Change in plans...

View from the driveway

Well, the past few days brought a few changes to the installation plans. First we found out that the original design for the fourth tracker to hold 9 panels had a flaw. The tracker manufacturer indicated we could mount the ninth panel at the top and center (everything has to be balanced for proper operation). When everything was being setup we found that they were incorrect, our make and model of panel would not allow this type of mount due to size and weight constraints. Oops.

So our supplier had to reorder an entirely different track rack to hold 9 panels. This also required that they disassemble the existing rack and replace it. That's a fair amount of work! It was completed yesterday and you can see the difference in the appearance. The panels mount at a 90 degree angle to the other racks. It's also a little bit larger...sorry neighbors.

Tracker number four showing the difference (#4 in foreground)


Close-up of number four


The other change was related to the inverters. We originally specified 2 4-kW inverters to accomodate the 7.5kW design. After further inspections were made to the house electrical panel it was determined that we could not use two inverters without major rewiring due to panel design. So one 8-kW inverter will be used instead. Downside is we lose some redundancy. If one failed we would still run on the other. Now it's a single point of failure. I'm assured that reliability is high and a replacement could be installed in a day or two if needed. Arizona Solar Power is giving me written guarantees of service levels and replacement plans to make it all acceptable. So we press on with one inverter.