Ronski's Solar & battery DIY build with whole house backup

Posted in the generation thread, but also here:

5.46kW Solar PV: 12 x 455W Panel 'AIKO Neostar + Mesh' System + 5.18kW FOX ESS - Hybrid Battery
PV Installation for a total cost of: £7,095.00 Inclusive of VAT

Given my 6 panel system was installed at a "cost" of £7.5k with no battery and half the amount of 405w panels, though that sounded OK. Also said they could move the old system to my garage roof...

What do we think?

James
 
I put a deposit on a 3 year old E-Niro 4+ today, so will be joining the EV club very shortly, and will need to get an EV charger, would like to go with the new Victron EV NS charger.
 
Ron-ski said:
I put a deposit on a 3 year old E-Niro 4+ today, so will be joining the EV club very shortly, and will need to get an EV charger, would like to go with the new Victron EV NS charger.
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May I ask how much it was? There were some cracking deals on Kona's recently that were beating deprecation even on used car market.
 
£18.5k, just under 40k miles, full Kia service history, done pretty much on time, which is essential for the remainder of the 7 year warranty, the 4+ is the top of the range model, and commands a premium, especially for a good one.

My brother was shocked at how much I paid for a car, but back in 2013 when I purchased my current car it cost £13.5k, using the Bank of England's inflation calculator, that would be £18,518 in today's money, I found that pretty amazing.
 
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Ron-ski said:
I put a deposit on a 3 year old E-Niro 4+ today, so will be joining the EV club very shortly, and will need to get an EV charger, would like to go with the new Victron EV NS charger.
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Going EV changes the calculation between Flux, Go and IO - something to think about.

No IO on the Niro or charger though - if you are paying for one, you might as well get one that is compatible?
 
I moved off Flux mid December on to Go, won't be going back to Flux, even before the EV Go made far more sense, and going by 2024's figures more profitable by a few hundred quid.

I have an extensive Victron system, so I'd prefer to stick to Victron for the charger as it would all integrate nicely. I have asked on the Victron forum if they plan to integrate it with Octopus.

Obviously IOG is 1.5p cheaper and will give more cheap hours, but I don't think it will make a huge difference to car running costs as I only do around 8000 miles a year. Wife's happy with her petrol car, and she does about 2000 miles a year, so if she did get an EV not much to save there either.

I'll also be adding an ASHP this year, so that would also benefit from cheaper IOG, so that 1.5p difference could add up. Of course we don't know how tariffs are going to change either.
 
If I were you, I just get a cheap used Ohme, and go with IOG. You can always swap it easily once it's in and signed off should you want to change it later down the line.

I'm also pretty sure the Victron still doesn't mean certain UK charging regulations, both physical and software based.
 
Agreed, I would get an IOG compatible charger. I think the current choice is Zappi, Hypervolt, Ohme, Wallbox and Indra.

When you get the HP, its not just the 1.5p that will add up, its the extra hour and all the additional cheap slots you get all the time.

I get the want for an integrated charger but it doesn't really matter. You can pole the Octopus API in NodeRed can't you? If so, you can trigger the battery to charge on the Octopus dispatching entity. It is also prudent to wire your charger so its not covered by your Victron system anyway so it can never fill its demand.

I doubt the Victron would even make it onto the IO 'to do' list let alone the compatible list, it takes development time to integrate each charger on the Octopus backend and they will be targeting the most popular chargers. I'd would have thought the Victron is the opposite of the most popular. It took Hypervolt over a good year to negotiate terms and for Octopus to give the dev time to actually integrate the charger into IO. They still have not done their old V2 units yet, that is another 3 months away.
 
Just done some simple but quick maths, IOG would be about £200 a year cheaper at current rates than OG for house use and EV, so certainly makes sense, and obviously the heat pump will further increase the savings.

Which chargers use a local network connection or wi-fi, neither is an issue, obviously wired will be better? This counts Ohme out as it only uses a sim card by the looks of it.

I'll likely have the charger installed after the inverter, I can easily stop it draining the batteries with a bit of simple automation, and it will give the option to charge off the batteries or solar if need be, and the Victron system will report total house load accurately (well within 5%). I know this isn't generally advised, but I have a highly controllable system, although I will need to figure out how to reliably automate stopping charging if the grid goes down.
 
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I think Ohme is the only one that is 100% 4G, the rest on the list have at least WiFi and some have both WiFi and Ethernet. Hypervolt has both, not sure about Ethernet on Zappi, it defo has wifi.

Not all chargers have a solar charging mode, hypervolt and Zappi do, not sure about the others.

Is the other priority that you have something to tap into API wise?

I know you use node red but the Zappi and Hypervolt you can tap into the API via home assistant so may be possible on node red. I’m not sure if it is fully local control or if it’s tapping into the cloud API though. Im not at all familiar with the others.

My neighbour has their zappi on home assistant so I can ask them and find out if needed.

My hypervolt is an old V2 unit so isn’t actually on OI yet (March apparently) and I do OI via my car which is supported, the charger is in dumb mode. I’ve only used the solar mode once when I didn’t have an export tariff!

I’ve not got the car on home assistant anymore, not sure why, I just never got round to it.

All my automations rely on the octopus dispatching flag which turns from off to on whenever you have a 7p electricity slot.

The automations surmount to:
If octopus dispatching goes from off to on, charge battery.
If octopus dispatching turns from on to off, stop charging battery and will go back to filling all loads, inc my car due to the way it’s wired.

Home assistant control of GivEnergy is fully local so it’s pretty reliable.
 
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I think the Zappi v2 does have an ethernet port on the PCB attached to the inside of the front cover, but I've never seen it open to check. I just use the Wifi and it has been problem-free.

I had mine installed so the hybrid inverter cannot see it (just after the meter via a henley block), but even then, it can still take the excess going to the grid if desired. I don't, so I just manually set the export margin to >8kW so it never does. It's nice to have the option there however.

I very rarely seem to get daytime windows on Intelligent Go, but often get an extended night-time window instead (I've seen 22:00 to 06:00 for example). I'm guessing this is dependent on location.
 
b0rn2sk8 said:
Is the other priority that you have something to tap into API wise?
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Yes, something I can control if need be, I've not put too much thought in to it, but if I have it installed so the inverter see's it, I'll need the ability to turn it off programatically should the grid go down whilst charging.

I haven't had any time to research, been a busy weekend.

A quick Google suggests the Zappi can be controlled in this way https://github.com/CJNE/ha-myenergi
 
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Zappi here all integrated with HA well on wifi, and my solar/batts controller by HA and Predbat. I only signed up to IOG last week actually from Cosy, and have found it best to just let Octopus control the Zappi and car charging rather than HA and Predbat, although HA still picks up the extra bonus cheap charging slots outside the normal IOG range and then schedules battery charge/discharges as appropriate. (My zappi+CT is wired in on the house/batteries side so it can sense the export, but Ive changed a setting on the Zappi so that the export needed before it diverts excess 'solar' is greater than our export limit so it never drains the battery during forced discharges)
 
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Picked up the EV last yesterday, set the granny charger to charge between 12:30 and 5:30, but had a slight hiccup.

To charge my house batteries I set my grid point to 7000w, which means with about 500w base load my batteries are fully charged by around 5am, except last night I plugged in the granny charger to charge the car off peak as well (first time), which meant the house batteries were only 72% full this morning.

Need to adjust my charging routine to allow for all loads, which it doesn't currently do, as previously they were just base loads at that time.
 
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