Solar panels have an average lifespan of about 25 to 30 years. It was after the year 2000 that solar panels started to be increasingly widespread, with the worldwide power generation attributed to solar power rising exponentially from less than 5 gigawatts (GW) in 2003 to over 75 GW in 2016.
Putting two and two together, it’s inevitable that as we approach the year 2030 and beyond, we will be dealing with a huge amount of used solar panels that are no longer functional. In the absence of immediate innovation in reuse and recycling, they will end up in landfills. Estimates claim that this could add up to 78 million metric tons of disposed material by 2050.
It’s not very different when it comes to used wind turbines. Most wind turbine blades can be used for up to 20-25 years, but are often replaced after 10 years with larger and more powerful designs. A 2017 study suggested that 43 million metric tons of decommissioned wind turbine blades will need to be disposed of by 2050.
The meteoric rise of electric vehicles heralds a similar problem: potentially millions of lithium ion batteries that are discarded when electric cars, buses and trains reach the end of their lifecycles. The EU is working towards 30 million electric cars on European roads by 2030. Factoring in the rest of the world (including enormous markets such as the US and China), you can see where this is going.
What makes it an even tougher problem is that the substances that stand to be released back into the environment are not exactly harmonious with it. Solar panels contain heavy metals such as lead (which can cause brain and kidney damage) and cadmium (which is carcinogenic) that are in danger of being leached into water and consumed by humans and other flora and fauna. A similar danger exists with lithium from lithium-ion batteries used in electric cars. Though wind turbines are not particularly toxic, the toughness of its fibre glass-plastics mix means that many of them may end up in landfills, which always come with dangers such as pollution of land and waterways.
But we simply do not have the option of ignoring solar, wind and electric vehicles if we are to achieve carbon neutrality and solve the climate crisis.
This leads us to the inevitable conclusion: Our ability to achieve breakthroughs in waste management will determine our success in green energy and ultimately our ambitions of a carbon-neutral future.
The most obvious solution is recycling. But this has some challenges.
Solar panels are predominantly made of glass which is a low-value material. This glass is embedded with impurities such as plastics, lead, cadmium and antimony which makes it next to impossible to recycle it with current technology. Only a small percentage of the materials in a solar panel, such as copper and aluminium, are high value materials that can also be recycled. Silicon and silver are high value materials but the processes to separate and purify them have not been fine-tuned yet, which leads to the silver and silicon often being shredded and dumped in landfills along with the glass.
But these challenges have not prevented companies like the Phoenix, Arizona-based We Recycle Solar and the French water and waste company Veolia from developing solar panel recycling technology. In 2018, Veolia opened Europe’s first plant dedicated entirely to recycling photovoltaic panels.
Wind turbines also offer good prospects for recycling. Turbine blades are commonly made of fibreglass which has wide applications in construction. Housing materials, playground equipment, carpentry, roofs and pedestrian bridges are some of the applications that have been proposed.
The Danish city of Aalborg has saved a step by reusing portions of wind turbine blades themselves as bike shelters without having to extract and recycle the fibreglass that comprises them. University College Cork in Ireland is attempting something similar by repurposing a decommissioned wind turbine blade as a bridge.
In September 2021, wind energy pioneer Siemens-Gamesa announced the world’s first recyclable wind turbine blades ready for commercial use offshore. It plans to install and pilot these blades at the Kaskasi offshore wind farm in the German North Sea in 2022. GE Renewable Energy and Vestas are two other renewable energy pioneers betting big on recyclable wind turbine blades.
Lithium-ion batteries in electric vehicles come with their own set of opportunities and challenges for recycling. Though lithium has low value in the recycling market due to wide availability of the raw material, the other common materials in a lithium-ion battery such as nickel, cobalt and manganese have high value. This gives it a viable recycling market. However, the fact that each lithium-ion battery uses several distinct materials in close proximity means that each material has to be delicately extracted without reacting adversely with one another. This requires new skills that millions of workers need to learn.
All this, and we are still only talking about the waste generated by decommissioned items at the end of their lifecycles. A discussion of the waste generated by mining the raw materials and manufacturing these items in the first place will require a separate article in itself. Just as an example, lithium mining is known to have caused contamination of groundwater, soil and air in several regions of the world such as Argentina’s Salar de Hombre Muerto.
The waste management challenges outlined above are NOT meant to give us excuses to avoid renewables and stick to the technology that created the climate crisis. They challenge us to respond to them the way our species always has: through innovation, ingenuity and inventiveness.
This innovation has infinite possibilities but broadly falls into two categories. The first is innovation in the recycling technology needed to extract and reuse the vast majority of the materials in electric vehicle batteries, solar panels and wind turbines. The second is innovation in the technology and composition of the items themselves such that they use different materials that are more easily reused or recycled.
As of now, the first kind of innovation (recycling technology) is in its early stages, with many issues yet to be resolved, such as the high percentage of solar panel material that’s unrecyclable with current technology. We need more efforts in this space. We cannot simply conclude that recycling is impossible in some cases and throw in the towel. The examples we discussed above pertaining to innovative reuse of wind turbine blades show that it’s possible with lateral thinking.
The second kind of innovation (the technology and composition of the items themselves) is already happening to a larger extent. Sodium-ion batteries are being explored as an alternative to lithium-ion batteries in electric vehicles. Their biggest advantage is that sodium is abundantly and cheaply available and doesn’t have to be mined in an environmentally damaging way like lithium. The world’s largest lithium-ion battery manufacturer, China’s CATL, has announced plans to commercialise sodium-ion batteries by 2023. Nickel-hydrogen batteries, vanadium redox flow batteries (VRFBs) and iron-air batteries are other alternatives currently under exploration.
Likewise, alternatives to silicon in solar panel photovoltaic cells are also being explored. This will tackle the issue we discussed above of our inability to extract and purify silicon from the panels. Cadmium telluride has been proposed as an alternative, but as mentioned above, cadmium is carcinogenic. Perovskite solar cells (PSC) have emerged onto the scene in the past couple of years, but their often-cited advantages are about increased efficiency and lowered costs rather than greater environmental friendliness. Besides, their shorter lifespans may actually increase the solar waste problem.
When more businesses, governments and universities invest in green innovation, our chances of solving all these above-mentioned problems increase manifold. Let’s first acknowledge that these are problems worth solving, worth investing our best brains and resources into. That would be the first step in delivering the kind of breakthrough innovations needed to solve the waste management issues and unleash the full potential of every green technology we are embracing today.
Our species has progressed not by wilting at the challenges of new technology, but by addressing and solving them with gusto. That’s exactly what we need once again.
Energy Voices is a democratic space presenting the thoughts and opinions of leading Energy & Sustainability writers, their opinions do not necessarily represent those of illuminem.