Unlike other energy sources, solar energy doesn’t generate air pollution or greenhouse gases when it’s in operation. By replacing less environmentally friendly energy sources, solar energy can help the environment.
Critics of solar energy point out that, while solar does produce clean energy, the energy and materials required to produce and dispose of solar panels at the end of their lifecycle are harmful to the environment.
Let’s take a look at solar panel development and try to get an answer to this debate.
The Production of Solar Panels
Energy – sometimes from fossil fuel sources – is required to obtain metals and make glass that comprises solar panels. According to the Energy Information Administration, a number of organizations and researchers have conducted lifecycle environmental analysis of solar energy systems. Studies have concluded that “PV systems can produce the equivalent amount of energy that was used to manufacture the systems within 1 to 4 years. Most PV systems have operating lives of up to 30 years or more.”1
Additionally, some of the metals and materials used to manufacture photovoltaic (PV) cells and panels are hazardous. These materials require careful handling during production and when they reach the end of their useful life. Fortunately, U.S. environmental laws regulate the use and disposal of these hazardous materials.
Disposal of Solar Panels
There are two types of solar panels most commonly used today. The different materials used in them impact whether they are considered hazardous and how they’re disposed of when their useful life ends.
- Silicon Solar (mono- and poly-crystalline). More than 95% of solar panels sold today use crystalline-silicon solar PV. These efficient, low-cost panels contain small amounts of valuable metals embedded within the panel. They have life expectancies of 25 years or longer.
- Thin-Film Solar. Solar cells for these panels contain thin layers of semiconductor material, such as cadmium telluride or copper indium gallium diselenide, layered on a supporting material like glass, plastic, or metal. These low-cost cells aren’t quite as efficient as silicon solar PV. Cadmium telluride is the second most common PV material after silicon.2
Metals such as lead and cadmium used in some solar panels are harmful to the environment and humans at high levels. That’s why solar panels are subject to federal solid and hazardous waste regulations when they’re disposed of at the end of their useful life. Certain models and types of solar panels even by the same manufacturer are considered hazardous waste while others aren’t, depending on the quantity and types of materials they contain.
Solar Panel Production, Disposal, and Recycling: Huge Topics for the Future
With the long life expectancy of solar panels, disposal of most of panels in use today has not yet become an issue. By 2050, the U.S. is expected to have the second largest number of end-of-life panels in the world, with an estimated 10 million total tons of panels.3
Several states have enacted laws and policies related to solar panel waste, but many more will follow as we approach the end of life for the 70% of panels in use today that became active in the past five years. Some hazardous waste solar panels may be recycled as long as certain criteria laid out in the regulations are followed.
In fact, PV recycling has been successfully implemented in Europe where regulation requires collection and recycling of materials used in solar panels. Solar PV waste will grow in size but also in value in coming decades – with the business of material recovery expected to soar. It’s expected that reclaiming minerals from end of life panels will be necessary to meet growing solar production demands. One study shows the projected value of end of life panels approaching $80 billion by 2050.4
While the production and eventual recycling of solar panels has environmental implications, the solar industry as a whole is proactively looking for solutions. Production advancements that use environmentally friendly materials and forward-looking recycling processes, rules, and regulations will make solar an even more environmentally friendly energy than it is today – and will help the industry meet future solar production demands.
- To learn more about solar panel regulations for your state, visit your state’s environmental agency website.
- The U.S. Environmental Protection Agency is a great place to start if you’re interested in learning more about how solar panels are recycled.
- The Solar Energy Industry Association (SEIA) is actively seeking and developing recycling partners, and has a growing national PV recycling network.