Whole-Home Battery Backup for a Northampton Home
Project Overview
When a Northampton homeowner wanted to add reliable backup power to their existing solar system, they turned to Valley Solar for a seamless, code-compliant battery retrofit. The home already had a functional Enphase solar array, but no backup capability — meaning power was lost during outages.
Valley Solar designed and installed a Tesla Powerwall 3 system, paired with a Tesla Backup Gateway 3, providing whole-home backup without sacrificing efficiency or aesthetics. The project included careful planning around existing Enphase equipment, complex conduit routing through multiple additions, and an outdoor battery installation optimized for long-term safety and accessibility.
Customer Goals
The homeowner’s goals were clear: make their existing solar system more resilient and ready for modern energy needs.
Whole-home backup
Ensure continuous power through outages without needing a generator.
Integrate with existing Enphase solar
Add storage without replacing panels or microinverters.
Clean exterior installation
Mount batteries outdoors with minimal visible conduit while preserving access and aesthetics.
Long-term reliability
Choose proven, maintenance-friendly technology with active monitoring and local service.
Valley Solar Solution
Valley Solar engineered a solution centered on the Tesla Powerwall 3, which integrates inverter and battery functions in one sleek, compact design. This setup enables full-home backup with simplified wiring and intelligent load management — ideal for homes with limited basement access.
Problems Faced
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Complex existing setup — pre-existing Enphase system with limited documentation.
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Long conduit run — required routing across basement, breezeway, and shed to exterior battery location.
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Low ceiling heights — basement ranged down to 63″, limiting equipment placement.
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Tight electrical layout — main service panel in a crowded space with subpanel nearby.
Solutions
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AC-coupled Tesla Powerwall 3 system — 23 kW inverter, 27 kWh battery capacity, connected via a Tesla Backup Gateway 3.
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Smart electrical integration — site export limited to 10 kW to meet National Grid interconnection requirements.
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Outdoor battery placement — east side of the garage, mounted under a protective overhang with safe clearances.
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Professional coordination — communication with prior installer (NE Solar) to confirm Enphase microinverter type for compliance and interconnection.
System Size
23 kW DC
Storage Size
27 kWh
Impact
This Northampton home now operates as a fully backed-up residence, with intelligent battery storage that automatically powers the home during outages.
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Energy Security — Full-home backup for heating, hot water, and EV charging.
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Seamless Integration — Enphase solar + Tesla storage communicate smoothly under the new gateway.
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Smart Performance — Automatic load control and solar charging during outages.
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Resilience for New England Weather — Batteries installed outdoors for year-round reliability.
