electrical conversion question

I heard that if you multiply the amperage of your alternator by the amount of voltage (which i'm assuming would be the 12 or so volts the battery gives) that you can figure out how many watts your putting out? So for example, my 78amp alt X 12volts=936 watts? Is that right?

That's what Georg Ohm said. Most of us consider him fairly accurate. He was pretty smart, for a Bavarian (I'm from the Saxony part, so you can understand the polarity of the comment - pun intended).