G99 application for a Solis hybrid inverter in UK
- Thread starter marky0
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Well top marks to Western Power South Wales, UK ?. I called them up last Thursday and raised a G99 query "which form do I fill in for a 6kW inverter with 15kWh battery and no grid export ?". The engineer rang me back next day and sent me the relevant form (A1-1) which I completed and returned over the weekend. Also had to attach a schematic of my install and inverter certificates for G99 and G100 compliance. A few queries back from them on Tuesday which I fixed same day and I got my G99 approval at 8:45am this (Thursday) morning ! Chuffed to bits 
. That's a 3 working day turn around from their side start to finish ! Fantastic service ! I thought I'd be on the hook for a 12week wait !
Lessons learnt in my case
(1) Call up the DNO as soon as possible and ask them what forms need to be completed. Don't try and figure it out yourself ! I am still not clear how I managed to fast track with A1-1 and I think the forms needed by each DNO are specific to their internal process. You'll never work it out from websites and the requirements seem a little random from the forums for each DNO. Talk to a human !
(2) Draw a schematic of your install (make sure it matches the inverter install manual) and download copies of all the inverter certificates seems key to a fast turn around. They will want pdf copies.
(3) No export in my case meant it was eligible for fast track. My approval limits export to no more than 3.68kW (16A) which is fine for me, I want to export 0kW! But timescales might be different if you want to exceed 16A.
. That's a 3 working day turn around from their side start to finish ! Fantastic service ! I thought I'd be on the hook for a 12week wait !Lessons learnt in my case
(1) Call up the DNO as soon as possible and ask them what forms need to be completed. Don't try and figure it out yourself ! I am still not clear how I managed to fast track with A1-1 and I think the forms needed by each DNO are specific to their internal process. You'll never work it out from websites and the requirements seem a little random from the forums for each DNO. Talk to a human !
(2) Draw a schematic of your install (make sure it matches the inverter install manual) and download copies of all the inverter certificates seems key to a fast turn around. They will want pdf copies.
(3) No export in my case meant it was eligible for fast track. My approval limits export to no more than 3.68kW (16A) which is fine for me, I want to export 0kW! But timescales might be different if you want to exceed 16A.
My experience phoning up UK Power Networks was vastly different. Wasn't passed through to an engineer, but dealt with by call centre who rather than admitting they hadn't a clue attempted to bluff their way through, which ended hindering rather than helping. The schematic for Western Power, was it a technical electric circuit diagram? Did you show breakers, isolators etc?
Ron-ski
Solar Enthusiast
My first email to UK Power Networks got a rather blunt reply. I then phoned and they were quite helpful and couldn't understand why I got the reply I did, and he found it unusual that there was no sender's name. After that phone call they were very helpful.
Technical schematic, almost identical to the schematic in the inverter datasheet but specific to my set up.
Like this one from the solis datasheet below
Last edited:
Well top marks to Western Power South Wales, UK ?. I called them up last Thursday and raised a G99 query "which form do I fill in for a 6kW inverter with 15kWh battery and no grid export ?". The engineer rang me back next day and sent me the relevant form (A1-1) which I completed and returned over the weekend. Also had to attach a schematic of my install and inverter certificates for G99 and G100 compliance. A few queries back from them on Tuesday which I fixed same day and I got my G99 approval at 8:45am this (Thursday) morning ! Chuffed to bits
Lessons learnt in my case
(1) Call up the DNO as soon as possible and ask them what forms need to be completed. Don't try and figure it out yourself ! I am still not clear how I managed to fast track with A1-1 and I think the forms needed by each DNO are specific to their internal process. You'll never work it out from websites and the requirements seem a little random from the forums for each DNO. Talk to a human !
(2) Draw a schematic of your install (make sure it matches the inverter install manual) and download copies of all the inverter certificates seems key to a fast turn around. They will want pdf copies.
(3) No export in my case meant it was eligible for fast track. My approval limits export to no more than 3.68kW (16A) which is fine for me, I want to export 0kW! But timescales might be different if you want to exceed 16A.
I'm with Western Power too, what contact details did you use for submitting the forms?
Taking a bit of a risk, but going to buy a Sunsynk 8kW inverter before G99 approval. Seen a good deal. Been a couple of weeks since I submitted to UK Power Networks. Had one email acknowledging receipt, that's it. Do they generally approve stuff?
Ron-ski
Solar Enthusiast
@Hartswood It depends entirely on the state of the grid you are connected to, such as how overloaded it is, how well it could cope with your export etc.
halecrater
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- Sep 5, 2022
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Hi everyone and so pleased I found this forum. Wish I had found it at the start of the year!
So I applied for G99 and was approved. Now I have reapplied as had a 2kw system installed through a Govt. scheme and now want to self install a Solax 3,7 hybrid with panels and Soalx triple power battery on top. Put the G99 application in and the DNO have queried the battery asking if it requires G100 limitation. I have read on this thread that if battery connected to inverter by dc cable then no need to put in application? Does that mean there are other ways to connect batteries?
DNO waiting for me to get back to them so thought I would ask for advice here. I am in Southend thanks Stew
So I applied for G99 and was approved. Now I have reapplied as had a 2kw system installed through a Govt. scheme and now want to self install a Solax 3,7 hybrid with panels and Soalx triple power battery on top. Put the G99 application in and the DNO have queried the battery asking if it requires G100 limitation. I have read on this thread that if battery connected to inverter by dc cable then no need to put in application? Does that mean there are other ways to connect batteries?
DNO waiting for me to get back to them so thought I would ask for advice here. I am in Southend thanks Stew
Did you apply via UK Network Power? If you did how long did it take for you to get a response? Do you need to do a G99? An inverter of 3.68kW can be installed and a G98 completed after installation. Maximum export should be limited to 3.68kW using a G100 device. The only reason you would a G99 is if you intended to export more than that or don't have a G100 compliant inverter / device.
halecrater
New Member
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I did apply and was granted 5kW system. Then had a 2kW system installed but I want to add a 3.7 system with a battery.
I spoke with Scottish Power Networks yesterday and they stated that as my inverter (Solis 8Kw 5G looking after 10Kw array) was G99 certified and will limit export to 3.68Kw only a retrospective G98 would be required.
Ron-ski
Solar Enthusiast
Now I thought that an inverter that was rated 8kw that limited export to 3.68kw would need to be a G100 compliant, and therefore a G100 application.
I have the G100 certificate from Solis for my inverter, just confused about Scottish Powers statement
Yes, that's not how I read the requirements, but maybe each DNO has their own interpretation and/or flexibility. I thought the whole point about the G99 application is the DNO would tell you the maximum you could export. And thereafter, you can go and install an inverter that is G99 and G100 compliant (and installed according to the regs - e.g. wired export limit connection + configured to cut-off if grid export connection goes down) - with the added condition that the DNO reserves the right to come and observe the commissioning if they want to. But I stand corrected if that's not the official case.
sijones2010
Solar Enthusiast
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- May 31, 2021
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The regulations are based on the inverter size not your export limitation, it's only g100 when the dno states you can't export your full rate and therefore needs limiting.
No idea why SP Networks is changing their tune, I paid £250 to them to sign a contract to even allow me to connect my 6kw inverter, no choice it was pay for that or no connection.
3.68kw is just notify after connect, everyone has this right, anything more and it's permission first and then they decide your limit or refuse.
No idea why SP Networks is changing their tune, I paid £250 to them to sign a contract to even allow me to connect my 6kw inverter, no choice it was pay for that or no connection.
3.68kw is just notify after connect, everyone has this right, anything more and it's permission first and then they decide your limit or refuse.
RetroGizmo
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- Sep 27, 2022
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As G98 (99,100) notification is for export, if your system is purely connected to the inverter / battery for power output and the inverter is not capable of back-feeding the grid in any way (i.e. no physical connection), are they required? This would be assuming utility power could be used for battery charging, therefore never AC coupled, or potentially bypassed with a transfer switch.
Obviously if it's entirely off-grid with no utility connection in any way there's no relevance.
Obviously if it's entirely off-grid with no utility connection in any way there's no relevance.
Can you explain what you mean here... if the inverter is connected to your supply, which is connected to the grid then DNO notification or approval is required, depending on inverter's output power.
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