A \"generator\"(not alternator) is rated at 30 amps , so I think it works like this..... 30 amps x 12 volts = 360 watts( if it's working perfectly)
your four 55 watt lights = 220 watts plus anything else you have on..... wipers , stereo , ignition , stock head lights and running lights etc etc
You could be close to the edge.
I'm not 100% sure this the correct calculation , someone correct me if I'm wrong.