Indiana University-Indianapolis has made sustainability a major part of their operations for decades. In fact, the university has used more renewable energy than any other school in the Horizon League since 2013, when they first installed 164 solar panels on top of the Business/SPEA building. Many students may not even know the solar farm exists, but it produces about 0.3 percent of the total electricity used by IUPUI (55,502 kWh/199,217,175 kWh). Another 9.3 percent of IUPUI’s total energy usage is purchased through AES green power. There may be environmental benefits of using solar power and other renewable energy sources, but what happens when it comes time to recycle these solar farms?
“Solar panels typically have a 30 year lifespan, with many lasting longer. We’re still a bit aways from dealing with end of life, and we would ID a recycling outlet as we get closer to that date,” said Jessica Davis, Chief Sustainability Officer of Capital Planning and Facilities at IU-Indianapolis in an email with The Collegiate Commons. “I would also expect the number of PV recyclers to increase over the next couple decades as the number of solar panels increases in the US.”
The amount of solar energy use is set to increase about tenfold by the year 2050, just as the older panels are set to reach the end of their lifespans.
Central Indiana’s current primary solar panel recycling company is Electronic Recyclers International (ERI), which is located in Plainfield.
The need for recycling
Since solar panels contain lead, simply throwing them in a landfill is not only wasteful and costly but also potentially hazardous to the environment and public health. Even small amounts of lead can be absorbed by the body through skin absorption or accidental consumption.
Older panels especially may also use small amounts of other metals, including amorphous silicon, cadmium telluride, and copper indium, which can also be hazardous to the environment as well as public health.
Finding better ways to recycle solar panels and use less of these metals has become enough of a concern that the Indiana legislature unanimously passed a bill to study the matter earlier this year.
How solar panels are recycled
The aluminum frames of solar panels are easily separated mechanically. The glass can then be separated from the solar panel by applying heat to melt the ethylene vinyl acetate binding that typically attaches it.
However, according to Michael Jefferies, Great Lakes and Appalachian regional coordinator for Citizens Climate Lobby, most of the value of the panels comes from minerals like silver, copper, and silicon.
“In the past, most of these minerals weren’t able to be recovered, making solar panel recycling unprofitable,” he said, “but there have been several recent advances in solar panel recycling which will make it far more profitable than it currently is.”
Last year, researchers in the United Kingdom were behind one of those advances, making the process cheaper and more environmentally friendly.
To extract silver from solar panels, they first put the solar cell in a solution of aluminum chloride. This allowed them to separate the aluminum cell and the silicon wafer. Next, they use iron chloride to dissolve the silver in a calcium chloride brine, a type of salt water, ensuring that the iron chloride is able to oxidize silver (by transferring its chlorine atoms), which then causes the silver chloride to dissolve.
When water gets added to the solution, the silver chloride precipitates out and becomes a solid again. On exposure to sunlight, silver chloride turns into chlorine gas and silver metal.
Innovation in the European Union
In 2012, the European Union (EU) banned photovoltaic cells from being thrown in the landfill, making the need for innovation in the recycling of solar panels much more prevalent.
The Full Recovery End of Life Photovoltaic project, or FRELP, is a product of EU-funded research, and it has been able to recycle up to 98 percent of glass, 99 percent of aluminum, 95 percent of silicon metal, 98 percent of copper, and 94 percent of silver in solar panels, although there is still more research needed to apply this to an industrial scale.
“There is also a plant in Grenoble, France which already is able to extract many of the [other] critical minerals making it profitable for them to exclusively process solar panels,” said Jefferies. “So not only is extracting the minerals doable, it’s already beginning to be done.”
Some have also looked for ways to recover lead that may leak from these cells from the environment.
There have also been several legislative efforts in congress seeking to make recycling of solar panels easier.
“Rep. Larry Bucshon’s (R-IN-08) “Securing America’s Critical Minerals Supply Act” would require the Department of Energy to develop new processes to recycle and reuse critical energy resources, like the minerals used in solar panels,” said Jefferies.
Jefferies also pointed to the recycling bill was part of a wider discussion on reforming the permitting process for constructing energy infrastructure that recently saw the Lower Energy Costs Act passed in the House and waiting approval in the Senate.
“[the recycling bill] will hopefully be included in the final bipartisan deal,” said Jefferies.
If you have an interest in interning with the IUPUI Office of Sustainability, you can find out more information here.
Jacob Stewart is a senior majoring in neuroscience at IUPUI. He is the editor-in-chief of The Collegiate Commons, a 501(c)(3) nonprofit student news publication in central Indiana. He also enjoys playing the piano and going for runs, but never at the same time. He has a special interest in public health, and firmly believes that environmental and public health are intertwined. Featured image courtesy of Performance Services. Research was performed with the assistance of Riley Abell, a senior majoring in chemistry at IUPUI.