Posted by: @davidb

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Posted by: @davidb

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Thanks @batpred It does and the article on chargers was really helpful.

A question.  The article asks Do I need DNO approval? The answer given is Yes. Any V2H install exporting more than 3.68 kW requires G99 approval, which typically takes 30 to 60 working days.

My query is the G99 required if everything is going V2H?

 

My understanding is that anything that is able to export and wired as such is in scope of the G standards. 

That's correct.

The DNO needs to verify that the proposed mechanism to prevent export to the grid is of an approved type, and cannot be over-ridden.

They aren't simply going to give permission because the manufacturer claims that the charger will operate in V2H mode.

The manufacturer will need to have already completed type-testing of the charger for G98, and that documentation have been accepted by the ENA.

Moreover, if there are two variants which would facilitate either V2G or V2H, then the DNO will check that it isn't possible to switch between those variants in future.

Since all EV chargers must now be "smart", there is an obvious risk that a subsequent software upgrade could change the classification. So it's unlikely that a 'software only' designation for V2H functionality would be deemed satisfactory.

The term 'smart' is incorrectly applied to EV chargers. They are simply capable of being controlled remotely. There's unlikely to be anything autonomous in terms of 'smartness'.

Posted by: @old_scientist

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I think the notion of having a large portable battery sat on the driveway for long periods that could be used to power our homes (or help balance the grid) is something that will clearly be hugely appealing as we move increasingly towards electrification with heat pumps etc. Hopefully one day this technology will be ubiquitous, but I feel we are currently a way off that being the case.

The time frame in which householders will be motivated to install large battery storage (portable or static) depends on

• DESNZ and Ofgem mandating that all suppliers must offer ToU tariffs
• that such a Directive be based on the availability of electricity (kWh) from renewable sources, rather than sterling (£)
• how long we've got until we suffer the next widespread outage (by equipment failure, or hostile attack)

For insight into the latter, see the transcript of the lecture by Anne Keast-Butler, Director of GCHQ, earlier this week (27may26).

Adding devices to the grid which embrace opportunities for remote monitoring or control should not be regarded as 'smart'!

I doubt that any V2H charger will be offering off-grid operation any time soon.

Thus the risk of impending widespread outages can't be mitigated by using a portable storage strategy.

That needs to change.

We used to have an Indra V2G/H charger, and a leaf, got them in 2020 I think.  We had the charger for 3 years, then gave it away as a spare - the company didn’t want it back (for free), and it can’t be used at a new property, so wasn’t really worth a lot, even tho it did still work.  We swapped it for a sunsynk inverter + 16kWh battery + extra PV.

The indra box worked mostly well; probably needed a reboot every couple of months, and the charge cable got stuck once a month or so - this was a nuisance.  The cable is electrically locked in place, and must be released before removal - because it’s a dc connection it must be extra secure - you mustn’t just unplug it, which you could with the AC connection.  Mrs RobL and I far prefer the simpler car charge only; you know what will be in it, it doesn’t go wrong, and it’s simple to unplug.  In contrast the sunsynk is bulletproof, and extra PV is great 🙂

V2G has been waiting for its day in the sun for a long time now, it’s always a few years away! 

Posted by: @transparent

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The term 'smart' is incorrectly applied to EV chargers. They are simply capable of being controlled remotely. There's unlikely to be anything autonomous in terms of 'smartness'.

Absolutely. We are going through another period when our EV charger decides how much it wants to charge overnight .. Needed a dumb charger yesterday! 

The other term I have issue with is “Pro”. I would rather be treated like the dumbest consumer that expects it to work..

Vehicle to Grid is the further step and here is the IEA’s prediction on this 

https://www.iea.org/reports/vehicle-to-grid-technology  
(They are historically predicting on the slower side of what actually happened on things like solar generation) 

Octopus now have a nice summary 

https://electroverse.com/community/ev-blogs-and-guides/bi-directional-charging  

the news that Nissan have theirs approved is something I’m going to watch carefully. In the meantime I’m hoping my elderly Toyota passes its mot this month 

We still have the "problem" that it's as cheap or cheaper to have a 32kWh battery fitted to the house than buy a fancy bidirectional EV charger. Whilst V2H/G capable devices are coming down in price they have a bunch of problems Octopus seem to want to gloss over so they can sell you boxes

- It's often cheaper just to get another battery fitted

- An extra DC coupled battery on an existing inverter doesn't mess up your G98/G99 limits, a separate AC coupled V2H/G system does, so you end up in the world of G100, hoping all your kit together an meet G100, your DNO approves it and it all costs even more money

- Your EV may well be at work all day when the sun is shining and in a couple of years between 11am and 3pm your export payments are down to 2p or 3p, and as it didn't charge all day you can't sell the spare car power back between 4-7pm

- Your EV comes and goes so it's not a reliable battery source for planning. For tariffs like agile where you can have entire "ouch price" days that's a big deal

It's certainly true that EV charger prices for V2H/G will come down (especially now it seems the industry has finally started getting its act together on standards based products) but battery prices are also dropping like a stone.

Finally the other thing we should be getting some point next year as part of the second phase of plug in solar is approval of plug in battery. So if you've got a V2L capable car you'll be able to buy a small box you plug into the wall and you plug the car V2L into that turns the V2L into grid tie at 800W limit so you can at least get a bit of something out of the car without being mugged for thousands.

Thanks, @judith. I hadn't noticed that summary and it is an excellent intro for anyone not having looked into it before. I can see myself forwarding that quite a few times.

Posted by: @etchedpixels

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We still have the "problem" that it's as cheap or cheaper to have a 32kWh battery fitted to the house than buy a fancy bidirectional EV charger. Whilst V2H/G capable devices are coming down in price they have a bunch of problems Octopus seem to want to gloss over so they can sell you boxes

Not so sure. When I read Octopus' article, they seemed to me pretty open about the issue of cost as well as the lack of regulatory framework and the issue of vehicle compatibility.

Posted by: @majordennisbloodnok

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Posted by: @etchedpixels

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We still have the "problem" that it's as cheap or cheaper to have a 32kWh battery fitted to the house than buy a fancy bidirectional EV charger. Whilst V2H/G capable devices are coming down in price they have a bunch of problems Octopus seem to want to gloss over so they can sell you boxes

Not so sure. When I read Octopus' article, they seemed to me pretty open about the issue of cost as well as the lack of regulatory framework and the issue of vehicle compatibility.

 

I’m keeping an open mind still. Our system is AC not hybrid so ‘just slapping another DC battery on” isn’t a possibility. Extra batteries aren’t always straightforward, that was one of the GivEnergy issues, further batteries of the same type often cross charged each other rather than supply the house or charge up from sun or mains.

The NexBlue point 2 bi-directional charger is ~£540 and gets good reviews but time will tell how good they are longer-term. That is no different to normal chargers.

There are certainly some good advertised prices on standalone batteries but when I looked they were all out of stock, possibly vapour-ware. That will change I hope.

Posted by: @judith

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The NexBlue point 2 bi-directional charger is ~£540 and gets good reviews but time will tell how good they are longer-term. That is no different to normal chargers.

I looked into that wallbox a bit more off the back of the article you posted and I found it does indeed differ from many other chargers, but in a hopefully good way.

It seems it comes with an ethernet socket as standard - something I view as almost essential - and they seem to also use that to provide ethernet to modbus functionality as well as just a wired alternative to wifi. As such, from what little I’ve read, it seems they have built in a way the wallbox can be run programmatically without hitting the Internet at all. Useful if they were ever to go the way of GivEnergy.

Only time will tell if they’re any good or not but if my zappi broke tomorrow, the NexBlue 2 is quite likely the one I’d take a punt on as a replacement. Not an endorsement, of course, but first impressions look good.