My solar roof (not Tesla, of course) is meanwhile 21 years old, and works almost like on day 1. Since I dont expect a sudden failure in 4 years, my guess it that it will last another 10-20 years.
Turns out that (a) the 10 year warranty actually meant "generating at least 90% of rated capacity in full sun after 10 years, but pro-rated across 10 years if not" and (b) they fell under this level after less than 5 years.
>Since I dont expect a sudden failure in 4 years, my guess it that it will last another 10-20 years.
Oh, you're just guessing.