I got a 290W solar panel with a shattered glass cover for free.
I asked Google about repair methods and found some results where people covered the panel with epoxy. Talked to composite specialists about resin that can be used for that purpose. They recommended a water clear, 2-component epoxy, that is UV stable and will not change color over time while exposed to sun light. A primer additive was also added for usage on glass.
Surface is smooth and sealed. The resin got obviously soaked in the glass cracks by capillary effect. With coating the glass seems to be more translucent than is was before.
Result looking good and ready for experimenting.
Used resin: Link
Primer additive: Link