Battery Storage recommendations

[SteamyTea]

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[Pocster]

1 hour ago, SteamyTea said:

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Nothing to say !?

Edited March 25, 2022 by pocster

[SteamyTea]

10 minutes ago, pocster said:

Nothing to say !?

I was just trying out posting from my Kindle, using Brave.

It won't let me post from my old one since the forum software upgrade (downgrade in my case). But works fine on my newer Kindle.

So time to root the old one and see what it can really do.

[Nickfromwales]

D/C coupled batteries = no DNO application. A/C coupled batteries = DNO application.

[TonyT]

Have a look over at the Camelot forum, many users of the Navitron forum on there, who have done lots of these projects

[Thorfun]

15 minutes ago, Nickfromwales said:

D/C coupled batteries = no DNO application. A/C coupled batteries = DNO application.

I have my G99 application and the battery was included in it so I’m good to go I think. But will double check everything 

Edited March 26, 2022 by Thorfun
Typo

[George]

40 minutes ago, Nickfromwales said:

D/C coupled batteries = no DNO application. A/C coupled batteries = DNO application.

Is that only for AC batteries which provide backup power (and hence need full grid isolation)? 

 

I'm looking at retrofitting an AC battery to my solar system, so don't want to mess with the solar set up. 

 

A side question, if I add an AC battery now, presumably I could add a DC battery if/when the solar inverter needs replacing. 

Edited March 26, 2022 by George

[Nickfromwales]

27 minutes ago, George said:

 

I'm looking at retrofitting an AC battery to my solar system, so don't want to mess with the solar set up. 

If you’re adding a battery inverter, A/C coupled, eg a second micro generator connected to an new circuit of the CU, then it’s notifiable.

D/C systems attract one less A/C >< D/C conversion so are also around 13-15% more efficient overall.

Why not just bite the bullet and go D/C ( modular / scalable ) now? Saves a mish-mash of equipment, and no permission necessary either now or later when you may sporadically add to the capacity. 

[George]

17 minutes ago, Nickfromwales said:

If you’re adding a battery inverter, A/C coupled, eg a second micro generator connected to an new circuit of the CU, then it’s notifiable.

D/C systems attract one less A/C >< D/C conversion so are also around 13-15% more efficient overall.

Why not just bite the bullet and go D/C ( modular / scalable ) now? Saves a mish-mash of equipment, and no permission necessary either now or later when you may sporadically add to the capacity. 

Is there an impact on the FIT meter if I do that? I had in mind that alterations before the ofgem meter could only be like for like (ie replace an inverter). 

 

The inverter is approximately 7 years old but has had no issues. My original plan was to wait for the 10 year point, then add a DC battery with the inverter replacement

But with the electricity prices rocketing the payback time for an AC battery seemed attractive enough. 

 

Is it possible for an AC battery to be barred from exporting and not needing DNO approval (if they refuse?). 

[TonyT]

The only thing that can alter the existing fit contract is a change to the equipment relating to that install.

 

a second install independent of the FIT install has no financial impact, it may impact the grid hence the DNO involvement if you choose to let them know.

[Dillsue]

When considering whether to let your DNO know about any increase in export capacity,  theres probably lots of reasons for and against but heres a couple worth considering.

 

Firstly, we're waiting for a FOC transformer upgrade but while we wait Ive temporarily hooked up 3kw of panels on top of the 4kw system we already have.  When the sun shines we're pushing the house voltage way over UK limit to the point that the temporary inverter shuts down. As we're the only house on the transformer its only affecting us and no one else is going to complain. If youre on the same LV supply as others and you push their voltage over the limits with unapproved generation, there could be bother coming your way. 

Secondly, if you install generation without approval and several of your neighbours do the same but get approval, if theres any problems it will be you that gets notice to disconnect and may have to pay for grid reinforcement before you can reconnect. With elec prices going skyward and the gov removing vat there could be a surge in install so maybe worth getting approval before others jump on the bandwagon and use up spare grid capacity.

We were going to connect up the extra PV and say nothing until we thought about it and put an application in. Once you got approval its fairly certain its there for life

 

[Pocster]

18 minutes ago, Dillsue said:

With elec prices going skyward and the gov removing vat there could be a surge in install so maybe worth getting approval before others jump on the bandwagon and use up spare grid capacity.

Excellent point . I asked my DNO what would happen if all my immediate neighbors all requested pv and export . She said their export limits would be capped lower than mine I.e so the infrastructure could cope with a potential for maximum export . So yes - do it sooner rather than later .

[Radian]

22 minutes ago, pocster said:

Excellent point . I asked my DNO what would happen if all my immediate neighbors all requested pv and export . She said their export limits would be capped lower than mine I.e so the infrastructure could cope with a potential for maximum export . So yes - do it sooner rather than later .

 

From a transformer's POV the current ratings for its primary/secondary windings hold irrespective of the direction of power transfer. If it can supply 25kVA from the grid it can absorb 25kVA into the grid. I wonder why 3.8kVA is used as a typical maximum for a single household? 

[Pocster]

29 minutes ago, Radian said:

 

From a transformer's POV the current ratings for its primary/secondary windings hold irrespective of the direction of power transfer. If it can supply 25kVA from the grid it can absorb 25kVA into the grid. I wonder why 3.8kVA is used as a typical maximum for a single household? 

I did ask what would be required to allow others to export more than the standard 3.8. She said extensive upgrade to infrastructure and sub station. So cost saving of not upgrading appears to be the factor . If this is true for a large majority of the country then it’s a severe limiting factor . “Fill yer boots “ but please don’t export too much 🙄

[SteamyTea]

42 minutes ago, Radian said:

I wonder why 3.8kVA is used as a typical maximum for a single household

WPD told me that technically more can be fed back upstream, but then it starts to interfere with the larger generators, they cannot easily be powered down and kept within the frequency range.

It is why domestic fridges are not turned on and off for grid balancing, but large refrigeration equipment is. 

All about knowing, the sinks and sources and their characteristics at startup.

Don't want the tail wagging the dog.

Edited March 26, 2022 by SteamyTea

[Radian]

1 hour ago, SteamyTea said:

WPD told me that technically more can be fed back upstream, but then it starts to interfere with the larger generators, they cannot easily be powered down and kept within the frequency range.

It is why domestic fridges are not turned on and off for grid balancing, but large refrigeration equipment is. 

All about knowing, the sinks and sources and their characteristics at startup.

Don't want the tail wagging the dog.

 

I wish I could remember where I read that microgeneration could supply a solution to the start-up problem. I know that this was the problem for the power network in Texas where they lost a critical amount of generation then couldn't restart quickly enough. IIRC a broadcast synchronisation signal would align the frequency of distributed microgenerators to bring it up by the amount to required. In this case the tail would be constructively used to wag the dog.

[SteamyTea]

7 hours ago, Radian said:

a broadcast synchronisation signal would align the frequency of distributed microgenerators

I am surprised we don't already do that.  Not even sure if we have a synchronisation signal.

Could use the old number station channels

Edited March 27, 2022 by SteamyTea

[Thorfun]

on the subject of informing DNO....our G99 application that has been approved has this:

 

 

if I'm not going for the PW2 any more but using another battery storage solution do I still need to inform the DNO? if so, is that a whole new G99 application?

 

[Pocster]

4 minutes ago, Thorfun said:

on the subject of informing DNO....our G99 application that has been approved has this:

 

 

if I'm not going for the PW2 any more but using another battery storage solution do I still need to inform the DNO? if so, is that a whole new G99 application?

 

I would *just in case * - but as your storage is off the pv inverter they won’t care …

[Thorfun]

1 minute ago, pocster said:

I would *just in case * - but as your storage is off the pv inverter they won’t care …

a whole new G99 application though? I've never done one of those before. 🤔

[Pocster]

5 minutes ago, Thorfun said:

a whole new G99 application though? I've never done one of those before. 🤔

Nor me 

I’d just ring the DNO and ask . In theory it shouldn’t matter as you are removing something rather than adding . But you know it could come back and bite you …

Edited March 29, 2022 by pocster

[Thorfun]

1 hour ago, pocster said:

Nor me 

I’d just ring the DNO and ask . In theory it shouldn’t matter as you are removing something rather than adding . But you know it could come back and bite you …

spoke to UKPN and they said new G99 application. guess I'll Google how to do that (after searching on here first of course. 😉 )

 

[Pocster]

1 minute ago, Thorfun said:

spoke to UKPN and they said new G99 application. guess I'll Google how to do that (after searching on here first of course. 😉 )

 

Isn’t that all part of your installers job though ??

[MikeGrahamT21]

Edit: Ignore me lol

Edited March 29, 2022 by MikeGrahamT21

[Thorfun]

43 minutes ago, pocster said:

Isn’t that all part of your installers job though ??

that's the thing isn't it. going to get my sparkie to install the battery system. Solar PV is already installed as per that G99 application. then the M&E consultants got taken over and are no longer doing batteries and so gave me a refund for the PW2 and dumped me to find someone else to do the work. that's what led me down this path! 

 

so I don't have an installer any more.