End-of-Life Solar Panels: How To Manage Solar Waste

Solar is fast-growing as the go-to renewable energy source that will cut the burning of fossil fuels globally to power homes and even complex installations, such as AI data centers. Recent advances in this sun harvesting technology and the batteries that keep the power flowing when the sun goes down have only made solar more viable and even cheaper. So all seems well for the world in terms of managing climate change. But there’s one major problem that is about to hit us; solar waste.

Solar panels have a lifespan of around 25–30 years. Looking at the history of solar adoption, the initial surge was from 2008–2010, which was when the global solar capacity started increasing due to favorable policies. This was followed by the solar cost crash in the 2010–2015 period, which pushed dramatic adoption growth in both residential and commercial applications. We are currently in the solar boom period, where these sun harvesting panels are maturing, advancing, and becoming more mainstream.

Going by this data, a solar waste tsunami is imminent as most of the solar panels installed in the 2010–2020 period are expected to retire by 2040–2050. According to the International Energy Agency, these retired panels could create a solar waste problem of a 78 million ton magnitude globally by 2050, making it the largest waste stream of any clean energy technology in history. So how do you manage this upcoming solar waste tsunami? The best route is through recycling. Let’s first look at the two primary types of solar panels to see how recycling comes into place.

Types of Solar Panels

Silicon Solar Panels

Crystalline silicon solar panels are the majority of the solar panels in the market (representing about 95%) because they are low-cost, efficient, and have long lifespans (25 years+). These feature solar cells made of a crystal silicon structure and contain tiny amounts of valuable metals embedded within, such as copper and silver.

Thin-Film Solar Panels

As the name suggests, these solar panels feature thin semiconductor materials, such as copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe), which are placed on a supporting material, usually glass, metal, or plastic. These panels can be made using low-cost manufacturing processes but are not as efficient at converting sunlight into electricity as their silicon counterparts.

Materials That Make Up Solar Panels

Regardless of the type, solar panels are about 70–80% glass (on the face), 10% polymers, 10% aluminum, and a small mixture of copper, silver, tin, cadmium, and lead. So recycling them should be driven by two factors.

1. To Extract Raw Materials and Valuable Components

Once decommissioned, each layer and material used to make the solar panel must be painstakingly separated to enable recycling. The glass face is perhaps the easiest to separate, and it can be used to make new solar panels or bottles for holding liquids in other applications. Silver and copper can be melted down and sold, or reused to make new panels that feature the latest solar harvesting technologies.

According to the International Energy Agency, If these materials are fully recycled and injected back into the economy, their value could exceed $15 billion by 2050, meaning this could be viable business that can be handled by the private sector profitably. If reused for solar production, the material influx from the recycling processes can help manufacture 2 billion new panels, which will reduce material extraction from the ground and the associated negative effects.

Overall, this raw material and valuable component extraction from decommissioned solar panels will increase the security of materials needed for future solar photovoltaic cell manufacturing or other raw-material dependent products because these recycled materials can also be sold in the global commodity markets.

2. To Prevent Soil and Water Contamination

Since solar panels also contain highly toxic heavy metals like lead and cadmium, recycling them helps to prevent these materials from leaching into the soil or ground water, which will mostly end up in human bodies in one way or the other.

How To Manage Solar Waste

Solar panels aren’t just installations where you fix them and forget about them. There has to be well thought out end-of-life solutions that manage this waste in the form of a lucrative business model to make the recycling process sustainable. The best way to enable these sustainable recycling business models is through developing favorable policies, both at the federal and state level.

First and foremost, there should be policies that ban or limit the quantities of heavy metals used to make solar panels to help prevent soil and water contamination. Heavy metals like lead and cadmium are harmful to human health and the environment if they exceed certain levels, so if their presence is high enough in solar panels (such as through using leaded solder to weld wires and parts), they should be considered hazardous. In the US, for instance, some solar panels are considered hazardous waste while some are not even if they are the same model and from the same manufacturer. It all depends on the materials used to make it. This is under the RCRA laws and regulations.

For the panels that are about to form the waste tsunami, policies must be put in place to prevent landfill dumping of solar panels. These policies must enforce solar panel manufacturers, home developers, and solar farm operators to seek out recyclers by making it illegal to dump solar panels in landfills. The goal here is to create a steady demand for recycling services to make it economically feasible for recyclers to stay in business. Selling the recycled materials isn’t enough to cover the bills because the processes involved in separating and extracting them are complicated and costly.

States like Hawaii and California have officially reclassified solar panels as universal waste, which gives manufacturers a clear path for collection and recycling after decommissioning.

The rest of the world should take notes from the EU, which is the world’s most advanced region when it comes to solar panel waste regulation. Here, photovoltaic panels fall under the WEEE directive (Waste Electrical and Electronic Equipment), which makes producers responsible for collecting and recycling solar panels in each member state after decommissioning. Producers in this case refers to manufacturers, importers, resellers, or installers. The union has also banned untreated panels from being dumped in landfills and requires member states to recover at least 85% of retired solar panels and recycle at least 80%.