UL Solutions releases UL 3700 for balcony solar safety certification
Updated
Updated · MIT Technology Review · May 7
UL Solutions releases UL 3700 for balcony solar safety certification
6 articles · Updated · MIT Technology Review · May 7
The January protocol comes as Utah has legalized plug-in solar and more than two dozen other US states consider similar bills, while no full systems had been certified by early May.
UL says the standard addresses circuit overload, GFCI malfunction and shock risks from energized plugs, and recommends a dedicated outlet likely requiring an electrician.
balcony solar, already used in more than a million German installations, is seen as a cheaper option for renters and households, but US deployment remains constrained by safety and regulatory questions.
As dozens of states approve plug-in solar, why are no products yet certified under the new mandatory safety standard?
Balcony solar was sold as DIY energy. Why do new safety rules mean you'll likely still need to hire an electrician?
With millions of mini power plants plugging into the grid, can the safety of utility workers ever be truly guaranteed?
UL 3700 Certification Launches in 2026 to Close Critical Safety Gaps in Plug-In Balcony Solar
Overview
In response to serious safety risks like fire hazards, electrocution, and grid instability from uncertified plug-in solar systems, Utah passed a law in 2025 requiring certification. This spurred UL Solutions to launch the UL 3700 certification in January 2026, establishing essential safety standards including overcurrent protection, touch safety, and ground-fault protection. UL 3700 has since driven manufacturers to develop safer products, gained cautious support from utilities, and enabled states like California, Maine, and Virginia to pass or propose plug-in solar legislation. Consumers benefit from easier installation and energy savings, while insurers are more willing to cover these systems. The standard also supports policymakers through technical guidance, accelerating nationwide adoption.