Do I need g99 if I don't export

[Huckleberrys]

I am planning a 8kw self install with battery storage. If gbere is a way of stopping any export at all do j still need to apply for g99 approval? 

 

 

Thanks 

 

 

 

Edited January 27, 2023 by Huckleberrys
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[JohnMo]

Yes - to keep it the point

[Marvin]

+1 with @JohnMo

[SteamyTea]

If it is connected to the grid, in an way, then yes.

 

[Huckleberrys]

Thank you. That is all. Best get that form done.

[Marvin]

Hi @Huckleberrys

 

Be aware that different DNO's seem to have different rules.

 

If your unrestricted inverter will work up to 8kW then that is an 8kW system. (its not about the total panel wattage - often you can add more panels than the stated rate of the inverter - check the inverter installation instructions for details) 

 

If the battery storage goes through the inverter to be used, then, as far as I understand, it's still considered a 8kW system.

 

If the battery storage does not need the main PV inverter to produce energy used in your mains system (another inverter for the battery power) then as far as I understand that power will need to be added to the 8kW PV inverter.

 

This all being said I'm sure someone will correct me if I'm wrong, however for ours with Scottish and Southern, this was the way it worked.

 

We had to pay for the survey. Some others haven't. Be aware that if you upgrade your system (bigger or more inverters connected to the mains) you will need to apply again

 

And finally the only other ways I know not to go through this is to have a system that is completely off grid.

 

Good luck

 

M

 

 

 

[Carrerahill]

3 hours ago, Huckleberrys said:

I am planning a 8kw self install with battery storage. If there is a way of stopping any export at all do j still need to apply for g99 approval? 

 

 

Thanks 

 

 

 

No. You could use DC coupled PV/batteries with DC charge controller, which also feed an inverter with mains AC backup - AC backup only kicks into run loads or replenish batteries (if you so desire) if PV output has been poor, no way to export the generated PV in this setup (although methods do exist). 

 

This is the initial system I will use to take my first floor of my house totally "off grid" with the security of a grid backup. The plan being to ditch DNO connection entirely once I am self sustaining with a suitable backup supply (probably a natural gas generator - maybe diesel initially).

 

 

 

 

 

 

Edited January 27, 2023 by Carrerahill

[Marvin]

10 minutes ago, Carrerahill said:

No. You could use DC coupled PV/batteries with DC charge controller, which also feed an inverter with mains AC backup - AC backup only kicks into run loads or replenish batteries (if you so desire) if PV output has been poor, no way to export the generated PV in this setup (although methods do exist). 

 

This is the initial system I will use to take my first floor of my house totally "off grid" with the security of a grid backup. The plan being to ditch DNO connection entirely once I am self sustaining with a suitable backup supply (probably a natural gas generator - maybe diesel initially).

 

 

 

 

 

 

Yes we also have a "charger/inverter only system" which is not connected to the mains, which charges when there is excess PV and only discharges to 'mains unconnected' low power items in the house. When the batteries are discharged the relays disconnect the live neutral and earth from the battery system and connect the mains live neutral and earth. 

 

 

M