Montoya Whole-Home Energy Upgrade
Windows, solar, and battery storage upgrade for a 1970s ranch home in Rio Rancho. Reduced energy costs by 85% and added backup power.
$3,100/yr
Annual savings
6.8 kW
System size
18
Panels
5.8 tons/yr
CO2 offset
“I called three solar companies before choosing Epex. They were the only ones who looked at my whole house — not just the roof. They recommended new windows first, which actually reduced the solar system size I needed. Saved me thousands.”
The Challenge: A 1970s Home Bleeding Energy
Jennifer Montoya's ranch-style home in Enchanted Hills was built in 1975, and it showed in her energy bills. The original single-pane aluminum windows offered almost no insulation, letting New Mexico's intense summer heat pour in and winter warmth escape. Her PNM bills regularly exceeded $300 during peak months, and the aging HVAC system ran constantly to compensate. Three solar companies quoted her a large system to offset those bills, but none asked why the bills were so high in the first place.
The Whole-Home Approach
Epex took a different approach. Before sizing a solar system, our team conducted a comprehensive energy assessment of the entire home. The diagnosis was clear: replacing the 24 original windows with energy-efficient, low-E windows would reduce the home's cooling load by nearly 40%. That meant Jennifer needed a smaller solar system — 6.8 kW instead of the 10 kW other companies had quoted — saving thousands on equipment costs. We also added a battery storage system to provide backup power and enable time-of-use optimization with PNM's rate structure.
Coordinated Execution
The project unfolded over eight weeks in a carefully sequenced plan. Our window crew started first, replacing all 24 windows over two weeks. This gave the home's envelope time to stabilize before we sized and installed the solar system. The battery storage went in during the final week, integrated with the solar inverter for seamless operation. By doing everything under one contract, Jennifer avoided the markup and scheduling headaches of hiring three separate contractors.
The Result
Jennifer's energy costs dropped by 85%, from an annual average of $3,600 down to just $540. The battery system keeps her home powered through outages — something she tested firsthand during a grid disruption last winter. The new windows transformed the comfort of her home: no more drafts, no more hot spots by south-facing windows, and noticeably less road noise from the nearby highway. Combined with the 30% federal solar tax credit and the 10% New Mexico state credit, the entire project will pay for itself in under seven years.