Approved list of inverters

They probably have the same issue as the rest of us. Constantly playing catch-up certifying the new models with backed-up certifying houses, etc. Meanwhile 85% of your market is off-grid and takes 15% of your time, while 15% of the market is grid tied and takes up 85% of your time :slight_smile:

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But I assume that the grid tied market would be growing fast while the off-grid market is largely serviced?

It is not… :slight_smile: Many many places on the planet simply have no power at all.

Yeah I get that, but is the rate at which it grows not much slower than grid-tied? I’d imagine that it is a massive market, but the up-and-coming market (i.e. the one with a lot of short to medium term growth potential) is the grid-tied market?

Does anyone know how much the NRS certification costs and how long it takes? And if I understand correctly, it is only required for the inverter. Are there other requirements for the battery itself?

many thanks

Certification is only required for the interface to the grid, in other words, the inverter.

If your inverter requires a specific setup (battery, meter, external anti-islanding relay maybe?), then the system as a whole must be certified. If not, then only the inverter.

How long does it take? Weeks, at least. The certifying houses usually have quite a bit of backlog. How much does it cost? Hundreds of thousands I believe. And you have to supply the system for testing too.

Best chance of getting a answer less vague than mine, is to contact a testing house. Such as SGS, TÜV Rheinland, or Primara.

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Thank you so much plonkster for your fast reply. It is a residential ESS with integrated inverter. We also have our own EMS with it.

Also thanks for sharing a cost and time estimation, that is very helpful. We will check with one of the testing houses suggested.

Have a good week! :smile:

@plonkster what exactly is NRS? As you know I am busy registering my system, and it’s NRS this and NRS that, but all I can figure out is that NRS # SANS.

NRS is “National Rationalised Specification”. I cannot quite work out the difference, but it seems to be that NRS documentation comes from a user group, not from a standards (governing) body, who makes the SANS stuff. Because it comes from a user group, it does not fit the definition of Standard, as specified in the Standards act of 1993.

The front page of NRS047, for example, says this:

This rationalized user specification is issued by the Technical Governance Department, Eskom,
on behalf of the User Group given in the foreword and is not a standard as contemplated in the Standards Act.

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from my understanding, NRS is basically a building block en route to a National Standard.

Does anyone know if any of the Quattro-IIs have been registered yet? If so, which models? It does not appear so from this list:,%20notices,%20tariffs%20and%20lists/Approved%20Photovoltaic%20(PV)%20Inverter%20List.pdf

Here you go, check for NRS certification:


looks like the Quattro-II-48-5000-70-50 had NRS 097-2-1: 2017 Ed 2.1 Certification finalised March 2024, so the CoCT list likely just needs updating

This is great news. Thanks guys.