Will Solar Panels Work During a Power Outage?
Quick answer: Not on their own. Grid-tied solar systems shut off automatically during an outage to protect utility workers. To keep power, you need a battery with equipment that isolates your home from the grid, a special daytime-only setup, a generator, or an off-grid system.
Many people are surprised to learn that a standard rooftop solar system goes dark during a blackout, even at noon on a sunny day. It’s a deliberate safety feature, and there are several ways around it if backup power matters to you.
Why grid-tied solar shuts off in an outage
Most home solar systems are connected to the grid. When the grid goes down, utility crews work on lines they expect to be dead. If your system kept pushing power onto those lines, it could injure or kill a line worker. So grid-tied inverters are required to detect an outage and stop sending power, a function called anti-islanding. The IEEE 1547 standard requires inverters to stop energizing the grid within two seconds of an outage, and inverters sold in the US are certified to the UL 1741 standard, which includes that requirement.
The panels themselves keep producing voltage in sunlight, but with the inverter off, none of that power reaches your outlets.
Option 1: A battery with a backup gateway
This is the most common way to keep solar working in an outage. The system needs:
- A battery, such as a Tesla Powerwall 3, Enphase IQ Battery or FranklinWH aPower 2.
- A device that disconnects your home from the grid when it goes down, often called a gateway, backup switch or system controller. This lets your home run as its own small, isolated grid safely.
- A plan for which circuits get backup power. Some systems back up the whole house. Others back up a “critical loads” panel with essentials like the refrigerator, lights, internet and furnace fan.
During an outage, the battery powers your home and the panels recharge it during the day. How long you can last depends on the battery size, what you run and how much sun you get. A typical 13.5 kWh battery costs about $15,650 installed, based on EnergySage’s July 2026 data. See solar backup batteries for the full picture.
Option 2: Daytime-only backup without a battery
A few systems can provide limited power during daylight without a battery:
- Enphase Sunlight Backup works with IQ8 microinverters plus an IQ System Controller and load controllers. It can power a limited number of circuits during the day only, and loads have to stay well below the system’s rated output.
- SMA Secure Power Supply on some SMA inverters provides one dedicated 120-volt outlet with up to 2,000 watts during the day.
These are useful for charging phones and running a refrigerator during daytime, but the power drops or stops when clouds pass or the sun goes down.
Option 3: A generator
A portable or standby generator doesn’t depend on the sun. It has to be connected through a transfer switch or interlock installed by an electrician so it can’t back-feed the grid. Some battery systems can also be charged from a generator during a long outage.
Option 4: An off-grid system
Systems that aren’t connected to the grid at all keep running during utility outages, because there’s no grid connection to protect. They need large batteries and usually a generator, and they cost much more. See going off-grid with solar.
Is backup worth the extra cost?
It depends on how often you lose power and how much an outage costs you. Backup makes the most sense if you have frequent or long outages, medical equipment that needs power, a well pump, or a home office you can’t leave. In areas where your utility pays little for exported solar power, a battery can also save money day to day. If you have an existing solar system, many batteries can be added later, though you may need additional equipment to make it work with your current inverter.
