Can You Add a Battery to Your Existing Solar Energy System?

Just as solar panel systems are becoming more and more affordable, so too are solar batteries. As the cost of batteries continues to fall, you may find yourself wondering if it's time to add a storage solution.

For many, especially early system owners, solar battery options were not at the forefront of their mind. But as homeowners see the savings that solar panels offer, they are left wondering how to get even more out of their renewable energy system.

Because solar panels are so efficient, many systems produce more electricity than the home can use before sundown. That translates into wasted energy. When the sun sets and panels are no longer able to collect daylight energy, your home switches over to the grid for the power that it needs, as it has lost any excess power that the system may have produced. For that reason, those who are looking to save even more on their electricity bill have turned their attention to solar battery options.

If you have yet to install solar panels onto the roof of your home, get a feel for how much you could save every month by making the switch!

Curious to know if you can add batteries to your existing solar system? In most cases, the answer is absolutely! Here's everything you need to know about available setups.

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First, How Solar Panels Power Your Home

Different battery setups work in different ways. To better understand how a particular setup functions, you have to first understand how solar panels power your home.

Solar panels collect daylight energy and turn that into DC electricity. However, your home uses AC electricity, so it needs to be converted—or, technically, inverted. How does it do that? With help from your system's inverter. The inverter takes DC electricity and turns it into the AC electricity that powers your home.

Option 1: Storage-Ready System

The first and most ideal solar battery addition method would be adding one to a storage-ready setup. What does that mean? It means that you knew you would eventually be interested in batteries and had your solar installer keep that in mind when getting your panels up and running.

Because your inverter is ready to work with a battery, it's simply a matter of installing one!

The perks of a storage-ready system:

  • Most affordable option
  • Easy for the installer
  • Requires few materials
  • Quick process

Option 2: AC Coupling

An AC coupled system uses a traditional inverter and adds a second, known as a storage inverter. This image breaks it down in an easy-to-understand way:

AC coupling requires inversion at three points: (1) from panels to home; (2) from home to battery; and (3) from battery back into home. 

The downside of an AC coupled system is that it's less efficient than other options. Why? Because batteries store in DC. That means that the DC power generated by the solar panels gets inverted to AC power for your home, turned back into DC power for storage, and inverted to AC again when drawn out.

The perks of an AC coupled system:

  • Flexible location
  • Compatible with a range of inverters
  • Typically less complicated to install
  • Relatively low cost

Option 3: DC Coupling

With a DC coupled system, your inverter is replaced by one that works with solar panels and a battery, called hybrid inverters. This setup is more streamlined than AC, as can be seen here:

DC coupling places the battery between the panels and the invertor so the current won't need to be changed to AC until drawn by the home.

As you can see, you lose less energy since fewer conversions are needed. DC electricity goes to the battery and then to the inverter, making it more efficient.

This setup has two downsides. First, it can be complicated to install. Second, it is generally the most expensive of the three options.

The perks of an DC coupled system:

  • Great for older setups that need a new inverter anyway
  • More efficient than AC coupled

Are Batteries Right for Everyone?

Because there are upfront costs, many homeowners are left wondering if solar batteries are right for them. Solar batteries are definitely worth exploring if you are dealing with any of these:

  • Frequent power outages
  • Time-of-use electricity plan
  • Costly peak demand charges

Discuss Your Battery Options Today

Most backup batteries that are designed for small-scale use, like a home, are compatible with solar panel systems. It's important to note that a single battery for home use won't be enough to take you completely off-grid. Instead, it's designed to provide you with a few hours of backup power to use during an outage and to avoid time-of-use or peak demand charges.

Related
Solar battery basics

If you're wondering what solar battery setups work with your solar panels, reach out to your solar provider. Don't have panels yet? Connect with a local installer now and opt for a storage-ready system so you can easily add a solar battery down the road!

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