Hi all, first time poster here looking for any advice on how I can get around SPEN limiting me to a 2kw export with our newly installed system.
Bit of a long story however the basics are I had a PV & battery system installed comprising of the following:-
20 Jinko 440w panels
Givenergy 9.5kWh battery Gen 2
Givenergy 5kW Hybrid Inverter Gen 3
Our installer did a G99 application requesting a 5kW export which was rejected, an extract from their initial response is below:-
I've modelled the network for your application and have confirmed that a 5kW export would cause a voltage rise of 257.1V, just within the G100 stage 2 temporary excursion limit of 257.6V. You can export limit to no greater than 2kW and stay with G100 stage 1 limits. Your inverter is both G99 Type A and G100 type tested so should be no issue to do this. There are two options:
Proceed with a quote for circa £320 + VAT using the 5kW inverter, export limited to 2kW. This will require an updated SLD and G100 Form A. A quote is required as this customer's earth loop impedance is above 0.18 Ohms and therefore detailed network modelling was necessary.
Go for a G98 connect and notify option. No quote required and we'll cancel this application down. This will likely cause voltage rise greater than 253V and may cause nuisance tripping if the customer has an electric vehicle charger. However, network reinforcement would be initiated at no cost to the customer if a voltage complaint is subsequently received.
If you can let me know as soon as possible I can proceed with this application.
I'm presuming that the option 2 that was proposed above for a G98 would be for a 3.6kW inverter, not the 5kW that we've already had installed.
After a couple of emails as obviously I was surprised and disappointed (we'd been advised by the installer that if 5kW was rejected they would give us 3.68kW, on which basis I was happy to proceed with the install) we had these further responses from SPEN:-
G98 connect and notify is allowed without restriction but it can and sometimes does cause issues on on network, particularly in cases where the customer's property is a long way from the substation. We are then forced to retrospectively reinforce the network to resolve the voltage rise issues. G99 is an application based process for larger than 3.68kW and may result in a fast track confirmation or a quotation depending on the network feeding your customer. In cases such as yours where the earth loop impedance is relatively high (0.41 Ohms), putting 3.68kW in would cause a problem and it would be wrong of us to to knowingly do this. You can have 3.68kW for G98 as it's a non application process but you're not automatically entitled to a minimum of 3.68kW export under G99.
and later
We could reinforce the network to reduce your customer's earth loop impedance by laying some new mains cable in the footpath and installing a new 2 way link box further down the street to reconfigure the network running arrangement. This would allow a headroom of 8kW of connected 1ph DG without exceeding the 235V limit. The problem is that this would cost circa £10,000 and your customer would be liable for 5/8 th's of this (£6,250). Under current apportionment rules for generation as detailed in our charging methodology statement (Statement_of_Methodolgy_and_Charges_for_Connection_to_the_SP_Distribution_plc_and_SP_Manweb_plc_Elec.pdf (scottishpower.com)), the customer will contribute to reinforcement if that reinforcement is at the same voltage level of connection (see point 5.18 on page 26). We don't usually go into this level of detail initially because in almost every domestic case, the customer won't be prepared to fund this level of reinforcement. It's also hard to justify spending money like this to reinforce the network for a single customer when it can be easily averted by controlling the export limit. The customer still gets the benefit of the larger inverter for their own use but has to export slightly less. The funds available for reinforcement can then then be directed towards the places that need them most. I'll pass this on to our reinforcement team to assess in general as they may wish to do something in the wider network for other purposes. If your customer sees this is happening in the local area, they can apply for the export restriction to be lifted.
Obviously I'm gutted that this has happened, and I'm kicking myself for not researching further before we gave the green light. I didn't realise until this came about that with a G99 nothing should have been installed until approval from the DNO was given. Currently our export is capped at 2kW (that's been controlled by our installer) but with that limit for some reason it won't discharge at more than 1700w on the Givenergy app.
Does anyone have any advice on how I could approach SPEN to get 3.68kW, or greater? Or any other way to navigate this situation?
Thanks,
Rob.
