Can I submit a G100 form myself?

[BISFBath]

Hi all,

I have had a 4.8 kW solar array, a Growatt SPH5000 inverter and two Growatt ML33RTA batteries installed. It's all working really well, however the installers were a nightmare. Getting an MCS certificate was like pulling teeth, they submitted the form to the wrong DNO (ie one that doesn't even cover my area) and used a G98 form even though the inverter is rated as 5 kW so it was rejected when it went to the correct DNO.

Can I submit my own G100 export limit form? The DNO already said I can't export more, and the installers said I was OK to submit the forms. If so, does anyone know how it should be filled out for a PV + batts system like this?

[nowty]

First of all MCS certificate is a separate thing to the DNO application. If you don’t get an MCS certificate you cannot claim for paid export via SEG or at least you will find it very difficult. The MSC certificate comes from the installer and not the DNO.

Yes you can submit a DNO application, several on here have done it but in your case it’s a g99 application with info showing its g100 compliance. However this should be done pre installation and not post installation. Only the simple g98 application can be done post installation, but you are where you are, so I would suggest you do the paperwork on the basis it’s not installed.

Most DNO have quite good info on their websites these days. There have been some changes recently to the process making it easier to go fast track G99. If you had a 3.6kW inverter version it could be a g98 application.

I’m a bit busy travelling at the moment with limited internet access. What’s your DNO or your rough location if you don’t know.

[BISFBath]

Thanks for the reply. I have the MCS form from the installer, by pulling teeth I meant it took a long time for them to send it to me and a lot of chasing up. My DNO is Western Power Distribution.

I think what has happened is that the installers intended to use an SPH4000 inverter which is what I was quoted for, but didn't have one to hand so used an SPH5000.

[nowty]

Info is here,
https://connections.nationalgrid.co.uk/ ... track-g99/

[NikoV6]

Let me open a can of worms!

I applied G98 to Scottish Power (after they told me to) stating my Tesla Powerwall was set to never export and my 10kW of solar was being handled by a G99, G100 compliant Solis inverter, limited to 3.6kW max export by CT. That as far as I know has been accepted as they have never been back in touch to question my application, even sending me the confirmation email that they had received my application.

During this process I also applied for G99 compliance (to be on the safe side) and have been granted a 5kW max export limit!

Go figure as our cousins may say!

[BISFBath]

Info is here,
https://connections.nationalgrid.co.uk/ ... track-g99/

Thanks, would it be SGI-1 (All Generation/storage devices are each rated* at no more than 16A and the total of all the ratings* is also no more than 16A.**) or SGI-2 (All Generation/storage devices are each rated* at no more than 16A and the total of all the ratings* is no more than 32A.)?

WPD haven't shown any concern that it's been connected, but they've turned down the G98!

[nowty]

Both the SPH4000 and SPH5000 are rated at 22A, only the SPH3600 is rated at 16A.

So the SPH3600 would be G98 or SGI-1, folk certainly got away with G98 before the new sub categories of G99 fast track process.

SPH4000 and SPH5000 look like SGI-3 to me irrespective of whether they are G100 compliant.

EDIT - I changed my mind over my last sentence, see later post.

[BISFBath]

Both the SPH4000 and SPH5000 are rated at 22A, only the SPH3600 is rated at 16A.

So the SPH3600 would be G98 or SGI-1, folk certainly got away with G98 before the new sub categories of G99 fast track process.

SPH4000 and SPH5000 look like SGI-3 to me irrespective of whether they are G100 compliant.

Is that because the batteries are counted separately from the inverter? The SPH5000 has a G59 (old G99) setting. Edit: and G83, which is probably more relevant.

[nowty]

Both the SPH4000 and SPH5000 are rated at 22A, only the SPH3600 is rated at 16A.

So the SPH3600 would be G98 or SGI-1, folk certainly got away with G98 before the new sub categories of G99 fast track process.

SPH4000 and SPH5000 look like SGI-3 to me irrespective of whether they are G100 compliant.

Is that because the batteries are counted separately from the inverter? The SPH5000 has a G59 (old G99) setting. Edit: and G83, which is probably more relevant.

No, it’s because the inverter is physically capable of outputting 22A if set up that way, so more than 16A. The SPH3600 can ONLY output 16A max no matter how you set it up or whether you have PV or PV and batteries connected so it’s G98 or the new SGI-1 G99 fast track.

The rules keep changing so it’s difficult to work out what you can get away with as the DNO can be either very strict or pragmatic depending on who you get to communicate with.

It’s pretty shocking your installer has left you in this position especially after submitting a G98 to the wrong DNO, then presumably taking your money and then saying its your responsability.

[BISFBath]

Both the SPH4000 and SPH5000 are rated at 22A, only the SPH3600 is rated at 16A.

So the SPH3600 would be G98 or SGI-1, folk certainly got away with G98 before the new sub categories of G99 fast track process.

SPH4000 and SPH5000 look like SGI-3 to me irrespective of whether they are G100 compliant.

Is that because the batteries are counted separately from the inverter? The SPH5000 has a G59 (old G99) setting. Edit: and G83, which is probably more relevant.

No, it’s because the inverter is physically capable of outputting 22A if set up that way, so more than 16A. The SPH3600 can ONLY output 16A max no matter how you set it up or whether you have PV or PV and batteries connected so it’s G98 or the new SGI-1 G99 fast track.

The rules keep changing so it’s difficult to work out what you can get away with as the DNO can be either very strict or pragmatic depending on who you get to communicate with.

It’s pretty shocking your installer has left you in this position especially after submitting a G98 to the wrong DNO, then presumably taking your money and then saying its your responsability.

It's pretty bad. To be honest I found them very stressful to deal with, so I'd rather try to do it myself than spend a lot of energy badgering them into doing it, though maybe I'll have to.

I don't really understand it as for SGI-1 it says: "All Generation/storage devices are each rated* at no more than 16A and the total of all the ratings* is also no more than 16A.** * For small Generation Installation purposes the rating can be less than the basic design capacity if the manufacturer has limited the output to the lower rating. This is not allowable for connections under G98."

So if the SPH5000 inverter can be limited to 16A, wouldn't that count?