If I get an electric vehicle (EV) do I need 3-phase power at my house to...

You don’t need 3-phase power to charge an EV. In fact, you can purchase charging cables that plug into a standard domestic socket. The most common way to charge an EV is via a "type 2" charger, and many EV drivers will opt to have a charging point installed in their home. A 3-phase connection will charge your car more quickly. A single phase type 2 connection will be slower than 3-phase but faster than your standard household sockets. Your local solar installer or electrician can assist with questions specific to your case. The cost of the charge will depend on the general cost of electricity, the capacity of the vehicle’s batteries, and whether you’re incorporating solar power. A fuel cost savings calculator can be found on myelectriccar.com.au, with plentiful similar resources available elsewhere online.