PV reflections and commentary

I've settled in on standard "hitching rails" of three joints of 33' oil field pipe.  Though I have several shorter rails installed, I consider ~100' to be my "standard".  Those rails support 28 panels each.  Total cost, excluding labor, is about $3k/rail.  Rated capacity is just under 7kw.  I would be pleased to find that I'm averaging 25kwh per day.  If BlueBonnet continues to pay me $.06+ /kwh, that would be $1.50/day, $45/month, $500+ per year.  I've estimated pay back periods as low as 4 years.  The above indicates 6 years.  Time will tell.  Clearly, I'm no where near that right now.  An estimated 31kw worth of production capacity is yielding less than $100/month.  One lives on hope.


Today, I took inventory of panels supplying my house electric meter.  I am overloading my level of electric service but have high hopes of a resolution in the next month or so.  The effect of trying to push more power than the service will accept is rising voltage on my side of the transformer which, in turn, causes inverters to shut down, losing power that might otherwise be delivered/sold.  My current transformer is a 15kva which places my production limit at about 15kw though I start seeing inverter shut downs as low as 10kw.  I have hope of getting a 37.5kva  transformer with lower static voltage, my request is for 230 volts.  Current "static", no production, voltage is 245-248.  Inverters seem to shut down at 260-262 volts.

So, here is what I have now:
1) 26 300w roof top panels on a single string inverter.  Though there is about 8kw in panels, the inverter is 5kw.  That is, power is limited to about 5kw.  Being very near my service entrance, this inverter almost never shuts down.  All my other panels are on micro inverters, one inverter for each panel.
2) My ground mount additions in the south yard:  30 240-245w panels.
3) Four rails in the "south field", two east facing and two west facing.  All panels are about 245w.  The west most two rails are east facing, 25 and 26 panels with space for 2 more.  The east most two rails face west, 21 and 1 panels with space for 7 plus 27 more.  I have suspended additions in this area due to inverter shut downs.
4) Newly planned and under construction in the north yard: one rail with space for 28 panels.  It will be about 100 unobstructed feet from an existing ~6kw wire.

It looks like my total panel count is currently  129 panels with space and planned space for 64 more.  Right now, my production capacity is about 31kw.  Due I hope mostly due to lack of service, I never see much more than 15kw with typical being 10-12kw for a few hours after noon.  Under good conditions, I hope to see my production capacity rise to about 45kw.

As a cost saving strategy, I have been installing PV at locations that are already close to 240vac wiring.  The ~15kw worth of wiring in the "new garage", I installed about 35 years ago mainly to supply a welder and a well.  In other locations on another meter, I am putting rails in near water wells and using the well supply wire.

I read "somewhere" that panel pointing did not make a great deal of difference in total year round energy production.  Any not much shaded site with pointing from due east to straight up to due west should produce within about 90% of optimal.  Tradition has it that panels should point about south with a 20-30 deg tilt.  With more cloudy mornings than cloudy afternoons, pointing a bit west of south might be a bit better than due south pointing.  I took that "pointing is not very important" to heart and started installing both east and west facing panels for a couple of reasons:
1) Avoiding ANY grid consumption by using battery power at night makes both early day and late day production attractive.
2) With wiring restricting my peak power I can produce more total energy by having some panels produce better early in the day and some later in the day.

In the midst of construction, I am running through supplies far faster than I envisioned.  I bought about 48 33' joints of salvaged oil field pipe from which to construct rails.  I am now down to less than 15 joints and am shopping for another batch.  I use old metal roofing between the ground and the panels that rest on the ground.  That is to make keeping the weeds a bay easier.  I am near out of old roofing material and seeking more sources.  I've exhausted my supply of 10 gauge romex wire which feeds rails.   I'll need to go buy more next week.  All in stock panels are in place and producing.  60 more are in the delivery pipeline.  I recently received drop cable for 240 panels; that should be a lifetime supply.  I have only 48 inverters in stock so I will soon need to buy more.


Only micro inverters in this area.  This meter has 39 ~260w panels on a roof top, 13 rail panels under the eave of the roof, and two rails recently added at a greehouse site.  Each, rail has 17 panels.  An older 6 panel on two post install is adjacent to the pool.  I am in the middle of installing two rails at a well site about 200' south of the pool.  One rail is complete, east facing, and half populated with 14 panels.
Total PV on this meter is about 106 panels and about 20kw.  14 more panels will be added as soon as panels are available.  I am not monitoring this power as closely as at the house.  There is no power wall and no Curb energy monitor.  All the monitoring is via the Enphase  online system.  I recently noticed I have a 15kva transformer for that meter so it is likely that I am experiencing inverter shut downs that I have not noticed.   Though the both east and west facing panels may be minimizing those shut downs.  I need to pay closer attention.

I have completed a 20 panel "Two Faced Rail" as discussed in comments.  Location is about 150 feet south of the "PV Shed" which supports 39 roof top panels.  Power connection is old water well.  I'm highly pleased with the first TwoFaced Rail.  Access is difficult but panels are at a steeper angle (about 45 deg) and are better secured.  I am about to start construction of a 38 panel TwoFaced Rail "across the road" near "RV building".  That electric service meter has not had PV additions in 5+ years.

On the house meter, the "North Yard" rail is complete and populated with 14 producing panels.  The other 14 panels will not be added until/if my service power issue is resolved.