Solar power is having its hockey stick moment. Since the early 2000s, the amount of solar panels being installed worldwide has been growing exponentially, and it’s expected to continue to do so for decades. By the end of 2015, an estimated 222 gigawatts worth of solar energy had been installed worldwide. According to a recent report from the International Renewable Energy Agency, that number could reach 4,500 GW by 2050.
But the solar panels generating that power don’t last forever. The industry standard life span is about 25 to 30 years, and that means that some of the panels installed at the early end of the current boom aren’t long from being retired. And each passing year, more and more will be pulled from service — glass and metal photovoltaic modules that will soon start adding up to millions, and then tens of millions of metric tons of material.