Is reducing the amount of light that these panels receive likely to increase their effective lifetime? Or: Does total energy absorbed dictate decay of solar panels? Does that affect EROI calculations?
Light-induced degradation of silicon-based solar cells generally saturates above 0.1 suns [1] for the predominant mechanism of boron-oxygen defect formation; thermal degradation is also a factor [2] and likely to be unaffected by this geometry. But ERoEI for solar cells can be high, even in Europe [3] so, considering the roof replacement as a necessary cost regardless, these may still work out favorably, but at this juncture, only for special applications.
The amount of light does decay the solar panels. But it is not the only thing causing degradation. I believe the other large item for degradation is thermal. Operation at higher temperature induces degradation faster and there is some degradation from thermal cycling. So if the covering also keeps it cooler and at a steadier temperature then it is probably good. But the covering might also cause some greenhouse effect that causes it to operate hotter. So...maybe?
