My experience getting G99 approval in the UK, for grid tied inverter over 3.68kW

Just found this thread. All sounds very encouraging, I too have been concerned about the whole application process.

I am in the UK Power Networks area. Can anyone comment on dealing with these guys?

I am installing a 5.5kW SunSync with battery. No solar as yet, just looking at time shifting Economy 7 unit prices. I don't intend to export but understand I still need G98.

I am less than 100meters from the sub-station and am the first house connected. Not sure if that helps my case!

Indeed the fee only covers Octopus’s admin, and as pointed out above, it isn’t in lieu of charges for the DNO and so on.

That being said, I have some sympathy with the “what is it actually for?” argument. There’s a spreadsheet to manage, and no doubt some element of process pushing. But it seems steep for the work entailed.

The other side of it is that you don’t actually need it. If you’re happy to feed in and get nothing but a warm feeling inside by return, then you can just from the DNO approval. The fee only unlocks the door to getting the feed in payments. If you have big loads (an EV?), and would only feed in a tiny amount, then just skip it.

I an in UK Power Networks area. Was easy. Talked to an actual human, on an actual phone. Very happy.

rpdom said:

Clause 5.8 is about MCS, not DNO's G98/99/100. Your electrician should have supplied you with the MCS certificate required. Or am I missing something?

Click to expand...

Unless the electrician is also MCS certified then he cannot register it as MCS compliant. To get himself certified for MCS will cost him £1000's and the install would be no different but would have cost more to pay for MCS. The £250 charge by Octopus seems to been forced on them by MCS to try to protect their monopoly. DNO's do not require MCS certification.

Grend said:

I am less than 100meters from the sub-station and am the first house connected. Not sure if that helps my case!

Click to expand...

No, its the total load on the transformer and the local network they are concerned with. They will not want to to upgrade the transformer until they really have to.

This is why I haven't gone through with it yet, I just can't bring myself to hand over £250 to Octopus to do seemingly nothing. Given you need to export 1666KWH before breaking even it's a bitter pill to swallow.