What in the solar panel wares out so that the panel can not convert the suns energy to electric energy? Please post were you get answers.
If they get smashed, they won't work. Keep them clean, and they will last many years. I suppose there is a 'limit' to the effectiveness of the cells lifespan, but it must be more than 25-30 years. Just glass, metal frame and silica. No moving parts. Seems like a good deal.
The plastic covering degrades slowly and becomes more opaque, The metal current carrying parts corrodes over time. The metal frames corrode but can be repaired. The photovoltaic cells also degrade over time from exposure to ozone and heat that builds up in the panel.
They really don't stop working unless there is some sort of manufacturers deficiency, where a connecting tab(wire) is broken. Generally their output just decreases over the years. There are plenty of solar panels over 40 years old still producing electricity, which is 0 years past the typical 30 year manufacturers waranty.
Panel degradation can occur in many ways, but they generally take a long time (40yr old panels are still working...). One problem is diffusion. Since the cells are at a finite temperature and receive energy from the light, atoms in the structure can migrate around the cell. If you mix up materials from either side of the junction, you can reduce or remove the internal field and so charge separation no longer occurs, meaning no more current output. This is generally a very, very slow process. My current research is on the back contacts of cadmium-telluride solar cells. CdTe forms a junction with metals, and this junction has a built in electric field that tries to stop the current going out of the cell. This is bad! It reduces the power you get out. To overcome this, copper is sometimes added. This really cuts down on the restrictions on current, but copper is very diffusive. Within weeks at room temperature it can jiggle its way along grain boundaries (the solar cells aren't one big crystal, but a load of small grains. Our lab makes ones about 0.006mm across). Whilst copper at the back contact is good because it cancels out the effect of the field there, once it gets to the cell junction it has a worse effect. It can act as a 'recombination centre' or 'shunting pathway' - it either absorbs the free charges or takes them somewhere useless and cuts the power output. Copper is a very obvious and quick acting cause of solar panels reducing in output. I believe a similar effect is true for other cells, just with different materials. The quality of the junction degrades slowly as heat and light give energy to atoms in the lattice and make them jiggle around a bit. Once you have things out of place, performance degrades.
