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jesusginard avatar image
jesusginard asked

Help me figure out what's going on, please

Summary of my system:

  • The system is installed in Mallorca, Spain.
  • Victron Multplus II 8000 connected to grid.
  • Fronius Primo 6 KW placed on AC Out.
  • 20 Jinko 455W solar panels placed on the main roof that go to the Fronius.
    • First string: 15 panels, 12 degrees inclination, facing south-east. Almost no shadows.
    • Second string: 5 panels, inclined 25 degrees, facing perfect south. A bit of shadows over one panel late in the afternoon.
  • 5 modules of Pylontech US3000C.
  • RS SmartSolar 450/200Tr connected to battery.
  • 20 450W Tenka Solar placed on a carport with only 3 degrees inclination, all facing south-east.
    • First string: 8 panels that have half of the panels shadowed at 11.30AM.
    • Second string: 6 panels that have half of the panels shadowed at 12:30PM.
    • Third string: 6 panels that have half of the panels shadowed at 1:30PM.

That battery charger along with the Tenka panels were installed past November, and since I got them I thought that they were under-performing. The Fronius (which I've had for more than a year) presents much better shadow managing in my experience.

In general, even though both sets of panels have the same peak energy, the charger generates roughly 30-40% less than the Fronius. I thought that was because of the inclination (12-25 degrees on the Fronius - 3 degrees on the RS SmartSolar). I think there is something more mysterious here than just that.

Today, I updated the firmware of the SmartSolar to a new beta version (1.16) which, in theory, improves the shadow management. And I experienced something very weird from 2:30PM to 3:00PM. Production from the Fronius halfed while the SmartSolar doubled. As an extra note, it could be that during that time a shadow of a chimney obstructed the second string of the Fronius for a while.

I can't wrap my head around that, since the Fronius and the RS SmartSolar don't speak to each other... Is it the Multiplus II then? What could be the cause of that? Do you think that my suspicions are right and there is something badly configured?

Attaching some pictures so I can better explain myself.

First image: Victron RS SmartSolar VS Fronius Primo 6.0.2. Today's production. See that dip on the Fronius along with that boost in the SmartSolar.

screenshot-2024-01-03-at-165816.png


Today's production only in the SmartSolar, seeing each string separately. You can clearly see when the shadows kick in.

screenshot-2024-01-03-at-165548.png


For reference, the last day that we had zero clouds. See that big difference between the Fronius and the Victron SmartSolar. Can inclination alone do this?

screenshot-2024-01-03-at-165525.png


Thank you so much for your help!

MPPT SmartSolarFronius
screenshot-2024-01-03-at-165816.png (123.6 KiB)
screenshot-2024-01-03-at-165548.png (139.7 KiB)
screenshot-2024-01-03-at-165525.png (153.6 KiB)
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2 Answers
Alexandra avatar image
Alexandra answered ·

@jesusginard

If you have a GX there is communication through the whole system so there is sort of communication and components can be throttled for various reasons. (The main ones being the battery and also then loads.)

The simple explanation for the dip on fronius and the RS producing is that is what the system needed, that's where it got it from.

Higher string voltage would give the fronius an edge in production on the RS. So I am not surprised there really. String voltage is affected by shadowing 1 from 15 panels is a lot less impact that say 1 panel in 6/8 (percentage is higher.) And then there is also the way the panel itself is designed and made that will affect it as well.

The system usually favours the device that has higher string voltage as it is easier production.or at least that is what I have seen.

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jesusginard avatar image jesusginard commented ·

@Alexandra Thank you so much for your answer!

Yes, I have a GX so I understand now that all elements in the system are inter-connected.

However, I see there is a big problem here. Is the system under-performing on purpose? If that's the case, how can I do so the system works at its full potential at all times?

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Alexandra avatar image Alexandra ♦ jesusginard commented ·
No idea here as I only have a part picture.

If you switch off the fronius does the RS pick up more?

If it does then yes it is the system throttling.

Usually adding more battery allows the solar to work harder as there is a place to sink the power if needed.


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jesusginard avatar image jesusginard Alexandra ♦ commented ·

I'll need to keep doing more tests as you suggest.

I installed these 20 new panels in order to charge my future EV with excess solar only, and also to sell the energy to the electrical company in order to gain credit. Decided to go with the RS SmartSolar because it's more efficient to charge the battery directly. I'm not happy with the results!

Seeing this behaviour now in winter, I can't imagine what will happen during summer when the batteries are at 80% in the morning and are easily charged in 2 hours. There will be tons of energy wasted... Anyone has experienced this?

Anyway, I found that disabling "Enable battery monitor" in VE Configure fixes the issue, but it lowers the battery lifespan and it's not recommended.

https://community.victronenergy.com/questions/237470/cerbo-gx-bug-mppt-stops-power-production-in-ess-wh.html

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Alexandra avatar image Alexandra ♦ jesusginard commented ·

I would think it is the battery throttling the MPPT.

5x 37A is 185A at max charge rate, (so lower than the mppt max) later on in the day when full the batteries will throttle it. If it is being throttled by the system then it is because your batteries are being protected. So adding more to the bank will aid more production.

If feedback is on, then the charge limit is ignored. Do you have battery life on or off? I have found this also affects production.

You have to enable the internal battery monitor if you are running ESS assistant. So maybe your programming is part of it. Not sure how that reduces battery lifespan, all the Victron recommended values for set up are lower than the Pylons max. 52v and 51v respectively.

Have you followed the Victron Pylon guide?

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basco avatar image
basco answered ·

I think this is relevant to you...

Users have already is dicovered that shadowmanagement of the mppt rs 450 /100 /200 is not up to standard (e.g. compared to fronius). New firmware is in development.

See this link.

https://community.victronenergy.com/questions/249458/rs-shade-performance-testing-v116-beta-02.html

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jesusginard avatar image jesusginard commented ·
Thank you very much for sharing this! I've seen that they released the new version officially and just updated. Let's see how it goes tomorrow.

However, I've done some more digging today (I connected one string that was previously on the second MPPT in the Fronius inverter to an MPPT input of the SmartSolar)... and surprise! The shadow management works well, even a bit better than the Fronius.

This leads to a conclusion: it's the Tenka solar panels. Tomorrow I'll do more shadow testing on the Jinko VS Tenka. My first impression was maybe correct; the bypass diodes are not working on the panels.

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