The solar panel industry requires all the stuff it can get. But, in the forthcoming years, recyclers will hopefully be able to get billion dollars worth of property from discarded solar boards.
That should reduce bottlenecks in the supply chain for solar panels while pushing them more endurable.
Right now, most dead solar boards in the US get shredded or chucked into a landfill. Unfortunately, the economics don’t shake out in recycling’s favor. The deal you can squeeze out of a salvaged panel hasn’t been enough to cover the cost of transporting and recycling it. But that’s on track to change, according to the recent research firm Rystad Energy analysis.
Rystad predicts that the value of recyclable materials from solar panels will grow exponentially over the next several years, ballooning to $2.7 billion in 2030 from just $170 million this year. That’s thanks to a growing demand for solar coupled with an anticipated pinch in the materials needed to make panels. Technological advancements also make extracting more valuable materials from old boards easier, making recycling a sweeter financial deal.
Currently, solar energy makes up just over 3 percent of the global electricity mix. But the world’s energy systems are at the start of a drastic makeover to bring more renewable energy online. The Paris climate accord commits countries to work together to quit releasing greenhouse gas emissions from burning fossil fuels over the next few decades to keep the damaging effects of climate change at a more manageable level.
Solar could account for upwards of 40 percent of the global power supply. It also helps that solar panels have grown super affordable, becoming a cheaper source of electricity than coal or gas in most of the world.
Still, some clouds are ahead in the otherwise sunny forecast for solar energy. For example, to build more solar panels, you need more materials. Currently, mining and processing of those materials are concentrated in a handful of countries. That’s left the solar supply chain vulnerable to disruptions and abuse.
The nonprofit Business & Human Rights Resource Centre has documented human rights abuses while mining materials used in solar panels. And polysilicon used in solar panels is made through an energy-intensive process tied to forced labor. Those revelations have led to sanctions on some solar products made in China.
Recycling will play a role in diversifying those supply chains. It might also lessen the toll that mining takes on the environment and the health of workers and nearby communities.
In the future, more of the materials used to make new solar panels will likely come from re-hashed panels. Recovered silver, polysilicon, copper, and aluminum can fetch the most cash on the recycling market, according to Rystad. Unfortunately, silver and solar-grade silicon usually aren’t separated from today’s recycling methods. Instead, it’s often shredded along with the rest of the panel and sold as crushed glass. Luckily, recycling could soon become more sophisticated, thanks to new research on salvaging the most valuable stuff inside photovoltaic panels.
Solar started to take off in the 2000s, and with a lifespan of around 25 years — we’re just now approaching the first big wave of discarded solar panels. However, if treated properly, that trash could become a treasure.
A solar cell is an electrical device that converts the energy of light directly into electricity by the photovoltaic effect, a physical and chemical phenomenon.
It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as current, voltage, or resistance, vary when exposed to light. Solar cells are the building blocks of photovoltaic modules, otherwise known as solar panels.
Solar cells are photovoltaic irrespective of whether the source is sunlight or artificial light. They are used as a photodetector (for example, infrared detectors), detecting light or other electromagnetic radiation near the visible range or measuring light intensity.
Solar cells are often bundled to make larger units called solar modules, coupled into even bigger units known as solar panels.
Like the cells in a battery, the cells in a solar panel are designed to generate electricity. Still, where a battery’s cells make electricity from chemicals, a solar panel’s cells generate power by capturing sunlight instead.
A solar cell is a sandwich of n-type silicon and p-type silicon. It generates electricity by using sunlight to make electrons hop across the junction between the different flavors of silicon:
- Photons (light particles) bombard the upper surface when sunlight shines on the cell.
- The photons (yellow blobs) carry their energy down through the cell.
- The photons give their power to electrons (green blobs) in the lower, p-type layer.
- The electrons use this energy to jump across the barrier into the upper, n-type layer and escape into the circuit.
- The electrons make the lamp light up, flowing around the course.
Types of Solar Cells
There are three types of Solar Cells, with each having outstanding features. They are as follows:
First-Generation Solar Cells: About 90 percent of the world’s solar cells are made from wafers of crystalline silicon (abbreviated c-Si), sliced from large ingots grown in super-clean laboratories in a process that can take up to a month to complete. The nuggets either take the form of single crystals (monocrystalline or mono-Si) or contain multiple crystals (polycrystalline, multi-Si, or poly c-Si).
Second-Generation Solar Cells: Classic solar cells are relatively thin wafers—usually a fraction of a millimeter deep (about 200 micrometers, 200μm, or so). But they’re whole slabs compared to second-generation cells, popularly known as thin-film solar cells or thin-film photovoltaics, which are about 100 times thinner again (several micrometers or millionths of a meter deep). However, most are still made from silicon (a different form known as amorphous silicon, a-Si, in which atoms are arranged randomly instead of precisely ordered in a regular crystalline structure). However, some are made from other materials, notably cadmium-telluride and copper indium gallium diselenide.
Third-Generation Solar Cells: The latest technologies combine the best features of first and second-generation cells. Like first-generation cells, they promise relatively high efficiencies (30 percent or more). In addition, like second-generation cells, they’re more likely to be made from materials other than “simple” silicon, such as amorphous silicon, organic polymers, perovskite crystals, and multiple junctions.