Fuenkli

Thank you very much for the information. I have no access to SANS 10142-1. Which installation method is this? Is this in open air, directly clipped or in conduits.

I would like to warm up this veeeeeeery old thread, because the issue of 10mm2 cables in a single phase 60A DB Board came up again during the upgrade of my PV system to 15.6kW peak with export permission. Because of ill health i had to give the install to an installer. He is adamant, that 10mm2 is sufficient for 60A after the main switch. In my old install i followed Jaco De Jongh's advice to use 16mm2. What is your opinion? Is the requirement still the same? I had a look at the SANS 1507 which is still the same. The problem is, that SANS 1507 does not refer to installation method in the DB board.

that is incorrect. The diodes will bypass the shaded panel/s and the string will now operate at a lower voltage. The output from the unshaded panels is not affected. The problem is, that without a good shadow management the inverter will not find the correct mpp and as a result operate the string at the wrong voltage. Another problem is, that the voltage of the string might fall below the inverter minimum operating threshold. This is why long strings (if some shading occurs) are better than short ones.

i think the cause of this behavior is not because of "DC injection high". DC injection high results in an inverter restart. Your problem could be because of "shadow management". If you have enabled shadow management try to disable it and check if the problems goes away.

I agree. Eskom in its present form will die soon. But a well functioning country needs an electricity grid. The grid will work best if as many people as possible are connected to it and share the building and maintenance cost. Looking at what is happening around the world gives us an idea what we have to do here in the future. Power generation and distribution has to be privatized. We have to be able to sell our PV surplus at a profit. Coal, gas and nuclear has to disappear (to dirty and expensive). Massive PV and Wind capacity has to be installed. Electricity distribution (across SA and Africa) has to be expanded.

That is true. I also agree, that a reasonable charge to use the grid is justified. I do however not buy the argument, that PV will overload the grid during the day (at least not for the foreseeable future). We desperately need more clean electricity to push out the very dirty coal power. And to cover the morning and evening peaks more wind power must be installed.

this is the average SA hourly electricity consumption. If anything PV would actually help flatten the curve 🤣

I think it depends where in SA you install a PV system. The CoCT for example requires professional Engineer sign off before they approve the system.

it is not only inefficient it is also incredibly expensive to generate, store and transport hydrogen. As much as the oil and gas lobby tries to push the politicians at the moment into distributing power using H2, i think it will never happen. It is much cheaper to do that with electricity. Sure we need hydrogen for industrial and (some) transport needs but that will be generated at the site it is required. I also think that the need to store renewable energy will not be as big as some politicians want us to believe at the moment. A well developed worldwide (DC) electricity grid will take care of that 🙂.

One other thing to consider is, that a single phase system will severely restrict the maximum possible feed in power. If we follow the rest of the world (which i sincerely hope so), it will soon be possible and viable to completely cover our roofs with PV and export the surplus to the grid 🙂.

this is the problem with an island system. It has to cater for the maximum power consumption of your house. My advice is to rather go grid tied. You can size the inverter for the average consumption and the grid will absorb the peaks.

does the CoCT still require connections to remain net consumers over the year or are you now permitted to feed in more than what you consume

i wonder what the real reason was why the CoCT has changed your existing prepaid meter 🙂. I am not aware of any one way prepaid meters who credit you (spinning backward) when you feed in.

yes. As long as it is a prepaid meter. And as @Tariqmentioned, the CoCT exchanges an old spinning with a prepaid meter free of charge when you register your system.

not necessarily. We have an option in the CoCT to remain on the normal tariffs and fees with a grid tie system if we agree not to feed in.