Retro fit AC Coupled Batter Storage

Post Reply
User avatar
pattisd
Posts: 5
Joined: Thu Jun 23, 2022 11:02 am
Location: Reading, UK

Retro fit AC Coupled Batter Storage

#1

Post by pattisd »

Hi Folks

I've had solar PV installed about 11 years now and finally decided to take the plunge and try and add some storage into the equation.

I'm thinking that modular batteries look pretty good as they are easily extended when money or need dictates and I also thought I may as well try and get a 5kw inverter rather than something smaller to ensure i can get reasonable charge and discharge rates.

I'd try and fill the batteries in summer with solar - but probably revert to something like Octopus Go for Winter.

I'm struggling to find anyone who can install something in the locality - I'm on the outskirts of Reading.

I did manage to speak with an electrician who'd def be up for it - but he doesn't really have much exposure this area specifically the moment.

I don't think they need be MCS accredited.

I would need to apply for G99 to my local DNO, who are Scottish & Southern. I'm in a couple of facebook groups and from comments i see, this DNO is probably one of the slow and less amenable ones. I've also heard that even with approval there may be the need for export limitation (potentially invoking G100). Maybe I'd just paranoid and it will be a doddle. Anyone dealt with S&S

I started off looking at Victron kit as they seemed to be indestructible and pretty configurable. But no local approved installers and maybe a bit too complicated.

FoxEss were my next choice. They have a 5kw inverter (FE-AC1-5.0) and batteries (FE-HV2600) and I believe the inverter is g99 certified (though not seen the certificate).

But then someone suggested looking at Sunsynk. So I have looked at them and found a 5kw hybrid inverter (SUN-5.0-ECCO )and its compatible with Pylontech batteries (I'm looking for 10kwh ...so could pair 3 x US3000C or 2 x US5000). Again, I think its G99 compliant but not seen anything about G100.

I checked on midsummerwholesale website and found a Sofar HYD5000-ES inverter. That's got G99 and G100 certificates on there. So that the moment this feels like I can present a better application to DNO with this inverter. I'd be happy to include an export stipulation in my request. After all, I really want to be using the power i generate (or pull at cheap rates) and not be sending it back to the grid!

I'm not sure what to do next. I've had some quotes from companies - but they seem pretty steep compared to just the kit cost. I still like the idea of a local tradesperson getting my business. Much prefer to do that than place my business with a national company. Should a competent electrician (part P qualified) be able to fit a battery & inverter? And will the DNO make anything of the installer I choose?

So wondering if anyone on here has any ideas ....
  • what kit to use
  • local installers
  • DNO application advice
I did make a list of things I'd want from the battery storage:
  1. additional AC battery storage (so as not to affect FIT).
  2. I hope to switch to a "time-of-day" tariff (probably Octopus Go) and need the solution to be able to charge when its a low cost period.
  3. I'll also be looking to get an EV and EV charger soon after switching to Go. So I'll need to be able to charge the EV battery and the AC battery in the same time frame (4 hours off-peak). And live off the battery as much as possible for the rest of the day.
  4. Ideally looking for modular storage that allows me to extend in the future if there's a need.
  5. Would like to be able to monitor the "Whole" system - to see what's getting generated, what's going to the battery, the car etc.
  6. Not essential but would like to know if the system can operate when there is a Grid power outage.
  7. annual elec use (estimate): 3500kWh.
Cheers everyone.
Best wishes
Dave
User avatar
Fintray
Posts: 1558
Joined: Mon May 31, 2021 6:37 pm
Location: Aberdeenshire

Re: Retro fit AC Coupled Batter Storage

#2

Post by Fintray »

Welcome to the forum Dave, I'm sure someone will be along shortly with some advice.
3.87kWp PV
10.24kWp PV SolarEdge system
Tesla Powerwall 2
100 x 47mm Navitron tubes (still being installed!) Now likely to be removed for more PV.
MK2 PV router DHW diverter
Morso 5kW WBS
Vaillant AroTherm 10kW ASHP
Nissan Leaf
User avatar
nowty
Posts: 5791
Joined: Mon May 31, 2021 2:36 pm
Location: South Coast

Re: Retro fit AC Coupled Batter Storage

#3

Post by nowty »

As you don't seem to use much leccy, I would question why you want a 5kW battery inverter. So much more straight forward to go G99 fast track with a 3.68kW battery inverter or even a hybrid inverter and add more PV.

Of course an EV may change all of that and by the way you now officially need the EV first before moving to the Go tariff.

What's the size of your current PV install ?
18.7kW PV > 109MWh generated
Ripple 6.6kW Wind + 4.5kW PV > 26MWh generated
5 Other RE Coop's
105kWh EV storage
60kWh Home battery storage
40kWh Thermal storage
GSHP + A2A HP's
Rain water use > 510 m3
sharpener
Posts: 430
Joined: Fri May 20, 2022 10:42 am

Re: Retro fit AC Coupled Batter Storage

#4

Post by sharpener »

pattisd wrote: Thu Jun 23, 2022 3:25 pm I started off looking at Victron kit as they seemed to be indestructible and pretty configurable. But no local approved installers and maybe a bit too complicated.

<snip>

I'm not sure what to do next. I've had some quotes from companies - but they seem pretty steep compared to just the kit cost. I still like the idea of a local tradesperson getting my business. Much prefer to do that than place my business with a national company. Should a competent electrician (part P qualified) be able to fit a battery & inverter? And will the DNO make anything of the installer I choose?

So wondering if anyone on here has any ideas ....
  • what kit to use
  • local installers
  • DNO application advice
I did make a list of things I'd want from the battery storage:
  1. additional AC battery storage (so as not to affect FIT).
  2. I hope to switch to a "time-of-day" tariff (probably Octopus Go) and need the solution to be able to charge when its a low cost period.
  3. I'll also be looking to get an EV and EV charger soon after switching to Go. So I'll need to be able to charge the EV battery and the AC battery in the same time frame (4 hours off-peak). And live off the battery as much as possible for the rest of the day.
  4. Ideally looking for modular storage that allows me to extend in the future if there's a need.
  5. Would like to be able to monitor the "Whole" system - to see what's getting generated, what's going to the battery, the car etc.
  6. Not essential but would like to know if the system can operate when there is a Grid power outage.
  7. annual elec use (estimate): 3500kWh.
Cheers everyone.
Best wishes
Dave
Yes, it is well within the scope of a Part P qualified electrician or experienced DIYer.

Victron ESS will meet all points of your spec (and they are introducing a compatible EV charger). For a whole-house solution you would probably need the MultiPlus II-GX 5000VA model for its 50A pass-through capability and turn it down to 3.7 kVA to meet the DNO's requirements.

See this link https://camelot-forum.co.uk/phpBB3/view ... =14&t=1036 for a more detailed discussion and questionnaire.

HTH
16 x 230W Upsolar panels S Devon, 4kW Steca, 3.9 MWh FITs/yr
8 x 405W Longi panels, 250/60 MPPT, 3.3 MWh/yr
Victron MultiPlus II-GX 48/5000/70-50
10.65 kWh Pylontec Force-L2
zappi 7kW EVCS
Villavent whole-house MVHR
5000l rainwater system
Vaillant 12kW HP
Thebeeman
Posts: 221
Joined: Tue Jun 14, 2022 8:56 am

Re: Retro fit AC Coupled Batter Storage

#5

Post by Thebeeman »

I'm in a similar position to you hunting for info and quotes. I've had a quote from ESS and one from a national company. The non ESS one is very close to the same price but includes installation, with a 2 year warranty on the installation, and the G99 etc. The spec difference is a Lux-Power 3.6 Kw inverter against a Victron at 5 KW. Rather than advertise for them please PM me and I'll give you the details.
Post Reply