Will my solar keep working? The answer can be yes, but without a battery backup system, that’s going to be a no. Learn how panels operate in a power outage and how adding a battery backup to your system can benefit you.
It’s one of the questions we hear all the time: Will solar panels work if the power goes out?
Short answer: No. But that doesn’t mean you’re totally in the dark. Here's why solar panels don’t work in a blackout and how to work around it.
Why Don’t Solar Panels Work in a Blackout?
The goal of solar is to produce the most that we can but you may not be able to use the power being produced. Fortunately, you don't need to turn off your solar just because you can't use it at that point: we send it back to the grid. Then your neighbors can benefit from it, and you can get compensated from the utility for all the energy you produce. (This is net metering in a nutshell. More on that here.)
So that’s a win—you get to save money off the power you can’t use. Without the grid or other electricity sink as a buffer, if your panels made more power than you could use right at that moment, you could cause damage to your home or solar system.
However, this becomes a safety issue during a power outage: Your solar has to stop producing, or you could put the linemen who are trying to fix those electric utility lines at risk.
How Can I Keep My Solar Working in a Power Outage?
Here's one big piece of good news: If you have a backup battery, your solar will keep producing.
Consider a scenario like this: On day one, there’s a big thunderstorm and the power goes out. It’s not sunny enough for your panels to make much power, but your battery kicks in and keeps your home running—lights, fridge, etc. On day two, if power hasn’t been restored yet, but the clouds have cleared and it’s now a sunny day, your panels are back in the game making enough power to run your home and recharge your battery. Your home is going to use any of the produced solar power before it even goes to the battery, which increases the utility of the system.
Learn more about backup mode and other ways to use a solar backup battery.
Battery backup systems have these devices to disconnect your home from the grid when you have a blackout. The idea is that this battery then becomes your buffer for that solar production—it can store any energy being produced that otherwise would have no place to go and it can even turn your solar off if it needs to. It's very similar to an automatic transfer switch for a standby generator.
This means a few different things for your solar and your battery: First, it means that you have backup power stored in your battery to run your home. And, because you’re temporarily disconnected from the grid, it means that your solar will keep producing power, keeping your battery charged.
Generator vs. Backup Battery for Home
Speaking of a generator, Marcus Shapiro, Senior Solar Advisor, rattles off several reasons why many people opt for a battery over a generator: “They're quiet. They're not stinky, no fossil fuels, no maintenance, no lag time when it kicks on.” And while portable generators are less expensive, a more apt comparison is a whole-home generator, which is going to be much closer in terms of cost.
What Can I Power with a Battery?
It depends on the size of your system, but we can do a lot more with the batteries that we have available now than we could five or 10 years ago. Everything beyond really heavy loads (you know, big motors turning on), we can do fairly comfortably.
This includes things like lights, the fridge, freezer, your internet router, even an electric range—they can all be powered by a battery. Within reason: You can definitely boil a kettle of water, but maybe don’t cook a turkey!
Appliances that may be too large for a conventionally sized system include heat pumps, big air conditioners, and power tools. But when the system is designed with your needs in mind, it should be able to handle just about anything.
Still on the fence? Want more info? Schedule a site visit with a solar advisor to talk through your options.