Certification hurdles inhibit growth of solar panel reuse market

A new white paper from Solar Panel Recycling argues that interconnection rules and unfavorable economics make large-scale, responsible reuse largely infeasible.

January 20, 2026 Phoebe Skok

Image: Shutterstock

Solar panel reuse is often hailed as the most sustainable option for end-of-life panels. But, according to a new white paper from Solar Panel Recycling (SPR), making reuse a large-scale practice is tricky due to regulatory constraints and difficult economics.

Interconnection and safety standards remain a key sticking point. To connect to the American grid, any solar system must comply with strict standards including the National Electrical Code and a range of UL certifications for panels and balance-of-system equipment. But, the white paper notes, any “reconditioned, rebuilt, refurbished and remanufactured equipment must have the original Listing Mark removed.”

In practice, that means that most decommissioned modules become “orphaned” and lose their certification status the moment they leave their original system, even if they can still generate electricity.

Coupled with the fact that only the original manufacturer or parties authorized by UL Solutions are allowed to rebuild or refurbish equipment in order for it to be eligible for recertification, preparing systems for reuse can be technically challenging. Plus, a report from National Renewable Energy Laboratory cited in the paper found that certain standards and testing protocols like IEEE 1547, UL 1741 and IEC 61730-2 “may directly prohibit the reuse of solar panels for grid-tied applications,” especially if the systems aren’t capable of rapid shutdowns.

That leaves little room for older, legacy modules to be legally reconnected to the U.S. grid despite the large quantity expected to retire in the coming years. In SPR’s eyes, the regulations make reuse “economically impractical” at scale; the need for case-by-case retesting at UL-approved facilities is too costly and time-intensive to be broadly feasible.

Could secondary markets like offgrid or DIY residential applications, then, absorb and reuse surplus panels? Per SPR, these markets could help stem the flow but already face their own challenges that make them “ill-suited” to take on the brunt of the burden. The white paper points out that California, which accounts for more than a third of U.S. residential capacity, saw installations drop 45%, and by mid-2025 national quarterly residential capacity slipped below 1 GWdc. When demand is already falling, it’s unlikely secondary markets will take on much uncertified equipment that risks performance troubles and liabilities.

Internationally, off-grid markets don’t offer much hope for reuse; World Bank data laid out in the report found that approximately three-quarters of off-grid products remain uncertified and are sold informally. That raises concerns of eroding consumer trust and creating unmanaged waste streams further down the line. At best, SPR argues, “off-grid and DIY applications may find homes for thousands of panels, but they cannot address a waste stream soon to be measured in the tens of millions.”

Panel reuse also isn’t always the most pocketbook-friendly solution. New, high-efficiency modules are often cheaper than used panels on a per-watt basis. They also come with warranties, bankability and higher outputs. For many large-scale developers, EPCs and utilities, “the economic case for used panels simply doesn’t exist.” Refurbishment alone can cost roughly $500 per kilowatt for standard systems and more than $750 per kilowatt for damaged equipment, before factoring in logistics, testing, and engineering work.

As a result, the white paper argues, reuse is likely to remain a niche solution compared to true recycling that includes full material recovery and traceable chain-of-custody. Solar recycling is on the rise nationwide; Comstock Metals recently announced the expansion of its solar panel recycling network in California and OnePlanet’s River City recycling facility in Florida is set to open early next year.

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