Solar panel recycling: A circular economy for renewable energy

The rise of solar power has been one of the great energy success stories of the century. From a very low baseline, solar panel technology ramped up very quickly, and for the past decade, solar has experienced an average annual growth rate of 49 percent. In 2019, the U.S. solar market installed 13.3 GW of solar panels – 40 percent of all new electric generating capacity added to the grid. Assuming every panel is 350 watts, that’s 38 million new panels sold and installed in the U.S. every year.

That’s a very good thing. Solar power is clean and renewable, and any pollution from manufacturing the panels themselves is more than offset by the fact that solar largely displaces coal and natural gas. These fossil fuels create orders of magnitude more pollution and pose direct risks to human health and the global climate. Every year in the U.S., coal-fired power plants create 130 million tons of waste ash, laden with cancer-causing arsenic and mercury. Oil and gas wells produce 1 trillion gallons of hazardous waste liquid that’s polluted and sometimes radioactive.

As we move toward a circular economy, however, we can’t ignore the end-of-life impacts of even those technologies that are driving us toward sustainability. And that includes solar panels.

In a circular economy, more of the products we make will be built to last and fixable when they break, as well as recyclable when they reach the end of their lives.

By the first, most important standard of durability, solar panels perform far better than disposable bags or fast fashion, and light-years better than fossil fuels that are burned once and create waste products — from coal ash to carbon dioxide pollution in the atmosphere — that can persist for generations. A typical solar panel comes with a 25-year warranty and can be expected to retain 90 percent of its power output capacity over that time, followed by several more years of useful life. That’s a longer lifespan than most of the products we currently make.

But by 2050, when renewable energy will hopefully be providing all of our energy, the waste stream of obsolete solar panels will become more significant — creating an estimated 6 million tons of global solar waste per year. The problem of how to recycle this waste isn’t yet fully upon us, because U.S. solar installations only took off in earnest around 2010. But to head off problems with the disposal of solar waste, we need to think now about how to make solar power a viable part of the circular economy.

Currently, only about 10 percent of solar panels in the U.S. are recycled, usually at e-waste facilities that use crude methods to break down the complex modules. The rest are exported or landfilled, which can be dangerous due to the presence of lead in the panels. Most of the material in those panels — the roughly 99 percent of a silicon-based panel that is made up of glass, aluminum, plastic and silicon — can be recovered. First Solar, for example, one of a handful of U.S. producers with a voluntary takeback and recycling program, can recover 90 percent of the materials from old panels.

Europe suggests a possible model for the U.S. in solar recycling. In 2012, the E.U. began to require that solar panel producers finance the cost of collecting and recycling the panels at the end of their lives. These types of “producer responsibility” laws have been successfully applied to many different industries, spurring innovation in the logistics and technology of recycling. PV Cycle, a European solar recycling stewardship organization, has dedicated solar panel recycling facilities and has claimed recycling rates of up to 96 percent.

Producer responsibility laws will play an important role in the U.S., because absent any policy nudge, the cost of recycling solar panels still exceeds the revenue generated. But investment in research and development could lead to new techniques for cost-effective recovery of high-purity materials, such as silver, copper and silicon.

Washington State currently has the country’s only producer responsibility law for solar panels. Manufacturers who want to sell solar panels within the state must submit a plan by July 2022 detailing how they or an authorized stewardship organization will collect end-of-life panels and “minimize the release of hazardous substances into the environment and maximize the recovery of other components.”

This is a good first step towards incentivizing a circular economy for a critically important piece of technology. But producer responsibility laws can lead to higher costs for manufacturers that get passed on to their products. This can be beneficial in some cases, such as reducing single-use plastic or making sure that fracking companies can pay to clean up abandoned wells after they go bankrupt, but could be harmful if it impedes a speedy transition to renewable energy. So these laws should be paired with tax credits that support rapid deployment of solar now, and responsible disposal of solar e-waste later.

Solar panels are an impressive feat of engineering, a complex sandwich of electronics that can power our modern lives with a sustainable and free energy resource. We should invest in research for the next generation of efficient panels, and technicians to repair and maximize the lives of existing ones. Manufacturers who know their products best should take on responsibility for their panels from the drawing board to the recycling plant. And we should do all that even as we deploy as many solar panels as possible to eliminate the problem of dangerous waste from fossil fuels and build a cleaner, healthier country.

Photo credit: OregonDOT via Flickr (CC BY 2.0)