How to deal with recycled solar panels?

As is well known, solar photovoltaic modules have a 25 year warranty life, which can even be extended to 30 years. Thirty years is long, but after all, it is not eternal life. In fact, the first batch of large-scale photovoltaic systems have gradually reached the age of aging and retirement. What should I do if a component fails? Next, we will discuss the recycling of solar panels.

Reuse the batteries inside the solar panel. Many times, the components that fail are due to the back panel not working properly, the adhesive film changing color, and the glass breaking, but the battery itself remains strong. And the battery is the valuable part of the component. The natural idea is to recycle batteries for reuse. However, to remove the components without damaging the battery inside, it is difficult to tear off the back panel. Either soak hydrochloric acid to remove the EVA film (time-consuming, damaging the metal battery); Either remove EVA with organic solvents (more time-consuming); Either ultrasound can remove EVA (electricity consumption); Either heat and pyrolyze EVA (the battery is basically useless). Ideal is full, reality is bony, and it's basically impossible to recycle batteries that don't affect performance!

Reuse the silicon wafers inside the solar panels. Since the battery cannot be retrieved, we will prioritize reusing the valuable part of the battery - the silicon wafer. After recycling, turn the silicon wafers back into batteries. This requires various chemical methods to remove silicon nitride, metal electricity, emission, and back electric fields. Specific combinations may include hydrofluoric acid, nitric acid, sodium hydroxide, potassium hydroxide, and so on. Reality has once again become a bone feeling - human calculations are not as good as sky calculations. With the development of technology and the requirement for cost reduction, the thickness of silicon wafers has decreased from 300 micrometers to below 200 micrometers and will continue to decrease. The consequence is that silicon wafers cannot withstand the torment of chemical treatment - they are shattered! This road is once again blocked.

Reuse solar grade silicon. Since the silicon wafers cannot be retrieved, let's take another step back and recycle solar grade silicon. Although we still need to pull single crystals or ingots again and slice them, at least we have saved the purification step! This plan is the current mainstream direction. Let it break, let it break. Once it's broken, we can re crystallize or cast the ingot. As with the previous method, frontal emission and back electric field are not required. Quickly remove a few micrometers of surface layer with sodium hydroxide, and then use square resistance testing to determine if the emission and back electric field have been completely removed, in order to produce solar grade silicon that can be utilized.