Replace AC Inverter with Hybrid and install batteries.

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hiddenhippo

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Good morning. My first confession is that I'm new to the forum (<24 old), however, having been bitten by the solar bug and wish to make changes to my system. Equally, I'd like to help others where I can, whether that's from my own learnings, or how my system operates and performs following various changes. With that said, I'll get to the meat of my query, which I've decided to add a new post as trying to pull together content, ideas and opinions from various posts has proven a little challenging.

September last year I had solar installed. A 3.6 Growatt inverter connected to 9*380w panels. It's a south facing roof with zero shading or obstructions, all day long. At the time my property had a very old mains meter installed; best described as a disk that spun when units were consumed. Favourably the disk also went backwards when solar generation was happening. Unfortunately, Octopus decided my meter was broken, and fast forward to today (well, about a week ago), they installed a smart meter. In summary each month my meter readings were less than the previous! Not any more, and hence I need to make changes.

Rather shamefully I was a bit gung-ho in "making changes" insomuch that I went onto the web, researched inverters and batteries and placed an order! I bagged myself a 5kw Solis inverter and 3 * 5.2 FOX ESS batteries, thinking that I could contact an electrician (NICEIC) I've used in the past. Over the last week I've discovered that it's not quite so simple as installing the equipment, than notifying your DNO. An abundant amount of Googling ensued, which is when I realised that the inverter would require DNO notification, and possibly the batteries (not entirely sure).

With all that said, I'm now trying to work out how to complete the necessary documentation, and which documents apply. I'm inclined to think that the G99 applies, as the inverter is 5kw, although I'll be looking at restricting the return to grid to zero. I can confirm that https://www.ena-eng.org/gen-ttr/Index lists my inverter as "compliant" (coloured green) but can't find anything on the batteries. Looking about on these forums I get the impression that some installations initially went with a G99 and were faced with extortionate fees, to then switch to a G100 and pass without any fee.

So I'm curious as to where I stand. Do I complete a G99, and if so, what do I list under the "existing PGMs" - the old Growatt inverter that I plan to remove, or should I not say anything? Should I just opt for a G100 application? Any help, guidance and experience on the matter would be appreciated.

Many thanks
 
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Bob Smith

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Hi
sorry I am new too and won't be able to assist you. I am nonetheless keen to see if you made progress as I am in a somewhat similar situation and I struggle to know what will be best and the installers I contacted, well, I wonder if there are simple rules that could exist instead of making the whole DNO thing so complex...
Thanks
 

hiddenhippo

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Hi Bob. The short version is that I commissioned an independent company to complete the G99 application on my behalf, which they've completed and submitted for approval. All being well I will then install the hybrid and batteries under the "competent persons scheme" - using a NICEIC registered electrician who I've used before for replacing my consumer unit, fitting a power feed for a shower, and numerous other things. Having the registered electrician take care of the installation, or parts thereof, gives me the assurance that we'll be regs-compliant, and more importantly, electrically safe. What I don't yet know is whether my export tariff will still apply. An export tariff is usually only granted by your electricity provider where evidence of DNO approval can be provided along with an MSC installation certificate. The original installation has DNO approval and an MSC certificate, however, the new hybrid won't and neither will the batteries. With that said I can hardly see that being an issue, in the sense that grid-tied inverters fail and need replacing, and would people call an MSC certified installer for this (costs more) or their local sparky... So I think I'll be fine to keep the export, although to be fair, I doubt there'll be much export as it'll be diverted to the batteries.
 
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