You could do that, too, if you want. The relevant questions would be how much of the electricity cost is buying solar panels, how are they stored, and how they age when not used.
Stockpiling uranium addresses a specific risk related to sourcing in an inexpensive way, I'm not sure what problem you address by stockpiling unused solar panels, and for what cost.
Stockpiling uranium addresses a specific risk related to sourcing in an inexpensive way, I'm not sure what problem you address by stockpiling unused solar panels, and for what cost.