How a solar-powered home works with generator backup
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Contrary to what you might think, most solar energy systems can’t power your home during a power outage, so many solar panel owners have generators to keep things running in an emergency.
We’ll explain exactly how solar panels and backup generators work together so you can explore all your options and design the best possible energy system for your home.
- Most grid-tied solar energy systems go offline during electrical outages because their output can pose a danger to people fixing the power lines.
- Fossil fuel-powered generators can work independently of solar panels to give you backup power.
- However, solar batteries (and solar generators) are a good alternative if you prefer to stick with green energy.
Why would you need a generator if you have solar panels?
Although they have long been associated with off-grid living, most residential solar panel systems in the United States are “grid-tied” and actually stop working when the power goes out.
So, unless your home is off the grid or you have a solar battery (which we will explore later), you will not be able to access the electricity produced by your solar panels during a local outage. That’s why some solar panel owners choose to have backup generators.
Why don’t solar panels work when the power goes out?
Grid-tied solar panels without battery backups go offline during power outages because they use the electricity grid to receive and process the energy they produce. If your solar panels were to send electricity out to the grid during a blackout, this could pose a serious safety hazard for those working on the utility lines.
Most grid-tied systems can’t function without that connection, so whenever the power goes out, properly installed solar panel systems will automatically disconnect from the grid. When power is restored in your area, you may have to reset your system to begin generating electricity again.
How generators and solar panels work together
Generators and solar panels work side by side but not necessarily together in one seamless system. Although there are some solar brands that support generator integration, solar panels and gas generators usually work in place of one another rather than truly “together.”
When the power goes out and your grid-tied solar panels shut down, an automatic transfer switch (ATS) is typically used to engage your generator so it will begin to produce electricity. Although there may be a short window before your system kicks on, a standby generator connected to your home’s electrical panel can allow you to continue using your home's lights and appliances as normal through the duration of the outage.
» LEARN: How long do solar panels last?
How to use solar power during a power outage
Solar batteries and solar generators (also known as portable power stations) are emission-free alternatives to traditional gas generators that can give you access to solar-derived electricity during a power outage, albeit in different ways.
The term “solar generator” can mean a lot of things, but it usually refers to small, portable solar energy systems that can generate and store electricity from the sun on their own.
A large solar battery can run your home in the same way a backup generator can during an outage, as long as you have enough solar power stored. That’s because these systems can temporarily disconnect themselves from the power grid, making it safe to use solar energy during an outage.
Meanwhile, solar generators are becoming increasingly popular as a way to produce smaller amounts of electricity during a blackout. Designed for easy plug-and-play setup and use, solar generators usually consist of their own solar panels, a battery, an inverter and several plugs or outlets for your devices.
Barbara, a ConsumerAffairs reviewer from Arizona, explained how easy it was to prepare for potential outages with a solar generator: “I'm 76 and I set it all up myself … I unplugged my refrigerator and plugged in my [solar] generator for about 24 hours. It gives me assurance that I have a backup if my electricity is cut off.”
(If you’re really committed to using green energy that doesn’t rely on the power grid, we should mention that there are other ways to use power from the sun. Even during a blackout, passive solar homes and thermal solar energy systems can still make use of the sun’s energy in their own ways.)
» LEARN: What is a solar generator?
Solar battery vs. standby generator: Which is better for you?
If you’re trying to choose between installing a solar battery or a standby generator, here’s a quick breakdown of how they compare.
|Solar battery||Standby generator|
|Power source||The sun||Gasoline, propane, natural gas or diesel|
|Ongoing power costs||None||Fuel and maintenance expenses|
|Operating noise||Nearly silent||Often noisy|
|Environmental impact||Zero emissions (can be used indoors)||Emits greenhouse gases during use (can’t be used indoors)|
Neither option is universally “better” than the other, but your priorities can dictate which is right for you, depending on whether you’re trying to be as green as possible or simply maintain power during a blackout at the lowest possible cost.
Just keep in mind that there are many different technologies, power capacities and products available in both the solar battery and standby generator markets, so the choice may not be as clear-cut once you compare specific options.
For example, Hayden Kelinhans, manager of land development at Invenergy, a clean energy provider, explained to us that opting for a solar battery may be an increasingly better option as clean technology continues to evolve: “Most people are used to gas generators, but solar batteries are the future. Clean power, no emissions and no noise — plus the technology is only getting better.”
Outside of full-home solar batteries, many sun-powered devices can be used during electrical outages. While you may have grown up lighting candles when the power went out, solar lights, solar phone chargers and other self-contained green gadgets can operate independently these days, no matter what your local grid conditions may be.
» MORE: Best solar batteries
How does a gas-powered generator work?
A gas-powered generator uses internal combustion to generate electricity. While some gas-powered generators are manually operated, there are also backup generators that can automatically turn on when grid electricity becomes unavailable. Just remember that for ongoing use, gas generators must be refueled, and oil changes may also be necessary.
Can you run a generator and solar panels together?
You can run a generator in place of your solar panels, but not at the same time since the ATS will kick in. If you have a grid-tied solar energy system without a battery backup, a separate generator is a great way to ensure access to power during a local electrical outage. While traditional generators are powered by diesel, gasoline or propane, solar generators are an alternative that runs on electricity produced by your panels.
What if your solar energy system is off the grid?
If you have an off-grid solar energy system, you can still use a gas generator as a secondary support for your solar battery. That means you can set up your backup generator to activate whenever you run out of stored solar energy.
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