Just to clarify... >The only time high voltage helps is when you need to have > long wire runs.... [and long means over a few tens of feet] > > However, if you're using small low-voltage individual inverters > mounted right on each panel to one big central inverter located > far away, then the small inverters can "win" and use less copper > overall.
Still not true. The output of microinverters is at 240 VAC and the average current in the wires will be double as the same number of panels at 480 VDC. Further, AC peak currents are 1.4 times higher than DC so the peak currents (where the losses are) are 2.8 times greater, and since losses in the wire are proportional to current squared, the losses in the same wire will be almost 8 times as much. Hence you always have the choise to either use much bigger wire, or accept the greater losses at low voltages. The difference in buying #6 wire instead of #12 is only $180 versus $30. Or you can ignore the extra 10% or so losses and use #10 wire. But over the life of the system (20 years) the losses in your solar system can add up to many thousands of dollars. Maybe I am just being nitpicky, but my solar arrays are all over my yard and house. Some runs are over 300 feet! (shortest is maybe 60'). >You have to carefully consider the specifics of the situation, and not >make snap judgements about low voltages being automatically worse. True, just be informed and make your design based on it. Bob _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
