4000w of panels! but what mppt?

[Toby10Surf]

ello you bunch of knowledgeable legends! Quite a novice here so please bare with my simple questions and I would really appreciate your thorough answers to everything / anything! - I have 16 x 250w panels (pictured below). If I bought a Victron Quattro 15kw (15kw because I may look to add arrays over time, is that a good idea?! For a small barn conversion and all being well, a workshop).

1) In the picture of the panels below - Does 37.4 Voc, mean they are considered 36v panels? and this is ok with a 48v battery bank isn't it?
2) Does 8.85 Isc, mean each panel has the ability to produce 8.85amp?
3) In layman terms - What sized Victron Mppt would be best for these panels? Currently set up as 2x strings of 8 panels (2000w each string). I have tried using the Victrom mppt calculator on their website but I wanted to double check with people with experience because the 250w sized panels aren't on Victron's website.
4) or Would it be better / more cost effective to do one string of 4000w? or what are the disadvantages of doing that?
5) Is there any other Victron kit that you would advise getting to go with the Quattro and Mppt? For a simple set up, I don't want to be remote controlling it or constantly monitoring it from abroad or anything.

Thank you in advance!
Kind regards,
Toby

 

[SplitUniverse]

Higher voltage = thinner wire required.
Decide which MPPT you want to use and the google a "solar string calculator", put in your panel data, environmental data and MPPT specs and it will tell you what works and what doesn't.
I expect you will need more than one string.
Voc = Voltage in Open Circuit conditions
Isc = Amperage when shorted
neither of the above is descriptive of conditions are maximum power (Vmp & Imp) but Voc is a hard limit for your MPPT strings.

 

[ScrodusGargleRotten]

37.4v is to low for a 48v charge controller

You still need at least 3 panels in series to have a good time.

 

[Daddy Tanuki]

37.4v is to low for a 48v charge controller

You still need at least 3 panels in series to have a good time.

I think 2P might work, but best to run a calculator to be sure... regardless you wont go wrong with victron and any layout either 2p8s or 3p5s panel layout you will be able to lay some serious watts down.

 

[Madcodger]

Here's a link to the Victron MPPT calculator: https://www.victronenergy.com/mppt-calculator

I find it a great resource, even though I've never used a Victron panel (I do use their MPPT SCCs, inverters, and other equipment). The big thing to avoid is exceeding the VOLTAGE limits of the charge controller, AFTER factoring in the fact that voltage increases the colder the panels get. Possibly not a worry in your location, but always good to keep in mind. The Victron calculator will help you figure things out with relative ease.

Watch some of the "basics" videos that @Will Prowse
has posted on YouTube, and that will also help a great deal.

 

[Brucey]

ello you bunch of knowledgeable legends! Quite a novice here so please bare with my simple questions and I would really appreciate your thorough answers to everything / anything! - I have 16 x 250w panels (pictured below). If I bought a Victron Quattro 15kw (15kw because I may look to add arrays over time, is that a good idea?! For a small barn conversion and all being well, a workshop).

1) In the picture of the panels below - Does 37.4 Voc, mean they are considered 36v panels? and this is ok with a 48v battery bank isn't it?
2) Does 8.85 Isc, mean each panel has the ability to produce 8.85amp?
3) In layman terms - What sized Victron Mppt would be best for these panels? Currently set up as 2x strings of 8 panels (2000w each string). I have tried using the Victrom mppt calculator on their website but I wanted to double check with people with experience because the 250w sized panels aren't on Victron's website.
4) or Would it be better / more cost effective to do one string of 4000w? or what are the disadvantages of doing that?
5) Is there any other Victron kit that you would advise getting to go with the Quattro and Mppt? For a simple set up, I don't want to be remote controlling it or constantly monitoring it from abroad or anything.

Thank you in advance!
Kind regards,
Toby

Just be aware the quattro 15k is 230V so if you needed 120/240 split phase you'd need an autotransformer. Or dual 10k in split phase. I like the 250/100s, with voc of 37V I would use 15 panels for 5s3p.

 

[kc130up]

You can use those panels with almost any modern AIO or MPPT. The question is how many panels in series/parallel.
That answer depends on the AIO / MPPT you select.

Whatever you get will have voltage and current limits, you just gotta size your strings of panels to meet the requirements of your equipment.
MPPT VOC is a hard limit, but you can exceed the current limits (a little) on the AIO/MPPT, just don't exceed the current limits of the panels.

If I was trying to connect those 37.4v panels to my Flexboss21, I could do 11-12 panels per string. 11 panels would be ~412v and 12 panels would be ~449v. I'd need to adjust for the cold voltage temps (in my zip code) so I would probably stick with 11 to stay in the happy range of my inverter.

Using those 16 panels with my FB21, I would either connect 8 panels in series to MPPT1 and 8 in series to MPPT2 OR if i only had a single MPPT, do 8 panels in series paralleled with another 8 in series (8S2P).

Battery wise, all the modern AIO's & MPPT work with a 48v battery. The panels VOC has no impact on the battery you use.

 

[ksmithaz1]

Having just pulled 16 x CS250's out of service. . . Roughly 40VOC 9A if memory serves. String 8x2 and get one of these if you just want MPPT:

https://eg4electronics.com/wp-content/uploads/2024/04/EG4-MPPT-100-48HV-Spec-Sheet.pdf

 

[bladerunnerpv]

A few queries...

Are you intending this to be off-grid?

Why quattro instead of multiplus? Generator use anticipated?

Why thinking of 15kVA version? How many watts of load are you anticipating? A smaller version may suit your needs, and save you money.

Edit:Ah see ur thinking of adding more panels later.

Enjoy your planning!

Edit: PS iirc bimble solar do a victron design service for a fee, other UK victron dealers may do similar or be able to offer advice. There's a dealer list on the victron site. Energy monkey and dragon breath solar also come to mind.

Edit: There seem to be four versions of those panels in victrons mppt calculator, suggest pick the one with largest temp coefficient to be on safe side.
RS 450/100 is suggested by the tool for these panels.

I can't comment on how good a choice that is.

I do wish it would allow selecting different models and see how well they 'fit' to compare options

Keep an eye on the min mppt startup voltage, lower is better

Edit: mention of "workshop" - need 3phase supply for any kit?

 

[J.H.]

ello you bunch of knowledgeable legends! Quite a novice here so please bare with my simple questions and I would really appreciate your thorough answers to everything / anything! - I have 16 x 250w panels (pictured below). If I bought a Victron Quattro 15kw (15kw because I may look to add arrays over time, is that a good idea?! For a small barn conversion and all being well, a workshop).

1) In the picture of the panels below - Does 37.4 Voc, mean they are considered 36v panels? and this is ok with a 48v battery bank isn't it?
2) Does 8.85 Isc, mean each panel has the ability to produce 8.85amp?
3) In layman terms - What sized Victron Mppt would be best for these panels? Currently set up as 2x strings of 8 panels (2000w each string). I have tried using the Victrom mppt calculator on their website but I wanted to double check with people with experience because the 250w sized panels aren't on Victron's website.
4) or Would it be better / more cost effective to do one string of 4000w? or what are the disadvantages of doing that?
5) Is there any other Victron kit that you would advise getting to go with the Quattro and Mppt? For a simple set up, I don't want to be remote controlling it or constantly monitoring it from abroad or anything.

Thank you in advance!
Kind regards,
Toby

VICTRON… and bigger than you think you need… no one knows the future…

 

[bladerunnerpv]

You might find pvgis useful too for estimating pv yield in your location.

https://joint-research-centre.ec.europa.eu/photovoltaic-geographical-information-system-pvgis_en

 

[TM48]

If your budget will allow the Victron RS450/100 or 200 will work and leave room for expansion. Keeping it all Victron has advantages with compatibility with the rest of the "eco sphere" of products.

 

[pollenface]

I'd pick a 150/70 and connect in 2s8p 74.8voc, quite fine