question

libor avatar image
libor asked

Multi RS solar or some combination of Inverter/MPPT?

Hello Victron comunity,

I value the answers I got in my first, orientational question about suitability of Multi RS (dual tracker), but after 2 weeks of researching manuals and forums, I'm still not sure. So for more clarity, I've created a schema of my setup in which I'm planning to replace chinese all-in-one inverter with Victron product:

victron-solar-system-upgrade.png

Basic requirements:

  • Confidently prevent exporting power to the grid - my homework found how to do it with ESS, but it says the manual is not applicable to Multi RS. I really must be sure this preventing exporting power is possible.
  • Run it in "Solar first, battery next, grid last" configuration - community said it's possible and I'm quite sure it is, but have found no examples. Manual is super confusing about the subject. Any resources with examples?
  • Meaningfully connect my server-rack batteries with their own BMSs
  • Meaningfully connect my current 9 solar panelsin series @ 455 Wp (432V, 4.1 KWp in total).
    • This seems to be disadvantage of Multi RS, since I'd have to split them into two strings (piece of cake) due to 3KWp per tracker limitation and run 2nd set of cables, which could mean major construction works. The protection tube has like 6 turns, some of them tight and I doubt it's possible to pull new cables through.
    • And do I count with theoretical panel power, or with real, which never goes above 89% (providing metering was precise)? The latter would mean I still can connect 7 panels (7 * 455 Wp = 3 185 Wp * 0.89 = 2 835 Wp), which would be at least temporary solution
    • to add more confusion, some resources say the limit is only 250V per tracker (probably error).
  • The output of old inverter was 5 KW on paper, but I believe the real one was lower. I'm aiming roughly at 5-6 KW of real output power.
    • Some are stating that Multi RS withstand up to 11 KW of momentary peak (like when something is starting), which sounds fantastic and is far above what I ask for.
  • Allow future expansion of my south-facing solar field (2nd string East facing approx same, or two smaller East and West), possibly also battery expansion.
  • meaningfully control the settings remotely via an Android and/or web app. I've tested a demo in Linux and Android, looks nice, but I'm not sure if it applies to Multi RS and what's missing (without Cerbo GX?).

Please someone tell me you run it in a similar setup :-D. (I'm starting to think, that Victron customers only do off-grid, grid exporting or grid-backup application, even though the one described - I'd expect - should be the mainstream these days)

What do you think is the best Victron product(s) suitable for this application? For a newbie, it's so confusing, even after deep dive into manuals and forum posts.

Whether a Cerbo GX or similar device is required for above is a different discussion I guess, but it's not a considerable disadvantage, if I have to add it.

Multiplus-IIvictron productsMulti RSQuattro-II
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1 Answer
nickdb avatar image
nickdb answered ·

@Libor we don’t encourage design topics like this, it is just too broad, so as per our guidelines we ask you to consult with a knowledgeable supplier, if that doesn’t appeal then to skill up using the free training and many guides and manuals available. Or even check the existing topics for this content- there are plenty.

When you have done that and have focused questions then you are welcome to ask those.

Thanks.

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