IdlePhaedrus

They called to make an appointment first. Wasn't a surprise visit. I asked the CoCT inspector about the 3.5kw limit yesterday, and he specifically mentioned the 25% of NMD in the NRS requirement (in other words it isn't a CoCT requirement, it's a NRS requirement). Didn't think to ask why they didn't make the limit 3.6 given that is typically the size of inverter in that range. I don't expect that to make much difference given the NRS requirement. So I still think the 3.5 number a bit arbitrary.

It is an existing installation. 3kw. I had to turn it off in 2016 as my inverter was not on the NRS list (old Fronius, you'll find it for sale in the classifieds) and my old style meter was running backwards (now have a prepaid Itron). I had to let everything slide since 2016 due to budget constraints, but the deadline essentially forced me to get the system sorted out. It has cost more than I would have liked, but I had to get a new CoC for the house, then there are the installer's costs for the application and tidying up the existing installation, and the new inverter (Solis mini 3kw). Haven't paid for the last item yet, waiting for approval, and then it can be installed. I'll be very pleased when the system is finally back up and running.

CoCT inspector came around earlier today. All very quick and efficient. He says he will approve my application this afternoon when he gets back to the office and get back to my installer so we can proceed with the inverter installation / testing.

The solcast calculator is supposed to take hourly satellite information into account and give a fairly accurate measurement for the last few days given cloud cover, and an estimate for the next few days. I am not sure how up to date the satellite data is for our part of the world, but it is an interesting concept.

Yes, correct, some calculators work with 0 as north and others at -180. I have been looking at another calculator and asked them about this, and they said it really depends if the software was written in the northern or southern hemisphere. It is quite interesting too if you want to take a look: https://solcast.com/ You have to create an account, but it is free.

@Minerva10210 I have played around with the JRC calculator quite a bit too, and to be honest I think it may contain a few bugs, especially when re-calculating after changing values. If I open the site fresh, and input the details for optimal slope and azi at your location, then I get (very) different results: That is more what I would expect given your location.

@plonkster has addressed the reason why this happens. This has already been discussed with regards the Conlog meters in various threads. In this thread, @Charl_CCU said: It would be interesting to know if you or Charl_CCU manage to get that token.

Exactly that. Besides SSEG there are other areas where legislation conflicts with the constitution, a quick example is you can't hold dual citizenship unless you have a permission letter from the associated ministry, but constitutionally you also cannot lose your South African citizenship. This has only been enforced once to my knowledge, and the legislation lost in the constitutional court. With specific regard to SSEG there are certain rights guaranteed under the constitution, and, if the government can't provide, and the only choice is self provision, and the legislation is in conflict, then the constitution Trumps so to speak. I fully expect SSEG to end up in the constitutional court eventually. Hopefully sooner rather than later. And, then, with regards to climate change, our new president has just signed the carbon tax bill into law I believe (that snuck by quietly). So, interesting times.

Got a call this morning. CoCT will be doing a site visit later this week to progress the application. So that was quicker than expected (just over three weeks), but the site visit at this stage wasn't expected.

I wonder if that retards evaporation or the opposite given the panels are black. Might be a worthwhile proposition for the dams in the Western Cape if the former is the case. Two birds, one stone...

On this note, I found this. There are two types of SolarEdge meters apparently, depending on which one you use, and where it is measuring load, response time may be impaired. If response time is too slow your Conlog may still trip. This is something you should take up with your installer if you have configured the inverter but the Conlog still trips.

In my opinion no except for personal consumption (non feed in). Feed in is not worthwhile given the current rules and regulations. Given this calculator your system appears to be under performing somewhat if at optimum slope and azi. I used a value of 6kWp for your system. The same calculator says optimum slope and azi are 30 / -175 respectively for Pretoria (read the help for these values). It's different to the optimum your calculator suggested. I am not sure why, perhaps it is optimising for Winter? The conlog will trip when you feed back into the system, it was briefly discussed here. You need to set your inverter not to feed back. Given your charts you already have the necessary equipment installed, it should just be a setting somewhere. Check the inverter's manual. Others here are more qualified / experienced to answer the rest of questions. Good luck...

Yes (according to installer). Sorted 🤣

Really? 🙄

The Blom discussion has de-railed your thread a bit @The Terrible Triplett So, lets get back on topic. How's your application going?

Replacing this inverter as it is not on the NRS list and too large for my breaker given CoCT's rules. Worked flawlessly for about two years until I had to turn it off (three years ago to the month). Location Melkbosstrand. Any offers? PM me.

I'm with @PeterP on this one. For now I am going to take Blom's R4.50 claim with a dollop of salt. Here are the contracted prices for each of bid windows (up to 4) by power source: https://www.sapvia.co.za/facts-figures/ and indeed the numbers were high for Windows 1 & 2, but no where near R4.50. So, what could explain his number? He might be doing the same as this article and extrapolating those prices to today's prices, but this doesn't mean that is the amount that Eskom is paying as the prices are contracted. Prices weren't negotiated in Rand. This would be unlikely, and stupid. Abnormally high contracted annual increases (non inflation linked for example). This seems unlikely, but see 4. Corruption. As we all know 4 is a distinct possibility, and if he knows about corruption in this sector he should take it to Zondo.

No, not yet, I tacked that on as it looked relevant. Am currently listening to the state capture enquiry wrt Transnet, which is just as scary.

Agreed, and with his announcement residential rooftop isn't covered either. IBIWISI To a certain extent yes, but they could have pushed the boundaries a bit, which they haven't, so I am sceptical regarding motives..

There was a brief interview with Ted Blom on CapeTalk this morning at the Africa Utility Week conference at the CTICC. I didn't catch the whole thing, and there isn't a podcast, but at the end they discussed peak rates. So, for example, CoCT gets charged by Eskom as much as R5 per unit during peak periods. IIRC winter time is the worst. Us as consumers get a blended single rate year round. Internationally, for rooftop, this is 'solved' by rooftop solar combined with battery storage and a 'smart' bi-directional meter. That can be exploited to the benefit of all parties in the value chain from consumer, through municipality to utility. So, you can export energy from your batteries at peak times and get a better rate than you would from your solar at mid-day. This implies a 'smart grid' also, which we don't have, or certainly no systems to manage this. But that is the basic theory and it isn't rocket science. Given the CoCT video you sent earlier, they don't consider your capital outlay as part of the infrastructure or deserves any reciprocal effort, and the rules they have in place clearly discourage feed back (which are amusingly discussed in the video I followed with). And CoCT is the best of the bunch. http://www.702.co.za/articles/348644/opening-up-electricity-generation-expect-an-explosion-in-the-market

Here's a discussion on embedded generation and Eskom (from around 11:44) and what it means for municipalities: https://www.businesslive.co.za/bd/opinion/2019-05-15-watch-what-embedded-generation-means-for-eskom/

@The Bulldog posted this great resource in another thread recently. Here is a simpler solar angle calculator.

Can't find the technical manual for that specific model. However for the BEC44 (http://www.ekhwesienergy.co.za/images/forms/product-docs/BEC44(09) Technical Manual - R00.pdf) the manual states: Given the last line it is unlikely you will be able to change this. You will either need to configure your inverter to not feed back or get bi-directional meter as mentioned above. For the first option the solution will depend on the make and model of your inverter.

Thanks, that is a great resource. I have bookmarked it.

15 degrees from horizontal is too low, even for Johannesburg in mid summer. Here is a handy calculator for angle (from vertical) http://www.solarelectricityhandbook.com/solar-angle-calculator.html This doesn't mean you are not running into the MPPT efficiency issue also, but I'd fix this first.