jimseng

I have just received this email from National grid regarding my G99 application. I am new to this and this is a self install so please be as clear as you can be. "I have just run the model for [my address] whilst the full 10kW is OK to connect via a G99 compliant device any exportation from site would need to be limited to 2kW via a G100 complaint device. If you are happy to proceed with the limited system please let me know along with the make model and ENA data base reference of your proposed inverter and I will send the relevant letter. To allow the exportation of the full 10kW then the local network would be required to be upgraded and the end-user would be expected to contribute to these works and I would estimate these costs could be in excess of £5000.00" So I am installing 10.2k solar on the roof and was planning on a Victron Multiplus 10k inverter. They are able to limit the export but I don't believe Victron deem it commercially viable to get them G100 certified (I am at the limit of my understanding here and I was waiting for the G99 application to go through before proceeding). My plan is to have as much battery storage as I can afford, perhaps 1 or maybe 2 Fogstar 16.1kWh batteries and I went for a 10kw inverter as it seemed about what would comfortably cover most of my energy demands without being too OTT. So what next. I am familiar with Victron kit but I don't really care what I install. If I were to install a Victron Multiplus then can I install a device between the meter and the inverter that satisfies the G100? or is it cheaper / should I be looking at an inverter that will satisfy National Grid? Please bear with my while I try and catch up on this. My original plan was solar PV, mppt, batteries, inverter. I don't really care about exporting as I don't think I would earn much without paying for an MCS install and I think I can divert the energy to the farm if I have too much (unlikely). Thanks Matt

Thanks for all the replies. I figured that the 25 year guarantee meant that these things don't go wrong, and £1200 extra is more than the cost of a replacement. It's good to get overwhelming backup on these decisions.

Hello. I have just been told that due to my new build having a bore hole for the water supply Steelflow won't provide a guarantee for the cylinder. I have been told I need to spend an extra £1200 to get one with a guarantee and it requires anodes changing once a year. Now I am fine with changing anodes, I have a boat which requires 3 of them each year, but this has just been sprung on me and I am new to this. Given that the cylinder has a 25 year warranty it suggests that they are not likely to fail and maybe the £1200 is kind of unnecessary. My installer suggested that he would be comfortable just forgoing the warranty and saving the money. I haven't had all the tests done but the initial water chemical test has come back as very clean, a ph of 7.23 and no nasty chemicals. The water is a bit hard but nothing off the charts. Anyone got any thoughts?

So are you running the two inverters together?

It seems to be a chicken and egg situation. I spoke to the DNO and they said I need to submit a G99 application for them to consider. I think I'll send one off and see what comes back.

The Victron Multiplus has certification for G99 but I don't believe it has for the G100 part. That is the bit I need guidance with. Is it just a case of choosing a different inverter which satisfies the G100 requirements?

I should add, I'm not actually interested in exporting to the grid, I think I can find ways of using the energy, even when my batteries are full. But <3.6kw inverter isn't going to cut it for me.

Hi. I'm new to all this so I am trying to find my way. I am just submitting a G99 application well in advance of installing solar on my new build. I just need help with the G100 part. I was planning on using something like a Victron 48/10000/140-100, mostly because I already have Victron gear on my boat and so familiarity etc. I don't have to, I haven't got to that stage yet. I need help getting this G99 application started. Can someone help me out with the G100 part and make suggestions. I don't expect the roof to be built for another couple of months but I am planning on 10.2kw PV and G98 isn't going to work for me. Do I need to be looking at alternative inverters or something else? Thanks

OK. So I am still G99 then. I'm hoping to cram 11kw on the roof and 3.6k isn't going to be enough for me.

This is something I haven't been able to establish. I don't currently care about exporting to the grid, I am only interested in keeping all the energy for my self. Are you saying there is a way of installing a > 3.6kw inverter but limiting its export to < 3.6kw and only having to submit a G98 and not go through the hoops of G99? If so how is the limit achieved and verified by National grid?

I live in the sticks and there will be two dwellings on the single run from the transformer. 1 is already connected and has a 6kw PV array so I don't know if the limit is due to the single cable running from the pole. I'm toying with the idea of limiting my inverter to g98 and having a second one dedicated to an off grid supply in the house. But I will see what a G99 application comes back with as that is the simplest solution. (if I can work out how to fill it in)

That is exactly what I am thinking. I have seen Solfit and made inquiries but what else can I consider?

I'm having an 18kva single phase supply.

I think I am going to have to go for G99 as I can't see 3.6k being enough. As for MCS 012 I'm still confused. My understanding is that GSE is MCS 012 compliant, many solar panels are MCS 012 compliant but NOT necessarily together, which is where I am at right now. But then if it is a DIY install MCS doesn't apply? Or does it?

Really? So I can get building regs sign off with GSE and a panel of my choice? I haven't seen that written anywhere but I am floundering around trying to get accurate information. If that is the case then I guess it makes it much easier. I certainly intend as much battery as I can afford. I was planning on not exporting to the grid but I think that means G99 application for a decent inverter, but I guess that is for another thread.

Hello. I am getting on with my self build house and was getting quotes for a 24 panel GSE in roof system when suddenly my supplier threw up the MCS 012 certification and the supply of solar panels approved for an installation. I was planning on doing the install myself, it doesn't seem that complicated, and I am only concentrating on the infrastructure for now. It makes sense to spend what funds I have on putting the solar on the roof at the build stage. Then this spanner has been thrown in the works. I have had a quote for JA solar and AIKO panels but I don't think I can install them as they don't meet the new requirements. So I joined this forum hoping someone can guide me through this. What are people's thoughts? For instance, does it make more sense to put a conventional roof on and not go with in roof? I don't want to because of the aesthetics but I need to look at all options given I don't have all the money in the world and I need to get building regs sign off. My goal is to cram as much solar on the roof as I can and I'm not interested in exporting to the grid, only running the house, if that is an important detail. ?