A do-it-yourself project is excellent at about one-thirtieth the cost of a commercial tracker. That is another ballgame entirely. The big issues with on the earth trackers is a) theft b)the wind may have an entirely different idea of where to place your tracker.
The first ten percent and last ten percent of a day's irradiation are not worth the trouble harvest wise IMHO especially Oct - Feb
THIS is the alternative to sitting next to the panel all day. This is why commercial trackers are heart-stopping expensive.
http://www.budgetastro.net/tracking-the-stars.html
