Does solar power work during power outage

Extreme weather events such as heat waves and hurricanes are becoming more common. Last year, the U.S. experienced as many as 22 weather or climate disasters, resulting in a huge spike in power outages. In fact, utility customers suffered 1.33 billion outage hours in 2020, a 73% rise from 2019.

This surge in unpredictable weather, coupled with an increase in working from home through the Coronavirus pandemic, means more homeowners are turning to solar and battery storage as an effective solution for keeping the lights on when the grid goes down. 

But there is some confusion around how to use solar panels during power outages and what to do if you have solar and the power goes out. This is where batteries come in. Here's a look at how coupling a battery storage system alongside your solar panels can enable you to keep the lights on in an outage.

Can I use solar panels during power outages? 

Since a grid-tied solar system must turn off (by National Electric Code) when the grid goes down, installing rooftop solar panels doesn't guarantee that you will have power during a grid outage. However, if you combine your solar system with battery storage you can tap into stored solar power during a power failure. Some home battery systems, such as the Panasonic EverVoltTM, enable you to keep your solar panels running throughout a grid failure so they can maintain a charge.

Graphic credit: Panasonic Life Solutions

What happens during a power outage?

Batteries are typically connected to the grid, as well as other power sources such as solar panels. A unique feature of the EverVolt battery system is that it can also be connected to an existing generator. This means that when the grid fails, and there is no solar power to charge the batteries, you can continue operating key appliances and mobile devices while living a somewhat normal life until grid power is restored.

As soon as an outage occurs, the battery detects it and turns on within milliseconds. The transition is so seamless that you likely won't even notice it happening. The battery will start delivering the power it has already stored, and if it's connected to solar panels or a generator it can continue to receive a charge. 

Graphic credit: Panasonic Life Solutions

"Many homeowners are now combining solar panels with batteries," says Vikki Kumar, systems engineer for energy storage and solar at Panasonic Life Solutions. "So if an outage lasts longer than expected, your batteries continue to charge from solar and provide power."

Can a battery power my whole home in an outage?

In a power outage the main purpose of a battery is to ensure you have sufficient power to be comfortable. At the same time, it's important to conserve power and minimize excessive loads to keep your battery operating for as long as possible.

This means that while it's possible to back-up your whole home, you will likely need at least three batteries to do this, which can be expensive. For basic backup, most homeowners choose to buy just one or two batteries and select which essential appliances they need in the event of a power failure.

The appliances you choose to keep running are known as your essential or backed-up loads and a certified installer will work with you to decide what these are. Typically, this would include your internet, mobile devices, lighting, and core appliances such as a refrigerator and coffee maker. A second battery can power your heating or air conditioner system.

Photo credit: Panasonic Life Solutions

How long can a battery keep my home running?

"An EverVolt battery system can provide power to select backed-up loads for about 6 to 9 hours, without solar charging the battery during this time," says Kumar. "You can prolong this with additional batteries and if you have solar panels you can expect battery charge to increase about 10 percent in a span of 30-40 minutes."

In an outage, it's your essential loads that automatically receive power. And while you can turn these appliances on and off to conserve electricity, you can't change which devices are backed-up unless you have a smart panel, which can be installed alongside your battery storage system.

A smart panel is controlled from a mobile app and gives you visibility on which appliances are being powered and how much power they are consuming. You can turn appliances on and off from the app too. This means you don't have to decide upfront which devices you want in your essential load.

Batteries powered by solar panels can keep your home running even when an outage lasts for several days. And while it is possible to back-up your whole home, just one or two batteries can easily give you what you need to stay comfortable and keep working with minimum interruption. 

For more information about making the switch to solar with Panasonic EverVoltTM solar and battery storage bundles, talk with a certified installer to get all your questions answered. To learn more about how going solar can be good for you and great for the planet, visit Panasonic's Green Living blog.

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