question

offgridwolf avatar image

10kw system plan, Please help!

Hello all,

I'm new here sorry if this question is redundant.


I'm building an offgrid system. I will NOT be selling power to the grid. I want to get an inverter/charger that's good enough so i can eventually add more panels and more batteries without having to get new ones and re-wiring all the time.


I was thinking on going with 2 3648a outback prewire inverters but I like the apps of Victron and outback is not available here.



  1. I want a 10kw system
  2. 48v to 60v system.
  3. 10x 500 watts panels from china ( another 10 later)
  4. 3 x Tesla smart lithium ion batteries ( 57v 2.5kwh) , I plan to get 11 of these.
  5. Victron charger controller and inverter


Questions are:

1) Which inverter/s should i get?

2) 250 charge controller will be enough?

3) Quattro or Multiplus?

4) Will the Victron inverter work well with tesla smart batteries?










MultiPlus Quattro Inverter Chargercharger48v battery
2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

4 Answers
ejrossouw avatar image
ejrossouw answered ·

Firstly, I personally think you may want to consult with a professional installer.

Answers to your questions:

1. That is ultimately for you to decide based on your requirement as well as local support available. Naturally this is a Victron forum so ...

2. Try the Victron MPPT sizing calculator. The exact specification of your panels is needed. https://www.victronenergy.com/solar-charge-controllers

3. Multiplus will suffice as I assume you won't need 2 AC inputs being off grid.

4. For compatible batteries start here. https://www.victronenergy.com/live/battery_compatibility:start

General suggestion, use the search feature as there is a wealth of useful information definitely not worth repeating everytime.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Paul B avatar image
Paul B answered ·

I agree with ejrossouw

My quick thoughts are

Questions are:

1) Which inverter/s should i get?

you will need a 10Kw inverter by the sounds so you can use a Quattro 10Kw oir even 2 x multiplus II 48 volt units (if you are ever likly to get the grid then these have built in Anti Islanding. or 2 x 5000 48v Multiplus units and you can add a 3rd or 4th latter if need be

if you get a 10Kw unit then its 10Kw steps

you can add 5 Kw of solar plus another at a latter date with no problems

keep in mind the 1-1 solar rule ie the solar has to be no larger than the total inverter size.


2) 250 charge controller will be enough?

with victron you can easly us AC or DC coupled, the differences are with efficiency manly

ie if AC Coupled you are going from say 300V DC or more (depending on panel config and grid tie invter specs etc) ( so long cable runs less loss) to 220 AC and if you are using most of this say 5KW during the day the system direct to your AC appliances, thus more efficient

if you are charging your batteries with most of the Grid Tie then you loose on the conversion to 48V DC and then back to 220 AC latter


DC coupled you are DC to DC charging less loss but converting to AC only one time

So it depends on whats being used most during the sun time hours

maybe half the system use AC coupled and the other half DC Coupled


AT LEAST with Victron you have BOTH options available


hope above makes sense to you


3) Quattro or Multiplus?

at 10 KW I think the option is only Quattro but if you can get a Multiplus thats fine as you are OFFGRID one AC input is all you need.

4) Will the Victron inverter work well with tesla smart batteries?

Victron system will work with 99% of batteries as its HIGHLY configurable, by the installer and if you are tech minded then you can learn how to do it yourself

Victron systems are very OPEN to letting the customer do everything themselves, so lots of options

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

offgridwolf avatar image
offgridwolf answered ·

Thanks for the answers

I still didn't make a step. a dealer approached me with the quattro but I guess the Multiplus would do.


Does anyone has a diagram for 5kw system with victron? If anyone can help with the setup, PM me.


I'm guessing the 250-100 is what I need:

https://www.victronenergy.com/solar-charge-controllers/smartsolar-250-85-250-100



Panels:

8 x 500 watts. I purchased 10 but 2 broke on the way :(


Here are the specs from the back of the panels.

pm 500w

vmp 48.63v

Imp 10.28A

Voc 59.01v

Isc 10.87A

Maximum system voltage 1000v

Maximum series fuse rating 20A


If anyone can help with this setup I'd be delighted, even a basic diagram would help and a list of components needed. I'm very far offgrid by boat.

I'd like to have a 230v or 240v system to run an appliance that requires 230v 20A dedicated circuit. Maybe use a transformer if needed for other things.


2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.

Anita avatar image
Anita answered ·

Hi @OffgridWolf,

I see this was posted in May already, so not sure if this is after the fact.

Need some clarity, before I can respond.....

First of all, when you say 10kW system, what are you referring to?

10kW inverter size,

10kWp solar panels, or

10kWh battery storage?


Secondly, you mention that you have 10 x 500Wp panels and will get another 10 later. Also that you want to start with 3 x 2,5kWh lithium ion batteries, and later get another 11.

The 10 x 500Wp will be sufficient to charge the 3 x 2,55kWh lithiums now, but the additional 10 x 500Wp, will not be sufficient to charge the additional 11 x 2,55kWh lithiums. You need minimum 1 x 500Wp to charge 1 x 2,55kWh lithium in 6 PSH. But better to work on 2 x 500Wp, to compensate for losses and less than ideal conditions. Thus for 3+11=14 x 2,55kWh lithium, you would need about 14 x 2 =28 x 500Wp panels. Some recalculation to be done there...

Thirdly, you say you are very far off-grid by boat. Where will the panels be installed then? 20 (or 28) x 500Wp will take up quite some space.

Cheers,

Anita

2 |3000

Up to 8 attachments (including images) can be used with a maximum of 190.8 MiB each and 286.6 MiB total.