In the past decade, wind and solar have made massive strides in our energy economy. As of 2022, they account for 13.6 percent of the U.S. energy sector’s total electricity generation. As this share of the U.S. energy production mix continues to grow, it is crucial to think about what happens to the wind turbines and solar panels when they reach the end of their lifetime, as each has its own unique challenges.
Because these are dilute and intermittent energy generation sources, we often install a huge number of turbines or solar arrays to increase total capacity to generate more power when wind and sun is available. These are also mining and material intensive infrastructure components. This also means an incredible amount of renewable waste to handle.
After a lifetime of around 25 years and installations in the late 1990s, many solar panels are reaching the end of their life. According to the EPA, the U.S. is expected to have up to one million tons of solar panel waste by 2030. This waste can often be toxic, containing heavy metals such as lead and cadmium that may be leachable, able to be carried by water through rock or soil, and are dangerous to humans.
Aside from the potential environmental and health risks associated with solar panel waste, the industry is missing out on using massive amounts of potentially reusable material. A significant portion of a solar panel can be recycled – glass makes up about 75 percent of a panel’s weight. Other recyclable materials in a solar panel include aluminum, copper, and plastic. As a result, the estimated value of recoverable materials is up to $60 million by 2030 in the U.S. Despite these factors, around 90 percent of end-of-life solar panels end up in landfills.
So, even with the potential benefits, why are solar panels so seldom recycled? As is often the case, the recycling process is expensive. Solar panels are designed to be durable and difficult to break down. This is because they need to last through the elements as they spend their lifetime outdoors.
There are two methods for recycling solar panels: mechanical and chemical. The mechanical process physically breaks down the panels and removes the aluminum frame for recycling as well as combining the glass, silicon, and other metals into a reusable building material. Chemical recycling uses chemical reactions to separate the materials, as is done by ROSI, a French solar recycling company.
It is estimated that recycling solar panels costs $15-45 per module as opposed to the $1-5 cost to dispose of them in landfills. The value of the recycled materials, either to be sold or reused, can vary greatly depending on the prices of metals and silicon. Between June 2020 and June 2021, the total value of recycled materials from a single module increased from around $10 to $19. These numbers continue to remain uncertain, however, as in addition to price volatility, the metals used to compose solar panels continue to change. Other factors like collection and transportation may threaten the viability of recycling renewable waste.
Wind turbines also face challenges in end-of-life disposal. Similar to solar panels, wind turbines often last 20 to 25 years and began widespread deployment at the end of the 20th century, meaning many are beginning to be decommissioned. Estimates expect the U.S. to have 728 thousand tons of waste from wind turbines by 2036. This is likely a conservative estimate, as it does not account for future wind turbine installation and potential blade replacements. Despite this, up to 95 percent of the material in a wind turbine is recyclable.
Like solar panels, the primary factor preventing turbines from being recycled is cost, for several reasons. First, wind turbines are massive, reaching up to 95 meters long. This makes both deconstruction and transportation extremely difficult and very costly. To do so, blades will be cut (often requiring specialized equipment) in order to be shipped to a recycling facility.
Also similar to solar panels, the turbines were built to withstand severe weather. As a result, they are very difficult to disassemble. This is compounded by the fact that 80-90 percent of the blade is made of composite material, mostly fiberglass, and carbon fiber. Composite material is notoriously difficult to separate. That is why a common method of recycling the blades is shredding the material and selling it to cement manufacturers who use it to replace coal, sand, and clay. This process even results in a 27 percent reduction in CO2 emissions from cement production. As it stands, many turbine blades ultimately make their way to landfills today.
Recycling technologies for these sources of renewable power are an important part of keeping the environment clean and cutting down on waste while increasing the amount of material available to manufacturers. While the costs currently outweigh the benefits for the firms disposing of the materials, continuing to improve our recycling technology can aid in reducing costs and allow them to reap the benefits of reusing or selling recycled materials.
Written by Andrew Barton, Public Policy Intern
The Alliance for Innovation and Infrastructure (Aii) is an independent, national research and educational organization. An innovative think tank, Aii explores the intersection of economics, law, and public policy in the areas of climate, damage prevention, energy, infrastructure, innovation, technology, and transportation.