GreenFields

Given the East/West split, you won't see the full 7.7kWp anyway, the peak should be lowered to around 7kW at mid-day in high summer (you can check it on an online solar calculator). Maybe calculate by another route and compare it to your current mid-day peak in summer, then add another 17% on-top of that. I'm not in a position to give a comment on the safety.

Winter solstice was just 3 days ago, so ja, poor power generation is still basically the worst right now that it will be all year. But the 1000W on a panel set of 4360W sounds like too little. What's the Voltage and Current on PV2? Around 250V and 4A? Do you generate any more on PV2 if the PV1 string is disconnected? Do you have any problems with shade being cast over that 2nd string?

Doesn't sound immediately like an issue, just the info communicated by the batteries (BMS) to the inverter. Sounds like 3x105A discharge rate, ie. 105A discharge spec per battery.And the charge rate may vary depending on how fully charged the batteries are. But in any case if you have just the one inverter you'd have a peak charge rate from grid of around 120A-150A give or take, just guesstimating. And around 110A from panels. So you'll basically never put stress on the batteries. Money wasted unless there is a clear sign of a fault.

You could check whether a 24V Victron Multiplus setup would work for you, but in the long run it's a strong consideration to transition to 48V or even HV batteries, if you want to increase the system power. What exact batteries have you got, and what's the spec for lifespan or number of cycles ? That might also help guide the level of expense to incur now for the 24V path. Maybe you could look at options for the best use-case, if you would dedicate this 24V / 3.5kW / 20kWh system to a feed a specific 15A sub-circuit in the house, and get a different 48V inverter system to feed the main circuit breaker. Similar to how you have an MPPT dedicated to a geyser. Meaning, maybe use this exclusively for running an aircon, or a pool pump, or get an electric vehicle.

Please try that for yourself and let me know. The last time I did that I had a residual usage of around 50-60W from my battery, but I may well have issues with inaccuracies because of my CT-coil cable length. If you set it to zero and really get exactly zero, I'd love to know.

This is unusual. The "Power" column specifically restricts the amount of power supplied from the battery. Try to change the end time for that slot, ie. don't let your time slots all end at 00:00, split it up to end say at 9pm for Time4, then end at 10pm for Time 5. No guarantee that this will resolve the issue, but I've got a similar setup that also limits my power drawn at various times in the evening (eg. when my geyser timer is running), and it works well like that. Maybe double-check that the system time on the inverter is perfectly correct, although looking at your screenshot and posting time, it might not be the real issue either.

Generally love it. Point of feedback, maybe a thought to display the SA map of daily peak sun hours, as an indication of how much sun hours one can expect in different parts of the country. And extend the inputs range to around 6.5 hrs to include major towns in the North-West part of the country like Upington.

Batteries look interesting. Installation looks very neat, but does it meet the inverter manufacturer's requirement for ventilation space on all sides of the inverter, if you are covering the bottom up to hide the cabling? Just my first thought, don't know the answer, and I'm too lazy to look it up. I just know I wouldn't want a warranty to be invalidated if it turns out it's not installed according to the manual.

Yes, the batteries are rated 1C charge according to the spec sheets, to take 105A each, so then if you charge at 100A that the inverter can handle, they will will still be charging at around 50A each, ie. well within in the battery manufacturer's spec. Basically at a 0.5C rate. But I'd set the inverter charge rate to 80A as a balance between going easy on your system (batteries as well as inverter), and extracting useful performance. That's around 0.4C or 4kW charging power, in your setup, on a panel set of just over 5kW. Any less, like if you're using a 50A charge rate on the inverter, then you'd be negating a fair bit of the benefit of having that many panels in the first place.

This is very close to the type of setup I was referring to in a previous post. Sorry, have to repeat this: it's a great setup for someone who needs more autonomy from the grid. But if you've got low usage of 15-20kWh daily, and typically under 6kW of peak power, then you could cut this system basically in half, I guess for around half the price, and still have a system that will meet your power needs 95% of the time (okay, I'm making that number up, but you get the point), as long as you stay grid-connected. And if you then still want to go more off-grid, then the logical upgrade path will be to buy the other half of the system.

If you are keen on fitting panels to the South-West roof, even if it's sub-optimal, bear in mind that the 12kW inverter has got three MPPT's, which can also take parallel strings. You could therefore combine your orange and red strings onto the first MPPT, two six-strings in parallel, leaving an MPPT free for the South-West side. Maybe you might struggle to fit at least 4 of the 600W panels, but if you could say fit 4, but better 5 of the 450W panels to MPPT3 facing SW, that could plausibly work.

Or else go with a 6kW Solis hybrid at the start, with just one 15kWh battery and 8x600W panels on just one MPPT, and keep the non-essentials on the grid side but powered from the inverter too. That's for a more cost-effective more grid-tied start-up that you could scale up by doubling everything up. Even if you don't, it should already go a long way towards covering the 15-20kWh daily usage with 6kW peak usage on most days. Your usage is not actually that much that a smaller system couldn't handle most of it even if it's sometimes a squeeze. How often is the grid out in your area, though? I'd be leaning towards the 12kW inverter and doubling from the start if grid-independence is the main immediate concern.

Please don't delete the question, you never know if maybe someone else comes looking for the same answers in the future. I want to say, though, that not everyone necessarily has the same experience. I've had my flat plate split system now for nigh on 10 years, and my pump has never given in. The panel itself has had a 10-year warranty, so maybe I should start expecting hassles soon, but so far it's been plain sailing. The only gripe is that it is not as effective in Winter as in summer, but it still helps by reducing the amount of top-up heating needed.

The usual disclaimer: Layman's opinion, personal 2c worth, use at own risk, to be adapted for your own situation, get professional advice. On the first comment, that you are early risers, etc. I agree that people have their own routines, own usage patterns, and that the optimum solution in one case might not work or make sense for others. The idea of increasing the water temperature to 70 degrees might work for people who want to store as much heat energy as possible for evening baths & showers for the kids, but if you then have adults who want to freshen up with a morning shower, I'm not sure if that using the geyser as a battery is always a workable strategy. For those who need hot water first thing in the morning, there's this idea to run off battery, alternatively a heat pump could do that heating for the morning (and generally) more efficiently off battery and solar. Finally, what I'm doing, is running the geyser from the grid in the early morning, using a timer, while on an off-peak time-of-use tariff that's cheaper. Back to the battery, though, I'm wondering if the concern about "using up the battery" on low-grade non-essential tasks like water heating really... yes I'm going to say it ... holds water. Firstly, if you need hot water in the morning for the family to wash and go to work, school, etc. then that to me is essential and time-critical. Beyond a point you can't shift all loads to the day. Next, though, I'm wondering whether the cost of the battery is really such a big factor as it was before, from the point of view that the cost per kWh cycled in and out of the battery has come down dramatically. Just using this 15kWh battery as an example (and I'm sorry for harping on it, I'm not a spokesperson for it, I just like the concept on paper), then 80% cycling down times 6000 cycles gives a cost of around R0.40 per kWh. A third of what it used to be when I first bought. You can't run from the grid at that price. Okay, one should factor in the capacity loss and installation costs and go on full quotations, but say that it ups the cost to R0.80/kWh. You still can't buy power from Eskom at that price, so I'd say to let rip, run a 2kW or even a 3kW element, well within the 100A recommended discharge capacity of the battery, without a second thought, and start treating home battery power like a disposable. The fact that some of these big batteries are floor-mounted and come with trolley wheels, tells me it shouldn't be that hard to swap them out while running on grid in the interim.

For the loads you want to run and the money you're looking to spend, while staying on-grid, I'd suggest to consider going big from the outset with a 15kWh single battery as in the link below to Powerforum store. But if you shop around there could be more alternatives also not too far away in price. Not too long ago that was the price on a 5kWh battery. Power Forum Renewable Energy Store | By Powerforum.co.zaKNY-P51300 15.36kWh Floor-Type LiFePO4 BatteryLimited Stock on this Special Price 51.2V 300Ah (15.36kWh) floor-standing LiFePO4 energy storage battery – Model KNY-P51300 from KNYSE Energy (part of the reputable Chilwee Group).This is a solid, no