The Bulldog

Register 43052. Value 0 to 10000 = 0% to 100% of nominal. Set a value based on your desired export - wait a bit, check again, keep adjusting until you get what you want. 100% refers to whatever your panels can supply at any given time so you will need to adjust this continuously.

I am not 100% sure about what you are asking. I think you are asking about your single phase system feeding into the net and drawing that power via the other two phases back into your house ? Well yes, sort of. If you are setup as SSEG and can feed back you will be credited for the power you feed in on that one phase but charged for the power you draw from the other two phases unless your meter is setup for net metering (it most likely will not). If you happen to have one of those old ferris wheel meters then you are OK (but are feeding in illegally - those meters always do net metering). If you have a prepaid meter it likely will trip if you feed in any power. Can you do it after the meter ? Yes you can but you need a somewhat more complex system using for example three Victron multiplus charger/inverters and a battery bank. With these you can shuttle power between the phases via the DC bus all the while maintaining proper phase relationship. Tying the three phases into one as suggested above is quite possible as long as the now single phase supply is big enough to handle your loads and of course you do not have any appliances that require three phase supply with the phase shift. Basically in most cases this is limited to three phase motors - aircons, lifts, pumps and the like.

COCT is increasing tariffs by 13.5% for home users, absorbing some of the increases forced on by Eskom. Those that are feeding in will see a 3.5% increase in what the city pays you for power you feed in. So you in fact contributing to the above subsidy by a fair margin. A further note: Any "green" credits for your production are for the benefit of the city. You cannot offset this against your own business or similar.

So that means alternative got over 15% cheaper. Way to go Eishkom !

Well in my case after they installed the meter my own accounting differed hugely with theirs (in their favor). I did read the meter registers in the kiosk and found the meter reading to agree with the SAP system. However a short look further I noticed that they reversed one of the phases. That's of course not a good idea. I took photos and sent them to COCT electricity east explaining the issue. Never got a reply. Eventually had enough of that and broke the seal and fixed the issue myself. Probably would have sent a tamper alarm but I took photos of the before and after (lots of them just in case). Since then my own accounting and theirs match closely. BTW with a three phase system at 100A you are only allowed a total of about 17KVA feed in - not 10KVA per phase. Your capacity can be higher but you have to prove that your system will never push more than the authorized limit. I actually have a three phase 150A feed but had to downgrade it to a 100A feed as otherwise they wanted to force me onto a commercial tariff. That would have completely screwed me over...

Well I guess the Mafia is worse - at least COCT stops short of dunking your feet in cement and throwing you over the peer wall... What meter have they given you ? In my case I can view the registers on the meter itself no problem as well as the corresponding readings on their website. It takes a bit of figuring out what is what as it has various time/day of week based tariffs so you have to figure out which registers to add to get to the totals. Yes the 600Kwh step is a nasty one - did catch me during the Winter as well - now I am wiser, I will set my system up to supplement with battery when needed to avoid that. Regarding three vs one phase - single phase does make it easier but it does seem my meter does a proper 4 quadrant job of metering so if say one phase is feeding out and two are feeding in (quite common in particular during low light scenarios) it seems to account import/export at net value.

That is correct - you have to pay COCT for the privilege of "selling" them your power. Like it or not - the cards are stacked against you.

Well just received COCT bill for the month (up to 16th of October) - about the middle split for my annual estimation. As you can see I am feeding in more than three times what I am taking at night. Obviously I am producing more than what I am feeding in as the property consumes power during the day - the feed in being the excess. This compares well with my estimates - I should be able to get relatively close to net-zero as averaged over a solar year but probably will not quite get there unless I add a few more panels. But since I already have 42 panels on the roof it is getting a tad crowded so I would have to align additional panels facing west - a bit less efficient but not too much. Considering this is the maximum size COCT allows for a residential installation and tariff you can see their calculations just allow net zero for this - anything smaller and its not worth your while. So the notion that COCT does not really want you to do this is a fair conclusion to make. It took a year of fighting to get this signed off and in total it cost around half a million bucks. To be fair that includes a large battery bank and related inverters as well. Total installed inverter capacity is 30KW.

There has been zero communication from COCT. We will have to wait and see. You are permitted to feed in as much as you like - subject only to the restriction on maximum power you may feed in based on size of your connection. The limitation is monetary - so if you somehow manage to get to zero Rands as averaged over one year - you would have fed in three to four times what you actually took from the grid - slightly dependent on the size of your connection - the fixed daily charge is the same regardless of the size of your connection. If you have a single phase 65 amp feed - just forget the whole thing and just use your power yourself or start looking at using batteries. This whole notion of using the grid as your battery - Hah ! Yeah right - it must be the Worlds most ineffective battery. You can do it if you feel your excess power is going to a "good home"...

Yes

It is effectively impossible to get to net zero if you sign up to feeding in in Cape Town. Unless you use batteries to assist you during times of low or zero production. That partly defeats the object. The problem is the vast difference between what COCT pays you for a KW/h and what you pay COCT for a KW/h - plus the increased daily charge (which you have to recover first using your measly income from COCT) plus the not insignificant cost of the bidirectional meter (about 15K in my case including installation). Add to this the limitation of just how much you can feed in at any point in time based on the size of your connection. If you decide to jump through the hoops and feed in legally you are best served by viewing your contribution as a "donation". Because that's exactly what it is. I have a three phase 100A feed and am pretty much maxing it out - I may just be able to break even over a year - not counting the cost of the meter. I doubt that I will be able to get to the point were COCT would owe me. In this scenario I have not utilized by batteries (saving them for loadshedding only) and am not even thinking of the cost of panels or inverters. I have 12KW/h of panels installed and have capacity to do another 5Kw/h before hitting the limit. Might do it just for fun...

Tends to vary a lot mostly based on complexity of your installation. A simple single phase with a single compliant inverter is not an issue. The problem usually starts rearing its ugly head if your installation is complex and has multiple systems. Now it does not fit the available molds and the fighting starts...

Correct - my connection was a three phase 150A. That caused trouble with my SSEG application as they only allow up to three phase 100A for ordinary single households. They actually did not tell me there was an issue - but simply proceeded to register this as commercial connection and yes - that is completely out of line. You have to use quite a bit of power FROM them before this makes sense. Got it changed to 100A - all they do is they came and took my very nice 150A three phase breaker away at the gate and replaced with three individual 100A breakers floating in mid air (the breakers did not fit the previous bracket so they just left it like that) and just for good measure broke the door right off the meter kiosk and just left it lying on the ground. Apart from wiring the wireless meter incorrect of course - they swapped one of the phases input to output around causing quite a bit of head scratching on my side as my accounting did not balance at all with that of COCT. I export a lot more than I use - but the reversed phase charges me for the export ! It left me wondering how this works with COCT customers that don't have much understanding of these things - how many are equally badly wired by COCT's electricians but would never know it...

Frequency shifting to control the Solis inverters works great - been doing that for quite a while now. Yes, you need an inverter that is able to do so AND you need to be able to control that frequency shifting process (setting the frequency limits) so you can balance the operation to perfection. You cannot change the limits in the solis (at least I don't know how) but if you look at the NRS test results which they publish you can see nicely how it works. So you need to be able to configure the other side to prevent this to become just a glorified on/off switch with sort of a ramp in the middle. There is more to this - your inverters must be able to use your batteries as load dump as regulation is not instant - this means your battery charging, battery capacity and inverter instantaneous power generation comes into it. This means your inverter cannot be a simple one - it needs a bit of brains to be able to control and handle this. If all of this is in place it does work well though and is a simple solution.

As to the question of if the landlord can sell your his solar electricity legally, probably yes provided it is below 1MW/h. This article gives a bit more detail: https://www.businessinsider.co.za/residential-complexes-can-now-rent-solar-panels-and-pay-for-the-electricity-instead-of-the-hardware-heres-how-it-works-2019-12 As for fitting your own panels - your lease agreement will provide the answer. You do not own the roof or any other part of the building. You can only do what the lease agreement does not prevent you from doing. If it is not specific then common law would ask you to consult the land lord. If he says "no". That's that. You do have the option not to renew the lease.