Solar System Installed in 2019 315RLTS

[howson]

*Finally* had some decent weather to install panels. Got half of them done.



During the install process I tested the output of each series pair. The output was remarkably similar. Result "a" below is a typical series-pair (2ea 100W panels in series) result.

I blocked one panel of the series pair to see what would happen. Result "b" is a typical result. (The wattage varied quite frequently, so the snapshot is literally just that--a moment in time.) I was surprised there was any output. Based on all that I'd read I expected nothing from the series pair when one was shaded.

Result "c" is with all three series-pairs online.

And yes, I'm sore and tired. Yikes--climbing on the roof is for youngsters!

@TucsonJim--since you're in contact with DMB, send him a link to this thread. This solar install is all his fault! (Remember that picture from long ago he posted?)

[TucsonJim]

Howard - Looking great! Your "result B" is similar to what I've seen with a shaded panel. If you get a chance, shade just one cell and see what happens. BTW, when did you move to Canada (temperature in Celsius)? LOL.

[howson]

TucsonJim -- the info below was originally posted in Al's "blowing diode" thread, but I'm posting it again here as the information is pertinent to your inquiry.

As I'd speculated based on the construction of the panel, when I shaded horizontally across all four columns the output of the panel dropped to 0. Didn't matter if it was one cell or multiple cells. If I shaded just the first two or the last two vertical columns, I still had an output from the panel. Hopefully the diagrams below explain why I got those results.

I'll get exact numbers and post them later. (I'm taking a break right now--installing the last six panels!)

--------------------------Below is duplicate info from https://gdrvowners.com/forum/solar/1...--------------

Let me emphasize the drawings are over-simplified to convey concept and impact, not to teach electronics or account for every source of power loss in a circuit.

First, the panel itself. The purpose for the first drawing in the graphic below was to understand how the system was wired together. As noted, the Eclipse is a 32 cell panel constructed with 4 columns of 8 cells. The diagram of the cell interconnection (I used a battery symbol for each cell) is an educated guess. The shot of the diodes was shot by me of the actual panel.

The rest of the slides were assembled without a lot of techno mumbo-jumbo with the hope of conveying what was happening with limited techno-speak. Those slides will follow next.



The first thing I wanted to understand is how I'd expect the panel to perform without diodes. My goal was to make the diagram easy to grasp--I'd appreciate some feedback (from anyone).



Now what would I expect if one of the 16-cell strings encountered shade? Note (in my over-simplified circuit) that power drops to 0 from the entire panel.



Now with the diodes--starting with ideal conditions.



Now what happens when there is a shade issue?



...see https://gdrvowners.com/forum/solar/1...2085#post12085 if you want to view part 2 of this original post...

[howson]

Nothing cosmic in this post--just passing along what I did as "food for thought".

If you watch AMSolar's videos, they cut off the MC4 connectors and hard-wire their custom 10ga to the panel.

I've chosen a slightly different approach so I can disconnect the panel easily if required.

What I've done is wire in MC4 connectors to the AMSolar wiring and left the MC4 connectors on the panel intact. I marked the MC4 connectors with heat shrink to make sure I didn't wire them backwards!

[howson]

...(temperature in Celsius)? LOL.

That was for Cate&Rob's benefit. (OK, in reality I didn't know you could change the setting. Found it here: https://www.victronenergy.com/blog/2...it-and-trends/)

[howson]

The system is fully operational! Whew--that was a LOT of work, and I still have a lot of interior finishing work to complete.

Worked out pretty much exactly as planned. I still have plenty of walking space on the roof, can access the air conditioners for maintenance/cleaning as needed, etc. So far so good!







Yes, it's still in C, Jim.

[howson]

TucsonJim -- some of the measurements were as expected, but some were not.

[gbkims]

The system is fully operational! Whew--that was a LOT of work, and I still have a lot of interior finishing work to complete.

Worked out pretty much exactly as planned. I still have plenty of walking space on the roof, can access the air conditioners for maintenance/cleaning as needed, etc. So far so good!

Looks great, nice job Howard.
Enjoy reading your posts.
Looks like you ended up with 6 series strings in parallel.

[howson]

Looks great, nice job Howard.
Enjoy reading your posts.
Looks like you ended up with 6 series strings in parallel.

Yes, that's right. For my roof that ended up being the best combination balancing the need for voltage (series connections) with shade-loss avoidance (parallel connections). The wiring is a wee bit overkill, but there's very little loss, that's for sure!

[kevinpo]

Great job Howard! I really enjoyed your excellent write up and that you included the reasoning behind the design.

Best regards,
Kevin

[bertschb]

Yes, thank you for sharing this project with us Howard. Very helpful for those of us considering a similar project.

[howson]

Finished up the detail work today. The DW's light cord messes up the sight lines, but I'm still very pleased with the result of the project.

Note that the paneling is inexpensive "pegboard" (without the holes) as I couldn't find a match to the OEM panel I broke during disassembly. As you can see, this is in the front closet where it isn't seen, so it works.

The completion of this solar project completes the entire electrical project first envisioned well over a year ago--it's been quite a journey. Now to learn how to effectively utilize all of it! Can't wait to try boondocking at a Harvest Host site.








-Howard

[howson]

Did a test tow today--everything was rock solid.

I will admit to one thing I would do differently--I should have bought tilting mounts. With the orientation of my camper in the backyard I'd get more production from the panels if I could tilt them toward's the sun, which at this time of year is low in the southern sky. The other benefit is they'd shed all the items cast off from the pine trees in the lot next to me. The panels are covered in seed pods, pine needles, and all sorts of "tree stuff". Oh well. Maybe a mod in the future. When I get bored.

[howson]

I was out experimenting with different settings (not ready to discuss them yet) but CHECK OUT the wattage coming from my 1200W setup! I must have done something right...

[bertschb]

Holy cow!!! Impressive.