Will solar keep my power on in a hurricane outage?
Not with solar panels alone. An ordinary grid-tied solar system is built to shut off when the grid goes down, so it does not send power onto lines that crews are repairing. A battery set up for backup, with equipment that separates your home from the grid, can keep chosen circuits running, and the panels can recharge it in daylight. What it covers, and for how long, depends on system design.
At a glance
Standard grid-connected solar
Grid goes down.
- Grid outage
- Standard solar shuts off
Panels alone do not mean your home has backup power.
System designed for backup
A different setup.
- Isolation equipment
- storage
- designed circuits
What stays on, for how long, and whether solar recharges during an outage depends on system design.
Why panels alone go dark
The U.S. Department of Energy explains that home solar generally relies on the grid and, for safety, is "designed to switch off if the grid power cuts out" (DOE).
A big reason is the safety of line workers. A home system that kept feeding a section of grid already cut off from the utility would create an island of live wires that repair crews may not expect. Equipment that meets the IEEE 1547-2018 interconnection standard and the UL 1741 safety standard must detect an unintended island and go offline, within 2 seconds by default (NREL, 2022; NREL is now the National Laboratory of the Rockies).
In Florida, the Public Service Commission's Rule 25-6.065 covers customer-owned solar on investor-owned utilities. To connect under it, a system needs an inverter or other certified device that automatically isolates it from the grid when the grid loses power. The utility may also disconnect a customer's system for emergencies or maintenance on its grid. If a city-owned utility or co-op serves you, check its own rules. This is general information, not legal advice.
What a backup-ready battery changes
DOE says solar panels need a properly configured inverter and a storage system, such as a battery, to produce power on their own, and it describes battery-equipped home systems switching to island mode in an outage (DOE). When the grid goes down, the inverter must cut the system off from the grid while still supplying the home from the panels, the battery or both (NREL, 2014). That separation is what keeps backup power off the utility lines.
A planning guide from Oak Ridge National Laboratory, written for critical facilities and communities, lists the equipment that lets solar and storage run on their own: transfer or disconnect switches, a critical-load panel, smart inverters and controls. In an outage, such a system uses solar when available and the battery when needed, but over a long outage it may be limited by how much sun there is (ORNL). DOE notes that solar with storage can keep delivering power at night (DOE).
A battery helps in an outage only if the system is built to run on its own, separate from the grid (NREL, 2014). Whether yours would keep anything on depends on system design.
Whole home or essential circuits?
A backup system can be set up to power only critical loads while it runs on its own (ORNL). Limiting backup to essential circuits means the battery does not need to be as large (NREL, 2014). Which approach suits your household depends on what you need running and on system design.
Generators: the other option
DOE notes that diesel generators, the most common source of emergency backup power, need fuel deliveries, while stored solar power does not (DOE). The U.S. Consumer Product Safety Commission says portable generators are one of the leading causes of carbon monoxide deaths after storms (CPSC). Federal safety advice:
- Never run one inside a home, garage, basement, crawlspace or shed, even with doors or windows open. Put working carbon monoxide alarms, battery-operated or with battery backup, on every level and outside sleeping areas (CPSC).
- Run it outdoors, at least 20 feet from windows, doors and attached garages (Ready.gov).
- Never connect it to your home's wiring unless a qualified electrician has installed it with a transfer switch; otherwise it can energize wiring far beyond your home and put utility workers at risk. Let it cool before refueling, and do not store fuel in the house (OSHA).
If someone at home relies on powered medical equipment, Ready.gov suggests making an outage plan with their medical provider (Ready.gov).
Storm prep for rooftop panels
A storm checklist from FEMA and NREL explains that strong winds strain the points where panels are anchored, which can crack a roof and let rain in, and loose parts can become flying debris. Its checks are meant for several days or more before a storm, never once the storm is affecting the site. If you see damage or suspect an electrical problem, disconnecting is the safest step; shutdown steps vary, so ask your installer. Only trained, qualified electricians should work on the electrical parts (NREL and FEMA, 2022).
Questions to bring to a consultation
- Would this system keep any power on when the grid is down, and how does it separate from the grid?
- Which circuits would stay on?
- What happens after several cloudy days?
- How is it attached for Florida wind loads, and how do I shut it down before a storm?
Want to talk through outage backup for your home? Book a free 30-minute online consultation. No commitment.
General information only, not legal or financial advice.