Do Solar Panels Work When the Power Is Out?
Last edited
Author
Andrew Giermak
Solar and Electrification Writer and Editor
Editor
Andrew Blok
Electrification and Solar Writer and Editor
If the power’s out, and the sun’s out, why can’t I use my own solar power? If you’re new to the possibility of going solar, questions like these are good ones.
Solar anti-islanding regulations shut down residential solar systems when the larger utility power grid is out. This is done for utility worker safety, to get the grid up and running quicker, and for the safety and protection of you, your solar system, and your home.
However, solar battery backup can keep the renewable energy flowing, even when the power’s out.
See how much you can save by going solar with Palmetto
What happens to home solar panels when the power’s out?
When the power goes out, a solar power system, via its solar inverter, automatically shuts down your solar panels to keep electricity from going to the larger grid. This is an electrical code requirement and sometimes called anti-islanding. It’s a requirement for utility worker safety and protecting your solar equipment and the larger utility grid.
If your solar panels were feeding electricity into the grid, it would be dangerous for utility workers.
Having solar battery backup is an option to make sure you have power during an outage. Instead of shutting down, your system will disconnect during an outage and your battery power will automatically kick on.
What are your options?
Solar battery storage is one way to have power during an outage while the grid and your solar system are down. (You can also store energy to use at night, join a virtual power plant, or to avoid costly grid energy during peak hours.)
You can opt to put only essential devices and systems (medical devices, lights, chargers, router/internet, a mini refrigerator) on battery power. Or, you could back up all of your home with battery power, which will necessitate a larger, more expensive, battery bank.
A reliable company, like Palmetto, can help you determine what level of battery storage, if any, is right for you.
See how much you can save by going solar with Palmetto
Percentage of home power covered by battery backup with solar in an outage
| Battery storage capacity | 1 day outage with heating and cooling | 3 days without heating and cooling | 3 days with heating and cooling | 10 days with heating and cooling |
|---|---|---|---|---|
| 10 kWh | Not in study | 100% | 86% | Not in study |
| 30 kWh | 98% | 100% | 96% | 92% |
From: Lawrence Berkeley National Laboratory, 2022
A gas generator may be the more affordable choice compared to battery storage if you would rarely use batteries. However, a gas generator is only useful during a power outage whereas solar panels give you electricity, savings, and energy independence every day. A solar battery system is silent and clean, using free, renewable energy.
Solar generators are typically small and portable batteries and panels that can be good for powering a few devices, although there are large solar generator systems (which are no longer very portable) with more power capacity.
Using home solar panels plus battery storage
Solar battery backup gives you power in an outage and the chance to recharge them when the sun’s out.
Factoring your likely needs with battery storage is important to making sure your investment fits your expectations. Getting a large battery bank makes sense if you will regularly use battery power (i.e. each night), need it for whole-home power, or if it makes sense with your state or utility net metering or VPP credit or reimbursement programs. In some cases, a battery may not be a good fit.
Batteries have a life expectancy of about 10-15 years compared to home solar panels which are often guaranteed for 25 years and can last longer than that.
Incentives, tax credits, and rebates from state, local and utility levels may be available to you. N.C. State University’s Database of State Incentives for Renewables and Efficiency is a searchable site for such incentives and rebates.
The new Palmetto app gives more ways to save money and energy, especially when you connect your utility to your account. Plus, you can find savings on solar batteries and more in the app’s shop. You can also learn more with Palmetto’s online solar savings tool.
See what solar can do for you:
Frequently asked questions
Why is anti-islanding necessary?
Anti-islanding of residential solar systems makes sure power is not being sent through utility lines during an outage for the safety of the workers restoring the power. It also stops potential damage to the grid and your home’s system and electrical components.
How much does a home battery storage system cost?
Residential batteries can cost from $10,000 to $20,000 or more depending on the battery’s size and the local cost of hardware, labor, permitting, and more.
