fstofberg

Just another update 5 months later and so far the system is running well only had to use the grid a couple of times when raining for a couple of days.

Just another update 5 months later and so far the system is running well only had to use the grid a couple of times when raining for a couple of days.

Will see the generation at my house in summer but starting to break 3MW per month after adding some panels on east/west roof.

For the past year I have saved a total of R83k on my Tshwane Electricity bill, now if they had a better incentive to push back to the grid the savings would be much better. total since installing the system in 2022 I have saved almost R230k so next year the system would be paid off.

For the past year I have saved a total of R83k on my Tshwane Electricity bill, now if they had a better incentive to push back to the grid the savings would be much better. total since installing the system in 2022 I have saved almost R230k so next year the system would be paid off.

Will see the generation at my house in summer but starting to break 3MW per month after adding some panels on east/west roof.

For the past year I have saved a total of R83k on my Tshwane Electricity bill, now if they had a better incentive to push back to the grid the savings would be much better. total since installing the system in 2022 I have saved almost R230k so next year the system would be paid off.

Will see the generation at my house in summer but starting to break 3MW per month after adding some panels on east/west roof.

My systems performance so far:

Assuming I sale R1100 this month and R1100 next month, my average monthly saving would be at R930.
I've since installed a 2nd battery in July which brought down my grid usage considerably. At this rate, ROI is 6.93 years.
I have done some changes since my last posting here which has taken my final install cost to R77285.40incl for the inverter, 8 panels and 2 batteries, with hook up which I've already used

Will see the generation at my house in summer but starting to break 3MW per month after adding some panels on east/west roof.

On older FW mine would clip at 21A but there was a big problem. If there were intermittent fast moving clouds and the current very quickly hit the 21A it would sometimes cause a DC over current error and the inverter would shutdown and restart. 
Since upgrading the FW and it clips at 19.5A I do not have that problem anymore. 

The 8kW is a solid inverter, but the 16kW machine is just in another class. Get one and you'll see the difference in build quality.

@Chris_S that is what I'm seeing on my inverters, I upgraded to the latest firmware, but it never goes above 19.5A per MPPT, I have 2 of the 8KW units the old unit showed 22A per MPPT and the new one shows 26A per MPPT but they both stop at 19.5A.
As @TimCam suggested my next step is going to be the 16KW as I don't have space to mount both 8KW units next to each other.

@fstofberg
Just make sure you disconnect before the sun comes up, and the reverse after the sun has set. No need to "test disconnect under (full/partial) load" if it is not an emergency!

According to Solar Assistant you are getting a combined +- 12 kW solar production from your 8.8 kW machine. That is very good and nothing to worry about, as @GreenFields has stated the supposed solar max is 10.4 kW. Excess going to batteries, and max AC going to load of +- 8.9 kW (discounting any pass through from Eskom).
If you want higher production or load try a 16 kW unit. (Built like a tank)
Welcome to the forum, and a nice setup you have.  Many people would like to borrow it.😂

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.

I joined you this month for the first time now that I am feeding back:


But... that was only from the 8th, and with an export limit of 3.45kVA. This month I'm exporting for the full month. If I was able to push all my excess out however, I'd be able to push roughly 3 times this to the grid.

Yesterday's generation (note the wasted potential... I need more battery)


Sunsynk 12kW Single Phase
14.2 kWh Volta Stage 4
15.6 kWp (28 x 550W Jinko Mono panels)

To answer the OP.... My electricity bill this month will be negative for the fist time, taking the fixed costs into account. And my fixed financing cost is already at least R1k cheaper than my eskom cost was... so I'm saving from day 1.

When I get my second battery, I'll obviously use the excess to feed back in the grid in the evening / morning... but I will use that in winter for more overnight use with heaters. As it stands, with heaters, the current battery is not enough to get through the whole night in winter. At the moment in summer, I still have 50% SOC in the morning, which I push to grid at 7am.

I installed in August, and got the tail end of winter... there was not a single day that I didn't fill the battery for overnight use. Generally in full cloud with rain I'm still generating 2kW.