Bobster.

This will vary from household to household as we all have different needs and routines. But since you asked, mine is about 350 to 400 in the evening until we go to bed, thereafter more like 150 to 210. Constants through out those two time slots are the refrigeration, security, external lighting, fibre & wifi, USB chargers. So really the TV is making the difference. I didn't know it consumed that much. We did some things deliberately, but we didn't got hard at it. EG water heating is on a timer, all lighting is LED, fairly new appliances which are more efficient than the old clunkers we had before (especially the deep freeze). 10kWh battery. Usually I will have 65 to 70 % remaining at 6:00, which is the first water heating time slot. NB: Two adults, no kids. But when we have a guest over I don't see that base going up a lot.

So the job is done, including an updated COC for the PV system. I was put in touch with a guy who does installations but also modifications to existing systems, even cleaning panels if that's what you want. Before I had 2 strings 6 * 325 JA panels. One string faced N, one E. I don't have a lot of N facing roof so... 1) The N array was replaced with 5 * 585 W Canadians. 2) 4 of the 325 panels from the N array were moved to the E array 3) The installer bought the other 2 panels from me. It was a good upgrade. On sunny days the system produces significantly more power, but not for long as the battery charges early. But consider yesterday. Some person we do not need to name here left the pool timer in the "on" position (not "auto") after backwashing the pool on Sunday. So the pump carried on running until about 18:00 before the problem was noticed. Not unexpectedly the battery hit the 40% reserved mark over night. I had anticipated this, but the weather app on my phone was telling me it would be a nice sunny Monday so I thought I won't panic, there is no loadshedding, it's going to a nice bright morning, I will be OK. But when the morning came it was overcast. But now I'm getting better production in adverse conditions, so from about 7:30 the battery was charging, not that fast, but faster than it would have before the upgrade. And that's why I did this upgrade, not for the sunny days but for the overcast days. Interesting thing: When demand is high, the inverter uses both strings. When demand is low it sticks almost exclusively to the E facing string, presumably because of the high voltage because there are 10 panels in series.

A lot of consumers have had an electricity bill split between fixed and variable charges for years. So we may be getting excited for nothing. There must also be some cost to the utility for providing a connection. I have had a pre-paid meter for years now. Until July last year I had no fixed fees per month, paid only for consumption. My neighbour was paying about a grand (current tariffs) before he used any electricity at all. Yet we both expect and both get the same attention from City Power. Their cost for supplying me is the same as for supplying my neighbour. Since last year there has been a fixed charge for pre-paid users. I actually went to the IDP feedback session and spoke out about this because, after all, it is a bit more load on my pocket. But although I wouldn't tell the executive committee, I did understand their point and would probably have done the same in their position. More and more people in Johannesburg are moving to pre-paid meters. The City loses revenue, and post-paid users like my neighbour increasingly subsidise the likes of me.

You currently have 9 550 on both strings. IE 4950 W. I've just had a panel upgrade. I have limited North facing roof. I had two strings (N & E) of 6*325. What I changed to was 5*585 facing N, and moving most of the old panels to beef up the E string. So E is now 10*325. I sold the left over panels. So depending on how much space you have maybe replace one string with new panels and then numerically boost the other. I've thought about having a timer that switches off an E string and switches on a W string. But 1) This is DC, so arcing is a very real possibility, so you can't use any old switch. 2) The E facing string produces useful PV until 14:30 or so (and was before the upgrade). I also see the N string coming online quite early in the morning. So panels can react to sunlight from quite a wide angle. Find out how the Sunsynk works. This may affect your decision. My inverter (Goodwe) prioritises the string with the highest voltage. So when the demand is low in the afternoon it pulls from the E string rather than the N string, because E has more panels in series thus higher voltage. I don't know if this makes a practical difference because it will use both strings when demand is high, but if you are trying to optimise for optimal optimisation then this may be a consideration.

Is there likely to be an immediate but short term increase in performance because the old element may have deposits from the minerals in the water?

This is protectionism. Very popular at the moment. It may drive prices up. The bargain, in theory, is a stimulus of the local industry and thus job creation. Let's wait & see what happens in the USA.

I doubt that. I think it's not impossible if you can change what the firmware on the meter is doing, but that would be a big job. Last year when the firmware on the pre-paid meters was about to expire the City did update the firmware, but they only had two ways to do it 1) Send a technician out to your property (they tried this, but lots of people weren't home or were refusing access, and it was time consuming) 2) Send you TWO codes when you purchased electricity. The first would perform the upgrade, the second would load the credit onto the meter So they can't reprogram the meters remotely. They don't run 100% accurately, and City Power will not act if there is a small variance because some by law allows a small percentage of over or under reading. But what you report is not a small percentage. You can ask them to come out and check the meter (they have a dedicated meter team, and in my experience those guys are pretty responsive) but if the meter is reading to the allowed degree of accuracy then you pay for the test. Where is the actual meter (not the CIU)? In a wall box on your property or in a box in the street? If the latter then it's possible it's been connected to the wrong circuit, or that somebody else has hooked an extra wire to it. But first thing to check is that your system is set up to not export power. The digital meters can't tell which way power is running, so if you export a kWh in day, the meter regards that as consumption by you and depletes your credit.

Has your water usage increased? A while back I noticed the overflow from my geyser running. Then I looked the next day and it was running again. I got into a flap about this, but what I wasn't seeing was an increase in consumption (I read my water meter every week). After a few weeks of noticing the consumption not getting out of control I also started noticing occasions when I'd check and the overflow wasn't running. I spoke to a plumber. He said some overflow is unavoidable, but it shouldn't exceed two liters per geyser per day. Now I worry about other stuff in the wee hours of the morning.

What time of day does this happen? Any time? When the sun is down? I'm thinking that maybe there is a load that's demand is within the capabilities of the inverter but is too much for the battery and so the BMS shuts down.

I think we can assume that they are OK and not causing problems. Have you checked SolarGo/PVMaster for any warnings? OK, Goodwe error messages are not that helpful, but some of them are dealt with in the troubleshooting guide that can be found on line. They might give you clues, especially if they correspond with the trips. I don't want to get more specific because, as my signature says, I am not an electrician.

A couple of years ago COJ's draft budget proposed a new tariff for households that A) had no PV panels on their roof B) would accept a 20 A main breaker You could have a solar geyser and qualify for this scheme - many RDP houses in the City already had solar geysers. They thought this could provide savings for poor households. This was a year of a big Eskom increase, and the if the scheme went ahead then people on this tariff would effectively get about half the Eskom increase. But it was shot down in council. All tariffs were left as is except for the Eskom increase.

There's multiple domestic tariffs in both cities. Though looking at free standing properties in the burbs, the default package in COJ does have lower per unit costs, though I can't be precise about the amount. But fixed fees are the best part of a grand in COJ now. Prepaid in COJ the per unit cost is higher, and there are only three steps in the tariff so you hit top rate more quickly, but fixed fees are R200. Unless you qualify as indigent - then no fixed fees. I think I'm right that in COCT pre and post paid basically cost the same. COJ has a TOU tariff. Winter peak time is expensive, but if you plan when you are going to use electricity you could save.

That's a calculation for each of us. I would need another inverter, more panels (I have roof space for maybe another dozen), another battery, and a good generator as a last resort. I figure a 25 year payback at current tariffs. IE I will be dead by the time I recover the outlay. OK... tariffs will increase year-on-year, so maybe 15 years. The other thing is that going off grid ties you to a property. Unless you are willing to uninstall everything, pay for a new connection, and take the whole shebang with you and re-install. Yep. I'm the sort of guy who will tell you the glass is 1/8 empty.

What would help is if that online tool gave a breakdown between fixed & variable costs. What seems to be happening in COCT is that variable (per kWh) costs have dropped for people not using a lot in a month, but the fixed costs have gone up substantially. This is playing out in COJ and with Eskom, maybe with other utilities. They want tariffs whereby you pay a fixed charge for provision of service and another for what you actually use. I can see why they think that way, but I push back against it anyway because my back pocket gets hurt. In COJ you could save a healthy whack each month if you switched to prepaid electricity. Fixed fees here are high (now about a grand a month) so even though you paid more per unit on prepaid, the savings were worthwhile. More & more people saving on prepaid meant reduced income for City Power. Which was a problem for the City because electricity sales had been their cash cow. Another argument to be made was that post paid users subsidised prepaid. When I made the switch I was paying zero per month for a connection, meanwhile my neighbours on either side were paying (then) 800 per month just for being connected. Last year COJ introduced a R200 fixed fee on prepaid meters and said that the long term plan was to have all users pay their fair share towards service provision. This year they announced that the R200 was going up (though they phrased this in vague terms). Now we are told that the City had listened to residents and the fee will stay at R200. This doesn't make me happy. They will grab the money from somewhere else, or they will put the brakes on subsidies for pensioners and the poor. TLDR: this is the way it's going to go. Higher fixed fees for services.

Just a thought: Did you check the surge arrestors?