By Christopher Mims
It sounds like a crackpot invention advertised on the back of an old comic book: DIY solar panels you plug into a standard wall outlet to pump electricity into your home. And yet they're totally real, and more states are now saying they're legal and safe to use.
It's called "plug-in solar," aka "balcony solar," because that's where panels are often placed.
Residents of Utah and Maryland can now use it to combat skyrocketing utility bills, and seven more states -- Colorado, Connecticut, Maine, New Hampshire, New York, Vermont and Virginia -- have recently passed laws to make it possible, too. More than 20 other states are working on legalizing this technology, according to Bright Saver, a nonprofit that tracks and advocates for this technology.
While we typically draw power out of our outlets, they're capable of receiving power as well. The safety concern is that, during an outage, this auxiliary electricity source could endanger electricians or utility workers. But the balcony solar products now being sold will shut off if they sense that the grid is down or the home's main power is off.
Plug-in solar is already widespread in Europe, says Moncef Krarti, a professor of architectural engineering at the University of Colorado, Boulder. In Germany alone, more than one million systems have been installed. Though each home's energy generation is capped at a relatively paltry 800 watts, their sum total across the country equates to a large power plant, he says.
If energy prices continue to rise, California or New York could one day eclipse Germany in total installed balcony solar capacity. That's a major reason plug-in solar is now taking off in the U.S., Krarti says. However, when electricity is priced below 20 cents a kilowatt-hour, the systems might not make up their cost in energy savings during their usable lives, he adds.
How it works
My state only made this legal on May 12, so I'm likely one of the first Marylanders to test it out.
I didn't read the instructions. I didn't watch any how-to videos. I just unboxed a panel and clambered onto my roof, praying I wouldn't fall off or electrocute myself. In the end, it really was plug-and-play simple: I unfolded a portable panel made by a company called EcoFlow, connected it to the provided inverter and plugged that into a standard outdoor outlet.
Along the way, I learned a few things: To take full advantage of plug-in solar, it has to be on its own dedicated circuit. That meant a bit of switch-flipping in my home's breaker box to verify my chosen outdoor line wasn't already supplying power to other appliances and fixtures.
Another lesson: Picking an unshaded, south-facing surface in a yard or on a roof maximizes energy production through the day. Luckily, EcoFlow's app showed a real-time readout of how much electricity my panels were generating. I soon found myself obsessing over whether I could add more panels -- and where to put them.
Will it save you money?
Anker Solix is one of the leading sellers of balcony solar systems in Germany, with a typical system -- including panels rated for up to 870 watts of production and a 2.7-kilowatt-hour battery -- costing around 2,000 euros (about $2,300). That battery is big enough to soak up the day's power and dispense it at night, when electricity prices in Germany rise and home power-use peaks, says Tianhong Hou, head of product development at the company.
EcoFlow sells a similar system in the U.S.: Two 400-watt solar panels and a 1.92-kilowatt-hour Stream Ultra battery cost about $2,300. Doubling the system's total solar capacity to 1,600 watts would cost an additional $1,000 or so, but in most states, plug-in solar is limited to a maximum output to the home of 1,200 watts. (Because of the varying angle and intensity of the sun, panels hardly ever operate at full capacity, and excess power can be stored in the battery.)
Anker Solix says it will release a comparable system for the U.S. by early next year. Because these systems are modular, you can start with something basic and add to it later. All you need is a 200-watt panel and a "microinverter," with setups starting at around $500.
In states with the highest energy costs, such as California (30 cents a kilowatt-hour or higher) and Hawaii (upward of 40 cents), plug-in solar systems can pay for themselves in three years or less, says Krarti.
The point of plug-in solar isn't to zero out a home's energy consumption -- that likely requires a big, professionally installed rig costing tens of thousands of dollars. But it can offset some energy use, and in some apartments, it could displace over half the electricity consumed.
Plug-in solar can also help in the event of an outage. The batteries sold by EcoFlow and Anker Solix typically have outlets of their own, so you can use them to charge phones and even plug in refrigerators and other appliances and medical devices. Competitors including Craftstrom, Zendure and Hoymiles offer similar systems, with varying capabilities.
What's driving adoption?
The lesson from Europe is clear, says Krarti: Stripping away the permits and cost barriers typical of solar installation has driven up adoption. Balcony solar is also uniquely well suited for renters, who can take them along when they move out.
My own experience suggests that these systems are for people who don't mind an upfront cost if it means longer-term savings. And the whole emergency-preparedness thing doesn't hurt either.
As utility companies continue to raise prices, it feels good to offset a measurable portion of my family's daily electricity consumption. It took me under an hour to set it up -- I timed it. And it felt empowering, the way it did when I ended my family's dependency on gasoline.
Write to Christopher Mims at christopher.mims@wsj.com
(END) Dow Jones Newswires
June 05, 2026 19:00 ET (23:00 GMT)
Copyright (c) 2026 Dow Jones & Company, Inc.
Comments