The What, Why, and How of Solar Panel Recycling
In the spring of 1954, a small team at the Bell Labs finished work on the world’s first silicon photovoltaic cell - the building block of solar panels. Little did anyone know, that the coming decades (and particularly the coming century) would churn out billions of solar cells in millions of panels, helping solar break all records of annual installed capacity, and stand on the cusp of becoming the single largest power source of the world.
However, a critical question accompanies the dramatic rise of solar, just as it does for anything that grows rapidly - “What happens to the millions of solar panels when their life ends?”
In Q1 of 2021, the cumulative capacity of installed solar in the US stood at a staggering 102.8GW. Considering an average panel size of 300 W, that’s close to 343 million solar panels - which is equivalent to over 30,000 statues of liberty!
So what exactly happens 25 years from now, when all these panels retire?
Opponents of renewable energy often consider this their favorite question, while proponents slightly sweat when answering it, and for good reason. Like most other electronics, solar panels are built from a complex array of mostly non-degradable components, and dumping them in landfills is far from being the best option.
The best option (or the least bad option) we have right now is to recycle as much of the solar panel as possible. The good news is that 80-100% of a solar panel can be recycled, while the bad news is that the speed of recycling is yet to match the speed of panel manufacturing.
But we still have time, and conscious planning and action can help us be ready to handle the overwhelming amount of solar panel waste in another decade or two.
Let us dive into the various aspects of solar panel recycling.
Understanding the Basics of Panel Recycling
Here’s a brief depiction of what happens when a solar panel enters a recycling facility:
As mentioned previously, solar panels do not degrade naturally, at least yet, since they are made from a variety of inorganic substances. Following is the breakdown of a typical crystalline solar panel’s composition by weight:
Glass: 76%
Plastic: 10%
Aluminum: 8%
Silicon: 5%
Metals: 1%
Here’s what happens to each of the components when a panel goes to a recycling facility, and beyond:
Glass: Separated during disassembly, 95% reused.
Aluminum and other metals: Separated during disassembly, 100% reused.
Silicon: Separated during thermal processing, etched and/or melted, 85% reused for:
New solar panels
Batteries
Other electronics
Plastic: Evaporated during thermal processing, high-temperature fumes reused as a heat source.
Among the above materials, the most interesting is silicon, firstly because it has multiple uses in its reincarnated life, secondly, because it can be extracted with a surprising level of purity - 99.9999% (also known as 6 nines or 6N), and finally, because it promises to open a new door for a complementary sustainable technology - electric vehicles.
Silicon can be used in electric cars in the anode of lithium-ion batteries, where they promise to improve battery range by up to a striking 20%. A few years ago, Elon Musk reported that silicon in batteries improved range by about 6%, a story reiterated by both Daimler and BMW.
Building a Fool-Proof Recycling Mechanism
A robust recycling mechanism, or any mechanism for that matter, is never only about what is technologically possible. There are a ton of other factors that contribute to creating a flawless recycling infrastructure.
Let’s discuss each of these in a bit more detail:
1. Innovation in the recycling mechanism
Let’s face the harsh truth - no amount of awareness or regulations can drive something unless it is commercially feasible. It is the same reason why solar power took a few decades to gain momentum.
Currently, recycling is a costly affair. As Meng Tao, a solar researcher at the Arizona State University puts it, “We believe the big blind spot in the US for recycling is that the cost far exceeds the revenue, it’s on the order of a 10-to-1 ratio”.
If for every dollar spent on recycling, we can only extract 10 cents worth of materials, we cannot expect recycling to ramp up nationally and globally in the limited time we have.
Fortunately, research and development on solar panel recycling has been steadily gaining speed, and we can be reasonably hopeful that we will have an army of recycling facilities ready when the large wave of solar panel waste hits us.
2. Scaling of the recycling infrastructure
Until a few years ago, end-of-life solar panels in the U.S. needed to be sent overseas for recycling. Coupled with the already high cost of recycling, the transportation involved made the option of recycling even more disinteresting.
Currently, there are less than 100 full-fledged recycling facilities worldwide. A lot of countries with a rapid rise in solar deployment do not have a recycling facility, sometimes even in a radius of a few thousand miles from them.
Panel recycling will not be efficient and effective if it is not easy, and an enormous network of national as well as global recycling facilities is absolutely essential. However, the role of finances again comes into play here, and with innovation, R&D, and low-cost recycling options, we can crack not just the cost problem but also the scale problem.
3. Regulations, Policies, Incentives
Here’s a fact - all the environmental arguments aside, no technology grows until it proves itself to be commercially beneficial. Again, we have seen the same with solar. We have known about the climate crisis for decades, but the last 10 years have seen the biggest growth in solar, because payback periods dropped from 20 years to as low as 5 years, and that is a powerful reason to purchase solar.
Now here’s a thought experiment - Who, and how does solar panel recycling benefit, if we are taking the ecological aspect out of the equation for a moment? There is no clear answer.
You may say it will benefit owners of recycling facilities if the extracted materials fetch a significant amount of money. But we just discussed that the ratio of cost-to-revenue is 10-to-1, and it will take decades until revenue becomes the primary motivation for setting up a facility, and we probably do not have enough time for that.
This is where the importance of legislation comes into play. We know that regulations have the power of creating large-scale change, from vehicle emissions control to the use of CFCs in refrigerators, laws have helped to a notable extent.
It is important for governing authorities to start rolling out regulatory measures now and update them gradually so that in a decade or two, we will be in a position to handle heaps of solar waste.
Unfortunately, not many governments seem to be doing so. The only place where there is clear legislation around solar waste management is in Europe, where the WEEE has done a commendable job in regulating solar waste management.
No discussion on solar panel recycling is complete without the mention of WEEE. In August 2012, Europe updated its electrical and electronic waste directive and put the responsibility of recycling solar panels on the producers. Now, in every European country, it is mandatory for the manufacturing company of panels to collect, transport, and treat (recycle) solar panels.
Subsequently, a non-profit organization named PV-Cycle was formed, to help photovoltaic companies manage the recycling process, not just in Europe but worldwide.
The picture here in the USA is starkly different. Except for the state of Washington’s PV Module Stewardship and Takeback program, there is no nationwide mandate on what happens to dying solar panels.
In fact, even globally, with a few exceptions, solar panels are not even categorized as electronic waste. This allows negligent organizations to dump solar panels in landfills toward the end of their life, which can be hazardous, since substances like lead and tin can seep into groundwater and increase toxicity. This is exactly why strict and clear legislation is inevitable.
Technology, costs, and policies always go hand-in-hand. Even if one of these does not deliver, achieving the final goal becomes challenging.
Into the Future
The global solar PV waste is expected to reach around 78 million tonnes by 2050, while the U.S. recycling market size promises to cross $100 million by 2027. ‘Research and Markets’ predicts that the North American solar panel recycling market is expected to grow by 18.3% annually, which is reassuring to some extent but still needs acceleration.
(source: Grandview Research)
In its report on panel recycling, IRENA mentions that an estimated $15 billion of useful materials can be extracted from solar panels by 2050.
This will not only ensure wiser waste management but also create and expand a whole new sector that employs a significant number of people in it.
Summing It Up
Overall, there is no debate on whether solar will take over, and that certainty means we should bring certainty to solar panel waste handling as well. This includes a mix of innovation to drive down costs as well as a strong will and action on the part of governing authorities to create regulations that will ensure reliable recycling infrastructure.
What presents itself as a problem always carries in itself some potential opportunities, and the same applies here - solar panel recycling can transform the cleantech world by aiding the economy, boosting jobs, and even driving down costs of new solar panels.
Ultimately, it is the choices we make and the actions we take now, that will decide if solar panel recycling is, in the long-term, a problem... or a treasure chest of opportunities!
