I may be wrong, but I think a lot of service wire (the wire that comes from the pole to your house) is AL clad steel. They rarely use copper conductors for these and transmission cables. As far as plumbing goes, plastic water lines (CPVC) break too easily when it freezes or is moved or rattled. PEX water lines (flexible plastic) is more expensive than copper but is easier to install, but is still unproven over time - remember polybutylene?. Galvanized pipe rusts from the inside out, and in hard water situations clog up really bad from calcium deposits, and these days is lucky to last 20 years. Copper is still the best choice for water lines, even at todays prices.