Saturday, June 22, 2019

Three concurrent projects

https://photos.google.com/album/AF1QipMnz-GWvdVQr5h0ydePEY98Zf08mgM0KQ7-yRFZ

 https://photos.app.goo.gl/UUxRuYNTcxWFw8Ut8

First two photos:
The "North Yard Rail"; house meter.  Rail has room for 28 panels.  My immediate goal is to install and get working 14 panels.  These 14 panels are from the recent shipment of 60.  I've completed about 80 feet of trenching to bring the power connection to the rail.  6 of the 14 panels are in place.
Next three photos:
The "Two Faced Rail Prototype"; pool/barn/guesthouse meter.  Single joint of pipe will hold 10 east facing and 10 west facing panels.  Panels also from recent shipment.  3rd photo has well, which will be be power connection point, in the background.  Zoom in for enough resolution to see the well.  Photos show the first pair of panels in place.  Holes are drilled near the tops of the panel framing so that pairs of panels can be wired to each other, the adjacent pair of panels, and to the rail.  At this time, I'm using repurposed salvage 12 or 14 gauge copper from romex cable.  I hope that single panels can be propped up to facilitate access to rear of panels.
Last three photos:
The two rail powered from well project; also pool/barn/guesthouse meter.  The first 14 panels shown have been operational for several weeks.  The pool and guest house are shown in background of the first two photos.  The markers near the panels are the well and the well power.  3rd photo is intended to show the Two Faced Rail Prototype in the distant background.   Visible only if you zoom in.  At the time of the photo, two pairs of panels are in place.  The vertical PVC pipe marks the swimming pool drain outlet.  This area was first intended to host two 28 panel rails with the hope that only 28 panels at a time would produce significant power.  If the Two Faced Rail concept works well, I'll probably change that pair of rails to a single Two Faced Rail.

The Two Faced Rail shows promise of holding panels at a steeper angle and holding them more securely.  The steeper angle is desirable to maximize early and late day production and, therefore, better share the limited wiring resources.  The draw back of the Two Faced Rail is limited and difficult access to the backs of panels to confirm functioning.   With a single rail, I can use a golf cart to drive behind the panels and check functioning with a clamp on DC amp meter.

The single pipe joint Two Faced Rail Prototype, with 20 panels, can likely deal with produced power as a single string even though the panel limit on the 12 gauge drop cable is 17.  This is due to only 10 panels at a time having maximum production.  My "standard" 3 joint rail feeds two 14 panel strings from the center of the rail.

The next Two Faced Rail, not yet under construction, with two pipe joints and 36 panels might work with one run of drop cable that has power connected on both ends.  That is, in a "U" configuration.

The pool/barn/guesthouse meter has the same type of service problem that is present at the house.  At times, I'm trying to push over 20kw into the grid through a 15kva (15kw) transformer.  Voltages rise.  Inverters shutdown.  Energy is lost.

Sunday, 6/23/19
I'm in the process of populating the Two Faced Rail.  It is working out extremely well!  But much slower than with a single face rail.  It is much like closing a zipper in slow motion.  VERY slow motion.  Put two panels near their home place.  Drill four holes,  both sides of one end of both panels.  Thread ~14 gauge copper wire through holes in previously placed panels.  Thread two wire ends through new panel holes while sliding new panels to the older ones.    Wrap a length of stiff 12 gauge steel wire around the rail so one end hangs down; push looped wire near the center of the new panels.   Plug two inverters into the drop cable and the panel wires.  Crawl under the two new panels and cinch down the copper wire holding four panels together and to the rail.  Hang the two inverters from the steel wire and bend so inverters are 1+ foot above the ground.  Crawl out from under panels.  Repeat.  Repeat.  Repeat.

So far, I have about 10 or 12 panels producing and hope to do the other 8-10 this afternoon.

I'll configure a loop of single conductor AC wire at the power end of the drop cable so I can measure current/power.  Maybe put a plug receptacle at the  other end of the drop cable so I can plug in an AC voltmeter.

7/11/19
Perhaps an update?

The "north yard rail" has been complete for some time.  14 panels have been installed and are producing.  That is half the rail; there is space for a 14 more panels.  On the house meter, I have a pretty severe service capacity insufficiency.  Adding more panels gives more production only early and late in the day; mid-day production is capped at around 15kw.  So, I will install more panels only when I get more service capacity; that is, a larger transformer.

The "TwoFaced Rail Prototype" has also been in full production for several weeks.  10 panels faced east and 10 face west, both at about 45 deg.  I have the same capacity problem on that bigbarn/guesthouse/pool meter.  Adding panels gives additional production only early and late in the day with a mid-day cap of about 15kw.   So, no more panels on that meter either until capacity is increased.

The next TwoFaced Rail is complete "across the road".   This successor to the prototype has a steeper slope; near 60 deg. Today, I start to install panels.  I expect that rail of more steeply sloping panels, 18 east facing and 18 west facing, may hit my capacity limit on that 3rd meter.  That will put a total of 77 panels on the meter.  About 18kw on the 15kw transformer.  Plans are for a second parallel rail also supporting 36 panels.  Since the TwoFaced Rails are intended to give early and late production at the expense of mid-day production, I may find I can use that 2nd rail.  Both rails, if completed, would give total rated power of about 27kw.

If my utility upgrades all three transformers, I should be able to eventually more than double my production on all three meters.

7/13/19
Some photos

https://photos.app.goo.gl/zHSQb55p67wGeCtQ6

First four photos are of the 2nd generation TwoFaced Rail.  Two joints of pipe should hold 36 panels; 12 are in place and producing.  Rail height is about 5' giving steeper panel angle than the prototype.   Rail is supported by three posts.

First photo: labor housing RV trailer is just to the left of the power pole.  Old barn just beyond the power pole which holds a 15kva transformer.  "Party Shed" is in the distance.  "RV Building" on right.  Sprinter van is used to haul two pallets of panels per load.  6 gauge wire is trenched in from power pole, across the gravel road, to the rail.  The 6 gauge wire supplies a breaker box under the rail which will be used to supply a second rail parallel to the first.

Perhaps interestingly, the length of drop cable, with 36 drops, is powered from both ends.  I should  not be getting max power from both east and west facing panels at the same time but, even when only one side is producing, 18 panels is too long, slightly,  a string for the 12 gauge wire in the drop cable.  I have hope that powering both ends will allow everything to work under all conditions.

A note on siting.  My first intention was to place the rail in better sun near the distant fence in 2nd photo.  I have old unused 10 gauge wire trenched in to that fence, placed ~15 years ago when I buried the high voltage fence charging wire.  But Ray Menke properly prohibited me from putting the rail there because it is in the spillway for the tank that is just off to the left of the first photo.  Then, I decided to use the water well electric supply; the well is shown near the center of the first photo.  That wire path would cross the electric supply line to the RV Building.   I located that line so that wasn't a big consideration.  But, I finally decided to cross the gravel road with my trench and directly access the service panel.  An unobstructed path and I plowed the entire length with my chisel plow.  The site is less than ideal in that the RV building will give some morning shade to part of the rail and the tree is likely to give some winter shade to the south end of the rail.  Trade offs and engineering judgments.

Last three photos are of TwoFaced Rail Prototype.  One joint of pipe with a short extension holds 20 panels.  Rail height is about 4.5'.   Rail is supported by two posts.

Fourth photo:  Guest house to far left.  6 panel, two post mount just in front of the concrete ring pool which is in front of "pool building".  Near center, a 15kva transformer on a steel pole.  South end view of rail.  To the far right is a water well which is used to make to rail grid connection.  10 gauge wire is being trenched in from the well to the north end of the rail.

4 comments:

  1. The link to the photos doesn't work.

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    1. Thanks! The first link worked for me but must be "private" or something. I made the second link from the "spare" button for that album.

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  2. Ground mounts are usually somewhat off the ground to protect the panels from a rock thrown by a lawnmower or string trimmer.

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    Replies
    1. I do much prefer off the ground mounts for a number of reasons including ease of mowing. Installation costs and install labor rules for me. Even old tires, concrete blocks, or similar are prohibitive when doing the volume I am attempting. Right now, I have ~400 panels sitting on the ground and aspire to 1000+.

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