What does solar energy mean to you? Saving the environment? Saving money? Or maybe it’s independence from the electric utility. Solar panels let you generate your very own free, sustainable electricity. However, most solar panel systems installed in the United States are tied to the electric grid.
With a grid-tied system, you can still generate free, clean energy and, in many states, get “free electricity storage” through policies like net metering or New York’s Value Stack. And you will also (almost) always have access to electricity.
Grid-tied systems have to abide by the rules of the utility, and that means no electricity when the grid goes down unless you have a battery-backed solar system.
So the quick answer to the question of whether or not solar panels will work during a power outage is no. Solar panels will not be able to provide your home or business with electricity during a power outage. There are, however, two exceptions to this: your system is equipped with energy storage, or you forgo the benefits of grid-tied solar and opt for an off-grid system.
The Difference Between Off-Grid and Grid-Tied Solar
Your utility generates and distributes electricity through the electric grid. If you install a grid-tied solar system, you’ll be connected to the grid. You’ll be able to draw grid power from your utility when your system isn’t generating energy, and you’ll be able to send your excess energy to the grid for credit in many states (this is called net metering).
An off-grid system is, of course, not connected to the utility grid. In exchange for that sweet freedom, you won’t have access to electricity other than what is generated by your solar system and what is stored in batteries or produced by an onsite generator. However, you will be able to power your home or business if the grid goes down.
When it comes down to it, most solar energy systems installed in the United States today are, at least partly, installed to save money on electricity. They are not installed with the intention of being a completely independent power source. For many people, the money they’re saving and the reliability they get makes grid-tied solar the more popular option. However, this also means that the majority of the solar systems in the United States won’t be able to generate electricity when the grid goes down.
Why Won’t my Solar Panels Work During a Power Outage?
The only thing a properly installed solar system needs to generate free electricity is sunlight. So why can’t you use this electricity in your own home or business when the grid goes down?
It’s because of how a grid-tied solar system works. Sunlight hits the panels, generates electricity, passes through the inverter, and is used to turn on your lights or keep your food cold. When your panels are producing more electricity than you’re using, the extra electricity is pushed onto the electric grid.
If the electric grid is down and your solar system is pushing that extra electricity onto the grid, that’s a big problem.
Utility workers are working on those same power lines fixing the issue to get the area back up and running. They are doing this with the assumption that the lines are dead. Electricity from your solar system would make that assumption incorrect and can cause serious problems. In order to protect the utility workers and the grid itself, all grid-tied solar energy inverters are required to automatically shut down when the grid goes down and the power goes off.
How to Use Solar Panels During a Power Outage
There are two main ways you can still have electricity when the lights go out with solar energy: installing an off-grid solar system or installing a method of energy storage, such as batteries.
Off-Grid Solar Systems
Off-grid solar requires enough batteries to ensure you have enough electricity stored to get through the nighttime and cloudy days. This often makes it much more expensive than grid-tied solar systems. Off-grid solar is rarely a wise investment for most homes and businesses. Additionally, you won’t have the option to draw electricity from the grid in case your solar system isn’t generating enough electricity and the energy you’ve stored has run out.
However, it does give you complete energy independence, meaning you can use your solar system when the grid goes down. Off-grid solar is a good option for buildings in remote areas where grid-tied electricity isn’t available. An off-grid system may be worthwhile if you have a very remote cabin.
Battery-Backed Solar Systems
A grid-tied system is often the better option for those looking to save money with solar panels. You can also still get backup power when the grid is down if you install an energy storage system. Because you don’t need as many batteries as an off-grid system, it likely won’t be as expensive.
Installing one or a couple of solar batteries will allow you to store unused power generated by your solar system. You’ll then be able to draw on that power without putting utility workers in danger in the event that the electricity grid goes down.
If a battery backup system sounds like something you’d like to have, it’s important to understand the limitations. Though solar batteries are becoming more and more commonplace, they are still quite expensive for most homes and businesses. They can substantially drive up the cost of your solar system. As a general rule of thumb, one 9.8 kWh battery might cost around $15,000 (with installation) before incentives.
Because of this, many solar installers will advise you to select just a few necessary items to which you want to provide power. These could be things like emergency lighting, medical equipment, refrigerators, or personal electronics/chargers. Installing enough batteries to keep your home or business running like usual over a couple of days will likely cost more than most people are willing to spend. Here's a guide to help you select the number of batteries you'll need.
If backup power is important to you, but you aren’t looking to spend the money for a battery system, backup generators are often a less-expensive option. For just a few hundred or thousand dollars at your local hardware store, you’ll be able to keep your home or business running. However, these generators often run on fossil fuels. Not only are fossil fuels non-renewable, but they can be hard to come by during emergencies or natural disasters.
If you’re looking for a way to keep backup power costs low but like the idea of having solar batteries, consider supplementing a solar battery system with a traditional gas-powered generator.
Learn more about solar energy by downloading our one-of-a-kind solar buying guide. We dive deep into everything that you should know before investing in solar energy.