Plug-in solar, also known as balcony solar, is a popular option in Europe, and it’s now starting to be introduced in the United States. Utah introduced legislation last year and became the first state to allow 1.2-kW plug-in solar panel systems without utility approval. Now plug-in solar is finding interest in the country’s largest solar state.
Earlier this week, Senate Bill 868 was introduced in the California Senate, authored by Sen. Scott Wiener (D-San Francisco). The “Plug Into the Sun Act” would eliminate red tape and set statewide safety standards for portable solar systems — often seen on balconies throughout Europe. Reducing permitting and interconnection barriers would allow households to generate their own clean power and cut electricity costs with plug-and-play solar technologies.
According to Environmental Working Group, balcony solar systems can attach to a railing or be tilted in a backyard and plug directly into a standard 120-V outlet using an integrated microinverter. Some plug-in systems also include a battery. The solar systems are small, often not more than 1.2 kW, and cost hardly more than $1,000.
Standards group UL Solutions has taken notice and unveiled a new testing program for plug-in solar systems. The program is an evaluation based on UL 3700, the standard for interactive plug-in PV equipment. It defines construction, performance and labeling criteria tailored to plug-in solar systems, offering manufacturers a reliable foundation for designing products that consistently meet safety and performance requirements.
“Our new plug-in solar system certification program gives manufacturers and consumers the clarity they need to embrace plug-in solar systems with confidence,” said Ken Boyce, VP of Principal Engineering, Industrial Testing, Inspection and Certification at UL Solutions. “By defining how these systems must be built, evaluated for safety and safely installed, UL 3700 helps mitigate potential risks, and opens a path for more people to access resilient solar power.”
Household-circuit connected solar systems bring certain risks, such as systems becoming overloaded and the possibility of power flowing back into lines. In addition to defining safety standards for manufacturers, UL 3700 addresses these additional risks by requiring features that mitigate accidental contact with hazardous electric parts, promote safe installation, protect against overloads and prevent electric current from flowing in the wrong direction. Plug-in solar systems certified to UL 3700 could be suitable for renters and homeowners who are unable to install rooftop systems and could be used to provide back-up power for essential devices during outages.
