We are in the process of building on 5 acres at the moment..To get underground power/phone connected from the road up to our house site (about 170m) cost us $7000 (but the distance it has to go will change your price). We found that different electricians varied HUGELY in their quotes, so shopping around was definitely worth our while. We have a temporary power box put in for the builders, then once the house is built they'll be another small cost to connect up to the house.

Septic tanks cost us around $10 000- $11 000 (our house is a 5x2).

Not sure about solar power.

Tanks wise, we put in a 125 000L tank that cost us around $9000.

GL!