An appraiser can support an owned system with an adjustment when there is documentation to back it: original installation cost, system age, panel condition and production data from SaskPower's net metering program. A newer, well-documented system supports a stronger case than an aging one with no records.
A leased system creates friction at exactly the point a sale depends on being frictionless. Some lenders hesitate to finance a house with an active lease obligation attached, and a buyer may insist the lease be bought out before closing, adding an extra cost on top of routine items like legal fees of $800 to $1,500.
So the value question really reduces to a paperwork question: is the system paid off, and can that be proven. Get your hand-reviewed valuation from Joel Dyck.