Washington State Tackles Solar Panel Waste, the Dirty Side of Clean Tech | Article

Solar Panels

On the slanted roofs of houses and covering wide expanses of fields, solar panels are generating more electricity every year. Currently, the United States has the solar capacity to power 16 million homes, and solar’s share of renewable electricity generation is expected to triple by 2050. However, this boost in carbon-free energy has begun a countdown to a major problem: what happens to solar panels at the end of their 20- to 30-year lifespans?

An estimated 10 million metric tons of solar panels will need to be uninstalled and disposed of by 2050 in the United States. Without proper regulations or recycling technology in place, much of this solar waste could end up in landfills around the country.

In most states, the responsibility of residential solar panel disposal currently falls on homeowners, adding another financial barrier to solar technology. Depending on the type of solar panel, solar waste has the potential to leach hazardous materials such as cadmium, telluride, and selenium into soil and water, which could harm surrounding communities and ecosystems. Solar panel waste may also place a disproportionate burden on communities of color, as landfills and hazardous waste sites are often located near such neighborhoods.

Washington State may offer a solution to the impending solar panel disposal crisis. The Washington Photovoltaic (PV) Module Stewardship and Takeback Program, first passed in 2017 as part of a solar incentive bill, requires solar PV manufacturers to finance the takeback and recycling of panels at no cost to their owners. The manufacturers must also meet specific recycling standards.

The program, which is the process of being implemented, will include both residential solar panels as well as large-scale utility projects, like solar farms. Washington is the only state besides California to have passed legislation with solar panels’ end of life in mind.

“We know there is going to be a time when solar panel disposal is needed and that section of the law was trying to have a program in place for that eventuality,” says Al Salvi, Technical Services Unit Supervisor of Solid Waste Management in the Washington Department of Ecology.

Stewardship models like the one in Washington, also known as extended producer responsibility (EPR) programs, seek to minimize the environmental impacts of a product by making the manufacturer responsible for its full life-cycle. These programs often center on the idea that the manufacturer has the greatest ability and knowledge to make the product more sustainable at all stages of its life. Washington has more EPR programs than most states do, with similar stewardship programs already in place for electronics, mercury lights, paint, and pharmaceuticals.

However, solar panels pose a unique recycling challenge compared to other stewardship products because of how the panels are constructed. Over 90 percent of a solar panel’s mass is made up of layers of glass, plastic, aluminum, and copper wiring. A semiconductor layer, often made of silicon or cadmium telluride, is sandwiched between these layers and harnesses sunlight into electricity.

Most solar panel recyclers are able to mechanically recover the layers of glass, aluminum, and copper wiring. However, strategies for improving recovery of the semiconductor layer, especially the market-dominant silicon, are still being tested by a limited number of companies in the United States. Recycling can cost around $25 per module, which, compared to sending the panel to a landfill, can be a steep rate.

But the law in Washington could encourage the solar panel recycling industry to grow.

“There are some groups that are thinking about this recycling mandate, trying to get ahead of it and position themselves to be that recycler or be that product stewardship organization,” Salvi said.

Stewardship laws could not only put infrastructure in place for the solar panels about to phase out, but also create a heightened demand for solar recyclers. This could improve and cheapen the technology, and take the burden of recycling costs off the consumer.

An estimated 850,000 metric tons of solar panels have already reached their end of life in the United States. Despite coming from earlier generations of solar technology, some of these panels can be recycled using current methods. But the high cost of recycling combined with the lack of mandates often drives down how many solar panels are recycled.

Washington’s program is still ironing out the details. The COVID-19 pandemic has put a hold on further work on the program, which was in the process of convening industry stakeholders to craft guidance that solar manufacturers would use to write their recycling plans.

After the program takes full effect, all solar manufacturers with sales in Washington will be required to participate in the stewardship program’s takeback and recycling mandates, as well as submit annual recycling reports to the Department of Ecology. The program aims to be fully functional by 2023, although this deadline may be pushed to 2025.

Washington’s initiative is the first of its kind in the United States, and would serve to make a growing clean energy technology even cleaner. Salvi notes that any solar recycling legislation “is going to take a lot of stakeholder work, because there are a lot of issues to work out.”

Salvi thinks that other states may be in the process of crafting similar legislation, which could follow Washington’s lead. If this is the case, the United States could divert millions of metric tons of waste, make solar panels more financially accessible, and help create a solar industry that is sustainable through its entire lifecycle.

Author: Rachel Snead