Plug-in solar panels, coming to an apartment balcony near you
DENVER — Damon Cox’s 1,500-square-foot cottage in Palmer Lake, Colorado, doesn’t use much energy. That hasn’t stopped him from finding more ways to lessen his carbon footprint.
A little over a year ago, after he read about the proliferation of balcony solar in Germany, Cox logged into Amazon and spent about $1,500 on plug-in solar panels of his own. Compared to larger rooftop solar panel set-ups, these balcony systems are simple to install and come at a fraction of the cost (they also generate a fraction of the electricity). There’s just one problem. They’re not legal in Colorado. Yet.
A bill from Colorado state lawmakers would open the door for plug-in solar in Colorado. Consumers would not need approval from their utility company before installing a certified system, according to the bill.
“When I saw that legislation introduced in Colorado, I mean, I was thrilled,” Cox said. “I would love for all of my activities to be legal … but also just to encourage everybody else to get [plug-in solar], because, to me, after my experience, this should just be an appliance in every home, just like a refrigerator or a stove or your TV.”
If passed, the bill would expand home solar — a technology long limited to the roofs of single family homes whose owners had the means to install the often-costly systems — to renters or people who live in multifamily housing, such as condos. The average cost to install a rooftop solar grid was $19,000 in 2021.
The bill comes at a time when the war in Iran is driving a spike in gas prices, especially in the Rocky Mountain region, where the cost of a gallon of gas has risen nearly 35%. Experts say the war highlights the risks of over-relying on fossil fuels. Heating and electricity bills are also rising as utility companies hike rates to pay for repairs to aging infrastructure — and as data centers demand more electricity.
President Donald Trump’s administration, meanwhile, is hostile to renewable energy. Trump’s “One Big Beautiful Bill” ended federal tax incentives for solar panels and electric vehicles, and earlier this week, the Interior Department announced the administration would pay a French energy company nearly $1 billion to abandon an East Coast wind farm project in exchange for more oil and gas operations in the U.S.
The White House has routinely attempted to tarnish renewable energy sources as unreliable and unaffordable, but data show that renewables like wind and solar are significantly cheaper than fossil fuel alternatives.
Rep. Lesley Smith (D-Boulder) is a prime sponsor on Colorado’s plug-in solar bill. The legislation is about “consumer choice of where their electricity comes from,” she said.
“There’s a lot of interest from people who, for whatever reason — because they can’t afford it or they’re in an apartment building — can’t have rooftop solar. But this is a way for them to harness some of the sun’s energy and have electricity feeding into their homes,” Smith said.
Smith got the idea for the bill after visiting Germany with her husband last fall. Germany is home to more than 1 million plug-in solar units, and Smith noticed how common they were on apartment balconies. The day she got back from her trip, a constituent emailed her an article about Utah lawmakers unanimously passing a plug-in solar bill, becoming the first state to do so.
“There's just been a lot of interest nationally,” Smith said.
Unlike some larger rooftop set-ups, plug-in solar panels do not generate enough electricity to power an entire household. “Perhaps a refrigerator,” Smith said.
Cox, 58, recently retired after a career in hydroelectric energy. Needless to say, he’s a fan of renewable energy. He has four plug-in panels. When he first bought them, he spread them outside his front door to test them out (after confirming they worked, Cox’s wife told him he had 30 minutes to find an “acceptable” spot).
Today, the panels lay on top of the roof over his deck. Each panel is roughly 4.5 feet by 2 feet. All together, his system is probably larger than what would fit on the average Denver apartment balcony. Cox’s set-up reduced his electricity bill by about 40%. He noted that his home doesn’t have air conditioning. HVAC usually accounts for the largest portion of home energy consumption.
Smith’s legislation has received bipartisan support, as well as backing from the governor. It has a clear path to become law.
“By helping more Coloradans access low-cost clean energy, we can break down barriers to clean energy, save Coloradans money on energy bills, and move us closer to reaching our climate goals, which the Governor believes this bill does,” a spokesperson for the governor said.
Colorado is one of dozens of states working to pass similar legislation. According to Bright Saver, a California nonprofit that advocates for plug-in solar, lawmakers in 30 states have introduced bills that would legalize balcony solar. Virginia is poised to become the next state to permit plug-in solar panels.
“We see this as an on-ramp to that commitment to wider solar development,” Cora Stryker, the co-founder of Bright Saver, told Rocky Mountain PBS. “We see this as kind of a gateway drug — you get a little bit of solar, you want a lot more.”
Cox also referred to his plug-in panels as a gateway drug. “Because now I am pursuing rooftop solar,” he said. “And it also made me very aware of my electrical consumption in the house that I didn't pay attention to that much before.”
Utility companies have delayed legislation in states like Georgia, Arizona, New Mexico, Washington and Wyoming, citing lineman safety. During a power outage, the utility companies argued, plug-in solar panels could continue generating electricity and send it back to the grid, which could harm people working on power lines.
Smith’s bill requires plug-in solar panels sold in Colorado to be certified by UL Solutions, a company that develops product safety standards. UL-certified solar panels automatically shut down during power outages, posing no harm to line workers. Germany has similar standards, and a 2025 U.S. Department of Energy study found there have been “no safety incidents reported, aside from cases of tampering.”
Smith said Xcel Energy, the largest utility company in Colorado, has not opposed this legislation. A spokesperson for the company told Rocky Mountain PBS that Xcel is “closely monitoring this bill, and our team has been meeting with bill proponents to address various aspects of the bill’s language.”
Rocky Mountain PBS multimedia journalist Cormac McCrimmon contributed to this report.
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