Can You Add Battery Backup to an Existing Solar System?

Solar batteries have many benefits for California homeowners. They allow you to keep your solar panels on during a power outage and give you backup power. Solar battery storage has become even more valuable under California’s new net metering policy because it allows you to store your excess solar generation for your own use instead of selling it to the grid for reduced rates. 

It’s best to install solar panels and batteries together, but it is possible to add battery backup to an existing solar system. You will need to make some changes to your system to accommodate the battery, but it can be done.

How to Add Battery Storage to an Existing Solar System 

There are a few ways to add a battery to a solar system. The best option for you will depend on how your solar panel system was initially set up.

Battery-Ready Solar Panels 

If your solar panels are “battery ready” you are in the best position. If you are installing solar panels now and think you may want to add a battery in the future, ask your solar installer for a battery-ready system. These types of solar systems are designed for easy battery integration so you can add battery backup for your solar panels at any point without making major changes to the system.

Alternating Current (AC) Coupling 

AC-coupled solar systems have two inverters: one converts the direct current (DC) power produced by your solar panels into AC power for your home; the other converts AC power back into DC power to be stored in your battery. Power is lost every time it is converted, which makes AC-coupled systems less efficient compared to DC-coupled systems. However, they are easier to retrofit than DC-coupled systems and are typically the best option when adding battery storage to an existing solar system.

Direct Current (DC) Coupling 

In a DC-coupled system, DC electricity flows directly from your solar panels to your battery. It is only converted one time (from DC to AC before being fed into your home) which makes DC coupling the most efficient option for solar battery backup. To add a DC-coupled battery, you will need to install a hybrid inverter, which can convert AC power to DC power and DC power to AC power. If you’ve had your solar panels for over 10 years, DC coupling may be your best option because your inverter is nearing the end of its life and will have to be replaced soon anyway. 

Adding Batteries to a Grid Tied Solar System Is Worth It 

Solar battery installation is worth it whether you already have solar panels or are planning to install them. There are three main benefits to battery installation for solar:

  1. Blackout protection – Solar batteries allow you to keep your solar panels on during a power outage and give you a backup source of emergency power. 
  2. Avoid time-of-use rates – Electricity is more expensive during peak demand times, which are usually in the evening after the sun sets. With battery storage, you can use stored solar power at night instead of buying grid power, avoiding expensive time-of-use rates. 
  3. Energy security – Battery storage reduces your reliance on the electric grid and brings you one step closer to energy independence.

Solar Battery Installation on the North Coast 

Six Rivers Solar has been the North Coast’s leader in renewable energy since 1980. We can retrofit a battery to almost any existing solar system and we also install new solar plus battery and battery-ready systems. Solar battery storage qualifies for the federal solar tax credit and we offer excellent financing options as well. 


Want to take your energy independence a step further? Ask us about off-grid solar and microgrids!

Install solar battery storage. Call 707-443-5652 or contact us to learn more.