Friends:
There has been recent discussion on this forum about PV production in
grid-tied with battery systems. I have been faced with this same problem
in a 3 XW system installed in 2009.
The customer's power bill never went down. PV harvest was abysmal. The
system would create great short circuit current but would not harvest into
the batteries.
It is starting to appear the XW firmware was at fault. The inverters would
charge the batteries too high so the charge controllers would back
off. Upgraded firmware seems to be helping, but the data set is still limited.
Remember this: just because a PV system can produce does not mean it
will. The charge controller knows only one thing: battery voltage. If it
is high, production is curtailed.
Off-grid production will also be reduced is consumption is curtailed.
Charge controllers that can be set for grid-tied applications help, but
only if the inverter(s) do not keep the battery voltage too high.
William Miller
Miller Solar
Voice :805-438-5600
email: will...@millersolar.com
http://millersolar.com
License No. C-10-773985
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