-----Original Message----- It is great to hear that Wrenches are having better luck with trackers. This recent thread, on the subject, is way different that what has been stated in the past. It sounds like trackers might really be a cost effective approach to net metering. Is it really more cost effective than adding more modules, as we had figured in the past? Drake
Drake, Yes it is, clearly, if the homeowner has the unobstructed space to take advantage of the long summer sun path. It won't help much in a forested site with a narrow south solar window. The logic about adding more modules is a holdover from the off-grid days. A tracker adds 35-40% more output in summer and ~15% in winter. Off-grid needs to maximize winter gain when tracking provides the least benefit. Grid tie allows all of that summer gain to be harvested, provided that the utility's true-up is annual and not monthly. Our rule of thumb: tracking adds about 15-20% to overall system cost, and adds 30-35% to annual production in our region. We install quite a few, all Wattsun. Allan at PosE _______________________________________________ List sponsored by Home Power magazine List Address: RE-wrenches@lists.re-wrenches.org Options & settings: http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org List-Archive: http://lists.re-wrenches.org/pipermail/re-wrenches-re-wrenches.org List rules & etiquette: www.re-wrenches.org/etiquette.htm Check out participant bios: www.members.re-wrenches.org
