why is there white smoke coming from my car after i changed the battery?

I have a 2002 Opel Zafira 1.8 petrol.

It's been lying up the last year by the previous owner.

I changed the battery. Negative first , then positive and the positive terminal keeps sparking.

I got the car started and there's white smoke coming from the left side of the engine. It's coming out of the starter or the alternator , it's a cast iron unit with a load of copper wire inside....