As is so often the case, the wattage claimed in the advertisement is just wrong. If you click through the ad it reads "25 Amp-hours/300-Watt-hours per day" - If this was REALLY capable of sourcing 100 watts @ 12VDC that would mean a CONTINUOUS current flow of 100/12=8.3Amps. Yes, the sun moves across the sky so the panel isn't peak-efficient all day unless it is tracking, but the only way to make sense of both "100 Watts" and "300-Watt hours per day" is to assume that essentially sun is shining only between 10:30 and 13:30 daily. One is left to conclude this panel NEVER outputs 8.3Amps @ 12VDC even at high noon.