UK Hybrid ESS / paper work / approval

[dslrx9254]

I've been so focused on what to buy that I hadn't looked too much at the paperwork etc. I've already ordered part of it and now full of regrets fully expecting that by the time I have negotiated sign off of my installation I'm going to have spent so much money it will never be worth it (especially if the difference between night / day prices get squeezed) lol Guess I'm one of the people that likes the maths to add up!

I have decided most likely on the following

• Sunsynk 8.8kW ECCO Hybrid grid tied limited to <3.68kW by CT
• 15kWh Battery

To be honest it does not look like a DIY friendly environment so just wondering what you guys have been doing?

Looks like main points for install are

• Wiring a new connection to the existing CU (probably 16th edition).
  • I considered if I could change the CU to a larger 18th edition and introduce the backup / load connection but it seems this requires a lot of paper work & approval etc. Changing a CU seems like a pointless DIY exercise, assuming you get it certified by a sparky they will basically re do everything and charge double. It is also obviously now notifiable work Part P / BC under penalty of ?
  • It seems like a more cost effective solution is to add a 50A RCBO on the unprotected side of the existing CU for the inverter grid connection and connect up with 10mm2 T&E. Pretty sure the CU manufacturer is defunct so it will not be the same company which apparently is another frowny faced endeavor. It looks like the RCBO I have will fit the unit though and align with the busbar which is another PITA sub standard manufacturer specific dumping ground.
    • It looks like this is still notifiable Part P work and I'm not really sure how much of a headache that is. If I mount the inverter and cable it then ask a sparky to connect it, will that be sufficient or will they say I need approval to alter anything going into the CU first / after?
  • Looking for a DIY friendly sparky sounds like a bit of a contradiction to me. Perhaps I've got the wrong impression but the forums populated by sparks seem to be full of trolls. They all seem very keen on sniffing out DIYers and stating whatever they are proposing is dangerous / illegal / stupid it's one of those protectionist methods of poisoning useful information on the internet & spreading FUD. I've noted it in reverse too, call them out on a bad practice and you'll be told to it's fine even though they just harassed someone they assumed is a DIYer for asking a similar thing. One even specifically stated he would screw over any cheap skate DIYer and charge them double to teach them a lesson. With that kind of attitude I seriously have concerns about asking anyone to even come and estimate for the job. Also I've had a ton of bad experience with shoddy work done by tradespeople in general which doesn't help matters.
    • Anyway if anyone with experience knows the best approach to reach a decent sparky that would be appreciated.
• Presumably it is a good idea to notify the DNO?
  • G99 A1.1 - I assume this form is OK if I'm planning to limit export but what would I put for the installer...? Sounds like if you are going to fill in DNO paper work you must get an accredited installer otherwise what do you fill in. Maybe I missed what everyone is doing or should I just put down the name of the electrician I get to connect it up even if that isn't totally appropriate. Surely I can't fill in my own details here, accreditation / qualification ... none / something sarcastic.
  • I'd consider hiring someone to do the install, presumably would have to be a sparky anyway but I'd consider setup of the inverter to be my domain. Got the impression there aren't going to be any DIY friendly options here either or maybe I don't know where to look?

 

[SeaGal]

My 2p worth below, see also my posting here re UK regs etc.

Octopus Energy will no longer require MCS certification in the UK

https://gtec.co.uk/clause-5-8-octopus-opens-up-the-solar-pv-market-with-a-paragraph/ I'm not sure how exactly the UK's permitting and approval process works but this sounds like a major win for DIY.

diysolarforum.com

I have decided most likely on the following

• Sunsynk 8.8kW ECCO Hybrid grid tied limited to <3.68kW by CT
• 15kWh Battery

Sounds good choice.

I'm not a sparky, but IMHO...

• I considered if I could change the CU to a larger 18th edition and introduce the backup / load connection but it seems this requires a lot of paper work & approval etc. Changing a CU seems like a pointless DIY exercise, assuming you get it certified by a sparky they will basically re do everything and charge double. It is also obviously now notifiable work Part P / BC under penalty of ?

Don't see the gain in just an upgrade - you could always have a separate CU if you did want to have backup/essential loads circuit.

• It seems like a more cost effective solution is to add a 50A RCBO on the unprotected side of the existing CU for the inverter grid connection and connect up with 10mm2 T&E.

Sounds like a better plan. Check your cable lengths to ensure 10mm^2 T&E is suitable.

• It looks like this is still notifiable Part P work and I'm not really sure how much of a headache that is. If I mount the inverter and cable it then ask a sparky to connect it, will that be sufficient or will they say I need approval to alter anything going into the CU first / after?

A new circuit will come under Part P, so a part P certified sparky will be suffice.

• Looking for a DIY friendly sparky sounds like a bit of a contradiction to me. Perhaps I've got the wrong impression but the forums populated by sparks seem to be full of trolls. They all seem very keen on sniffing out DIYers and stating whatever they are proposing is dangerous / illegal / stupid it's one of those protectionist methods of poisoning useful information on the internet & spreading FUD.

LOL... I think I can guess which forum that is... elec****ians***ums dot net, maybe?... complete with all the dodgy adverts of women in skimpy underwear

• Anyway if anyone with experience knows the best approach to reach a decent sparky that would be appreciated.

I'd try to get personal recommendations if at all possible. Have any friends/relatives had work done recently?

• Presumably it is a good idea to notify the DNO?

More than good idea and more than notify. For inverers over 16A per phase you need DNO approval before installation, and then complete a commissioning form after install. Having said that it is relatively straightforward and, in my case, was quick.

• G99 A1.1 - I assume this form is OK if I'm planning to limit export but what would I put for the installer...?

"Self install" is sufficient. Obviously the work will need to be done to BS7671 standards and comply with Part P if/where needed.

• Sounds like if you are going to fill in DNO paper work you must get an accredited installer otherwise what do you fill in. Maybe I missed what everyone is doing or should I just put down the name of the electrician I get to connect it up even if that isn't totally appropriate. Surely I can't fill in my own details here, accreditation / qualification ... none / something sarcastic.

You can.

• I'd consider hiring someone to do the install, presumably would have to be a sparky anyway but I'd consider setup of the inverter to be my domain. Got the impression there aren't going to be any DIY friendly options here either or maybe I don't know where to look?

Not sure exactly what you mean... do you mean labour to install panels on the roof?

 

[dslrx9254]

@SeaGal Thanks for taking the time to reply sort of as expected, useful info about the installer details and octopus (although I refused their service for other reasons and I believe their site still says the opposite) and yes correct about the forum, seen similar on screw*** but less surprised about that.

What I meant about the last part was actually the battery self install (or any hint I may like to do my own DIY work at any point - basically anything that wouldn't give them the expected margin on the sale), especially a kit battery, mostly I was thinking at the time that there could be some hostility if I indicated I wanted to shun their choice of battery and put in a cheaper option of my own. To be honest feedback so far has actually been positive at least in so far that no MCS installers have refused to quote or started in on me about this (perhaps bit of a different attitude to dedicated sparks who are just thinking about turning around a quick buck changing the CU which is probably a set job for them). I have also been quite specific saying I want my own battery and told a few it would be a kit, surprisingly one of the installers said they had never heard of Seplos but did admit the price was good. I figured if they are hostile or rude I will just avoid them as I don't want anyone like that turning up.

One of the installers initially insisted on a CU change then seemed to back track when I said it wasn't convenient.

Interestingly one of the installers was quite adamant that pulling the DNO fuse is illegal which I believe is technically the case, presumably means that they are actually happy to quote for connecting to an old CU (I stated it was not current when asking for quotes). Probably shouldn't be suprised that MCS installers are OK with this (because it's convinient for them and they make the same amount either way) and sparks don't seem to be (because they won't make money without changing the CU and no way most of those guys will hesistate about poping the fuse). So I think there is maybe quite a lot of hypocrisy with sparks as in the usual we can break the rules but you can't, something I've heard more than a few times from other similar setups (you must use the expensive approved option or else).

With sparks it has been a totally different story either no reply or straight out refusal to do the job. Perhaps I just need to keep trying to find someone who will do it but they are actually looking pretty unhelpful right now.

I was going to ask about possibly connecting a small inverter via the ring because someone mentioned it elsewhere but it's not what I want and I can see it's probably just going to get a negative reaction. Plus doubtful anyone would say it is OK and also probably would not sit well with home insurance even if they did.

Also it's really nice to see that the home builder has installed 3x32A MCBs through a 63A RCD and cabling connected directly to a 100A incomer. This was apparently perfectly OK at the time probably through a loop hole or flimsy regs designed to save the builders money but I think it may not be any more. Seen other similar things around the home, obvious unsafe stuff the builder got away with and inspectors of that era said were OK. Unsuprisingly the sparks on the same electrics forum were very quick to say this is perfectly OK when someone asked a similar question about overloading an RCD. They seem to bleat about diversity making this safe and how it would be impossible because your electric bill would be so high. Clearly it has the potential to overload the RCD and unprotected wiring (especially with a wiring fault inside the CU) and maybe not that unthinkable if you have an electric hob. Personally I would never consume so much juice but can imagine during a party / gathering some people might be able to and it's really just over the past few years electricy has gone to a stupid unit price so stupid comments about the cost clearly not applicable to the older units where this is relevant.

 

[kommando]

The non MCS Octopus loop hole seems to have disappeared, now you have a fee to pay and limited numbers allowed.

 

[dslrx9254]

@kommando thanks for confirm that, explains why their site is not updated. Got the distinct impression there may be some kickbacks involved in this. You pay for your saving in advance and they just give you back your own money.

 

[kommando]

I think they were got at themselves by vested interests and the new limited scheme saves face.

All my schemes are DIY, 2nd hand and based on never being paid for any excess, if it financially works on that basis then I go ahead. If I ever get paid its a bonus.

 

[dslrx9254]

Seems fair enough guess I'd definitely like to proceed in whatever way is going to be the most cost effective way that I am allowed to use. After a circa 40% increase in the night rate (and lowering of the day rate which makes the potential savings much lower) from one energy provider as well as sneaky increases in the standing charge it could easily get to the point where it will take decades to get a pay back on it especially if I went the fully MCS installed route. Part of me definitely has issues when I am told there is no choice of supplier and I have to pay whatever I am told.

I mean ESS is still a green project regardless right. We take surplus unused energy from renewable and other sources and use it during times when renewable energy may be limited therefore making more renewable energy available to everyone. My understanding was that most countries were keen on adding / upgrading distributed energy storage because of this. Seems like there should be an effort from those in charge to make this available in a safe cost effective way if they want that but guess other interests get in the way.

 

[kommando]

I do it only for financial aspect and insulation from the expected winter power cuts when the nukes are turned off. I get 2nd hand panels for £35 as it costs the installers doing upgrades to dispose of the old panels in land fill, how green was that upgrade from silver to black panels with slightly higher output. I doubt once you add up all the coal burnt in China to make all the kit and the mining for the minerals in the batteries that Green comes into it at all. However someone has to buy all this stuff at full retail plus MCS margin for me to then pick it up a few years down the line at prices that finally make it economical.

 

[MisterB1959]

i 'almost' self installed my inverter and battery installation - i say 'almost' because although i did most of the 'apprentice work', running cables, fixing 'stuff' to walls etc, i still got a competent/qualified electrician to initially advise (after discussing) and then check everything before he made the connections - luckily i have a decent electrician we use for our rentals aswell as our own home who recognises my competence is sufficient to run a cable from one point to another !!!

if you check stuart pittaway on you tube, he did all his own install and just got an competent/qualified electrician to do the grid connections .....

 

[dslrx9254]

Honestly that would work for me but guess I'm having trouble finding anyone happy to do it (or even a basic CU connection) except by an official installer.

It sounds like the key is already knowing someone who does work for you directly/indirectly. Guess if you just contacted at random it's probably more like I am seeing. It's probably not worth the effort for them to get involved in a non standard job unless it is well paid (possibly by other work they will do for you by association etc).

 

[SeaGal]

I was going to ask about possibly connecting a small inverter via the ring because someone mentioned it elsewhere but it's not what I want and I can see it's probably just going to get a negative reaction. Plus doubtful anyone would say it is OK and also probably would not sit well with home insurance even if they did.

I'm not a sparky I'll chip in as to the reasons that not a good route to follow...

Firstly, it doesn't meet with BS7671 regulation 712.411.3.2.1.1 (yes, really!!)... where it states "The PV Supply cable (on the AC side) shall be connected to the supply side of the protective device for automatic disconnection of circuits supplying current-using equipment."

The key issue is.. If your house has a standard UK-spec 2.5mm2 T&E ring mains, that wire is protected by a 32A MCB = roughly 7000W. If you then connect a PV supply into that ring mains, via a 13A socket then - depending on the power of the PV/Battery - you could be adding a further 3000W into that wiring - meaning that a total of 10kW could be drawn before the MCB trips. That is not safe. Some will argue that the wire can carry more than the rated amount and/or that the MCB won't trip until a much larger current flow. That is probably true. But what is also true is huge number of ring-mains circuits that aren't... aren't rings I mean. It only takes one bad connection at one of the many 13A sockets around the house for the circuit to actually be two individually connected circuits. The huge disadvantage of the ring-mains is that such a fault can go undetected for years or even decades. Then you have a single 2.5mm2 wire taking all of the 32A. For those of you who have not fallen asleep yet, apparently the reason we in the UK adopted the 'ring' configuration was to save on copper when we were all poor after the war. i.e. we could run bigger loads by sharing the load across two wires.

I get 2nd hand panels for £35 as it costs the installers doing upgrades to dispose of the old panels in land fill

Hopefully you can negotiate an even better price now that new panels are only twice that amount, trade prices