[RE-wrenches] Abysmally low production from FLEXpowerTWO GVFX3648 system

[boB at midnitesolar.com]

Hi Bob !  Long time no see...

A good sanity check is to note the Voc of the array connected to a specific
controller and then see what the voltage is that the controller is 
running it
at.  Without shading, the input voltage should be running somewhere 
between 75%
to 82% of that Voc.   If Voc is 100 volts, then MPP voltage will be 
around 80 volts
or so.  Much higher than 80% and it usually means that the batteries are 
full
or inverter is not selling to grid or the tracking is off.

Too low of MPP V usually indicates partial shading or tracking.

boB


> Dear Wrenches:
>
>
> What am I not seeing with this situation?
>
>
> Only 133 DCkWH (120 ACkWH) during mid-December through April 6 (at least
> that is what the mate and the MX80 CC say).  PVWATTS predicted ~600 ACkWH.
>
> Here are the major components of the system:
>
>
>
> 24 - Silicon Energy 190W solar modules in 8 series of 3 modules for 4560W
> nominal
>
> 1 - Midnite Solar, Combiner box, MNPV12 with 8 circuit breakers (one for
> each string)
>
> 1 - MX80 charge controller
>
> 16 - Concorde SunXtender Sealed AGM Battery, 6V, 405Ah, L16, PVX-4050HT (2
> parallel series of 8 batteries for 48V and 810 AH)
>
> 1 - Outback FlexNet DC System Monitor, FN-DC
>
> 2 - GVFX3648 inverters
>
> 1 - Mate2
>
> 1 - HUB10
>
> 1 - Remote Temperature Sensor
>
>
>
> The insolation this winter has been, if anything, more than usual.  The
> electrical usage noted on the utility bill was approximately 170 ACkWH more
> than the same winter period last winter.  No appreciable change in usage
> pattern this winter compared to last winter (in fact, if anything, there has
> been less use this winter).  Everything appears to be functioning (normally,
> I think).
>
>
>
> What is going on?  It cannot just be a malfunctioning utility meter.  It
> seems to me that regardless of the functionality of the utility meter, the
> Mate and the MX80 should show greater production.
>
>
> What is being overlooked?
>
>
> Thanks for your help.
>
>
> Bob Clark
>
> SolarWind Energy Systems, LLC
>
> (509) 826-1259
> --- end of quote ---
>
>
>