Will Solar Keep the Lights On During an Outage?

Grid-tied solar shuts down for safety

Most grid-connected solar systems automatically stop sending power when the utility grid is down. This protects lineworkers and the public from unexpected backfeed. Solar panels alone therefore should not be marketed as whole-home outage protection.

A battery changes the plan

A properly designed battery system can isolate from the grid and power selected circuits or, where the equipment and design allow, a larger portion of the home. Runtime depends on battery capacity, state of charge, solar production, and what you choose to run.

• Prioritize refrigeration, lights, internet, medical devices, and selected outlets.
• Air conditioning, electric water heating, pool equipment, and EV charging can reduce runtime quickly.
• Ask for a written critical-load plan and realistic runtime scenarios.
• Confirm utility interconnection and local permitting requirements for the battery configuration.

Design for your version of resilience

Some homeowners want a few quiet essentials for short outages. Others want longer-duration support during hurricane recovery. Those are different systems. We start by identifying the loads you care about and model the storage around them.

Make a backup list before comparing batteries

Walk through the house and list the things you want working during an outage. Start with refrigeration, lights, internet, and the outlets you rely on. Put larger loads such as air conditioning and EV charging on a separate part of the list so the designer can evaluate them explicitly.

Then describe the outage you want to prepare for. Getting through a short interruption and supporting a home through several cloudy days call for different planning. Ask what the proposed system can power at the same time, what it will leave off, and what assumptions the runtime estimate uses.

• Essential circuits you want included
• Larger appliances you want evaluated
• How long you want backup to last
• Whether you already have solar