will you please remind me of your rectifier question as the egregious fairies have stolen it along with the quiz, and I didn't get a chance to write it down.
In a car, yes, but the same design of alternator may be used without a battery with a bit of cunning. - it is common to find one configured as a variable mechanical load in the more professional exercise machines for example, this being more repeatable then springs and brake pads, and of course electrical loads can be switched on and off under software control to give varying difficulty as part of the training cycle,
The odd hundred watts are eventually dumped into resitors in all the ones I have seen, but it has occurred to me that you could easily design it to work more like a grid tied inverter, and maybe in a big gym you could rival a small domestic solar panel.
