the star. you would need something like 3-4 42 watt cfl's every foot to equal lumen output. if everything was equal like same nutes same strain (although all plants grow different but for shits and giggles lets say it is the same plant all in all) same light schedules, etc... i am gona say 99% of the time the sun will win. yes it can be beat like all things in nature but you are really gona have to put forth that extra effort to do it. that includes studying up on our sun to find its limits and exploiting them for gain. PEACE!