I just did this last week. I trenched and laid 1" pvc. I had lots of 10 awg thhn on hand so I ran 2 parallel sets of it to minimize the voltage drop. Paralleled 10s came in with less voltage drop then 8 awg did and the copper was free.
Now before anyone gets their pants in a twist I know I am using smaller than 1/0 conductors but there is an exception in the NEC provided all the conductors are in the same conduit and the condcutors are sized than any one of them can carry the full load should you lose one. They are all in the same conduit and they are all 10 awg.
