Distance = about 15-20 meters, diagonal.
Solar = a great idea but won't provide nearly the amount of power I need with the roof size I'm going to have. 8 m^2 won't do for four 4,5kilowatt heating elements, let alone the pumps. In the new house, whenever that gets built, of course I'll throw some panels on because yes, there are plenty of credits, but the best thing to have is wind turbines.
As far as digging the trench goes, I'll do it by hand, it's not very far, and I've got a post hole digger that'll make it easier than with a shovel alone.
Could you give me more details on what an umbillical would look like? I'm concerned about above-ground because I don't know what gauge I'm going to be needing for that kind of power draw, and I'm nervous about having the water line next to the power line, fraying, etc...