2nd Day Highlights: Components, Supply Chain, Power Optimizers and System Monitoring

The second day of the inverter forum focused on supply chain issues, electrical connection technology, power optimization technology, and system control and monitoring.  The overall tone of the day was less technical, more salesy in my opinion, and also quite a bit more contentious. (The panel that discussed distributed power optimization vs traditional inverter MPPT was especially fun; I'll do a special post for that one!  Stay tuned.)

There was also an interesting discussion given on how to choose the optimum inverter type for a new PV installation, presented by Dr. Berhhard Plail of Siemens.  As one might expect, the answer was basically, "well...it depends."  There are CapEx and OpEx cost tradeoffs that must be analyzed to compare overall system cost of many string inverters in series vs. one central inverter.  In brief, for large utility type installations where the sun is predictable and the ground is stable, a central inverter makes the most sense because maintenance and operational issues can be handled with a contract up front.  For small scale residential installations, areas where shading is a problem, or where the topography mandates special panel placement, string inverters with power optimization at the panel level can maximize energy harvest.