profa

Domestic High Winter (ex vat)
Block 1(0-350kWh) - 180.17c per kwh
Block 2(>350kWh) - 218.59c per kwh
Domestic High Summer (ex vat)
Block 1(0-350kWh) - 145.73c per kwh
Block 2(>350kWh) - 168.24c per kwh
Use approximately 30kwh-50kwh per day. Thus 900kwh-1500kwh per month. 

Hi everybody
So the time has come that I have become pretty fedup with a R2k-R3k per month electricity bills and am now seriously considering solar but would like to get as much independant advice as I possibly can. I reside in Bloemfontein. Still have electric geysers, 2 in fact. One for my main house and one for the currently unoccupied granny flat. I have a 1.1kw borehole pump which is used for about 1.5 hours per day to fill my Jojo tank. Then I have a 2kw water pump for my irrigation system which sees about 1 hours worth of usage a day. Then I also have a 750w pool pump which sees about 2-3 hours worth of usage which I know is too little, but I have become like a electricity scrooge so save as much as I can where I can. Stove is gas, but oven is electrical. All lights in the house are LED. Still have a plasma TV in the lounge which almost never gets used, and then an LED in the bedroom which sees almost constant usage while we are home. I also have quite a monster PC, but prefer PS4 just because its lighter on electricity. 
I use anywhere from 30kwh-50kwh per day. 
The two suppliers in Bloem I am looking at for quotations are these two:
Unilec
Olivia
and I am considering the 15KVA systems from both. I know the pages I linked to are not very specific, but I would just like to know if the prices are ballpark more or less OK?

Colleague has the water running down the roof problem. His solution is that twice a year he has to get on the roof and use shadenet to cover a portion of his tubes so the water doesnt get too hot. In winter he has less covered than in summer. 

FYI...Cheaper brand new than your advertised price...

So just a final update. I had another 6mm2 cable installed, so 3 panels in parallel per set of positive and negative cables so each set of cables only has to handle a maximum of about 24-25 amps instead of 48-50. Panels are now producing 1250w quite easily. Actually want to add another set of 6mm2 cables so that each only handles 2 panels. 

No, 6mm GP cable is rated at 45A for 220V.  Delivery 45A at 24V is a whole different ball game

No, I'm just saying that IF the voltage drop is the problem, it must be quite a large drop. 50 A is certainly more than I'd consider pushing through 6 mm² cable.

Unfortunately the whole solar industry (in Bloemfontein anyway) is just FILLED with this type of dishonesty. They are screwing people over left and right. 

Yip sorry I missed the parallel so it seems all your cables are incorrect.

That's the nature of PWM charge controllers. Your battery voltage is around 25 V, so your panel voltage (when running flat out) is around 25 V. The extra 6 V is just wasted. If you had  an MPPT charge controller, it could make use of the extra 6 V ("transforming" the panel power from 31 V @ 8 A per panel to ~25 V @ 10 A (ignoring losses, which are typically only 2% for a charge controller anyway).

So it seems it has to do with the inefficiency of a PWM inverter. Tested yesterday, by connecting 3 panels only (out of the total of 6). Put at least 1500w of load on the system, and the 3 panels produced 590-600w (25v and 24amps) which makes sort of sense as the panels are rated at about 8 amp each. So the amp rating makes sense as panels are in parallel (the voltage is very low from the rated voltage of about 31V the panels are supposed to provide). Then did the same experiment with the other 3 panels. Same exact result. However when all 6 are connected, I get about 1000w total from the panels (higher volts at about 27-28 but not double the amps or even close to double the amps at about 37-38). 
Lesson learn. School fees paid I suppose. Only good thing about this is that I am learning. And am in the solar thing now with zero debt. All paid for cash. Wouldve pissed me off if my R150k system I took a loan to get was doing this LOL. 

Correct on all accounts. No surge protector on the solar panels. Also no earthing on the solar panels as far as I know. 

1. Correct
2. Correct
Additional items, check to ensure that you have an inline fuses close to panels as well

One of the main reasons for the 15kva inverter. But I dont think mine uses 8kw. I wouldve had a much higher electricity bill I think. I think about half that. 
Thanks for the advice. I really appreciate it, and it does make sense. My problem is however space for all the inverters and that I want to buy the inverter once and just add panels and batteries as I think its easier than adding more and more inverters. 

...just for interest - how much energy do you discharge from it daily?

I never though I would live in a world where people show off their DB boards. LOL.

I would start smaller but allow myself to scale, and also just find a reliable installer that is willing to travel a little, you would probably need to provide accomodation or be willing to pay for it if the job goes over a day which it probably will.

Colleague has the water running down the roof problem. His solution is that twice a year he has to get on the roof and use shadenet to cover a portion of his tubes so the water doesnt get too hot. In winter he has less covered than in summer. 

my 2 cents. If you are looking only at the ROI it makes no sense to spend so much money. If it is your hobby and/or you are concerned about the environment this is a different story and probably the reason most of us here on the site have PV systems. After 2 years of experience with a PV hybrid system and solar geysers (and only looking at the cost benefit) my advice would be to install a PV grid tied system without batteries and 2 solar geysers. 
If the law in your city allows it I would size the PV system to cover on average about 80% of your daily consumption. For load shedding either get a cheap UPS for the very few essential loads you can not live without for 2 hours or invest in a quiet generator. 
The choice of solar geysers depends on your pressure requirement in the hot water system. In my case I needed I a high pressure system. But even a high pressure system will give you an acceptable ROI.  

Yes, now the big inverter makes sense.