• Have you tried out dark mode?! Scroll to the bottom of any page to find a sun or moon icon to turn dark mode on or off!

diy solar

diy solar

Quiz, which of these 3 systems has optimizers?

Oldphile

Solar Enthusiast
Joined
Mar 30, 2023
Messages
745
Location
NH
It's an overcast day and there's no direct sunlight, only diffused. It's near noon. Which system or systems do you think has optimizers? I'll give the correct answer Monday.
OPT or not.png
 
Assuming optimizers do anything useful at all, the 8.1 is operating at a 25% higher efficiency, so that's the obvious answer, but I find it hard to believe that optimizers do anything meaningful when shade is not involved, so I'm stumped.

More info would help. Are all three arrays at the same azimuth and tilt?
 
I would say not enough info given without digging out the panel specs in your signature like and guessing at the install configuration. And making the assumption that the built in mppts are in use verse something else.

What would make it an easy guess would be to know the average production per string.

And what egg-on-his-face asked as well.


right now we are at "Which is bigger A or B or C? bigger in terms of what?
 
The 8KW and 6.8KW systems have optimizers.
The 8.1KW system does not have optimizers, in this scenario producing 50% more KWH than the other 2 systems.
 
The 8KW and 6.8KW systems have optimizers.
The 8.1KW system does not have optimizers, in this scenario producing 50% more KWH than the other 2 systems.
Interesting, so in marginal conditions (not panel shading per se) the optimizers did a real shit job.
 
Can you give us more info on the sccs etc used?
All 3 systems are Sol-Ark 15k. The optimizers are TIGO.
The system w/o optimizers has Sil-Fab 370 watt panels. The other 2 systems have Panasonic 400 watt panels.
 
So basically they just serve as rapid shutdown modules for code compliance in your case?
I like the panel level production information. If had to do it again, I'd get the TIGO's that only do monitoring. The optimizers cause false arc faults with the Sol-Ark.
 
I like the panel level production information. If had to do it again, I'd get the TIGO's that only do monitoring. The optimizers cause false arc faults with the Sol-Ark.
Does the solark shutdown the pv charger when it falsely detects an arc fault? Do you have to do manual operation to get it charging again? Or just a warning and continues working?
 
Does the solark shutdown the pv charger when it falsely detects an arc fault? Do you have to do manual operation to get it charging again? Or just a warning and continues working?
Yes, Sol-Ark shuts off PV production until reset. I can reset through MySolArk App, but since this new App was introduced last June, I don't get a notification and I'm not aware that I've lost production. So, I operate with arc fault turned off.
 
I guess the other possibility is the silfabs just do better in overcast conditions versus the Panasonics?
This seems much more likely that the optimizers causing the slightly lower efficiency. Optimizers are meant to help a panel with shading keep up with the rest of the string. If everything has crappy sun exposure, an optimizer isn't meant to address that.
 
I currently have 16 Tigo TS4-O units installed on my system and have yet to see any "real" optimization. I'm not sure what type of shading the optimizers need to have in order to "optimize" the panels' power. I know there is a difference between a small shading blockage like a leaf landing on the panel, and say several tree limbs that are casting shadows on the panels from a little ways away from the array. But to me, if I'm spending $40-$50 per optimizer, they should be able to produce more results. I'm not a huge fan honestly, I wouldn't suggest anyone to purchase them.
 
I like the panel level production information. If had to do it again, I'd get the TIGO's that only do monitoring. The optimizers cause false arc faults with the Sol-Ark.
You can't get just monitoring anymore as NH uses NEC 2020, meaning panel-level rapid shutdown is required.

But at this point I'm suspicious of TIGO and would like to know of better quality MLPE? I'm on friggin' NEC 2023 and need panel rapid shutdown, and want monitoring which does not require somebody's specious 'cloud'.
 
Modern solar panels have bypass diodes that can significantly reduce the impact of shading. Even a single bypass diode can reduce the shading impact to a single panel. Most panels these days have 3 diodes some have as many as 6 diodes. 6 diodes could reduce the impact to 1/6 of a panel. That is a lot better than the old days when you could lose the whole string with just a little shading.

The bypass diodes significantly undermine the benefits of optimizers. One study claimed that optimizers on modern panels only improve production by 5-10%. I have not tried to run numbers recently, but it seems that buying a couple more panels might be more cost-efficient than optimizers....and it puts a lot less electronics on the roof. (If I did run the numbers I would need to compare RSD receivers vs Optimizers with RSD.)

NOTE: YMMV. Studies that look at things like this are typically not rigorous enough so you have to take them with a bit of skepticism. , but almost all studies I have seen on optimizers have shown improvements in the low teens or less.
 
You can't get just monitoring anymore as NH uses NEC 2020, meaning panel-level rapid shutdown is required.

But at this point I'm suspicious of TIGO and would like to know of better quality MLPE? I'm on friggin' NEC 2023 and need panel rapid shutdown, and want monitoring which does not require somebody's specious 'cloud'.
I described that wrong. It's monitoring + RSD, no optimizing.
 
(NEP) was founded in the United States. It has its R&D facilities in San Jose, California, the heart of Silicon Valley.

May be a good choice. I've had to use TIGO tech support. Initially great, then disappointing. In the end it's working. I'm not a fan of TIGO, but not a hater.
 
Shading management at the inverter level can help resolve shading issues. The Global Scanning function allows the MPPTs to identify the global MPP and maximize the yield of your PV system in case of shading.

However, optimizers can be used in specific cases where you need to connect modules with different inclinations or orientations within a single string
 

diy solar

diy solar
Back
Top