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avontuur avatar image
avontuur asked

Blue/Smart Solar MPPT

I live on a canal barge with 4 generic solar panels and need to update my old PWM system to a modern MPPT system.

There are 4 panels each of 255w parallel feeding 1020w in to a 12v system.

Voc 35v

Isc 9.12A (as tested)

I have attempted to use the VE MPPT Calc which appears to indicate that the Blue/Smart Solar 100/30 would do the job- although I cannot input my particular panels.

The problem is that when I look up the characteristics of this controller it appears to be only good for 400w on a 12v system and I need 1020w.

Where am I going wrong? Please advise.

Cheers, Mark

MPPT Controllers
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3 Answers
dsolar avatar image
dsolar answered ·

I think is not possible to use blue/smartsolar 100/30 with 4 225w panel with 12v system.


Have a look at the datasheet:


https://www.victronenergy.com/upload/documents/Datasheet-BlueSolar-charge-controller-MPPT-100-30-&-100-50-EN.pdf


with 100/30 you can have max 440w on pv side; even with 100/50 you can have a max of 700w


Are you sure you cannot change system voltage? 1020w @ 12v is a lot. There are some controllers that can handle your pv power @ 12v but are quite expensive.

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dsolar avatar image dsolar commented ·

For reference you can see here:
https://www.victronenergy.com/upload/documents/Datasheet-BlueSolar-charge-controller-MPPT-150-45-up-to-150-100-EN.pdf

you can find for example 150/70 or 150/85 that can handle your pv power

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Mark avatar image
Mark answered ·

You would also exceed the 35A Isc limit for the 100/30 if you were to wire all 4 panels in parallel.

Maybe also consider 2 x 100/30 or 2x 100/50 with only 2 panels wired to each MPPT.

Note that it is OK to exceed the 'nominal' PV power - the MPPT will just limit the charge/output current & power when the panels can provide more PV power. But you must NOT exceed the Voc or Isc limits.

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avontuur avatar image
avontuur answered ·

@dsolar

@Mark

Thank you for your suggestions. That got me thinking and more research.

I inherited a 12v system with the 4 panels and a Multiplus 12/3000/120. From measurements I know I need approx 4kw/day and I've been wondering if the high currents involved would be feasible with the multiplus I have. I am already going to upgrade the battery system to LiFePo4 anyway so it now seems as if the best way to go would be for a 24v system .with a 24v Multiplus and change the engine second alterator to 24v. That should also reduce the number of smartsolar mppts' I would need. So at 24v I could run my 4 panels with a 100/50 and get anothe one for the extra 1000w solar I will need to be autonomous for 9 months of the year.

Thanks, Mark

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