UCC-1 is a personal property fixture filing. Remove the panels, store them and notify the solar company they have 90 days to come pick them up then they will be disposed of.

Provide photos of no panels on the property to your title company, they will be able to issue clean policy with proof no panels are on the property.

You did not sign a lease or any other agreement with the solar company, therefore their only recourse to enforce the agreement is against the prior owner.