GreenFields

It's possible, the difference has to be low, but just the Wattage isn't the full picture. Panel Voltage specs must be compared, and this can vary even if Watts are similar.

Try this: On the inverter's screen, find the Status Page, and then give the values for Volts in the blocks for Solar Power 1 & 2. My guess is it's around 125Volts, give or take a bit, when the sun is shining.

Please confirm the exact make & model of your Trina solar panel, or take a pic of the back data label on your panel. Just a quick Google Search, and I found this Trina Solar 545W panel: This panel is not suitable on your 5kW Sunsynk inverter. Even if you put on more panels to increase the Voltage and get it to start up, the problem is that the current rating (Imp and Isc) of that panel is too high. On the assumption/risk that you could have this panel - again, you should please check and confirm, and if it's indeed the same, then get an entirely new set of suitable panels. It's not about the brand or the Wattage, in this case it would be about the current. Maximum rated power 545W Voc 37.7V Vmp 31.4V Isc 18.52A Imp 17.37A Efficiency 20.90% Mechanical warranty 12 years Linear output warranty 25 years Supplier SKU TSM-DE19-545

I rather wouldn't do that. These panels are connected in series, and if you add another panel onto the string, you'd be skirting with the upper end of the allowable Open-circuit Voltage. @CaziquesYou cannot add any more panels in series. The issue as I see it on this series setup is the current limitation that the less-sunny panels could place on the more-sunny panels at any time of day. Improvement should be to place all the panels facing in the same direction, either all North or all West, if it should remain in series. Option 1. Assuming you have enough space in one direction to fit all the panels. Otherwise if you want to place them in parallel, Option 2, then drop one panel from the West-side string, or add one more to the North string, to keep it to the same number, 5+5, or 4+4. Not a mix and match of different numbers either side. Note it's also not clear what's the maximum current input on the MPPT from the specs, but the installer can check that. The simplest to solve all these issues is probably to use a Sunsynk, maybe a 5kW, like the installer suggested, Option 3, but it might not be the cheapest. Then you can go with up to 6 panels per MPPT, but I think 4 North and 5 West will be just fine, as long as you split them into two separate series strings, one per MPPT.

Although if you say "backup load" it somewhat implies there's a backup battery for that port. Just not exactly explicit, I'll give you that.

I don't think you should be looking at upgrading before checking what's the optimum configuration for the current panels, or how to improve the output using what you've got. 4 Panels North and 5 West on what looks like a single-MPPT inverter could be sub-optimal. Please give details on how they are connected. Are they in series or parallel? Either way it could explain your poor output of 2kW on 4.8kW of panels in summer. Also info on your loads at the same time if it can be drawn onto one graph.

First thought is that the CT coil could have been fitted the wrong way around during the upgrade installation.

On the Battery Setting screen there's a setting for Max A Charge. As above, setting it to 15-20A should be okay since you've got lots of solar panels relative to battery power to keep charging throughout the day. A further benefit of this, since you're exporting, is that if you can set it up to still do some battery charging at around 15-20A at mid day, you can hopefully make use more of the full 6300W. If your batteries are already full by 9am, you'll only be generating 5000W of power for self-use and export at noon.

Go check the value under the battery setting menu. That there is the baseline/universal/global setting of maximum discharge on your setup. It is valid whether you run in time-of-use mode or as a ups. Not 100% sure if this would solve your issue.

Would that be under the battery settings or the time of use setting?

For the amount of battery capacity you want, I'd consider just to make the jump straight to a 48V system and shop around for the best offers for a 5kWh battery and 5kW offgrid inverters around.

No, I wouldn't do that. For one thing, in Winter you want the panels angled higher, more towards the sun which will be lower on the horizon. For your location, around 45 degrees, and not flat. But also, at the back of the house you are more likely to catch shadows from peak of the main house's roof, again because of the lower angle of the sun in Winter.

UPS power is the essential load I would have thought.

Not with the out-of-the-box SolarMAN customer monitoring app.

It's normal for Voc to be different to Vmp but the difference sounds a bit high. Start with finding your panel specs for open-circuit voltage vs max-power Voltage. That 53V sounds like a battery charging voltage.

Funny thing, we had a similar topic in a recent thread, and someone was insisting that this 25% limit according to NRS-097 was obsolete, and Cape Town was far more advanced, etc. or something like that. Thank you for this feedback from the source.

I don't think it's a firmware issue. You just seem to be hitting up against the power limit of the MPPT's, which is 10400W. I guess this is one of the downsides when you're over-panelling an inverter, the 14720W of panels are likely to be clipping down to 19A to stay within the 10400W DC input limit. If you want to test that theory, try to disconnect one of your MPPT's at night (edit: [not mid-day, taking correction by @Sidewinder]), and see how the remaining MPPT behaves at mid-day. My guess is, that MPPT will be producing closer to 7360W of power by itself with half of your panels connected to it, and probably at around 336V, at 22A of current. I make full allowance for the possibility that I could be wrong. If I'm right, your options would be to either upgrade to a more powerful inverter like the Sunsynk 12kW 1P inverter with 15600W max DC input power, which would make full use of your 14270W of panels (as long as your batteries are busy charging). Or a 2nd 8kW inverter in parallel, alternatively the 16kW Sunsynk, so you can use the full 14270W output for AC as well. Otherwise, you could consider adding a micro-inverter or string inverter to AUX of the existing 8kW Sunsynk inverter, and transfer around 8-10 panels from the existing strings to it. That's if you find that you're not getting enough power to charge all your batteries and run your loads, but considering that your batteries seem to be charged by around 2pm, it might not be really necessary to do anything, just run in load priority, and you might be fine as-is.

Did the inverter not come with a manual in the box, one that's including installation instructions? What does that booklet say?

I wouldn't say the battery has been abused outright, maybe just over-used by cycling it more than you maybe had to. With a 4.6kW Goodwe inverter you basically cannot exceed the 0.5C discharge rate on a 9.6kWh battery, it's peak power is just within the 4.8kW discharge limit recommended for the battery. The 4kW geyser is the big one I'd try to get off from the battery, and onto using solar PV directly (on cloudy days grid) as much as possible. Ways to do this might be to use a smaller element (eg. 2 or 3kW), and/or adding more solar panels, and/or starting your 2-hour afternoon charging slot even a little later. Maybe it could help to add a geyser blanket to reduce heat loss, and increase the geyser thermostat's temperature, so that you maybe don't have to run the geyser from battery again later in the afternoon.

That is fine. I'd suggest to increase the discharge amps to 111A, and the charge amps can even be a bit lower, say 80A. The current 40A is almost too low to be practical, though some might say that's the way it should be to protect the battery.

If you are planning to remain connected to the grid, this system will get you far. Put the geyser on non-essential loads, and you don't have to worry about anything tripping. If you're going to go more off-grid, though, I'd go bigger for the 8kW, and add maybe double the battery capacity and panels for less sunny days, and to last you through the night in Winter.

Maybe need to be a bit more precise on the units. It's possible that you and the installer are talking past each other. The installed battery capacity is 222Ah (Amp-hours) (at +/-48V). This value doesn't change. It's the size of your "storage tank." It's probably more likely that your installer is saying that the battery discharge rate should be limited to 111A of current (Ampere), since these are 0.5C batteries. The typical specs for this type of battery say you can reach higher discharge rates like for example 150A if you had to, but that it's not ideal for regular ongoing operation. You could shorten the battery life. I'm just repeating the typical battery manufacturer's info, and it's probable that the installer is playing it safe and doing the same. What type of inverter have you got? If it's something like a Deye, personally I'd set the work-mode power to the lower value, say 5000W discharge for normal operation like daily cycling, but then allow the battery to drain more quickly in the unlikely emergency event of a power outage.

Pretty sure it's illegal to sell electricity over a neighbour's fence. But instead of trying to charge per kWh, why not charge per kilolitre of water to run a pipe to a neighbour's storage tank? Or is that also dodgy?

As was said above, your big issue is not the number of panels, but the shading. Even if you need to shorten string B to 4 panels, or move it around, that will help. Give String B more sunlight especially in the morning, and mid-day. Similar with String A, try to keep it in the sun during noon and late afternoon. If you want to add any panels, for example at C, they will be sub-optimal no matter what if you can't get rid of shading, and if they are pointing Southwards. You could do better by putting them on micro-inverters rather than by trying to connect it to existing strings.

Just going by the datasheet for the H48074 battery, if you've got 9 in series, you'd be looking at a Battery System Charge Upper-Voltage of n*54 = 486V. Lower Discharge Limit n*43.5V=391.5V. And the battery charge/discharge current is best kept to 37A for normal operation. Battery capacity 666Ah. [Edit. Correction: Battery Capacity is still 74Ah at (9x48V). Thanks @Scorp007]. Are these in line with the values you're reading from the BMS? Do you have a possibility to set these values manually through your inverter in a "Voltage mode" to see whether it operates as expected?