Neighbor did this and got me thinking.
My power pole is directly behind the driveway, who's the rocket scientist who said "OK" to this.
Anyway I hand dug 7 holes 2' deep and filled with concrete then stuck the pipe in the concrete. Hand dug holes so not to get any surprises especially around the power pole.
If you've spent anytime on a tractor or other equipment you know you'll eventually run into something. You can be as careful as you want but sh*t happens.

Wife said "NO" to safety yellow so Kubota orange it is.

Wise man!

Beautiful place

I like it.
..I also know my wife. I would need to use 4" or 6" pipe and fill it with concrete.

My wife has had 3 accidents, with 3 different vehicles. Each was backing into a yellow pole, so hopefully your choice of colors saves you a "discussion".