Hoymiles introduces first UL 3700-compliant plug-in microinverter to U.S. market

Hoymiles Power Electronics Inc., a provider of module-level power electronics, launched its HiFlow Pro plug-in microinverter for the U.S. residential solar market. The product is designed specifically for plug-in photovoltaic systems, which allow homeowners and renters to generate solar power from highly constrained residential spaces such as balconies, patios, and compact rooftops. 

The microinverter is the first of its kind in the United States to comply with the UL 3700 safety standard, which was recently introduced as the first dedicated North American safety framework for plug-in solar applications. Traditional residential rooftop PV hardware is certified under different standards, but UL 3700 establishes a consistent benchmark specifically for consumer-installable, plug-and-play solar appliances, offering utilities, local authorities, and consumers clear guidelines on grid safety, rapid shutdown, and backfeed protection. 

The device features a static maximum power point tracking efficiency of 99.8% and a dynamic maximum power point tracking efficiency of 99.5%, which the manufacturer says optimizes energy harvest under rapidly changing weather conditions. Operating at low-voltage thresholds for increased safety, the hardware is housed in a Type 6 enclosure to protect against dust and heavy water-jets. Hoymiles said the product operates reliably in temperatures ranging from minus 40 degrees Celsius to 65 degrees Celsius and has been backed by 250,000 hours of reliability testing. 

The plug-in microinverter supports the parallel operation of up to four separate units installed in individual electrical sockets. This parallel capability allows the system to scale up to a maximum cumulative output power of 1,200 W, which enables users to maximize local solar production while staying within the standard physical limitations and electrical codes of standard residential branch circuits. 

Hoymiles said the product can be commissioned and set up in less than 60 seconds. The installer or homeowner connects the system via a localized dual Bluetooth and Wi-Fi architecture, which communicates directly with a mobile application for monitoring, pairing, and system setup. 

By lowering the technical barriers and high upfront costs associated with traditional, permanently installed rooftop solar systems, Hoymiles aims to target renters and multi-family home residents who have historically been excluded from the clean energy transition. The company said that by bringing a highly regulated, European-style plug-and-play approach to the United States, the certified hardware establishes a new benchmark for residential solar that balances safety, simplicity, and performance.