Pillar guide
Solar, Batteries & Backup Power
Rooftop solar, battery storage, and standby generators all connect to the same place — your electrical service — and each has its own code requirements. This guide explains the electrical side of going solar, how to choose between a battery and a generator, how to size backup power, and how the permit and utility process works.
Updated 2026-10-15
Solar is an electrical project first
Panels on the roof are the visible part, but the decisions that change the price happen at the electrical panel. Where the solar connects, whether the busbar can accept it, rapid-shutdown equipment, and utility interconnection rules all determine whether you need a panel upgrade, a supply-side connection, or a main-breaker derate.
Backup power: batteries vs generators
Batteries are silent, need almost no maintenance, and pair with solar to recharge during long outages, but their stored energy is finite. Standby generators run as long as fuel lasts and handle large loads like central AC easily, but need annual service and produce noise and exhaust. Many homes in outage-prone areas end up with one or the other sized to essential circuits rather than the whole house.
- Typical outage length where you live
- Which loads must run: well pump, sump pump, medical equipment, HVAC
- Fuel availability: natural gas, propane, or solar recharge
- Budget for install plus ongoing maintenance
Incentives changed in 2026
The federal residential clean energy credit (25D) ended for systems installed after 2025, so the economics now rest on local utility rates, net-metering or net-billing rules, and state or utility rebates. Get a payback estimate that uses your actual rate plan and export compensation, not a national average.
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Frequently asked questions
Does adding solar require a panel upgrade?
Not always. Under the NEC 120% rule, a 200A busbar with a 200A main can usually accept up to about a 32A solar backfeed breaker. Larger systems may need a main-breaker derate, a supply-side tap, or a panel upgrade. Your installer's electrical design will show which applies.
Can a home battery run my whole house?
Usually not for long. Most single batteries store 10–15 kWh and deliver 5–11 kW continuously. That covers essentials for a day or more, but central AC, electric ranges, and EV charging drain them quickly. Whole-home backup typically needs multiple batteries or a generator.
How loud is a standby generator?
Most residential air-cooled standby generators run in the low-to-mid 60s dBA at about 7 meters under load — similar to a conversation or a window AC unit. Many local codes set placement distances from windows, doors, and property lines.
Related topics
This guide is general information, not engineering or legal advice. Electrical codes are adopted and amended locally — consult a licensed electrician and your local building department for your project.