My new house has a 20 X 20 detached workshop about 25ft from the house. Currently is has a small subpanel fed by 8 gauge wire (4 wire) from a 50 amp breaker (which I think is too much for 8 gauge) in the main service panel. I originally planned to try to make this work but I think it would be best to go ahead and bump everything up to 100 amps in the workshop. That way I can seriously think about adding HVAC.
What size feeder wire do I need for 100 amps? I've heard conflicting info. I'm thinking 2 for copper or 1 for aluminum. Is voltage drop a concern for a 25 ft run? Can the ground be smaller than the hots and neutral?
Also, the 8 gauge feeder wires are in 3/4" pvc conduit for the entire run. What size conduit is necessary for my new wires for 100 amp service?