the fight against climate change.

 

State	Approximate Daily Sunshine Hours	kWh per Month
Alabama	7 Hours	1,145 – 1,211 kWh
Alaska	6 Hours	552 – 632 kWh
Arizona	10.5 Hours	1,049 – 1,114 kWh
Arkansas	7.8 Hours	1,060 – 1,133 kWh
California	8.6 Hours	557 – 605 kWh
Colorado	9 Hours	711 – 723 kWh
Connecticut	7 Hours	703 – 752 kWh
Delaware	7 Hours	935 – 944 kWh
Florida	8 Hours	1,078 – 1142 kWh
Georgia	8 Hours	1,081 – 1,088kWh

State	Approximate Daily Sunshine Hours	kWh per Month
Hawaii	8.5 Hours	515 – 537 kWh
Idaho	8.4 Hours	955 – 1,055 kWh
Illinois	7 Hours	698 – 755 kWh
Indiana	6.8 Hours	938 – 1,005 kWh
Iowa	7.5 Hours	865 – 908 kWh
Kansas	8 Hours	883 – 926 kWh
Kentucky	7 Hours	1,073 – 1,154 kWh
Lousiana	7.4 Hours	1200 – 1273 kWh
Maine	7 Hours	551 – 567 kWh
Maryland	7 Hours	964 – 1,031 kWh

State	Approximate Daily Sunshine Hours	kWh per Month
Massachusetts	7.4 Hours	610 – 638 kWh
Michigan	6.7 Hours	665 – 676 kWh
Minnesota	7.6 Hours	775 – 817 kWh
Mississippi	7.6 Hours	1,146 – 1,220 kWh
Missouri	7.5 Hours	1,028 – 1,086 kWh
Montana	7.5 Hours	848 – 860 kWh
Nebraska	7.7 Hours	1,013 – 1,034 kWh
Nevada	10.2 Hours	924 – 971 kWh
New Hampshire	7 Hours	622 – 629 kWh
New Jersey	7 Hours	673 – 687 kWh

State	Approximate Daily Sunshine Hours	kWh per Month
New Mexico	9.6 Hours	655 – 670 kWh
New York	6 Hours	600 – 602 kWh
North Carolina	7.5 Hours	1,041 – 1,098 kWh
North Dakota	7.7 Hours	1,085 – 1,205 kWh
Ohio	6 Hours	888 – 892 kWh
Oklahoma	8.7 Hours	1,078 – 1,142 kWh
Oregon	6.5 Hours	916 – 976 kWh
Pennsylvania	7.3 Hours	822 – 857 kWh
Rhode Island	7.3 Hours	599 – 602 kWh
South Carolina	8 Hours	1,081 – 1,124 kWh

State	Approximate Daily Sunshine Hours	kWh per Month
South Dakota	8 Hours	1,037 – 1,055 kWh
Tennessee	7 Hours	1,168 – 1245 kWh
Texas	8 Hours	1,132 – 1,174 kWh
Utah	8.5 Hours	769 – 798 kWh
Vermont	6.5 Hours	567 – 569 kWh
Virginia	8 Hours	1,095 – 1,156 kWh
Washington	6 Hours	969 – 1,041 kWh
West Virginia	6 Hours	1,051 – 1,118 kWh
Wisconsin	6.8 Hours	694 – 703 kWh
Wyoming	8.6 Hours	869 – 894 kWh

How many solar panels to power a house can be estimated using the basics of the method above,⁴ with the average peak sun hours, the monthly usage, and consulting a solar panel size chart for your region for additional information.

How Many Solar Panels To Power a Mobile Home? (How Many Solar Panels To Power a House?)

Mobile homes have to conform to the same rules as when calculating how many solar panels to power a house, such as the square footage, peak sun hours, the monthly kWh usage, and even the budget available.

There is a bit more flexibility in regard to power requirements as generally mobile homes don’t need as much energy to go on the road as residential houses.

A standard mobile home has a square footage of between 500-800 and will need approximately 4-5 kWh a day, about 150 kWh per month. If we presume that a smaller solar panel of 100 watts is used, and only 3 hours of peak sun a day, the calculation could look something like this

150 ÷ 90  = 1.7
1.7 x 150 = 255
255 ÷ 100 = 3-4 solar panels

Always overestimate the solar panels needed as it is better to have an energy surplus rather than be powerless. For larger mobile homes in different locations, replace the peak sun hours and the square footage to calculate more accurately how many solar panels you would need to power your mobile house.

One of the main advantages that mobile homes have over a house is that it has easier access to the roof. How to install solar panels on roof on a mobile home will be less complicated and will be a simpler process when it comes to how to wire solar panels.

Carbon Footprint: Solar Panels

Using a solar panel for ac unit will take quite a large amount of kWh a month to run, and will add to the upfront carbon footprint solar panels have at the beginning of their lifecycle. The carbon footprint of a solar panel starts at the point of collating all the individual components together from near and far, manufacturing the actual cells and frames, assembling all the parts together, and finally transporting and installing and eventual disposal.

How to make a solar panel carbon neutral is based on its energy payback potential.

It has been calculated that (on average) within 3 years, carbon neutrality can be reached,⁵ and then previous CO₂ emissions from electricity generated from fossil fuels will be eliminated.

Solar Panels: Improving the Value of a Home, and Saving the Planet

Greenhouse gas emissions, climate change, and carbon sequestration concerns have millions of Americans wondering how many solar panels to power a house, and if they should join the revolution.

This topic of conversation has alerted some to other advantages of having solar panels- in more ways than one.

Savvy house sellers, for example, are installing solar panels for a dual reason. By doing so, they are not only helping the planet by reversing climate change, but also adding resale value to their property.

It has been estimated that a home that has a fully functioning solar panel system set up in a state with the maximum peak sun hours, can have at least $15,000 added to the value of the property.

Additionally, many homeowners opt to go solar because they want to be free of the cables that tie them to the local energy grid – and to be independent.

Others were thinking long-term and just wanted cheaper bills and to be able to contribute towards fighting global carbon dioxide emissions.⁶ Whatever the reasons for embracing solar panels, uncertainty about cost and the number of solar panels needed to fully run an entire household dissuaded many more from taking the leap.

Deciphering, unmasking, and simplifying the seemingly complex equations for calculating the energy requirements to power an average home will hopefully attract more converts into the light.

Knowing exactly how many solar panels to power a house all depends on the specific location and energy use they’ll be expected to provide.

Frequently Asked Questions About How Many Solar Panels to Power a House