Adding a battery to solar you already have
Holly Voss · 2026-07-15 · 2 min read
A lot of homeowners in Folsom, El Dorado Hills, Davis and Roseville installed solar years ago and learned during their first shutoff that the panels sit politely in the dark when the grid goes down. That is by design: a grid-tied inverter has to shut off so it does not energize lines a crew may be working on. A battery changes the deal. Here is how it fits with what you already have.
AC coupled or DC coupled: which do I need?
An AC coupled battery connects on the house side of your existing inverter and works with almost any system, including SolarEdge, SMA and older string inverters. A DC coupled battery ties in before the inverter, which is slightly more efficient but usually means replacing the inverter. For most existing systems, AC coupling is the practical answer; if the inverter is near the end of its life anyway, we price both.
What gets backed up during an outage?
You choose. A backup subpanel with the essentials (refrigerator, well pump, internet, some lights and a few outlets) lets a modest battery run for a long time. Whole-home backup covers everything, air conditioner included, but it needs more battery and often a soft starter for the AC. We walk your panel with you and put the circuits you care about on the backup side.
Does adding a battery change my utility agreement?
Adding storage is a modification to your solar interconnection, and your utility reviews and approves it on its own timeline. We prepare and submit the application and tell you what to expect. Your existing net metering agreement generally stays in place; utility rules on battery sizing and grid charging vary, and we go through them with you before anything is ordered.
Which home batteries do you install?
Tesla Powerwall, Enphase, FranklinWH, SolarEdge, Qcells Q.HOME and LG batteries, matched to your inverter and your goals. We match the battery to the equipment you already own, not the other way around.
What does a solar battery cost?
Battery cost depends on capacity in kilowatt-hours and how many units you need; the electrical work depends on whether a backup subpanel is added and how far the battery sits from the panel. State and utility incentives for storage have existed and changed over the years. We point you to the current programs with your quote, and we never promise a rebate we cannot confirm.
Batteries need a permit, an inspection and a utility interconnection application. All three are separate lines on the quote.
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