Alternative power for cars is fine, but at this point they lack the infrastructure to make them viable, in a country the size of Australia (based on a recent test) a range of 300K on the open road is not going work, good for Urban driving but that's it for now.
I have a problem with the amount of bullshit coming from manufacturers about 'clean and green', aside from the sticker price, Mercedes, BMW, Audi, Porsche, Ford, GM. Toyota, Nissan and all the other players continue to churn out oversize petrol or diesel powered outsized 'Trucks' and the heavily promoted 'Family SUV', both of which require greater resources to build and run than an average sedan or wagon. Stop flogging this type of environmentally unfriendly vehicle and maybe the 'Green' promises will have a ring of truth too them! So far it's all been promotional advertising and publicity.
FWIW, we run Solar Panels into a Battery Farm on our property, along with contributing to a communal fund for a proper Wind Turbine (Costly but worth doing) that will generate power for some 50 rural properties in our area.