Hello,
Looking at new stuff and have done the calc below at MPPT Calculator - Victron Energy
Is it correct? Maybe pushing it a bit but 4x identical strings with 8x 430W panels per string is accepted by the calculator.
Can I count on this or should we have more headroom? The values for the intended panels are accurate.
Grateful for any knowledgeable comments!
As a 450/100 owner that looks fine.
I once ran 10s2p of 375W panels on each of the two trackers for 15kW of panels without issues. It does unlock a whole new level of fan speed when the sun peeks out from the clouds :). Ive since added additional sccs to switch to slightly underpanelled versus the 3x overpanelling I did have.
Thanks @Brucey for your reply, appreciated!
I am not completely clear on the real world limits of the RS 450/200 and what over panelling is technically ok.
This config I am looking at means 8x 430W panels in 4 strings for a total max of 13.7kW, but the max on the specsheet is 11.5 kW
May I also ask what “sccs” means? You have since added more solar controllers to get more top end charging?
SCC = Solar Charge Controller.
4 strings are fine on a 450/200. Are they all facing the same direction? If you would have 2 strings facing east and 2 west, it’s unlikely you’ll ever get to the max panel output anyway.
Generally one would expect to get 70%-80% of nameplate value in day to day production so its unlikely you would hit the 200A max output limit of the 450/200, which if you charge to say 56V that would be 11.2kW.
In my case with 15kW of nameplate and a max output of 100A, and charging to 55.2V I was limited to a max 5520W of charging, so in sunny conditions I was leaving a lot of production “on the table” so to speak. Solution was to add a 250/100 and move 15 panels over to that, in 5s3p, and a 250/85 with 10 panels in 5s2p.
This way I was running 8s on one tracker and 7s on the other tracker of the 450/100, and then with the other 25 panels on the 250/100 and 250/85 I had closer to 15kW of charging output combined. This is so I can capture maximum potential solar during intermittent sunny conditions in winter. In day to day production I would only expect say 80% of that, but thats fine, and expected.
Basically the rs450s can take plenty of overpanelling if needed, in your configuration of four 8s strings that should be a good balance of potential panel output to scc output.
Appreciate the comments, many thanks!
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