If you are going to seal the cells behind some plexy or glass it might be possible to have it double as a solar water heater allowing for slightly cooler temps in the summer and be able to run it in reverse to keep snow off in the winter. The issue is how much heat you can get out of it with out blocking the light to the cells.
To protect the contacts you could try Marine Varnish For Alternators, or see
Waterproofing