Do Solar Panels Work During a Power Outage?

Reviewed by John Ihle, MN Master Electrician (AM005101) · NABCEP-credentialed · iSolar, Saint Paul Park, MN · Last reviewed October 2026

Why your panels go dark when the grid does

It surprises almost everyone the first time. A summer storm knocks out power across the neighborhood, the sun comes back out an hour later, and your solar system is producing nothing. Nothing is broken. A standard grid-tied system is designed to shut off when the grid goes down.

The reason is lineworker safety. When Xcel or your co-op sends crews to repair a downed line, they treat it as dead. If thousands of rooftop inverters kept pushing power onto that line, it could be energized while someone has their hands on it. That situation is called an unintentional island, and the rules exist to prevent it.

The standards behind it: UL 1741 and IEEE 1547

Every grid-tied inverter we install is listed to UL 1741, the safety standard for inverters, and tested against IEEE 1547, the national standard for connecting distributed energy to the grid. An NREL primer on IEEE 1547-2018 summarizes the requirement plainly: when an island forms, the inverter must cease to energize and trip within 2 seconds. The inverter constantly watches grid voltage and frequency. When they drift out of bounds or disappear, it disconnects, waits for the grid to return and stabilize, and then reconnects on its own.

So your panels still make DC power in the sun during an outage, but without an inverter that can safely form its own island, that power has nowhere to go.

Your four options for outage power

Option 1: Add a battery

A battery is the most complete answer. During an outage, a backup system opens a transfer switch that isolates your house from the grid (so you are not energizing Xcel's lines), and the battery inverter forms a stable "mini grid" for your home. The solar inverters see that local grid and keep producing, recharging the battery during the day. With the right size battery and some load discipline, a Minnesota home can ride through a multi-day summer outage.

Things to know:

• Size to loads, not marketing. Sump pump, furnace blower, fridge, freezer, well pump, Wi-Fi and some lights are the usual list. Our battery sizing guide and battery sizing tool walk through it.
• Winter outages are harder. Short December days and snow-covered panels mean little recharge, so a battery that lasts days in July might last a day in January.
• Incentives exist. Xcel's battery incentive pays about $175 per kWh, up to $5,000 (or $370 per kWh for income-qualified customers). Minnesota's separate state storage rebate was running low on funds as of August 2026.

See our battery backup page for the systems we install, and how we choose between Enphase and Franklin.

Can I add a battery to my existing solar?

Usually yes. Enphase systems can add IQ Batteries with the system controller. String and SolarEdge systems can add an AC-coupled battery or move to a hybrid inverter. Your panel and service capacity matter, so expect an electrical review.

Option 2: Enphase IQ8 Sunlight Backup

Enphase's IQ8 microinverters are "grid-forming," which means they can create their own local grid without a battery. Enphase markets this as Sunlight Backup: power for essential devices during daytime outages, even without a battery.

The fine print matters, and installers sometimes skip it:

• It needs extra hardware. IQ8 microinverters alone do not provide backup. The house must be isolated from the grid by Enphase's system controller (the backup transfer switch), and Enphase's installer guidance says at least one IQ Load Controller is required to keep the system stable off-grid by shedding non-essential loads.
• Daytime only. With no battery, there is no stored energy. When the sun sets or a heavy cloud passes, available power drops with it.
• Small loads only. Enphase describes Sunlight Backup systems as designed for essential, low-load appliances. A fridge and phone chargers, yes. A well pump starting up or central air, likely not.

If you have IQ8s already, Sunlight Backup can be a step toward full backup, because the same system controller later works with IQ Batteries. If someone told you "IQ8 means you have backup," ask what else was installed. If there's no system controller, you don't.

Option 3: A generator, with or without solar

Generators remain the most cost-effective way to power a whole home through a long winter outage. A natural gas standby unit runs for days, and solar has no effect on its operation. The two can share a house as long as each connects safely:

• A generator must connect through a transfer switch or a listed interlock, never a backfeed cord through a dryer outlet.
• When the generator is running and the house is isolated, your grid-tied solar stays off unless the system is specifically designed to work with the generator. Most standard systems simply wait for the utility.
• Some battery systems can accept a generator input to recharge the battery. That is a design decision to make up front.

We compare the two head-to-head in generator vs. battery for Minnesota outages.

Three outage myths we hear every storm season

• "My system is broken because it went off in the outage." It's working exactly as listed. A system that kept exporting during an outage would be the dangerous one.
• "I can just flip off my main breaker and use my solar." No. Opening the main does isolate the house, but a standard grid-tied inverter still sees no grid and stays off. Backup requires an inverter or battery that can form its own grid, plus listed transfer equipment.
• "A bigger solar array means better backup." Not without storage. Panel size affects how fast a battery recharges, but the battery and the backup equipment decide what you can run and for how long. In an outage, the controller and battery sizing matter more than the panel count.

What to do during an outage if you have solar

1. Grid-tied only? Do nothing. The system will restart on its own a few minutes after power returns. Don't flip breakers trying to make it work.
2. Battery system? Trim loads. Skip the dryer, oven and electric water heater, and let the battery handle essentials.
3. After power returns, check your monitoring app the next sunny day. If production is still zero, a tripped breaker or offline gateway is likely. Our guide to fixing offline solar monitoring helps you tell a communication glitch from a real fault.
4. Storm damage? If you see hail damage or loose panels, stay off the roof and call your installer.

Plan backup the right way

Start with the loads you can't live without, then choose the battery, generator or IQ8 setup that covers them for the outages you actually see. Request a backup quote and we'll size it to your home's essentials, with the electrical work done by our own licensed electricians.

Sources

• NREL — A Primer on the Unintentional Islanding Protection Requirement in IEEE Std 1547-2018
• Enphase — Sunlight Backup installation support
• NREL — Highlights of IEEE Standard 1547-2018