A rural home in a grassy pasture with solar panels on its roof and cows grazing out front

Off-Grid Solar System Sizing Calculator

When preparing to live off-grid, you have to be ready for the independence that comes with this lifestyle. In addition to physical separation from modern stores and neighborhoods, you'll be living without the energy resources available to your grid-tied friends and family. So how will you get the energy you need to power your off-grid home?

One of the most popular ways to generate your own electricity when living off-grid is to build a solar panel system. Unlike a grid-tied (residential) system, an off-grid system must meet all of your electricity needs and therefore must be sized accurately. We developed an off-grid solar system calculator to help you determine what size system you need.

How to Use Our Off-Grid Solar Calculator

Sizing an off-grid solar system takes precision, but it's still relatively simple. Follow the steps below to use our off-grid solar system sizing calculator:

  1. Enter the ZIP code where you will install your system.
  2. Fill out our load calculator with the appliances in your off-grid home, confirming their wattage as well as how much you use them per day.
  3. Factor in inverter and battery inefficiency.
  4. Confirm how many days of backup power you'd like your battery bank to store.
  5. Let us calculate your solar system and battery size.

Off-Grid Solar System Sizing FAQ

Some unique considerations go into sizing an off-grid solar system. We answer some common questions about these systems below.

How Big of a Solar System Do I Need for Off-Grid?

Four illustrated off-grid solar system setups with average system size suggestions

Your solar system's size depends on several factors, including how much energy your household uses, the components you use to build your system, and how many winter sun hours you get where you live.

Here are some system sizing approximations depending on the setup you have in mind:

  • RVs and small cabins: 0.5 kW - 1.5 kW
  • Standard-size cabins: 3 kW - 4 kW
  • Standard-size homes and lodges: 4 kW - 9 kW
  • Large homes, farms, and businesses: 9 kW - 14 kW

How Many Batteries Do I Need to Go Off-Grid?

As a rule of thumb, it takes upward of eight batteries to go fully off-grid. The size of your battery bank ultimately comes down to your individual energy usage, which can be determined using our calculator above.

How Many Solar Panels Do I Need to Run a House Off-Grid?

The number of solar panels you need to run an off-grid home depends on your energy usage. If you fall around the average 7 kW, you'd need over 20 solar panels of at least 325 watts.

Planning an off-grid solar system can be tricky, but it doesn't have to be disheartening. Solartap makes it easier than ever to get a solar system up and running that will reliably power your entire off-grid setup.

Give our off-grid system sizing calculator above a spin or explore our off-grid solar kits today.