From my understanding and intensive research on LEDs, which is something I have been looking into for a while I have found out the following. Most Led panels come in a 1 foot square configuration, so you would need around 17 of them. Also the best and really the only way to use them effectively at this point IMO is as supplemental lighting. Has anyone seen a full grow using LEDs? Has anyone seen a "good" grow using LEDs?
Also I noticed that you really have to read the fine print on some of those LEDs, I saw one on Ebay looked nice and cheap, something I could experiment with and as I read I noticed that in small print it said that the lights must be 7 feet above the canopy, 7 feet is useless to me. Also LEDs can sunburn plants badly, so do a lot of research before you buy some.