Langjan

Inverter manual stipulates PV Array MPPT Voltage Range 120Vdc~430Vdc ?

Am I barking up the wrong tree? The 22 A limit seems illogical to me.

Here is a screen shot of the Growatt SPF 5000TL HVM-WPV manual, shows Max. PV input current 22A:

According to our calculation the 2s3p configuration will generate 24 amps. The inverter Max. PV Input Current is only 22 amps. Add the other 2s1p and the total amperage will increase to 30 amperes which exceeds the specified limit by a large margin. Please confirm if you agree and comment on the desirability of the proposed change.

You've lost me a bit here - I have six 365 W panels in any event. I intend to disconnect the third 455 W panel from the bank of 455's so then I will have three sets of 365's and one set of 455's and one spare 455 for which I may add a mate later on. As I understand it, the total wattage produced by different panels is the sum of their individual capacity as long as the voltage is the same. I don't agree that the lower wattage panels will in effect lower the output of the others. To illustrate the point in practice, the array has, at the height of summer, produced up to 4 000 W from a total rated capacity of 3555 W.

Thanks hoohloc. I am in the process of connecting them correctly. Now I need to confirm whether the Canadians and the Haitis are compatible.

Specs of the two brands of panels: Haiti Canadian Maximum power Pmp) 455 W 365 W Open circuit V (VOC) 49,68 V 47,2 V Short circuit current (Isc) 11,67 A 9,75 A Maximum power voltage (Vmp) 41,34 V 38,8 V Maximum power current (Imp) 11,13 A 9,18 A Module efficiency at STC (nM) 21,16% 18,4%

Many thanks Scorp007.

Scorp007 many thanks for your inputs, do you have anything to add or do you think that I should stop being concerned?

Considering that all three of my panel sets are producing more or less the same result, I have put these questions to AI and received these replies: What voltage is a typical 48 V solar panel in the 350-500 W range supposed to generate in normal sunlight? ChatGPT A typical 48 V solar panel in the 350-500 W range is designed to generate a voltage range of around 40-60 volts in normal sunlight conditions, depending on factors such as the type of solar cells used and the temperature of the panel. It's important to note that the actual voltage output of a solar panel can vary depending on a number of factors, including the angle and intensity of sunlight, the temperature of the panel, and any shading or obstructions that may be present. Additionally, the voltage output of a solar panel may fluctuate throughout the day as the angle and intensity of sunlight change. Would 36 to 37 volts in winter sun conditions be regarded to be too low? ChatGPT A voltage output of 36-37 volts from a 48 V solar panel in winter sun conditions is within the normal range of expected output. During the winter, the angle of the sun is lower in the sky, and the daylight hours are shorter, which can result in reduced solar panel output. Additionally, colder temperatures can also impact solar panel performance, as solar panels are typically more efficient at converting sunlight into electricity at lower temperatures. Many thanks for your inputs, do you have anything to add or do you think that I should stop being concerned?

Inverter is Growatt SPF 5000TL HVM-WPV

The three with the previous 35, 38 and 55 V readings are set no. 2 - Canadians. However, these were not taken at the inverter and might not be very accurate, using a cheap multimeter. I tested them with the multimeter again and they all tested at 36-37 V.

Here are the readings taken from the inverter at about midday today: Set 1 - 3x365 W panels: 90 V, 9 A and 870 W Set 2 - 3x365 W panels: 94 V, 10 A and 800 W Set 3 - 3x455 W panels: 117 V, 11 A and 940 W At 16:15 I connected sets 1 and 3 to test in weak sunshine: 115 V and 450 W Your inputs and assistance is appreciated. Have I been expecting too much from the wintry sunshine days? We also had quite a bit of rain and clouds lately, but we were away for almost three months so I was unable to monitor the effect of the coming winter and the full set was only completed in August so it's my first winter using it.

Many thanks Scorp007, will get back to you soon.

Yes they are all monos. Thanks for the feedback guys, now to complicate matters - both of the other sets of three are producing 140-150 V when tested individually but when connected together in parallel production goes down to 105 V. My understanding is that different wattage does not matter as long as voltages are the same but could this be incorrect and be leading to incompatibility?

Three sets of panels, each with 3 panels in series and all 48 volts with a combined output of 3 555 W have been working perfectly, producing up to 4 000 W on occasion. A while ago I noticed a drop in wattage output, where total output would have been expected to be around 3 000 W, only about 1 800 to 2 000 W was being produced. Investigation thus far indicates that two of the sets, when isolated from the rest, are producing the expected 140-150 volts while the third set is only producing approximately 100 volts. When the sets are combined, the total output drops to around 100 volts, indicating that some weaker sets may be affecting the others. Tests on the three panels in the set producing 100 volts, when isolated, show 55 volts on one and 35 and 38 on the other two adjacent to each other. The panels are two sets of 3 x Canadian 365 W monos and one set of 3 x 455 W Haitai monos. The Canadians were installed in January 2022 and the Haitais eight months later. They feed to a Growatt 5 Kw inverter and 3 x Growatt Hope 3,3 Kw batteries. There is no visual indication of a suspect connection, but it seems surprisingly co-incidental for two relatively new Canadian panels to malfunction in similar fashion. Any thoughts and suggestions would be welcomed.

Thanks. As mentioned in my original post, the proposal is 4 105 W at 144 V and 28,5 amps. The inverter capacity is 6 000 W at 150 V and 100 amps

Agreed thanks and yes, I initially installed an extra set of PV cables for exactly this purpose.

Power loss: Mixed voltage yes, mixed wattage no.

I had an interesting experience with a major supplier of solar systems in Johannesburg. When I tried to accept their Black Friday special offer on three extra panels for my existing system, their technical staff informed me that the panels will not work because the wattage differs from the existing. This flabbergasted me. Existing is two strings of 3x365 W in series connected in parallel to provide potentially 2 190 W @ 144 Vdc and 15,2 amps. The proposal is to add another string of 3x605 W panels in series connected to the existing string at the PV combiner box to provide potentially 4 105 W at 144 V and 28,5 amps. All panels are 48 V and the system capacity is 6 000 W at 150 V and 100 amps with a 5 kW Growatt inverter and 2 x 3,3 kW Growatt lithium batteries. Therefore 3 sets of 3 panels in parallel, two of which are all 365 W and one set of which all are 605 W. I am well aware of the pitfalls in trying to combine different voltage panels but fail to understand how different wattages can create a problem.

Good day, I am charging one Growatt Hope 3.3kwh lithium battery from a Growatt inverter model Growatt SPF-5000TL HVM and six Canadian 365W panels as a backup to beat load shedding. When fully charged (by solar in daytime or utility at night) the battery powers the household for 5 to 8 hours. The system was installed as new on 17 January 2022. The panels charge the battery in quick time, about two hours from 40% to 100%. I would like to connect a second identical battery to the system, any comments as to whether this is feasible and possible complications will be appreciated. I visited a friend in Vereeniging on the weekend, he is charging two 4.8kwh lithium batteries using six identical panels to mine and his system seems to be performing very well.