Export Limitation Scheme installation and commissioning tests

[Bramco]

Hi,

 

Wonder if anyone can help - we applied for a G98 connection through National Grid. The installed PV is 6.5kW but we have set the inverter to G98, so limiting export 3.68kW. We supplied all of the documentation we understood we would need to submit but National Grid are asking us to complete an Export Limitation Scheme form - does anyone have an example of one of these that have been submitted? This is a self install, so no MCS or sparky to help us...

 

Thanks in advance.

 

Simon

[MikeGrahamT21]

You'll need to be both G98 and G100 compliant to submit an Export Limitation Scheme Form. 

 

https://connections.nationalgrid.co.uk/export-limitation/

 

So if you haven't got an Export Power Manager which is G100, you may well need to get one. Having not done this myself, I can only go on what the information provided says. Have you spoken to them directly? Its possible they've misunderstood something.

[Dillsue]

G98 is self limiting to 3.68kw by definition so it's almost certainly a G99 + G100 application that you did/ need to do.

 

It's technically not possible to DIY a G100 compliant system because the limitation setting has to be password protected with a password that only the manufacturer or certified installer knows. The reasoning behind that is if the user has access to the password they can raise the limitation setting whenever they want. Be conscious of this in any discussion you have with your DNO.

 

Don't know what inverter you have but there are G98/3.68kw inverters that will accept your 6.5kw of PV. Latest data I've seen for Solaredge is you can have twice the inverters rating in DC input so a G98 SE3680H can have 7.3kw of PV hooked up to it. No peeing around with G99 or G100, just notify your DNO when the system is up and running.

Edited November 16, 2023 by Dillsue

[Bramco]

1 hour ago, MikeGrahamT21 said:

So if you haven't got an Export Power Manager which is G100, you may well need to get one.

 

Thanks Mike - think I need to do some more digging before I call them.  I thought I'd done everything needed when I submitted the G98 form.

 

Simon

[Bramco]

2 minutes ago, Dillsue said:

Don't know what inverter you have but there are G98/3.68kw inverters that will accept your 6.5kw of PV. Latest data I've seen for Solaredge is you can have twice the inverters rating in DC input so a G98 SE3680H can have 7.3kw of PV hooked up to it. No peeing around with G99 or G100, just notify your DNO when the system is up and running.

 

Ours is a Solis S6 which will take the 6.5kW, so I assume comparable to the Solaredge.  And I thought there wouldn't be any peeing around, so notified National Grid....

 

Simon

[Dillsue]

It's not comparable as the Solaredge unit is factory limited to 3.68kw so it's G98 compliant out of the box, yet can still handle a large PV input.

 

Your Solis can handle the PV input but needs to be installer throttled to get down to 3.68kw max, hence the G99/G100

 

I'm not sure if there are other G98 inverters that can take your PV input, but a change of inverter could take you back to a simple G98 notification.

 

One other thing to be aware of is that your DNO reserves the right to witness the export limitation and if its not professionally installed may want to?? Although we ultimately didn't need export limitation our DNO charged £360 to witness the limitation!!

[Bramco]

@Dillsue  Thanks for the reply.  Would be annoying to have to change inverter but I guess I could find a G100 hybrid inverter which would allow us to attach batteries - although that probably opens another can of worms....

 

Out of interest what did the witnessing amount to?  

 

Simon

Edited November 16, 2023 by Bramco

[Dillsue]

We didn't need to implement limitation so I can't tell what they do practically.... I was just giving you the heads up on cost/risk and potential hassle giving a demonstration for them to witness.

 

Might be annoying to change the inverter but it might be better for you when you factor in the hassle and possible cost to you of continuing with current inverter set to a G98 limit. Only you know if its worthwhile.