Sell the equipment to the new buyer with all of the future FITs. We would be happy to help determine a discounted value of the Solar PV array.

Sell the property but retain ownership of the Solar PV array. This would mean that the buyer enjoys lower energy costs but you retain the rights to the FITs.

Take down the equipment make good and re-install to a new property. This is probably the least likely option that people will use but it is available. PV Modules are moveable.