C solar

Hi @Freakazoid I noticed now the same 20A limitation on my system. Also using 2x strings of the JA 540W panels, supposed to be providing 12,9 + 12,9 = 25,8 Amps. My 16Amp DC fuse in the combiner box recently popped, and we since replaced it with a 20Amp fuse. However these graphs were always, and are still showing a Max of 20.1Amp on the MPPT, irrespective whether the 16 or 20Amp Fuses was installed. Do you have the correct fuse rating in your combiner box? 25A I think is the correct rating actually. Regards, C

@Freakazoid Rudolph, perhaps all theory, but if you could produce about 31kW on your Mppt 1 in April, the mirrored and combined curve for both Mppts together may deliver 63kW I suspect. I actually don't agree with your assessment to keep North facing panels on a separate Mppt. The partial light (at minimum) that falls on both your strings help the multiplication math in terms of watts and amps. My understanding is with parallel strings, You need some light on your one shaded string whilst the other is producing good watts so the "zero production" of one string don't compromise the other too much. You need "some" amps on your shaded string so the volts don't drop to zero. So East and west on one mppt wont work well at all I think. The two strings on one Mppt does affect each other some. Perhaps this 'math' may help us think about it. 10(sunny string) x 2(somewhat shaded string) = 20(production), however 10(sunny string) x 0(very poor exposed string with no volts) = 0 (zero production). The difference between 2 and 0 is infinite. again: 10 x2 = 20, but 10x0=0 I know in reality your sunny string would still produce somewhat, but this thought experiment shows that the setup might not be ideal facing two strings on the same MPPT in complete opposite directions. Still curious about your December KWh/day production on Mppt 1?

Hi Rudolph @Freakazoid, I couldn't resist. Here I took your december MPPT 1 curve , and mirrored it as a theoretical MPPT2 facing West & North (mirroring your current eastern panel setup) and overlaid the two of them .The white (and black lines) shows the combination production curve. I reckon this April setup might deliver about 64kWh for the day. This setup looks optimal for long productive sun hours. What do think? C

Hi Rudolph @Freakazoid, If this blue curve is typical for a sunny day on your Mppt 1, then I'm surprised and impressed. 1) Its a wiiide steady curve with strong production early in the morning already. 2) In April you are getting very close to the 4kW (+-) upper limit of your Mppt for a good wide chunk of the day. 3) It appears as though the two string directions is actually not affecting your Mppt's production bad at all. It actually looks benificial... Would love to see a December curve on this blue Mppt. Guessing you are producing close to 30kWh/day on a sunny December day? Fascinating! Compare your april curve above width mine below from a few days ago.:

Hi @Freakazoid Thanks for your detailed response. No doubt your west facing panels is where your greatest potential is for improvement. Shadows is your enemy with solar no doubt. However also if you could re-align your north, and east panels to face a similar direction, you would see a good improvement there also I think, simply because the Mppt would start working with greater optimization. I do have an important question regarding your production curve for your PV1 Mppt (N & E), considering this Mppt is rated for 4000w (5200w max), what is your daily production for just this half, and how long does your production curve peak for during a typical day? ...I'm trying to assess whether there might actually be an advantage to combine the two parallel string (on a single) Mppt the way you did it. ... I.o.w. if both your mppts produced the same as your Mppt 1, would the Kwh daily production look good, great, or just okay? Especially if you 'mirrored' this 2 parallel string in a North and west format on your PV2...?

Hi @Freakazoid, We recently installed the 8kw Deye also in PTA. My understanding is that the Parallel strings you connect onto a single Mppt still needs to be identical. i.t.o. size, specs, orientation even. Because the max Power point control applies to 1 string's best case curve, and cant cater the same setting for different facing strings to charge optimally. So to compare, with your 8,75kw worth of panels, what is your winter (clear weather) daily KWH production? (We have 8,5kw worth of panels all facing NNE, with a winter daily production of around 45KWh at the moment) Kind regards, Clinton