How Many Solar Panels to Run a House?

how many solar panels to run a house

Solar energy is growing more popular by the year. In fact, the cost to install solar has dropped by more than 70% over the past decade.

According to the Solar Energy Industries Association, roughly 4% of homes in throughout the U.S. are powered by solar energy.

And this number keeps growing. 

Today, one of the most common questions people ask, how many solar panels to power a house? And, how much does solar cost in total?

In this article we aim to answer these question in detail.

We will even teach you how to work out the ROI of going solar, to help you better understand why going solar is good for your wallet.

How Many Solar Panels to Power a House?

how much solar to power a house

This seems like a simple enough question doesn't it?

If you ever ask someone and they respond telling you that you will need X amount of panels to run a house.

Run away, they don't know what they are talking about.

Or at least, they are giving you inaccurate information. 

But why?

Well, the amount of solar panels you need to replace your electricity depends on 3 things: 

  • Your current electric bill
  • Your homes location
  • Your budget

Without this information, it would be impossible to give you an accurate answer. 

(It is worth noting there are more important factors to consider when going solar, but for simplicity, we will focus on these 3 things as they are the most important.)

Your Current Electric Bill

First things first. 

How much electricity do you use month to month?

The best way to establish this would be to look at your annual electricity bill. 

On there you should find your average monthly usage. 

For our example we will assume your usage is $115 per month as this is more or less the current U.S. average. 

Now, I want you to times that monthly bill by 12 months to get your yearly spenditure. 

$115 X 12 = $1380 a year spent on electricity. 

We also need to work our how many kWh this equals. 

This largely depends on where you live as every state has varying electricity costs. 

For our example we will assume our home uses 1200kWh a month. 

Your Homes Location

Next, we need to establish where exactly you live. 

You see, different locations receive varying amounts of sunlight. Without this information it would literally be impossible to determine whether solar panels can completely replace your electricity or not. 

So, for our example, we will go ahead and assume you live in Columbus Ohio. 

Now, we want to use a tool which can be found online to establish how much peak sun hours our homes location receives. 

(Please insert your own homes location in the total and follow along with us.)

Step 1 - Enter your homes location

Step 2 - Check out the amount of peak sun hours your home gets

In our case we got 3.96 peak sun hours. 

Make sure you are looking at the GHI (Global Horizontal Irradiation).

Obviously, by inserting your homes actual address you will have a much more accurate estimate of your daily peak sun hours. 

Next, you want to times your number by 30 days. 

3.96 X 30 days = 118 peak sun hours a month. 

Your Budget

It is of our believe if you have an unlimited budget, then replacing your electricity with solar would be possible no matter where you lived.

However, as this is not the case for 99% of humans on earth, we recommend you establish a maximum budget.  

In the next section we will teach you how to figure out how many solar panels to run a house, and subsequently how much your solar system cost.

How Many Solar Panels to Run a House?

For this we input the data we've collected into a simple formula. 

Okay, so here we have a basic formula, now you just need to follow along to roughly establish how many solar panels you will need to replace your electricity. First we take our monthly electric usage and divide it by our homes peak monthly sun hours. 

1200 / 118 = 10.16kW 

Now we must take our result and times it by 1000 to get the total wattage. 

10.16 X 1000 = 10,160 watts. 

In order for our homes electricity to be completely replaced, we will need a 10,160 watt solar system. 

Now, to figure out how many solar panels to power house that would be, we simply divide that number by the power rating of the solar panels we decide to go with.

(Most homes go with 365 watt, 400 watt or 500 watt solar panels.)

For our example we will assume you go with 400 watt panels. 

Therefore, 10,160 / 400 = 25.4

So the answer to how many solar panels to power a house is that, our home will need 25.4 (26) solar panels to completely replace our electricity. 

How Much Does Solar Cost in Total? 

how many solar panels to power house

The average cost per watt is currently around $2.50 per watt. 

So, as our system equals 10,160 watts, the total costsolar system cost for home comes to around $25,400.

However, don't forget about the current solar tax incentives, this will reduce our costs by 26%. 

So the total solar system cost for home we will pay would rather be around $18,796.

What is the ROI of Going Solar?

The greatest thing about solar is your return on investment and solar savings. 

Let's work out ours. 

We spend $115 a month on solar. 

So, $18,796 / $115 = 163. 

163 / 12 = 13 years.

It is going to take approximately 13 years for your solar system to pay for itself. 

But what happens after that is done? 

Well, you effectively generate 100% free electricity. 

Given that a solar system will last on average around 25 years, you could expect to save approximately $16,560. 

Now, it is important to remember, we used Ohio as our example. 

The more sun your area has, the cheaper your system will be and the more your will eventually save. 

In fact, some homes (in California for example) can save more around $40,000 in total!

Now that, is a lot of money. 

Final Thoughts

Can solar panels completely replace your electricity? 

They most certainly can, and whilst they're doing that, will also save you thousands of dollars. 

Go solar, its good for the environment, and for your wallet!


1. How many solar panels does the average house need?
In general, the average solar system for a home consists of 20 to 26 panels, but the exact number you'll need will depend on numerous factors, including where you live, how much energy you typically use, and how much power your panels can generate.

2. Is it possible to run a house completely on solar power?
One of the most frequently asked questions by homeowners in regard to solar power is, “can it really power my entire house?” The answer to that is actually quite simple – yes, solar can indeed power your entire home.

3. How long does a solar panel last?
The industry standard life span is about 25 to 30 years.