Considering how long Tesla has been in existence and how financially leveraged Tesla is I would take discount warranty value (lifetime of house or infinity whatever comes first).
Can't project finances much more than 10 years max. At the moment cost of capital is low but that may well change in that time-frame. Things have to make sense in a decade or so also considering that this new technology that is obsoleted by incremental innovation.
Yeah there's a pretty legitimate possibility of Tesla/SolarCity collapsing if their stock had a long bad run, don't think your warranty is worth much at the back of the line in bankruptcy court.
Can't project finances much more than 10 years max. At the moment cost of capital is low but that may well change in that time-frame. Things have to make sense in a decade or so also considering that this new technology that is obsoleted by incremental innovation.