Why Backup Solar Power Is Better for the Planet and Your Health

Instead, she and other experts recommend investing in more planet-friendly sources of backup power, namely solar and battery technology. These units can range from portable solar-powered batteries to larger home setups with rooftop solar panels connected to battery storage systems. Depending on the technology and how much energy you use, some of these systems can power an entire home for days during an outage. They can also provide year-round benefits, including lower utility costs.

“A gas backup generator for your home is like an insurance policy that offers no value until you have a really bad day,” said Mark Dyson, managing director of zero-carbon electricity at energy think tank RMI. “Other solutions we’re looking at, like solar plus storage, for example, save money every day and also provide a backup in an emergency.”

We looked at how solar-powered batteries compare to traditional fossil fuel generators. Here’s what you need to know.

The size of a generator or battery backup depends on how much power you need, says Noah Kittner, an energy systems expert and assistant professor at the University of North Carolina at Chapel Hill.

These are the oldest and most common types of generators. They run on a variety of fuels, including diesel, propane, and natural gas, and can be portable or permanently installed.

You can use them to power various electronics, larger appliances, and entire homes. The number of devices a fuel generator can power depends on its size, power, and the amount of fuel you have.

Batteries also come in different sizes and can be portable or installed. Smaller batteries may be enough to run a small electric fan, charge cell phones, or power a radio.

For a refrigerator, you might need at least eight to 12 hours of backup power, Kittner said. Common lithium-ion rechargeable batteries designed for home use can generally provide that amount of power.

Standalone batteries have a limited lifespan, Dyson said. Even larger batteries can run out of power pretty quickly if you’re using them to power devices that use a lot of energy, like stoves or air conditioners. That means if you’re using these batteries during a power outage, once they’re flat, You have to wait for the power to come back or find another way to charge them.

Portable batteries, which also vary in their power, can be equipped with small solar panels, so that they can be charged without being plugged in. If the battery is completely empty, it can take several hours to charge it using solar energy.

You can also have larger systems with rooftop solar panels connected to battery storage systems. These residential setups can benefit homeowners even when the power doesn’t go out, says Z. Smith, director of sustainability and building performance at EskewDumezRipple, an architectural firm with offices in New Orleans and Washington, D.C.

“The economics of a battery and solar system means you always get a benefit, whereas the generator is a loss-making system and only provides a benefit during an outage,” Smith said.

Rooftop solar and storage systems connect directly to the home’s electrical grid, Dyson says. Most portable batteries connect directly or via extension cords to individual devices. Like a fossil fuel-based backup generator, some larger batteries can be connected using transfer switches, which connect them to your electrical panel, Dyson says. If the power goes out, the switch lets your home draw power from your backup source instead of the grid.

According to Dyson, backup power sources can be more effective if your home is well insulated and weatherproofed to prevent air leaks.

Regardless of the type of emergency power supply you have, you should be aware of your energy usage during a power outage, Burke says.

“It’s usually necessary to be … sensible about how you use energy in your home,” she said. “You wouldn’t run the dishwasher, your washer and dryer, everything in your house at the same time. These are emergency situations.”

One of the main benefits of not using fossil fuel generators is that no harmful, polluting fumes are released.

These generators produce exhaust fumes that contain dangerous pollutants, including sulfur dioxide, nitrogen oxide, particulate matter, and carbon dioxide. Running them can also release carbon monoxide, an odorless, colorless gas that can kill people in minutes if it builds up indoors. The generators also tend to be noisy.

“One of the biggest concerns is local air quality,” Burke said. “Imagine a neighborhood that loses power and every home or every other home has some kind of fossil fuel plant running all the time, it’s incredibly hot and humid — all of that creates really bad ground-level ozone, which causes serious respiratory problems.”

You should never use fossil fuel-burning generators in your home or garage, even with the windows open. Place portable generators at least 20 feet away from homes, open windows or garages, with the exhaust pointed away from the home, according to the Centers for Disease Control and Prevention.

“It’s important for people to understand that when they do something as informal as buying a gasoline generator, powering it up and putting it on their porch or something like that, they’re essentially bringing something into their home that could be a source of danger in or near their home,” Smith said.

The cost of each type of generator depends partly on the size and technology, but prices can also vary by model.

For example, a portable 5,000-watt diesel generator, a common size that can be used for small homes, apartments, and RVs, can cost anywhere from $500 to more than $5,000. A solar-powered battery model that can generate 5,000 watts continuously runs about $4,700.

If you want a more robust, permanent form of backup power, it will cost money. The initial price of installing a residential solar array and battery storage system will be significantly higher than a comparable gasoline or diesel generator, Dyson said. But these systems can provide long-term savings for homeowners, and there are federal tax credits and, in some cases, no-down-payment financing options to help reduce the cost of the technology and installation.

“If you just look at the value of solar, it pays for itself pretty quickly in most places in the country,” Dyson said. Battery storage, he added, is also becoming more cost-effective.

Meanwhile, the cost of maintaining and powering standard generators can add up over time. Without regular maintenance, your generator may not be working when you need it.

“The difference is that the diesel generator just sits there and wastes away, whereas the solar and battery system gives you value all the time and adding a battery can give you resilience,” Smith said.