UL Solutions Debuts Testing and Certification Framework for Safer Plug-In Solar Across the United States

Key Terms

plug-in solar systems technical

Plug-in solar systems are small photovoltaic setups designed to connect directly to a home or building outlet without complex wiring, functioning like an appliance you can plug in to generate electricity. Investors care because they lower the cost and technical barrier for people to adopt solar, which can expand consumer demand, change electricity consumption patterns, and affect companies that make panels, inverters, home energy products, and utility services.

balcony solar technical

A balcony solar system is a small, self-contained photovoltaic setup designed for use on apartment balconies or small terraces; it plugs into the home’s electrical circuit or feeds a dedicated outlet to generate power for the household. Think of it like a personal, portable power plant on your balcony — it matters to investors because widespread adoption changes electricity demand patterns, creates new retail markets for compact solar devices, and shifts revenue opportunities toward modular hardware makers, installers and related service providers.

photovoltaic technical

Photovoltaic describes the technology that converts sunlight directly into electricity using panels made of semiconductor materials; think of it like leaves turning sunlight into usable energy for a plant, but producing power for homes, factories and the grid. It matters to investors because photovoltaic systems represent assets, revenue sources, cost structures and regulatory exposure for energy and manufacturing companies, and their adoption rates and efficiency gains affect long-term profitability and market demand.

back-up power technical

Equipment and systems that provide electricity when the main power supply fails, such as generators, battery banks or uninterruptible power supplies. Like a spare tire for a car, back-up power keeps critical operations running during outages, protecting revenue, customer service and regulatory compliance; investors watch it because the presence, capacity and cost of back-up power affect a company’s operational risk, capital spending and potential disruption-related losses.

• UL Solutions has launched a dedicated testing and certification program for plug-in solar systems, also known as balcony solar, creating a clear safety framework to support their installation and use across the United States.
• The program establishes construction, performance and labeling criteria that help manufacturers design plug-in solar products meeting safety standards.
• By addressing safety risks associated with plug-in solar systems, UL Solutions is helping to enable safer, more accessible solar power options for residents of multi-unit buildings and supporting emerging state-level legislation.

NORTHBROOK, Ill.--(BUSINESS WIRE)-- UL Solutions (NYSE: ULS), a global leader in applied safety science, today announced that it has launched a plug-in solar system testing and certification program, establishing a clear, dedicated testing framework that will help provide a pathway for the safer adoption of this energy generation technology.

UL Solutions has launched a dedicated testing and certification program for plug-in solar systems, also known as balcony solar, creating a clear safety framework to support their installation and use across the United States.

The new program is an evaluation based on UL 3700, the Outline of Investigation for Interactive Plug-In Photovoltaic Equipment and Systems. It defines construction, performance and labeling criteria tailored to plug-in solar systems, also referred to as balcony solar, 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, vice president, 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.”

Legacy plug-in solar systems that have been used outside the U.S. differ from permanently wired rooftop solar panels because they are intended to connect to household circuits through a plug and receptacle. That simplicity makes solar easier to adopt, but it also brings 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.

Interest has been amplified by recent policy changes. Earlier this year, Utah became the first state to allow use of up to 1.2 kW plug-in solar panel systems without seeking utility approval. Other states, including Maryland, Minnesota, New Hampshire, New York, Pennsylvania, Vermont and Virginia, are considering similar legislation. UL 3700 can support state legislative and regulatory efforts with a clear framework to enable the safety of the product and its installation.

“UL 3700 marks a major step forward, helping remove regulatory uncertainty and making plug-in solar a potential choice for consumers across the U.S.,” said Robert Slone, chief scientist and senior vice president at UL Solutions. “By addressing key safety gaps that could slow adoption, we are helping to make plug-in solar a viable option that complements larger rooftop systems and supports a stronger, more reliable energy future.”

About UL Solutions

A global leader in applied safety science, UL Solutions (NYSE: ULS) transforms safety, security and sustainability challenges into opportunities for customers in more than 110 countries. UL Solutions delivers testing, inspection and certification services, together with software products and advisory offerings, that support our customers’ product innovation and business growth. The UL Mark serves as a recognized symbol of trust in our customers’ products and reflects an unwavering commitment to advancing our safety mission. We help our customers innovate, launch new products and services, navigate global markets and complex supply chains, and grow sustainably and responsibly into the future. Our science is your advantage.

View source version on businesswire.com: https://www.businesswire.com/news/home/20260108334847/en/

Media contacts:

Tyler Khan

UL Solutions

ULNews@UL.com

T: +1 (847) 664.2139

Steven Brewster

UL Solutions

ULNews@UL.com

T: +1 (847) 664.8425

Source: UL Solutions Inc