Expanding an existing PV System with more panels

Screwdriva

Greetings! 

I was fortunate to be able to help a forum member with their system last year and then expand their system substantially this year, in a manner not too dissimilar to my own PV system expansion.

I wondered if:

1) The DNO needs to be notified of the additional panels if the inverter has not changed? He's on a G99.

2) Should a new MCS certificate be pursued?

Just wondering if there's anything else that should be done as part of this.

BEFORE:

AFTER:

Netexporter

The G99 application asks for a list of the generating sources, but I think it only the inverter output that interests them. If you can check the paperwork and it doesn't mention the panels, then I don't think you need to inform them. It is power output, not energy output, that is relevant.

70sbudgie

Isn't there a post somewhere on this board about the MSC not matching the installation? And this causing problems when applying for a new export tariff? As the MSC identifies the total generating capacity, this is the main issue I can see. (for example, my system is described everywhere as 4.3kW, but I only have a 3.6kW inverter).

70sbudgie

Netexporter said:

The G99 application asks for a list of the generating sources, but I think it only the inverter output that interests them. If you can check the paperwork and it doesn't mention the panels, then I don't think you need to inform them. It is power output, not energy output, that is relevant.

I think that the inverter is all that the DNO has cared about in the past. However, as domestic PV deployment increases, I can see the DNOs becoming more concerned with power flows and this is where the difference between installed capacity and inverter capacity will have an impact. The inverter limits the peak export, but over capacity will impact the duration of that peak impact.

Updating the MSC and notifying the DNO of the increase (if they have a process for that which isn't a new notification) may be easier sooner rather than later and therefore may "future proof" the system a bit.