That will be dangerous to use!
1. The cracks will generate hotspots
2. The hotspots can heat up so far that a fire can start
3. Water or moisture ingress will cause electrolysis and further damage the panel
4. Water ingress will bring the internal voltage to the outside
5. Voltage on the outside will make the panel unsafe to the touch.
6. Water will cause a DC drain to the ground or anything else on its path.