First, how much can you save by adding batteries, and what's your payback time? 

A couple factors can help answer this question: what’s the final cost of adding batteries, considering they’re eligible for the 30% federal tax credit and, quite likely, state or utility incentives to help bring the cost down? Also, what's your energy rate plan, and what are peak rates in the afternoon and evening for time-of-use rate plans (in states like California, Nevada, or Arizona, for instance)? This is when batteries provide the most value because you can store excess solar generated by your system and then use it to power your home during peak hours around and after sunset when your solar is generating little or no power.

Working with an installer, you can determine roughly how much energy you use during peak hours, your peak electricity rates now, and an estimate of future rate increases. Then your installer can estimate how much money the batteries could save you over time, what the payback period might be, and how much you’ll continue to save long-term.

Second, how frequently do you experience power outages? Are you in an area that experiences extreme weather like storms or heat that affects the electric grid? Do you want to protect yourself against these outages? If so, then adding batteries with backup power capability is probably a good idea.

If you have an Enphase Energy System that doesn’t have batteries (or you already have batteries and want to add more), Enphase technology makes it easy to add Enphase IQ Batteries down the road to store, use, and sell excess solar energy—or add resiliency against power outages, day and night.

Based on your electricity usage, your Enphase-certified installer can help you determine the right amount of battery storage to keep your house powered during outages. They’ll also be able to determine the best place to install new batteries, whether that’s inside a garage or on an exterior wall of your home, depending on the amount of free space you have for them.

For homeowners in NEM states like California, adding batteries along with new panels can take your energy savings even further—by using the new panels to charge your battery for nighttime use, you free up more of your system's original production capacity for exporting to the grid and getting increased credits in return.

Any IQ Batteries you add are eligible for the 30% federal tax credit, as well as potential state and utility incentives that help bring down the cost, shorten your payback time, and increase your return on investment.

If you already had an Enphase IQ Battery installed with your Enphase Energy System and you decide you want more backup, it's easy to do. You can add up to 16 Enphase IQ Battery 5P units, totalling 80 kWh of capacity, to your system. Just ask your Enphase-certified installer, and be sure to have them help you take advantage of any state and utility incentives for the new batteries. You’ll also get the 30% federal tax credit for those batteries.