Wisconsin Solar Panel Recycling

The Rise of Solar Power in Wisconsin

Despite the common belief that Wisconsin receives less sunlight than sunnier states, the solar capacity in the state has seen remarkable growth. As of March 2024, Wisconsin has more than 1,400 megawatts (MW) of installed solar power, a significant jump from 612 MW in 2023, with plans to add another 650 MW by the end of 2024. This expansion includes around 30 utility-scale solar farms.

The potential for rooftop solar in Wisconsin is especially impressive. Estimates indicate that up to 23,600 MW of rooftop solar could supply over 40% of the state’s electricity needs. A 2022 study by RENEW Wisconsin found that the technical potential for rooftop solar could reach nearly 37 gigawatts (GW) by 2026, increasing to 39 GW by 2034—enough to cover about 70% of the state’s total electricity demand from rooftops alone.

This growth is supported by various incentives, including the federal Investment Tax Credit (ITC), state-level sales and property tax exemptions, and programs like Focus on Energy, which offers rebates for residential and commercial solar installations, alongside net metering policies.

However, the rapid deployment of solar technology, with panels typically having a 25- to 30-year lifespan, necessitates a robust plan for their eventual decommissioning.

The Critical Need for Solar Panel Recycling in Wisconsin

As Wisconsin’s solar infrastructure continues to develop, we can expect a significant increase in the number of solar panels reaching the end of their life cycle. Worldwide, estimates suggest that by 2050, we could be facing up to 78 million metric tons of solar panel waste if we don’t manage it properly.

While solar panels are a clean energy source during their use, disposing of them at the end of their lifespan poses challenges due to their materials.

Solar panels are made up of valuable components, such as glass (which can make up to 75% of their weight), aluminum, copper, silicon, and small amounts of precious metals like silver. However, they also contain hazardous materials like lead, cadmium, and hexavalent chromium. If these panels are simply thrown away, these dangerous substances can seep into the ground, polluting soil and groundwater.

Currently, Wisconsin lacks specific state regulations that require the recycling of solar panels or categorize them as universal waste, which is different from some other states in the U.S. As a result, businesses that produce solar panel waste must figure out whether their panels are considered hazardous waste according to federal Resource Conservation and Recovery Act (RCRA) guidelines, often necessitating toxicity testing (Toxicity Characteristic Leaching Procedure – TCLP).

If the panels are deemed hazardous, they must be disposed of according to strict regulations. The EPA is working on a rule that could include solar panels in universal waste regulations, which would simplify their management and promote recycling.

The financial case for recycling is also strong. Although the costs of recycling can currently be higher than those of landfilling, the value of materials recovered from photovoltaic modules in the U.S. could reach $60 million by 2030 and $2 billion by 2050 (NREL). Investing in recycling infrastructure not only helps the environment but also opens up new economic opportunities and bolsters domestic supply chains for essential materials.

The Recycling Process: Unlocking Value and Mitigating Risk

Advanced solar panel recycling technologies are designed to recover the maximum amount of valuable materials and safely manage hazardous components. For crystalline silicon panels, the typical process involves:

Dismantling: Separation of the aluminum frame and junction box to recover valuable metals.

Glass Recovery: The remaining module undergoes processing to separate glass sheets, which can be 95% reusable in new products.

Thermal Treatment: Heating processes are used to break down plastics and prepare silicon cells for further extraction.

Material Reclamation: Sophisticated techniques extract and purify silicon, copper, silver, and other materials for reuse in new solar panels, electronics, and other industries.

Thin-film panels follow a different process, often involving shredding and chemical separation to recover semiconductor materials. The aim is to achieve high recovery rates, with leading recyclers striving for over 90-95% material recovery.