Another issue with trackers in the wind is the failure condition can be catastrophic; an actuating arm smashed through the middle of its little array is not a p

Another issue with trackers in the wind is the failure condition can be catastrophic; an actuating arm smashed through the middle of its little array is not a pretty sight after a wind storm. Presumably this can be engineered around, though. I think the absence of this category of flaw is a distinct advantage to the gravity-powered design of the OP.