A home solar array is one of the most increasingly popular ways to generate electricity for your home and rely less on the local utility to provide power.

solar panel inverter

A solar system project is no small undertaking and requires a great deal of consideration and planning before it is started. One of the biggest questions that homeowners often have is, how many solar panels would it take to run my home? Because every home is slightly different, there is no one cookie cutter answer for this question.

Instead, we can look into some of the determining factors. So, what questions must be answered before being able to determine how many solar panels it would take to run your home?

  • Do You Live In Your Home Year Round?
  • What Is Your Average Annual Energy Load?
  • Are You Looking For A Grid Connected Or Off The Grid Solar Project?
  • Do You Live In A State That Allows Net Metering?
  • What Is A Rough Calculation To Determine The Number Of Panels?


Do You Live In Your Home Year Round?

The sizing of a solar system can be greatly influenced by how often you or a family member are occupying a home.

Some homeowners choose to fly south to a vacation home for the winter and then move back north in the summer. This is important to consider because it can drastically change the sizing of your system. If you are only planning to live in a home during the summer months, you may be able to build the solar system slightly smaller as there is more sunlight each day in the summer. If you plan to love in a home run by solar in the winter, it may need to be sized larger to account for fewer hours of sunlight each day.


What Is Your Average Annual Energy Load?

One of the most important factors to determine the size of a solar system is your average annual energy load. This is the amount of energy that your solar system would need to produce in order to offset using the utility generated energy entirely. Working out kilowatt hours usage can usually be done by tracking your monthly electric bills. This way, you will be able to see how your energy usage fluctuates throughout the year. Typically, homes use far more electricity in the summer, for cooling, than they do in the winter. For reference, the average single family home in the United States consumes just under 11,000 kilowatt-hours of energy per year but your specific consumption may be slightly higher or lower than this.


Are You Looking For A Grid Connected Or Off The Grid Solar Project?

A home solar array that is connected to the grid may look far different than one that is off the grid.

A solar utility company will have input on your solar system if it is grid tied but none whatsoever if it is off the grid. A solar power generator with backup batteries are one of the most common ways to live off the grid. Typically, the batteries will charge all day while the sun is shining and discharge at night when the sun goes down and no more energy is being produced. There are advantages to both of these styles of system. Typically, you will need to oversize an off gird solar system to account for extended periods of little sunlight to ensure you will always have necessary power. With grid connected systems, a smaller system is fine because the grid is always there to make up for any shortcomings of the solar system. As solar cells price falls, it is becoming more and more cost effective to install larger systems to meet the full demand of the home.


Do You Live In A State That Allows Net Metering?

Because the sun does not shine around the clock, there will be some times when you are pulling energy from your solar utility company. Luckily, many states include a policy known as net metering which allows homeowners to export excess solar energy to the grid when they are producing more than they are using. Then, this exported energy is credited back to your bill at the end of every month. The utility will be working out kilowatt hours on your bill so you won’t ever have to worry about it. The advantage to state like this are that you do not lose any of the value of the solar power generator when it’s energy is exported. In other states without net metering solar laws, exported solar may only be valued at the wholesale rate as opposed to a regular resale rate. Net metering solar out to the grid also acts as a form of a “battery” without having to actually purchase one which can be quite expensive. Typically, states that have net metering laws typically already have the solar power infrastructure in place to accommodate energy flowing both in and out of a home.


What Is A Rough Calculation To Determine The Number Of Panels?

While there are a variety of solar pv tools which can be used to design a solar system for your home, they can often be expensive as can hiring someone to do this.

Instead, some rough calculations can be completed which will at least get you in the ballpark of what size your solar system will need to be in order to meet your entire home electricity usage. First, you must decide what wattage solar panels you will use on your home. Some free solar pv tools will be able to show you common wattages and estimated prices for them. You will quickly notice that higher wattage and more efficient solar panels are more expensive which will raise the total cost of the solar system project but may prove to be worth it in the long term.

For the cases of this example, we will consider a 365 watt solar panel. Next, we will assume that this panel gets around 8 hours of sunlight per day on your rooftop. A 365 watt panel receiving 8 hours of sunlight per day will produce almost 3 kilowatt-hours per day. This, multiplied by 365 days per year results in solar output of roughly 1,095 kilowatt-hours annually. Next, we’ll look at the average consumption of a single family home. Most recent data suggests that a typical home consumes just under 11,000 kilowatt-hours annually. So, when we divide our total consumption by the expected output of one solar panel, we see that roughly ten solar panels of this size would be enough to power the home. Ten solar panels at a size of 365 watts per panel results in an on or off the grid solar system of around 3.65 kilowatts.

This number can of course be higher or lower depending on your average amount of sunlight, personal energy usage, and a variety of other factors. It is also important to remember that there are some losses involved in solar energy usage and thus you may need to slightly oversize the solar system to account for this.

Solar power infrastructure is booming in the commercial and residential spaces. Thanks to the falling cost of solar paired with robust financial incentives at both the federal and state levels, solar cells price is lower than ever before. This is leading many homeowners to seek out what size solar system would meet or exceed their home electricity usage. By carefully considering all of the factors that go into solar energy usage, homeowners are able to gather a much better understanding on how they can make they switch to solar.