The nominal output of the alternator is 18 amps at 3000rpms. You'll have about five or so amps to spare at the maximum output of the alternator on the bike......
Do you mean that total output of alternator is 216 WATTS (18 amp x 12 volts) ? I have been also searching for these values for UCE, G5 but the manual does not have any information. The closest I could come up was a service manual for AVL Electra - page 02-5, line G. Under Electricals and Ignition, it mentions - Generation Magneto assembly 12 V, 196W. Does the G5 have same alternator as AVL or is it improved version ?