Patel Solar Battery Retrofit
Added 13.5kWh battery storage to an existing Epex solar installation in Albuquerque's Northeast Heights. Seamless integration with the original system.
$800/yr
Annual savings
13.5 kWh
System size
2.1 tons/yr
CO2 offset
“After the power outages last winter, we added battery storage to our existing solar system. Epex made it seamless — same crew that did our original install came back and had everything running in a day. Total peace of mind now.”
The Challenge: Solar That Stops When You Need It Most
David Patel had been an Epex solar customer for two years, and his 7.2 kW system was performing above projections. But during the winter storms of early 2025, he discovered a frustrating limitation: when the grid went down, his solar system shut off automatically. This is a standard safety feature — grid-tied solar systems must disconnect during outages to protect utility workers — but it meant David's family was left without power despite having solar panels on their roof. After two outages in three weeks, David called Epex about adding battery storage.
The Solution: 13.5 kWh of Backup Power
Epex recommended a 13.5 kWh battery system that integrates directly with David's existing solar installation. The battery stores excess solar energy produced during the day and provides seamless backup power when the grid fails. During an outage, the system automatically islands the home — disconnecting from the grid and powering essential circuits from the battery while the solar panels continue charging it. The result is reliable backup power for refrigeration, lighting, Wi-Fi, and medical equipment without a noisy generator or a single gallon of fuel.
Same Crew, Same Day
Because Epex had designed and installed the original solar system, the retrofit was straightforward. The same crew that wired David's original inverter returned and completed the entire battery installation in a single day. No new permits were required for the battery addition, and the existing monitoring app was updated to include battery charge level and backup status. David went from scheduling the appointment to having a fully operational battery system in less than a week.
The Result
David's home is now resilient against grid outages while saving an additional $800 per year through time-of-use rate optimization. The battery charges from solar during midday when PNM rates are lowest, then powers the home during the evening peak rate window. The system has already carried the household through two brief outages since installation, each time switching over so smoothly that the family only knew from the app notification. For David, the investment was about more than savings — it was about peace of mind knowing his family is covered no matter what happens with the grid.