A Home Backup Generator or Solar Battery?

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Keeping your power on during an outage is crucial. There are a few ways to do this, depending on your household needs. Find out whether a generator or solar battery is right for you.

If you've invested in solar panels, ensuring you have a constant energy supply — even when your panels aren't generating power — is important.

Why You Need Backup and Not Just Standalone Solar

Photovoltaic (PV) solar panels convert photons from sunlight into electrical energy you can use to power your home. Therefore, they can only generate power during the day and not at night. Plus, if your home solar system is connected to the grid and you don’t have a way to store the power you’re not immediately using, then your panels will stop working when the grid goes down.

To keep your power on during an outage, your most dependable options are a permanently installed home backup generator and an energy storage system (aka solar battery backup) for your rooftop solar system.

How Does Solar Battery Backup Work?

A solar backup battery stores the excess energy your solar electrical panels produce so you can use it later.

Installation – Solar battery backup for your home is typically wall-mounted and can either be installed by an electrician or, in some areas (like California), by a non-electrician when solar is installed simultaneously. Your home solar battery will be connected to both your solar and home electrical panel. It can be programmed to turn off and on automatically as power is needed.*

How long it can power your home – The size of your house, the size of your home solar battery, and how much energy you need will affect how long your battery backup system will be able to power your home. It could be overnight. It could be over a week. (Use this handy calculator for an estimate.) That’s why it’s important to talk to an expert before installing. You’ll get an idea of what you can expect and be able to make an informed decision about how many batteries would be right for you.

Cost – A solar energy storage system for a medium-sized home usually starts around $10,000 and increases for larger homes or greater energy needs.

Power when you need it – A home solar battery can be configured to meet your specific needs. For instance, you can set it to provide power when the price of electricity is high during peak demand times, like in the evening. You can also set your solar battery to “maximum self-consumption” mode, where your solar battery is automatically used to power your home whenever your solar production is not able to meet your home’s energy needs (such as during a rainstorm, heavy cloud cover, or at night).

Portable vs. Permanent Generators

There are notable differences between portable home generators and permanently installed home backup generators, also called standby generators. Portable generators, which can cost as little as a few hundred dollars, typically use gasoline for their power. You can buy these at home improvement stores; they’re small and can be moved to wherever they are needed. Portable generators are not wired directly into your home’s electrical panel, and they typically supply a limited amount of power compared to permanent home generators.

How Does a Home Backup Generator Work?

An automatic home backup generator offers last-resort backup power that is separate from your rooftop solar system.

Time – Because a permanently installed backup generator can be fueled by natural gas or another fuel source, it can run for an extended period of time during a power outage. This can be especially important during a severe weather event or extended grid failure.

Installation – A permanently installed generator can’t be moved. It’s typically housed outside in a durable metal casing, much like an air conditioning unit and is installed directly to your home’s electrical panel. It will automatically turn on if your power goes out.

Fuel – Rather than using collected solar energy, a standby generator usually uses natural gas, propane, or even diesel. This is unlike a portable home generator, which often relies on gasoline (which may be scarce during a disaster) to produce a limited amount of power.

Cost – The smallest standby generators cost around $2,000, but larger homes with more electricity needs and appliances will require larger, more expensive generators to reliably power all essential appliances and lights. It’s important to speak with a local energy dealer to find out what a home backup generator might cost, including installation.

Emergency vs. Regular Use

If you have a rooftop solar system but no backup option, then your house switches from solar energy to electricity from the power grid whenever the sun goes down.

Homeowners who want to rely less on the electrical grid for daily power can install a battery that collects, stores, and uses renewable energy to provide power at night. Solar with battery backup is also an ideal source of power during an outage, so you’re getting double the benefit with a single solution.

If you simply want to be prepared for an unexpected power outage, a permanently installed home generator — powered by an independent fuel source — will give you that protection.

Combining Standalone Generators and Solar Storage for Maximum Security

Many people seeking the ultimate level of stability have paired both a home energy storage system with a home generator. This combines the ability to use solar power, day or night, with the safety net of a generator that can provide power for your home when the electrical grid is down and the solar battery is depleted.

What Generator Option is Best for Me?

It’s wise to boost your home’s energy resilience if you live in a state that is subject to:

  • Power outages, like California
  • Hurricanes, like the Gulf Coast or Eastern Atlantic states
  • High winds, like in the Plains states
  • Tornadoes, like in the Central and Midwest states

If you already have solar or are thinking about solar and live in one of these regions, then solar + battery storage is a smart choice. If your power has gone out even once in the past 12 months, it’s a good idea to think about broadening your protection by adding a standby generator.

Maybe solar electric panels aren’t an option for you — yet. Say you’re restricted by your HOA. Or your home needs a roof replacement before installing panels. Then opting for a standby generator is a proactive way to keep the lights on during an outage. You can always add solar or solar with battery backup later.

If an outage is imminent and you don’t already have solar energy storage or a standby generator, try to get a portable generator and a container of gas before severe weather hits. Once the outage hits, shelves are often bare, and there may be a gasoline shortage. Severe weather may also cause icy roads or flooding, making it impossible to get to the gas station. You can be sure of one thing: You’ll be better-prepared next time. And as extreme weather events are likely only to increase, there will be a next time.

Click here to learn more about adding battery storage to your home solar system