A huge benefit of investing in a solar power system is the energy independence it offers. When you have a solar panel system tailored to your lifestyle and energy needs you can nearly eliminate your monthly utility bill. It’s only natural to wonder if having a solar panel system also reduces your vulnerability to power outages.

Unfortunately, the answer is most likely no. There are ways—like batteries and home storage solutions—to upgrade your solar system to keep your lights on if the power goes out, but they are not generally the default design option. It’s important to understand how this works (and why) before investing in solar.

Why Won’t My Solar Panels Work When the Power Goes Out?

When your home solar system is installed, your home remains attached to the local utility grid. While your solar panels generate electricity for your home, if you aren’t using as much as you’re producing, the power gets sent to the grid (which allows you to participate in net metering programs).

During a power outage, utility workers are sent to fix the problem. To protect these workers and the grid, any grid-tied solar energy inverters are required to automatically shut down. It’s a critical safety issue.

It’s because your solar panels are operational; they do not work during a power outage.

Why Not Go Off-Grid?

If you have enough solar panels to make it through the day, why not rely on them alone?

Unfortunately, being completely off-grid isn’t as simple as flipping a switch. There is equipment to disconnect and legal tape to navigate—it may even be illegal, depending on your area, and doing so may invalidate the certificate of occupancy for your home.

Even if you did everything required to go off-grid, you’ll be left with no backup power solution. If there isn’t enough sunlight, you won’t have the energy required to run your toaster, let alone important necessities like your heating system during the winter.

Once again, this is a safety issue. Remaining tied to the utility grid is both easier and more reliable for you and your home. However, you may still want to keep your lights on when the grid goes dark.

What’s the Solution?

If you have solar installed on your roof and the power goes out, your solar system stops working for the safety of utility workers. However, this isn’t the case for any solar battery backups you may have. Depending on your solar system layout, you can invest in a series of batteries designed to store the power you generate.

When night falls or when the power goes out, these batteries are available with previously stored power to keep your lights on, HVAC system going, and common household appliances running. The batteries do not push excess power out onto the utility grid like your solar panel system, so they can remain accessible even if the grid is down.

How Does a Battery Backup Work?

There are two types of battery systems: Direct Current (DC) coupled systems and Alternating Current (AC) coupled systems. Solar panels generate DC power, but your home runs on AC power. (Find definitions for these and other solar terminology here.)

DC-Coupled Battery Systems

These systems are efficient up to 97.5% due to only one inverter within the system. Sunlight hits your solar panels, which sends DC power to your batteries. Your batteries charge and once they’re maxed out, they send DC power to a battery system controller. From there, your battery battery system controller inverts and distributes AC to your household appliances and as needed.

This system is more simple, but it is nearly impossible to integrate into existing solar panel systems.

AC-Coupled Battery Systems

With this system, your solar panels and batteries each have their own inverters. Within the panels the power is converted from DC to AC power, which you can use in your home. Then, in the battery, the power is inverted back to DC power for storage. 

An AC-coupled battery system is the best option if you’re integrating into an existing solar panel system. However, because of the multiple inversions, there is a slight power loss.

Whether your house uses DC-coupled or AC-coupled battery systems, these inversion steps help you:

• Keep your house compliant with city requirements to turn off all power during a power outage.
• Provide your house with power from a safe source, which does not push excess energy out to the grid if it is down.

With your battery backup, the electricity you store is not stuck in one place when the power goes out. If the utility grid is down, your batteries or other home storage solutions are available and will kick in to power your home.

How Long Will Batteries Support My Home?

The answer to this question is complicated. The easy consideration is the size of your battery backup. Residential batteries can store anywhere from 5 kWh to 15 kWh per battery, and more batteries equals more storage.

An average home in the U.S. consumes about 900 kWh of electricity per month—or about 29-30 kWh per day. This means a small battery would cover your basic household usage for a few hours while a larger backup system could keep your whole home running for a day or longer.

However, how long your batteries will support your home changes with the optional configurations available. There are many ways to adjust your backup battery power distribution to customize how it works including:

• Keeping your battery in working mode to only dispense power during an outage.
• Adjusting your batteries so they provide power any time your solar panels do not meet your energy needs.
• Customizing your battery distribution to supplement your electricity during peak hours to reduce typical utility bills.

Where Can I Get a Battery Backup?

At Blue Raven Solar, we partner with multiple solar battery manufacturers and can help you pick the best option for your household’s electricity needs—whether you’re adding a battery backup system at the time of your initial installation or later on.

When you contact us for a free savings estimate, we’ll evaluate:

• Your home geographical location and how it affects your potential power production.
• Your average energy usage and overall energy goals.
• Your budget and lifestyle.

From there, we’ll provide information on how much you can save on your monthly utility bill by switching to solar energy—with or without a battery system. We adjust the recommendations based on your preferences, including what kind of battery backup you might like to add.

With the right partner, you don’t have to investigate every solar battery brand before making your choice. Our solar experts do the vetting for you and are available to answer any questions you have.

Reach out today to discuss your goals for a solar system and battery options to ensure you’re not left in the dark when the power goes out.