micro-inverters or optimizers when shading is major issue ?

[ButchDeal]

That demonstrates to me a real understanding of the problem.

Diodes fail and optimizer can detect that, and be proof for warranty claim.

I would say that optimizing PV array output over a wide range of conditions
including shading, is a rather complex technical problem. I am not impressed
with this explanation. It seems to me to be grossly over simplified, inadequately
or poorly explained and justified. I see no curves, pictures of optimizer connections
and explanation of their functions, or adequate explanation of inputs to the math shown.
Perhaps it is really an attempt to justify the product, not to be carefully scrutinized.
Bruce Roe

The argument put forward by NWDiver is that in a heavily shaded environment there is "roughly" the same output for a string system as an optimized system.

with the difference in cost of the equipment assuming SMA inverter in both (he tried to compare to SolarEdge to better his figures) is very little.
If the system requires NEC 2017 rapid shutdown AND OP wants Secure power feature then the price is almost exactly the same (really the same as I am not sure his solution for using the TS4-R-Fs with an Emergency stop switch is approved, but even that would add costs and make the price within a few dollars).
So SMA inverter and TS4-R-O VS TS4-R-F with E-switch hack

I agree there are complex situations often with shadows and they rarely cover just one cell or even cells in one group, or even cells on one PV module.

The SolarEdge document describes the situation with multiple static situations and no not completely with SMA optimizer as they work rather differently but clearly showing situations were the optimizers would produce significantly more (NWDiver has several times talked about <1% and this document is talking > 1% at the least for single cell to cases with much more difference).

Bruce and I disagree about the usefulness of optimizers on UNshaded situations, though this is different. OP needs MLE for NEC 2017 anyway so go full optimizer or just meet NEC 2017 requirements is the proposal by NWDiver, although OP asked Optimizer or micro.

[ButchDeal]

This seems a bit like a duel between titans.

Both are experienced and knowledgeable. Something genuinely helpful and informative might come out of it.

I plan on staying tuned - hopeful of learning something.

I actually would love to find a great video or tech document showing the situation of unoptimized, SMA optimized, and SolarEdge optimized, toss in enphase micros too, with a gradually increasing shadow on identical arrays.

Any one see anything like that?

[RShackleford]

OP asked Optimizer or micro.

Indeed I did. But considering SPS makes me lean heavily towards optimizer, IF I believe Tigo optimizer (TS4-R-O) works as well as SolarEdge's. And I've seen nothing to dissuade me from that.

The discussion of the efficacy of optimizers is interesting, but of little practical relevance to to me, since I need theTS4-R-O's in order to get SPS to work.

[ButchDeal]

Indeed I did. But considering SPS makes me lean heavily towards optimizer, IF I believe Tigo optimizer (TS4-R-O) works as well as SolarEdge's. And I've seen nothing to dissuade me from that.

Well SolarEdge is going to be a bit more efficient but practically not all that much. If you prefer the Secure power then go the SMA route. If you have plans of eventually getting real backup power with a battery then you would be stuck with either swapping the inverter (but keeping the optimizers though adding communication gateway) to get a DC coupled solution, or going with an AC coupled solution. I would recommend swapping out the inverter for an Outback at that time over the AC coupled solution.

The SolarEdge StorEdge interface with a DC coupled battery is a cleaner more efficient solution than an AC coupled solution, but no cheap secure power option.

The big difference between the technology is the input Voltage range. The TS4-R-O has an input range of 16-90V where SolarEdge optimizers are 8-105V (top is 48V for P320,P340, 60V P370, 80V P400, 87V P505, 105V P405) because the Solaredge has MPPT with buck/boost where the SMA optimizers can only reduce voltage.

[J.P.M.]

I actually would love to find a great video or tech document showing the situation of unoptimized, SMA optimized, and SolarEdge optimized, toss in enphase micros too, with a gradually increasing shadow on identical arrays.

Any one see anything like that?

FWIW, I have not, but it's probably a worthwhile subject for investigation. An opinion: If you want serious information that's vetted and more than more than the usual u-tube nonsense or what amounts to a sales pitch masquerading as serious stuff from mfgs. that has a built in bias. I'd check the open literature in the journals as a start.

If you find anything, I'd suggest you consider checking to see if the increased surface reflection as f(incidence angle) is accounted for, if at all.

My guess/opinion is that you're one of a few or so posters here with the background and experience to benefit from a serious dive into serious academic and engineering investigations of such matters.

[bcroe]

I would just throw in, sometimes another option to optimizers and micros, is the chain saw. In
this 2013 pic look past the construction to the row of trees trying to dominate my southern fence
line. Then in 2019 looking north note the new fence line, no trees but a few stumps. That field
of green close to the camera is on a friendly neighbors land but kept mowed by me, assuring
nothing else close will get started soon. Bruce Roe


NSbase.jpgRear19.JPG

[RShackleford]

I would just throw in, sometimes another option to optimizers and micros, is the chain saw. In

Yeah, I definitely intend to employ my chainsaw, though not to such a dramatic extent. And neighbors' property will not be an issue.

Anyhow, it won't eliminate the need for optimizers, since evidently those are required to use SPS.

[ButchDeal]

I would just throw in, sometimes another option to optimizers and micros, is the chain saw.

So the thread should be " Micros, Optimizers, or Chain saw, when shade is a major issue?

[nwdiver]

The discussion of the efficacy of optimizers is interesting, but of little practical relevance to to me, since I need theTS4-R-O's in order to get SPS to work.

I'm 99.9% certain a RS4-R-S will work since you can mix it with the O and they use the same communication protocol. I have a system with 18 Ss and 1 O. Works fine. I don't see how an O would work with SPS but a S won't. The S is ~40% cheaper than an O.

[J.P.M.]

So the thread should be " Micros, Optimizers, or Chain saw, when shade is a major issue?

Well, that does add another energy source to the mix - firewood.

[ButchDeal]

Well, that does add another energy source to the mix - firewood.

YES and on top of that no shadows are always more production than shadows with optimizers or micros.
So you have more production, and alternative carbon neutral energy source (wood), cost would be a little fuel for the chain saw and splitter, maybe buying a used chain saw...
not an option for everyone but most production if it is.

[RShackleford]

YES and on top of that no shadows are always more production than shadows with optimizers or micros.

Yes, a somewhat facetious suggestion no doubt, but wasting trees helps you whether you have optimizers or not, so not really relevant to the OP.

So you have more production, and alternative carbon neutral energy source...

I've been taking advantage of that alternate source for decades, but it's not very good at running the refrigerator; and some nay-sayers would argue its carbon-neutrality, which I don't buy into, not the way I do it (but a valid objection for mass-production of pellets for foreign markets). But, PLEASE let's don't get derailed into THAT discussion here. Unfortunately, the trees I'd tke down for solar would be crap firewood (but still useful for SYP lumber, tulip-poplar furniture, and if all else fails, pulp).

[RShackleford]

I have a system with 18 Ss and 1 O. Works fine. I don't see how an O would work with SPS but a S won't. The S is ~40% cheaper than an O.

You're saying that SPS works on your system ? What family of inverter ?

What's the diff between 'S' ("safety") and 'F' ("fire safety") anyhow ?

Anyhow, like I said before the price diff between 'O' and 'F' or 'S' is noise compared to the price diff between different makes of panels, and I still don't have a clue how to make that decision. Speaking of which, this could be a sweet deal, anyone have opinions on these: https://www.renvu.com/Browse?website...Brands/Solaria

[nwdiver]

You're saying that SPS works on your system ? What family of inverter ?

What's the diff between 'S' ("safety") and 'F' ("fire safety") anyhow ?

Anyhow, like I said before the price diff between 'O' and 'F' or 'S' is noise compared to the price diff between different makes of panels, and I still don't have a clue how to make that decision. Speaking of which, this could be a sweet deal, anyone have opinions on these: https://www.renvu.com/Browse?website...Brands/Solaria

The 'S' has monitoring and the 'F' is only for rapid shutdown (no monitoring). The S is an O without optimization... There's a ~$10 jump from the F to the S and another ~$20 jump from the S to the O. That adds up to a ~$450 difference in hard cost for a 5kW system or ~10%.

Those are good panels of you're space constrained but a bit pricey if you have the room to throw up a few more lower wattage panels. You should be able to get good panels for <$0.50/w.

[ButchDeal]

The 'S' has monitoring and the 'F' is only for rapid shutdown (no monitoring). The S is an O without optimization...

Those are good panels of you're space constrained but a bit pricey if you have the room to throw up a few more lower wattage panels. You should be able to get good panels for <$0.50/w.

So secure power is working with your system?