Dear EarthTalk:

How are we going to deal with all the waste when the solar panels everyone is putting up now wear out in 20-30 years?

Paul B., Chevy Chase, MD

When purchasing green alternatives for home power generation, there are many features that the average consumer looks for. Most are hoping to find options that are the most efficient, or the lightest, or the most durable, but what about the most recyclable? 

This question is often overlooked when making such purchases. Unfortunately, ignoring a product's life cycle can have disastrous consequences, especially if reducing your environmental footprint is a concern.

Take solar panels, for example. The average solar panel lasts roughly 25 years, and the vast majority of them were purchased and put into use within the last 10 years. This means that within the next 15 years, millions of retired and broken solar panels will be flooding landfills. A 2020 study out of the federally funded National Renewable Energy Laboratory (NREL) found that as much as eight million tons of solar modules could arrive in landfills globally by 2030, and by 2050 these solar panels could make up to 10 percent of all e-waste on the planet. 

To make matters worse, if the waste isn’t disposed of properly, it could cause problems for the groundwater in its vicinity. Solar panels contain trace amounts of toxic compounds, such as lead, and a carcinogen known as cadmium telluride. If either of these chemicals were to leach into a freshwater source, the water would become unsafe to use in most capacities. 

Although solar panels are recyclable, there is little incentive to do so. Made from materials such as aluminum, copper, silicon and glass, approximately 80-85 percent of a solar panel can be recycled; however, the process would actually cost more than the raw materials are worth. 

Thankfully, the U.S. Department of Energy’s Solar Energy Technologies Office has been hard at work developing a comprehensive system for handling and recycling solar panels. By 2030, they plan on reducing the cost of solar panel recycling to a mere $3 per panel. This reduction would actually make solar panel recycling an economically feasible venture!   

That said, there is still the option to rebuild new solar panels from old ones. However, to accomplish this would require a direct reuse of the materials recovered. Silicon, for example, can be directly recycled back into solar panels, or it can even be used in the anodes of lithium-ion batteries—the functional storage unit of power generated through the use of solar panels. 

But what about simply making the solar panels greener? Instead of silicon solar panels (what people normally buy), there is another option available known as Sunflare thin-film solar panels. The lightweight modules have a carbon footprint that is 20 percent that of silicon, they do not require toxic chemicals such as lead, cadmium, hydrofluoric acid or hydrochloric acid to produce, they require less water, and are 80 percent less energy-intensive to make. They are also paper-thin, require no silicon purification, no glass, and no mounts, and are even more efficient in low-light conditions!

CONTACTS

• Solar Photovoltaic Module Recycling: A Survey of U.S. Policies and Initiatives, www.nrel.gov/docs/fy21osti/74124.pdf; Sunflare Solar, www.sunflaresolar.com.