They were never really on the list…
What Mark said. Off-grid inverters are off-grid, exactly as their label says, off-grid, not on the NRS-certified list of inverters certified to work with the grid, being GRID-TIED.
You can still install them today in Cpt. Just do it off-grid.
In dead simple terms, you cannot use Eskom to recharge the batteries or have Eskom take over when there is insufficient sun, being off-grid.
Easy see.
The joke is (not) that this enforcement of only being allowed to connect NRS-certified inverters to the SA grid is coming to all in SA … just be patient. Tswane en Jhb are making subtle moves recently.
But hey, not my horserace …
But hey, not my horserace …
…but you have been warning the horses for yonks 
Ok, I’m getting the message that these off grid inverters have their issues.
What I can’t get my head around is why the utilities have a problem with them…
I’m aware that they have a changeover switch that either connects your supply to the grid and then when that fails you switch over to your battery inverter.
But what is the issue??
In a nutshell, none of them have any SABS certification due to Gov mess.
In other words, they are brought in en-mass, sometimes even with badly translated manuals, they can cause serious drama due to:
a) their quality of manufacturing (goes back to a SABS stamp, NRS certification),
b) DIY installs by non-experienced qualified people,
c) ignoring the existing regulations already in place in SA to HELP people do it safely.
So what some “expert” says the inverter cannot feedback, maybe 100% true, but it has no SABS or similar document stating that fact anywhere bar some YouTube video “proving” the fact.
So WHEN things go wrong badly, who is left to take the responsibility?
End of last year I heard a story or two about Fire Departments complaining of the new fires they have to deal with … fires caused by a) inferior equipment, b) badly installed solar systems.
Fire Departments and insurers see the bigger picture of the actual problem brewing.
Generators/UPSs have been around for decades, connected properly into DBs. It is not a “New” thing.
These Off-Grid inverters are connected to solar panels connected to a DB, THAT is a “New” thing.
Just follow the regulations as published in all Sparkies “Law Books” (updated with grid-tied/off-grid inverters) and we are sorted.
What is the solution? NRS-certified inverters, installed as per the regulations.
… or OFF-Grid, installed as per the regulations.
As @mmaritz said, those “off grid” inverters were never on the list. Cape Town allowed you to install such an inverter, than declare (on your own conscience, etc) that you’re running something entirely disconnected from the grid, and then CoCT would ignore the panels on the roof.
All that changed, is they stopped doing that. Because too many people abused it, and then when the house goes on fire… they want the fire brigade to deal with it, passing the issue on to the city.
Is there any specific safety issue with these off grid inverters?
What typically goes wrong??
PS: I’m not wanting to buy and install one at my house just to find out…
My reply: Compared to what?
All inverters can cause havoc.
Also depends on the installation. What designs have the engineers built in to mitigate some of the risks?
To mitigate risks, inverters are certified.
Must be installed by a certified installer.
We need proof, in light of all that can go wrong, methinks, in the form of SABS or NRS certification provided.
Cause some of the makes have no certification one can find.
Some makes may have international certifications for some countries.
Some adhere to some international standards, allegedly, but who can certify that? Test it?
So it boils down to one simple question:
How big is your capacity for risk, powering your house with a brand that has not spent the big bucks to have its products certified to some reasonable internationally acceptable standard, imported and serviced by a supplier that can be held accountable IF an insurer (due to a settled claim) wants to recoup their losses?
And what if the installer messed up … what then?
Was it a bad design or fully the installer that caused the drama?
Caveat Emptor.
That is my take …
This business isn’t a black art. There are reasons why things go up in flames (which is what I’m reading is the issue here)
The question is are the off grid inverters (i.e. the simple switch over versions with switchgear) more of a liability than the approved ones. If so why is this the case??
I think it was mostly a case of bad installations, in other words, the problem was not the inverter but the unqualified installer. By kicking the cheap inverters out, you also kick out the cheap installers.
Maybe that oversimplifies it a bit, but ask the question in reverse: Will any solar installer worth his salt really install a “five star” for you?
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Hence that question, which further went on talking about the installer’s impact.
Now I can add, will reputable installers install that due to their risk in the matter?
Cheaper brands tend to attract cheaper installers due to a lower level of customer spending tolerance.
I had the “pleasure” of debating with a close family member exactly that. The same person who told me about the fire department complaints about solar fires, who has installed a 24v 5-Star (because of his years old 2 x 200ah AGMs) who is now so chaffed with how much he is saving with his 3 x 600w panels on that 5-Star … off-grid.
Now I KNOW the path he is on … he is going to end up with a brand name system, 48v Lifepo4 batteries, grid-tied, registered with a new brand of panel … and try to sell ME on why he had to do that. 
Somehow the “Survivorship bias”, or similar bias, comes to mind.
I got that T-shirt.
I thought about that … you are right.
I also know you will advise others on what to buy based on your experiences/trials and errors. You tell others not to buy cheap, do it right, same as we are doing here.
Some of us here have been dabbling in solar systems for +15 years … I think some of us may know a few things seeing as we made all the mistakes so that others don’t have to. 
Advice that may save newbies big bucks over the years … these systems can operate for a decade or more if done right.
Additionally, I think the guys at CoCT just got tired of essentially proof-reading every guy’s “smart plan” with some inverter they have never heard of, while totally drowning in applications. If the inverter has paperwork, that offloads a HEAP of work from them. And besides, requiring that electrical equipment has paperwork is not some far-fetched idea. If we were in the US (or Germany), all of it would have to be UL-listed (or TUV approved) anyway. If we’re building a “world class city”, as they are fond of saying, it really cannot be any other way.
So are there any approved off grid inverters? And if so what do you get for buying one??
I think the answer is no. They will only approve it if it is on the list. The list only contains NRS097 approved inverters. That implies grid connectivity, aka not off-grid.
There are two very legit use cases I wonder about.
- Water heating via PV modules. There are several solutions on the market where two or three solar modules are wired via some MPPT to the heating element of a geyser.
- Solar pool pumps. There are solutions on the market where the pool pump runs via a VSD directly from some solar panels.
These are perfect examples of off-grid systems, which normally would not require you to do anything, but if there is a risk of some drone taking a picture of your roof and having someone show up to cut your power, surely there is a way to let the city know that your solar panels mean no harm.
Maybe they send you a registered letter (as they do), and you simply send them a letter telling them how it is?
I have one of these off grid PV hot water systems. I did apply to CoCT (but no response a year or more later) and there is a tickbox for this kind of installation…
In a meeting with to CoCT last year they told us they were planning on removing the option of the “Passive standby UPS” from the SSEG application, because a lot of people were installing unapproved grid-tied inverters and just ticking the off-grid option on their application. They apparently discovered this by doing spot checks of installations. It is much simpler to remove the off-grid option than to find a way to police all the installations.
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This makes sense as far as the utility is concerned.
They can only determine the rules with the buildings that they provide power to. So those sites that don’t have grid power are on their own and can do what they like…
This is really bad news for local manufacturers Microcare and MLT/APEX.
Well, MLT had input into writing the NRS097 regulations, and their inverters were approved, but certification expired, so I don’t really see how it’s bad news for them? Or at least, I don’t see how the blame would lie with anybody but themselves?