The 3 Key Factors That Go into Sizing Solar for Your Home

3 key factors contribute to sizing a home solar energy system; energy usage, space, and budget. Once you have these pieces of information, the smallest of the three determines the size of your system.  

Energy Usage

Understanding how much electricity a house uses is important to properly size a solar panel system. This information is normally on the utility bill and is listed in kWh (kilowatt hours). Some utilities give a monthly breakdown; others give an average monthly or daily figure. If you don’t see it on your bill, you may need to request it from your utility.

For example, energy is the deciding factor:

If your house only uses 5,000 kWh a year, even if you have unlimited land for an array, and you just won Publisher’s Clearing House, you wouldn’t buy much more than a 4kW system, because you don’t need the extra power.  


The second thing to consider is space.  How much space do you have facing east, south, or west on your roof? Or, if you have a better space on the ground, how much space do you have for a ground mounted array. Whether roof or ground, the square footage available for a solar system factors into the sizing for your home.

For example, if space is the determining factor: 

If your home is a tall, skinny town home with very limited square footage on the roof , that space determines the system size.  It doesn’t matter if you use more power than your roof space will allow for panels or if you have unlimited funds, your system will be limited by the space available. It would however guide us towards using the most efficient and productive panels possible.


There are two ways to pay for a solar system, cash or financing.  If you want to pay cash for the system, your savings available will determine your budget.  If you are considering financing, then think about a monthly payment that works, understanding you will have savings from your current utility bill that you can redirect to the solar system.

For example if budget is the determining factor:

If you have a set amount set for this project, but you have higher energy usage and plenty of space, then the budget will guide your system sizing. If this is the case, consider possible future expansion of your system which can be designed in as a possibility from the start

Bonus Tip!

Once you’ve decided with your Solar Consultant, what makes sense for your system, don’t forget to discuss any future energy needs so you can plan for them now. While you don’t want to pay for more energy than you need, if you do plan to add a large energy user to your home, like an electric car, pool, etc, planning for that at the beginning will save you money later. We have a detailed familiarity with EV energy consumption (we are owners too!) so can advise on how to size an array to include your driving requirements.

Learn more by talking with one of our Solar Consultants today. A remote quote is free and it’s a great way to start.

Schedule your free solar assessment today. Call 877-312-7456 or contact us below to get started.