Growing B.F Sweet Tooth Auto indoor's with only sunlight through large window????????

So I wanted to try out growing sum auto's in a spare room that gets TONS of sunlight through out the day directly for about 5-8 hours and also use a 125W sunblaster CFL when the sun dies down, im gunna grow 5 plants, does anybody think the sunlight will help more than the CFL?? Considering the room is much brighter when the sun shine's in on it I think it will work awesome, almost works like a semi-detached greenhouse/room with big wiondows that open all the way to allow air flow. any input would be great thanks guys,