[TowerTalk] Urgent: Should solar panel array be grounded to station ground and/or house ground?

David Robbins k1ttt at verizon.net
Tue Oct 9 12:45:08 EDT 2012



>The NEC rules (and similar.. NFPA 780 for lightning) are evolving fairly 
>rapidly for solar panels. Solar panels raise all sorts of complex 
>issues.. For instance, you can't turn them off.. if there's light on 
>them, there's power coming out.

John's, like mine and many other new installations, use a system that does kind of turn-off... each panel has a micro-inverter that takes the output 
from the one panel and converts it to 220vac and feeds it back into the house and grid.  they sync with the grid and if they don't sense the incoming
grid voltage they shut off.  this is a safety requirement to prevent backfeeding the street in case of power outage. see http://enphase.com/products/microinverters/

these systems have no battery, heavy dc wiring, large inverter, or load switching system.  They are more efficient since there is no chemical conversion, and there are also
no battery maintenance issues.  they are modular so if one panel or inverter dies the rest keep right on going, and since they
allow monitoring output from each panel so you can diagnose problems easily.  they also communicate their output to the manufacturer's web site
where you can get reports and graphs of your output as well as real time email notification of problems... see https://enlighten.enphaseenergy.com/public/systems/BpbD5251

there is some more information on my installation at: http://www.k1ttt.net/misc/pv.pdf



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