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When I enter my panel selection into the calculator it adds the series panels to the total wattage, when adding panels in series only the voltage should increase, eg- 2x40v 190w panels in series should = 80v @ 190w. Am I missing something here? I have 26 panels at 45v 190watt, I would like to see if I can run them at 13 parallel strings of 2 in series to make 90v x (190x13strings=2470watts)?
26 x 190W gives you a maximum potential yield of 4940 watts. This can be limited by the amperage output of the charge controller you use.
For instance if you have a 150/70 and a 48 volt system then the max your charge controller will put out it 70*48 (or whatever you system voltage is) is 3360W. So if you now use a 150/100 you can potentially use all the pv you have installed in peak sun = 4800W (leaving out heat losses of course.)
The 150V refers to the max VOC of you string at min temperatures get as close to the 150V as you can without going over it. it is a hard limit. You should be able to get 3 in a string, you would need another panel to make a full set of 3). The higher voltages give you better yields in lower light conditions. Also when combining your strings you don't want to go over the amp output limit either which i think your proposed 13 strings will do depending on what charge controller you have chosen.
Knowing what amp rating your panels are will help with a better answer, also having two charge controllers may make better use of the number of panles you are proposing.
Hi Alexandra, I am still a bit confused, yes if all 26 panels were run in parallel then my potential yield would be 26x190=4940watts, but by running 13 strings of 2 panels in series therefore my potential yield should be 13x190watt=2470watts but at twice the voltage?
Hi D,
You might find the book Wiring Unlimited helpful to understand series/parallel connections, page 43.
Going even further with your logic, if you connect them all in series, your potential yield should be 190W. (1x190W) :)
No.
Power of the PV array does not depend on how you connect panels.
If you have 26 panels 190W each, no mater how you connect them, you will have potential yield 26x190W=4940W
Parallel = current increases (A or I)
Serial = voltage increases (V or U)
The power (P=U*I) increases in both parallel and series (W or P).
Hi Matthias, thank you for your answer, so in your expert opinion what would be your recommendation for a mppt to suit my above situation? 48v battery bank, 26x190w panels and a 48/5000or8000 inverter, looking at approx 8000kws daily consumption. Panels will be on ground mount facing north with no shading.
Thanks Dan.
Sorry for the delay, I was on the road the whole day.
If you want to use only one MPPT and a 2S13P config, you will need a 150/100.
But I would recommend you to use at least 2 MPPTs (if one fails you still have the other) and at least 3 or 4 panels in series (higher efficienzy).
Maybe one 250/70 with 4S4P and a 250/60 with 3S3P.
If you never get temperatures below -6°C you can also use a 150/45 for the 3S3P array.
For the calculations I used the Victron MPPT calc Excel Tool:
https://www.victronenergy.com/upload/software/VE-MPPT-Calc-3_7.xlsm
and the panel specs from this sheet:
https://www.secondsol.com/index.php?page=ad_showup&ID_AD_UPLOAD=424
