With conversations of climate change and decarbonization increasing globally, solar is brought up often as a convenient and green alternative to fossil fuels for powering the grid. According to the 2021 Solar Futures Study by the United States Department of Energy, solar has the potential to provide up to 40% of the country’s electricity production by 2035 and up to 45% by 2050. Solar is clearly on the upswing as a renewable power source, but the process takes time. The project life cycle starts with a piece of land and an idea. After years of development and decades of energy production, the vast majority of the solar facility can be recycled.  

The lifecycle of a solar project – from beginning to end  

• Development – Diode is a development expert when it comes to solar projects. There are numerous activities that have to happen before the project can be built. First, there must be a concept. Sometimes this is a need from a company who wants to green up their energy profile, a utility who wants to increase their renewable sources, or a community who wants to add greener energy to their neighborhood. Next comes site selection and development, which is composed of feasibility review, environmental studies about the area and land, as well as city and state zoning and permitting requirements, and  interconnection studies. Once development is complete, securing financing or funding for the project happens.  After all that, the site is ready to enter the design phase.  
• Engineering and design – Initial design can begin in the development phase, but this is where the bulk of the project is designed. Information to consider is where the project is going, local design requirements, where panels will fit best on the land, and how the panels should be mounted. This is where an EPC contractor, like our parent company, Black & Veatch, would step in.  
• Construction – Finally, the project is built! This is what comes to mind when most people think about building a project. Materials will be procured, panels will be mounted onto their racking system, and construction crews will be working regularly for months to get the site ready for operation. The project will undergo certification and commissioning before it finally gets connected to the local power grid or to the customer to directly consume the power.  
• Operations and maintenance – The project is complete and operational! Now its job is to soak up the sun and convert it to energy. The standard life cycle of a solar panel is about 20-25 years, so that is about how long we would expect the original equipment to provide energy. This will come with regular maintenance to keep the panels operating to their fullest extent. Panels can be replaced once they reach the end of their lifecycle to enable the project to continue producing power.
• Dismantling and recycling – The project has completed its useful life and is ready to be retired. What happens to all those panels, though?

Solar panel afterlife

After a solar panel is no longer considered useful, there are usually two ways to deal with them – throw them away or recycle them. In the United States and Europe, solar panels are considered e-waste and must be dealt with accordingly. According to Attila Tamas Vekony in a 2021 GreenMatch article, while there are no US federal guidelines, the European Union has mandated that developers and owners of solar projects must incorporate the cost of recycling panels into the cost of the project so as to not place additional burden on the environment. Washington state is the only US state to have a similar mandate.  

If it were not for recycling, GreenMatch lists that up to 60 million tons of solar panel waste could accumulate by the year 2050, which is why recycling them is so important. Because most solar panels are made from one of two materials, there are two different recycling processes: silicon-based panel recycling and thin-film based panel recycling.  

Silicon based panels are the most commonly used panels that we have today. The process begins by separating the panel’s aluminum and glass parts. “Almost all (95%) of the glass can be reused, while all external metal parts are used for re-molding cell frames,” says Vekony at GreenMatch. In addition, a significant portion of the hardware (80%) can be reused after the initial recycling treatments. The silicon parts are also able to be recycled and reused. Often, all the pieces of old solar panels can be recreated into new solar panels.

Thin-film based solar panels are less common and require more processing to be reused and recycled. After being shredded and crushed into tiny pieces, both liquid and solid materials are leftover to be processed. “Liquids go through a precipitation and dewatering process to ensure purity. The resulting substance goes through metal processing to completely separate the different semiconductor materials. The latter step depends on the actual technology used when producing the panels; however, on average 95% of the semiconductor material is reused,” according to Vekony at GreenMatch. After that, there is solid matter to be further processed which leaves behind pure glass that is recycled easily.  

What starts out as a piece of land and a plan to decrease our carbon footprint turns into a project that generates clean energy for 20-25 years or more and solar panels that can be recycled into new solar panels. There are lots of moving pieces, but solar is one of the simpler renewable technologies to install which makes it a prime candidate for potentially powering up to 40% of the United States grid in the near future.  

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