I don't suppose there is much difference in concept, but the specification of the alternator would be a much larger AC output voltage and alternator rating.
Additonally I have had an idea for measuring voltage at the peaks of the waveforms. As the alternator will output 50Hz, can I use some kind of zero-cross circuitry and then programme a delay of 5ms after each cross, before measuring the AC output through the A/D converter?