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Solar energy has gained worldwide popularity--not only as a renewable energy source and a beneficial investment, but also as a blackout protection solution.
In this article we will delve into what happens to solar systems during a grid outage, and explore the available options that can help you have access to the electricity you need.
What Happens to a Solar System During a Grid Outage?
During a grid outage, most solar systems are designed to shut down, which seems counterintuitive at first--why would I install a solar system if it's going to become inoperable during outages, like everyone else's power?
However, this is actually an important safety feature implemented to protect utility workers who may be working on downed power lines or other grid components. Solar systems can produce more energy than required, which is usually sent back into the grid. If the grid is being serviced, this process could create dangerous and unexpected live wires.
Besides, most areas don't have frequent or extended outages; according to the EIA, electricity customers in the US experienced 7 hours of power interruption on average. Even without backup options, solar has proven itself as a worthwhile investment for homeowners.
Still, some areas experience more power interruptions than others. Areas with regularly occurring large storms, such as hurricane zones in Florida, can benefit greatly from blackout protection.
Luckily, there are a few solar options to provide backup power that are completely safe, and won't create dangerous grid conditions.
The obvious choice for solar backup is a battery--we'll get to those later. First, let's discuss options that don't require this additional purchase.
Systems that provide functionality during an outage generally do this by creating a "micro-grid", or a localized electric grid that can disconnect from the main grid to operate autonomously.
The most prominent example of a micro-grid without a battery is Enphase's "Sunlight Backup" feature. Sunlight backup uses Enphase's IQ8 microinverters and System Controller 2 (essentially an automatic grid transfer switch), enabling customers to utilize their solar system for powering specific outlets when the grid is down.
It is important to note that this functionality is contingent upon the system's production of electricity, which means the results can vary. If it's cloudy outside, production will be less, and this option cannot be used during evenings or nighttime after the sun has set.
This feature also only provides power to a maximum of 8 outlets, and costs around $5,000. As this tech is still relatively new to solar, it's expected to improve in the future.
For now, though, It's usually more cost effective to add a battery.
Solar Batteries - Nighttime Protection
Solar panels do not generate electricity at night, which means options like Enphase's Sunlight Backup cannot provide nighttime protection.
To ensure power availability during the night, especially during outages, a battery becomes essential. Integrated solar batteries typically include a grid transfer switch—Enphase’s IQ Batteries are no different, as they require the same System Controller 2 that is used for Sunlight Backup.
The System Controller can disconnect the system from the grid, routing excess energy to the battery/batteries instead.
Solar Without Batteries
Solar With Batteries
After the excess solar energy is captured, it can be used at night or during power outages. This allows you to keep your lights on and essential devices powered, providing a reliable energy source when the grid is down.
Solar batteries have come a long way, and now many of them also include features like uninterrupted backup power, storm detection planning, and grid use minimization--all accessible from an app on your smartphone, computer, or tablet.
Another method for backup that won’t create dangerous backfeed is an off-grid system or a grid-independent power source like a portable power station or a generator. Since they’re not connected to the main power grid, off-grid systems continue to supply power even during outages—however, they’re often quite expensive, particularly with the amount of battery backup required.
True off-grid systems will usually require enough battery backup for around 3 days, and costs can stack up quickly. For areas without frequent or extended outages, this doesn’t always make sense.
An off-grid power station or solar generator, like our Power Bank, is a good affordable alternative for battery backup.
These batteries work similar to a gas generator, where devices are connected directly. Some generators can be connected to your home’s essential loads with a manual transfer switch.
Unlike gas or diesel generators, however, solar generators are environmentally friendly, emit no harmful emissions, and do not require fuel, making them a convenient and sustainable off-grid power solution.
One of these power stations can harness solar energy from standalone solar panels, the grid, and even vehicles. They are perfect for providing power for appliances and devices during outages or in remote locations.
Plus, you don’t even need a home solar system to use one.
Solar energy systems can continue to function during power outages with the right equipment and configurations. If you're interested in backup power, we highly recommend investing in a solar-integrated battery system or purchasing a portable power station.
It's crucial to assess your budget and energy needs before deciding on the best option for your circumstances.
Portable power stations typically cost less, and can be used even without a home solar system, while integrated solar batteries will usually provide longer, more seamless backup at a higher price.
At Project Solar, we offer both integrated solar batteries and portable backup solutions. Check out this article, "Our Top Picks for Home Solar Backup", for more information on which option may be best for you.