Enphase Energy Highlights Commercial Solar Repowering Projects Across the U.S. Using IQ9 Microinverters

Enphase Energy, Inc. has highlighted commercial and industrial (C&I) solar repowering projects across the United States that are using its IQ9 Commercial Microinverters to restore energy generation from aging solar installations without replacing existing solar modules or mounting structures.

The initiative focuses on upgrading commercial solar systems affected by aging or failed string and central inverters. By replacing conventional inverter architectures with Enphase microinverters, system owners can improve operational reliability, restore electricity production, and extend the useful life of existing solar assets.

According to the company, many commercial solar installations developed over the past decade are experiencing reduced performance due to inverter failures rather than deterioration of solar panels. Enphase’s distributed microinverter architecture allows individual module-level performance monitoring and helps prevent faults in one module from disrupting electricity generation across the entire system.

The company’s commercial microinverter portfolio includes the IQ9N-3P and IQ9S-3P models, designed for 480 V three-phase electrical infrastructure, and the IQ8P-3P model for 208 V applications. The IQ Gateway Commercial Pro supports revenue-grade monitoring and remote management of up to 300 microinverters per site. Enphase also offers domestic-content versions of certain products and plans to introduce additional energy storage integration through its IQ Battery C80, currently available for pre-order.

One of the highlighted projects is located at Furman University in Greenville, South Carolina, where Detail Solar has completed the first phase of a planned repowering programme for the university’s 988 kW solar installation. The initial phase involved upgrading 30 kW of capacity affected by underperforming legacy string inverters.

Paul Zimmer, founder and owner of Detail Solar, said the project demonstrated the benefits of modernising existing solar installations through microinverter technology. He noted that the upgrade helped restore energy production while reducing the risk of future system downtime.

In another project, Endless Energy is repowering a 240 kW AC solar installation at Peirce Welding and Assembly in Bethel, Pennsylvania. The project involves deploying 561 Enphase IQ9N-3P Commercial Microinverters to replace equipment that had reached the end of its operational life.

Both installations use a two-to-one configuration, connecting two existing solar modules to each microinverter. This arrangement is designed to optimise microinverter capacity, reduce equipment requirements, and accommodate older solar panels that have experienced gradual performance degradation.

Enphase stated that its commercial microinverters provide flexibility in system design, allowing installers to match existing modules with new power electronics while remaining within applicable electrical specifications. The products are also supported by a 25-year warranty.

Ken Fong, Senior Vice President of Sales at Enphase Energy, emphasised that inverter failures are a major contributor to declining performance in older commercial solar systems. He said repowering offers asset owners an opportunity to retain functional modules and mounting infrastructure while improving system safety, monitoring capabilities, and long-term reliability.

The company also highlighted the availability of certain products designed to meet U.S. domestic-content and Foreign Entity of Concern (FEOC) requirements, subject to applicable regulatory and tax eligibility criteria.

The projects demonstrate the growing importance of solar repowering as a strategy to extend the operational life of existing C&I solar assets, reduce unnecessary equipment replacement, and improve the performance of installed renewable energy infrastructure across the United States.