I suggest green giant or steeplechase. Whichever you can get a good price for. Plant them about 6' apart. You don't have to get big plants. They grow very fast.

Green Giants placed 6 feet apart center-to-center would be ideal. Avoid Steeplechase as they are prone to winter wind burn in your area.

no green giants with power lines above ...

the plant on the other side of the yard would probably already be in the power lines ... yes.. no??

and i dont recommend anything that requires you to buy a cherry picker to trim them at 10 or 12 feet or something ...

look like a blank mowed field out there.. what are you hiding from????.. are they going to develop it or something????

ken

Your last man standing looks like a Smaragd (Emerald Green) to me.

An assumption is your fence is at the utility easement edge (maybe 5' in from the prop line where the utility poles are placed?). Any plantings should be placed so that their mature spread will not impede beyond this easement line, and if arborvitae they won't have an extended canopy to infringe upward on the power lines if placed as such.

Don't want to make a mountain out of a molehill, but looking at what's behind you, hard to tell from the pics, but if that is just a landscape berm for the development, and their top of grade on the other side of that berm is close in elevation as yours is, then you should be fine planting screening and be done with it (it is unfortunate many cities are very "loose" in requiring developers to provide planting screening between different zoning uses).

However, if the continuous grade for the development is as high as the top of that "hill," then you might want to think about having a small landscape berm that, especially if arborvitaes are chosen, will sit on top of to help direct any water that those same "loose" regulations didn't account for. Often, a small berm can kiII two birds with one stone by allowing well-drained soil which arbors need.

And I got to sneak in 3 old school idioms in this comment.

I think you can plant GG and not have to worry about the power lines. They don't grow out much at that height and there's little to no chance of a branch falling on the lines. Worst case scenario is the power company may come out and trim them on their side for you.