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Battery use during a grid power failure


Jimcub

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So I have a 4.4Kw set of panels with a 3.6Kw inverter and a 5Kw battery, newly fitted and now working as best it can in winter.

my question is in the event of a grid power failure I cannot use my panels or my battery to power my house, I realise this is a safety issue for workers who may be working on the grid not to get a shock.

There must be a safe system that will auto change to panels and battery, with limits set to keep batteries etc from harm.

my installer said it is not cost effective due to high instillation cost, would make better use of sun power if there is a way to do this without breaking the bank.

Edited by Jimcub
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There are systems which can legally do this, but they will be expensive. For instance the SMA Sunny Island inverters can be set up to do this and I believe that they are now certified for grid connection. However they aren't cheap the SI 8.0 is about £3500 now, before battery and ancillary costs.

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Most battery or hybrid inverters will come with an EPS output that lets you tap the batteries from a separate circuit. Easy enough to attach a consumer unit to it and move the lights, at least, onto it. I currently have a simple double socket in the loft that'll work in the event of a power cut - it cost £20 extra at install time.

 

More complex options per https://www.deegesolar.co.uk/eps_for_solar/

 

You definitely don't need tesla stuff to get it done.

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Victron can do it, I will be having whole house back up with a Quattro 10000, but its expensive. I'm literally running the grid supply through the Victron inverter, as it has anti-islanding built it.

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13 minutes ago, Kelvin said:

How expensive is expensive? 

Probably more than 35p/kWh

 

Was chatting to my MCS contact last night, he has just put in a 5 kWh battery system at his own place, cost him £5k.

He only did it as he wanted to know more about them.

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37 minutes ago, Kelvin said:

How expensive is expensive? 

 

The Quattro 48/10000 (they do smaller and larger capacity inverters) cost me £3389, then there is everything else which adds up to an awful lot. The 48/10000 can supply 8kW continuous and can peak a lot higher, it can also pass through 100A.

 

You can view my build thread below.

 

https://forums.overclockers.co.uk/threads/ronskis-solar-battery-diy-build-with-whole-house-backup.18957434/

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1 hour ago, Ronski said:

The Quattro 48/10000 (they do smaller and larger capacity inverters) cost me £3389, then there is everything else which adds up to an awful lot. The 48/10000 can supply 8kW continuous and can peak a lot higher, it can also pass through 100A.

 

How did you deal with G99 with this?  

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I'm planning this with an 11kW Iconica Hybrid inverter, just looking at the number of strings ill end up with before purchasing. Change of £2k and does UPS / EPS etc with full throughput from batteries to house CU, with micro-second changeover so pretty much seamless transition. G100 approved so no issues getting signed off.

AFAIK MCS only applies to the panels, and not the inverter / batteries as the panels are the generators ( Microgeneration Certification Scheme ).

The Tesla kit is very complex / expensive, and the changeover times IIRC are around 5 seconds; from power cut to EPS on. You need to buy a Gateway / Bridge or something to get their changeover facility bolted on. 

With a hybrid, everything on the D/C side is invisible to the grid ( so you can have as much capacity behind the inverter as you like ) whereas regular A/C coupled equipment needs a DNO approval for the sum of the panels + battery, which sometimes gets refused or a 'set amount' is granted.

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6 hours ago, Dan F said:

How did you deal with G99 with this?  

 

I filled out the G99 application, sent it off with the appropriate certificate for the inverter, and it was approved. The system hasn't been commissioned yet so we've still got that hurdle.

 

6 hours ago, SteamyTea said:

Could shorten the life of your fuses.

 

Could you elaborate please?

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1 hour ago, Ronski said:

I filled out the G99 application, sent it off with the appropriate certificate for the inverter, and it was approved. The system hasn't been commissioned yet so we've still got that hurdle.

 

Good to know.  I thought it had to be listed as "compliant" on https://www.ena-eng.org/ list in order to get G99.  It strange though as. while it doesn't show compliant, it does have a cetificate avaialble! 

 

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@Dan F I originally applied in June when it was fully compliant, there was a new requirement added in September which it appears to be compliant with, but it appears they need further information before its approved again - hopefully it won't cause me any issues.

 

Quote

Manufacturer's Compliance Notes

 

Firmware update since previous version to meet LFSM-O requirements. The submission is in line with EREC G99 Issue 1 Amendment 8 and is fully compliant with the changes that apply from 01 September 2022 for electricity storage.

 

It's the same for the Multiplus II (3000 & 5000) which was approved, they both state further information required as well.

 

Just noticed its got a published date 2 January - awaiting assessment for the Quattro's, so hopefully things are moving along.

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30 minutes ago, Ronski said:

@Dan F I originally applied in June when it was fully compliant, there was a new requirement added in September which it appears to be compliant with, but it appears they need further information before its approved again - hopefully it won't cause me any issues.

 

 

It's the same for the Multiplus II (3000 & 5000) which was approved, they both state further information required as well.

 

Just noticed its got a published date 2 January - awaiting assessment for the Quattro's, so hopefully things are moving along.

 

Got it. When I last looked earlier last year only Multplus 3kva and 5kva had approval, nothing else (even before the new requirement), but looks like they been working on approvals since.

 

I'm 3-phase, so going to use 3 x Multiplus II 5KVA's anyway which I see are compliant, so should be good.   Just need to work out what batteries I use and who to uuse to install (or if I do some of itself myself).  

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@Dan F I believe the the Quattro 8000, 10000 and 15000 have had approval for a long time, same as the Multiplus II 3000 & 5000. I've been told the Mulitplus II 8000, 10000, 15000 and newer Quattro II's as being applied for at some point.

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8 minutes ago, Ronski said:

@Dan F I believe the the Quattro 8000, 10000 and 15000 have had approval for a long time, same as the Multiplus II 3000 & 5000. I've been told the Mulitplus II 8000, 10000, 15000 and newer Quattro II's as being applied for at some point.

Yeah, sorry. Maybe I got mixed up with the Mulitplus II 8000 and 10000.

 

How is your system build coming along and what has your experience been source bits and building this yourself?

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1 hour ago, Dan F said:

How is your system build coming along and what has your experience been source bits and building this yourself?

 

Its taking a long time, but that's mainly because I need to learn and understand each bit as I go, and then I only really get weekends when I can build stuff, but its all coming together now. See this thread for full details. Sourcing the major parts has been very easy, smaller parts have been more problematic, I've had some copper tube terminals on back order from a UK supplier since mid November, but they arrived the other day. I've got quite a lot of stuff from China which takes time, but hasn't really held anything up. I discovered that a lot of DC breakers are not bi-directional, so I re-ordered different one's of those, various other bits I've ordered then changed my mind on. I think the last piece of the puzzle is how to compress the cells (I wasn't going to, then decided actually its best to), ideally I'd like Poron EVExtend foam, but that seems impossible to buy, I'll still go with Poron foam, but a different type. One thing I have discovered is that it costs a lot more than you think, its all the small bits, and then there's carriage costs, that adds up as well. Hopefully I'll be up and running this month or next, but that very much depends on the electrician, who's not great at communicating.

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On 07/01/2023 at 19:11, Dan F said:

 

Got it. When I last looked earlier last year only Multplus 3kva and 5kva had approval, nothing else (even before the new requirement), but looks like they been working on approvals since.

 

I'm 3-phase, so going to use 3 x Multiplus II 5KVA's anyway which I see are compliant, so should be good.   Just need to work out what batteries I use and who to uuse to install (or if I do some of itself myself).  

I can put you in touch with a decent battery / inverter installer. Decent and knowledgeable chap. No direct affiliation, and standard caveats would be applicable "try before you buy" etc etc. He doesn't want to be 'famous' so PM me if that's of any interest / help.

 

PS, only one "u" in use, OK ;)

Don't worry, I don't think anyone noticed..... ;) 

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1 hour ago, Nickfromwales said:

I can put you in touch with a decent battery / inverter installer. Decent and knowledgeable chap. No direct affiliation, and standard caveats would be applicable "try before you buy" etc etc. He doesn't want to be 'famous' so PM me if that's of any interest / help.

 

PS, only one "u" in use, OK ;)

Don't worry, I don't think anyone noticed..... ;) 

 

Definitely. I'm in the progress of sourcing the kit from someone that is doing a bulk buy of batteries and victron inverters. I plan to do the Victron configuration myself, but I'll need an electrian with some battery storage (and ideally victron) familiarity who isn't going to run a mile and not want to touch it.   

 

I would ask our electrican, but he hasn't been back in 9mths and still hasn't installed any LED strips or labelled consumer unit and grids 😞 But that's another story.

 

Edited by Dan F
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12 hours ago, Dan F said:

 

Definitely. I'm in the progress of sourcing the kit from someone that is doing a bulk buy of batteries and victron inverters. I plan to do the Victron configuration myself, but I'll need an electrian with some battery storage (and ideally victron) familiarity who isn't going to run a mile and not want to touch it.   

 

I would ask our electrican, but he hasn't been back in 9mths and still hasn't installed any LED strips or labelled consumer unit and grids 😞 But that's another story.

 

Hi @Dan F

Give Tom Barrand ( EcoCell ) a call, he's on 07927 082118. Great guy, and he's pencilled in supporting / commissioning for my own install also.

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1 hour ago, Nickfromwales said:

Hi @Dan F

Give Tom Barrand ( EcoCell ) a call, he's on 07927 082118. Great guy, and he's pencilled in supporting / commissioning for my own install also.

Thanks!  What part of the country? 

 

What batteries and inverters are you planning to use?

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