Do I need a battery with my solar system?

One of the most common questions I get from homeowners is: “Do I need a battery with my solar system?”

The answer depends on two key factors:

1. Your utility’s net metering policy

   
   

2. Whether or not you want backup power in case of a blackout

   
   

Let’s break down both of these and walk through a couple of real-world examples to help you decide what makes sense for your home.

When Net Metering Isn’t Enough

Batteries become necessary when your utility company doesn’t offer a strong net metering program. In my opinion, a good net metering policy means you’re getting at least 75 percent of the retail rate when you send power back to the grid.

Once the buyback rate drops below 50 percent, a battery becomes pretty much unavoidable. You’re just not getting enough value back from your excess solar production, and storing that energy becomes the smarter move.

This varies a lot depending on where you live. Some areas still have one-to-one net metering, while others have shifted to time-of-use or avoided cost rates. If you’re not sure how your utility handles it, reach out and I can run the numbers for your specific location.

Want Backup Power? You’ll Need More Than Just a Battery

Another reason people consider batteries is to have backup power during outages.

But it’s important to know this upfront: Just because you install batteries does not automatically mean you have backup.

To actually power your home during a blackout, your system needs a transfer switch or similar component that disconnects your home from the grid and allows it to form a microgrid. This setup is what allows your home to run off stored battery power plus real-time solar production.

This is a crucial difference. A battery-only setup may not give you any emergency backup unless the right equipment is installed. The cost difference for full backup capability is usually between $4,000 and $7,000 depending on your equipment, installer, and panel setup.

Two Homes, Same Usage, Different Battery Needs

Now let’s get into how usage patterns can impact your battery size. Even if two homes use the same amount of electricity overall, they might need completely different battery setups depending on when they use power throughout the day.

Let’s say both homes use around 12,000 kWh annually. That’s about 33 kWh per day.

Example 1: The Young Family

Home number one is a young family with two kids under the age of 10. They’re up early, cooking and using appliances in the morning, then leave for work and school. Most of the electricity is used in the morning and evening when everyone is home.

That means only about 10 kWh of solar production gets used in real time during the day. The other 23 kWh needs to be stored for use later.

To cover their daily needs, this home would require at least a 23 kWh battery. That number could be higher depending on seasonal changes, but this gives us a good baseline.

Example 2: The Retired Couple

Home number two is a retired couple who spend most of their time at home. They do laundry, cooking, and most of their energy use during the daytime when the sun is shining and the solar panels are producing.

This couple uses about 23 kWh in real time directly from solar, meaning only 10 kWh needs to be stored. So their battery requirement is much smaller, even though their total energy use is identical to the young family.

So, Do You Need a Battery?

That depends on:

• Your utility’s net metering policy

• Whether or not you want backup power

• Your household’s daily routine and usage patterns

Solar battery storage is an incredible tool, but it isn’t always required. The key is designing a system that fits your goals, your location, and your lifestyle.

If you want help figuring it out, I offer free consultations in over 30 states. I’ll break down the math and give you real answers, not just sales fluff.

Reach out today and let’s design something that actually works for you.