How to Size a Solar System: What We Look At and Why It Matters

One of the first questions homeowners ask when exploring solar is:"How many panels do I actually need?"

The answer depends on a few things—mainly your energy usage, your goals for the home, and your roof’s layout. Here's how we figure it out.

Step 1: We Look at Your Usage History

If you’ve lived in the home for at least a year, we’ll start by looking at your electricity usage over the last 12 months. That gives us a clear baseline for how much energy your system should generate.

But we don’t stop there—we also ask about any future plans that could increase or decrease your usage. For example:

• Switching gas appliances to electric

• Home is downsizing

• Adding an EV charger

• Building an ADU or converting your garage

  
  

This helps us design a system that not only works for today, but also grows with you.

Step 2: We Size the System in kW to Match Your kWh Needs

Solar systems are sized in kilowatts (kW), but the goal is to hit a specific energy production target (kWh) for the year. Most homeowners fall somewhere between 15 and 35 panels, depending on roof space, equipment, and how much electricity they want to offset.

No Usage History? No Problem.

If you just moved in and don’t have a year’s worth of usage, we’ll look at the square footage of your home, your household size, and how you plan to use the space. These cases are more of an educated estimate, but we typically recommend starting a little conservative—you can always add panels later if needed.

What If You Can’t Offset 100%?

Best case scenario: we design a system that covers all (or more) of your annual usage. But if you’ve got shade or limited roof space, you may not be able to reach full offset, and that’s okay. Even a partial offset system can lead to big savings, and we’ll make sure you’re getting the most out of every panel.

Design Backed by Real Tech

When sizing your solar system, we use LIDAR 3D software to analyze your roof’s sunlight exposure. That data helps us pick the most efficient panel placement, so you can hit your offset goals using fewer panels.

The Bottom Line

Every system we design is customized for your home, your energy needs, and your future plans. If you're thinking about solar and want a clear idea of what your roof can do for you, let's talk. We’ll run the numbers and help you decide if now’s the right time.