V2L, V2H, V2G - How does it work with MG EVs?

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Hi all, new to the forum. Ordered an MG4 a week ago and expecting delivery in the second shipment Oct/Nov.

Having done a bit of research on V2G it still seemed a way off with only one very expensive chademo bidirectional charger model out, so I was about to order an Easee charger. Then on Saturday I saw that EO's new mini pro 3 charger is "ISO 15118" "V2G Ready" but it's the price of a normal smart charger. Does anyone know what the heck this means and whether the MG4 is likely to be compatible with it for V2G at some point?

As far as I can understand, current V2G bidirectional chargers do all the conversion of AC-DC to charge and DC-AC to discharge so they're inherently more complicated and therefore expensive than normal chargers, which I believe just directly provide AC to the car which then converts it to DC internally.

My best guess is that there's going to be AC-only bidirectional chargers that are much simpler and cheaper than the current ones, where the car does all the heavy lifting of converting AC to DC and back again. Any car that uses a type 2 AC socket and also has V2L from the charge port (which includes the MG4 and I think the new MG ZS) should in theory be able to do this already, so it makes sense to use the onboard conversion hardware instead of having it in the charger.

However, this is just speculation based on the words "V2G ready" being used in the marketing for an unreleased low cost charger with no further information available. I'm hoping someone on here is more knowledgeable than me and can explain everything!

 

[MichaelJHunt]

In the UK the V2L uses the onboard system to provide a 230V AC output with an advertised 2.2kW limit.

V2G is completely different. This needs a very high cost and complex dual direction charger and complex connection to your home to match AC waveform cycle and have islanding protection in the event of a power failure to the house.

A V2L system should not be connected to your household circuits.

Info here:

Bidirectional chargers explained - V2G vs V2H vs V2L — Clean Energy Reviews

Bidirectional EV charging is an emerging technology that is set to transform how electric vehicles are used. We explain how bidirectional chargers work and the various technologies available including Vehicle-to-grid (V2G) and Vehicle-to-home (V2H), and Vehicle-to-load (V2L)

www.cleanenergyreviews.info

 

[Jomarkh]

The V2L on the ZS face-lift and MG4 is very limited.
You probably won't even be able to run a kettle on it.
It would be ok for a few Led lights while camping.

 

[BugEyed]

ISO15118 is the AC bidirectional charging standard whose adoption is delayed over difficulties with the certificates necessary for the required information exchange. The charge point are similar to existing ones but allow grid integration to negotiate the power exchange. Some manufacturers have pledged to support the system and retrofit the required software and firmware to their existing cars (VAG), but I have not seen similar from MG/SAIC. The wiring standards for UK homes has not been agreed, and so even if you buy a suitable charge point it may require rewiring to work.

 

[Ads]

In the UK the V2L uses the onboard system to provide a 230V AC output with an advertised 2.2kW limit.

V2G is completely different. This needs a very high cost and complex dual direction charger and complex connection to your home to match AC waveform cycle and have islanding protection in the event of a power failure to the house.

A V2L system should not be connected to your household circuits.

Info here:

Bidirectional chargers explained - V2G vs V2H vs V2L — Clean Energy Reviews

Bidirectional EV charging is an emerging technology that is set to transform how electric vehicles are used. We explain how bidirectional chargers work and the various technologies available including Vehicle-to-grid (V2G) and Vehicle-to-home (V2H), and Vehicle-to-load (V2L)

www.cleanenergyreviews.info

Thanks, so you're saying V2G/V2H definitely not possible with an AC-only charger. Any idea what the "V2G Ready" marketing might mean?

 

[MichaelJHunt]

The V2L on the ZS face-lift and MG4 is very limited.
You probably won't even be able to run a kettle on it.
It would be ok for a few Led lights while camping.

You can certainly run a kettle on it - I have. It is advertised as 2.2kW limit but will easily exceed this, and is far far more than needed to run a few LED lights while camping. I have tested with a 2kW heater and running lighting while camping with no issues.

 

[MichaelJHunt]

Thanks, so you're saying V2G/V2H definitely not possible with an AC-only charger. Any idea what the "V2G Ready" marketing might mean?

A special charger is required, the standard “chargers” won’t do it. In fact the existing units are not “chargers”, they just funnel the household AC to the charger that is in your car.

Well, as there is no agreed standard yet for V2G in the UK, it could be a long wait.

The Nissan Leaf has supported V2G since its inception. I know of no commercially available V2G system for the Leaf. There were some test systems released.

 

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ISO15118 is the AC bidirectional charging standard whose adoption is delayed over difficulties with the certificates necessary for the required information exchange. The charge point are similar to existing ones but allow grid integration to negotiate the power exchange. Some manufacturers have pledged to support the system and retrofit the required software and firmware to their existing cars (VAG), but I have not seen similar from MG/SAIC. The wiring standards for UK homes has not been agreed, and so even if you buy a suitable charge point it may require rewiring to work.

Interesting, so it's an attempt to future-proof the charger for a time when AC bidirectional charging becomes a thing.

 

[BugEyed]

Thanks, so you're saying V2G/V2H definitely not possible with an AC-only charger. Any idea what the "V2G Ready" marketing might mean?

Not currently, but probably in the future only for supported cars and for charge points where the manufacturer follows the defined standard IF the UK follows the standard which is far from certain.

 

[profdraper]

Quite a while away as yet, only the Leaf has this. Only V2L charger is the rather expensive Wallbox Quasar. Wallbox Quasar | The first bidirectional charger for your home

 

[Ads]

Quite a while away as yet, only the Leaf has this. Only V2L charger is the rather expensive Wallbox Quasar. Wallbox Quasar | The first bidirectional charger for your home

Apparently there's going to be a Quasar 2 that has a CCS connector. Not sure what cars it's compatible with though.

 

[BugEyed]

Quite a while away as yet, only the Leaf has this. Only V2L charger is the rather expensive Wallbox Quasar. Wallbox Quasar | The first bidirectional charger for your home

Just to clarify, neither the LEAF nor the Ariya currently support AC V2G. I haven't heard of anybody actually getting an AC or CCS DC V2G product from Wallbox, let alone getting a car to work with it.

 

[MichaelJHunt]

And our friends across at Tesla don’t even have V2L !

 

[Gomev]

Just to clarify, neither the LEAF nor the Ariya currently support AC V2G. I haven't heard of anybody actually getting an AC or CCS DC V2G product from Wallbox, let alone getting a car to work with it.

This trial has completed, is this anything relevant ?

Powerloop | V2G | Octopus Electric Vehicles

Learn more about the Octopus Vehicle-to-Grid bundle called Powerloop, a UK first for next gen energy grid management with the Nissan LEAF + Wallbox charger

octopusev.com

 

[BugEyed]

This trial has completed, is this anything relevant ?

Powerloop | V2G | Octopus Electric Vehicles

Learn more about the Octopus Vehicle-to-Grid bundle called Powerloop, a UK first for next gen energy grid management with the Nissan LEAF + Wallbox charger

octopusev.com

That was a Chademo DC based trial, not AC. So whilst the control results are interesting it doesn't show that AC V2G is here.

 

[BugEyed]

It looks like Indra (who have made and run more V2G units in this country than anyone else) are looking to stick with DC and will be producing 6kW V2H grid tied units initially for Chademo but also for CCS in the future.

 

[Coulomb]

Any idea what the "V2G Ready" marketing might mean?

As far as I can tell, it's an outright lie. [ Edit: But see the far better informed next post. ] The ISO 15118 standard seems to be for DC connectors, possibly CCS only. The OP's EO EVSE isn't even tethered, so it can't possibly have a CCS (DC) connector. So as far as I can tell, the EO and any other ordinary AC EVSE will never be V2G compatible.

Think about how V2G over AC would work. It would not be impossible electrically for your car to sense the grid phase, turn the on-board charger into an inverter, synchronise to the grid, and connect safely to it. Though it would need a somewhat bulky inductor and contactor to do this, I believe over and above what is needed for V2L, but EVs have space and are heavy already. If there was a blackout, the car's charger/inverter would have to sense this, and disconnect. So your house would have no power anyway. Grid-tie inverters that do this have to have all manner of expensive regulatory approval, because literally lives are at stake.

To power just your house (assuming the loads happened to be low enough when the blackout starts, and you're somehow aware enough to keep the loads low), the car would have to talk to some piece of hardware that could safely disconnect your home from the grid, so that no grid cables are live. It would also be good for that box to disconnect heavy non-essential loads, like water heaters. Also, the car's on-board charger/inverter will be hard pressed to run all of your house, let alone the whole blacked-out region. Then the car could power the house safely, up to its power limit. But then what happens when the grid comes back? Now the grid and car/house are out of sync, so it's not safe to reconnect. You could stop the car then reconnect, but that could cause a brief drop-out. The car's on-board charger/inverter can't see the grid to synchronise. Also, if the car and the box reconnecting the grid don't talk perfectly to each other, over some very low latency, high reliability connection, then this is just not practical or safe.

So sadly, I think it just doesn't make sense to have bidirectional AC power flow to/from EVs. It's a shame, because 90% of what you need is already in an EV (the on-board charger), and none of that would get utilised in a DC V2G situation. So in effect, with ISO 15118, you would be duplicating all that expensive water-cooled power electronics in an expensive external charger/discharger. Maybe someone will figure out a clever way to work around these problems and avoid the duplication, but I can't see it happening. Though consider the following thought bubble:

Maybe there is a market for a new gizmo to make this happen. Imagine a special, highly regulated (and therefore expensive) gizmo that you plug your car into, running in V2L. Most of the time, the output isn't needed, so the car doesn't enable the V2L and the computers sleep. When the gizmo detects a blackout, it drops off unessential loads, disconnects from the grid, connects the house load to the car, wakes the car somehow (that might need a new standard), and the car outputs V2L and powers the house after a brief blackout or brownout. The gizmo lights up a warning to say that there is a blackout, and that it's a good idea to limit power usage now. When the gizmo detects that the grid power is back, it either switches over the house to the grid (with another brief brownout), or perhaps it waits for the grid to be in sync with the car (this could take minutes), and achieves a better switchover by paralleling the car's V2G and grid for a moment. It then disconnects the house from the car, tells the car to go back to sleep or perhaps start charging it if certain conditions are met.

So this gizmo could be a fancy AC EVSE, but with several additions that are critical and difficult to achieve: the heavy current contactors for the non-essential loads and the entire grid connection, and of course the EVSE somehow needs heavy cables to these things. Maybe there is one part that could live in or near the switchboard (perhaps it's DIN rail mountable, or more likely it could be placed near the switchboard), and connects to the EVSE via some dedicated cable. The system would have to be designed so that it fails safe: if the comms cable disconnects, or a contactor is detected as stuck, it would so whatever is needed to be safe. Difficult and expensive, especially a contactor that can switch the ~100 amps of your grid connection, but perhaps doable. I somehow doubt that the EO mini pro 3 has all this in mind. But it would be nice if I'm wrong about that. They don't seem to mention anything on the web page (that I noticed) that suggests any of this.

In summary, for the foreseeable future, I think it's safe to ignore any marketing about an EVSE being "V2G ready".

[ Edit: added "and contactor", "power is back" → "grid power is back". ]

Edit 2: Leaving an EV connected to the EVSE for long periods would have to be something the car can do without killing the auxiliary battery. Early model LEAFs in particular would drain the auxiliary battery doing that, as the computer was continually checking to see if charging could be started. Hopefully EV technology has gotten past those early hurdles, but as far as I know, there is still no standard for waking a sleeping car. My MG ZS EV Mk 1, for example, snoozes soon after my EVSE disconnects AC, so if I pause charging for more than a few minutes, the car won't resume charging. I have to fish out my keys and press the "close" button, the car wakes up, handshake starts, and the EVSE clicks indicating that it's closed its contactor, and charging resumes. My hypothetical gizmo obviously requires a better way to wake the car.

 

[BugEyed]

ISO15118 is a family of standards regarding V2G communication to allow bidirectional charging for both AC and DC transfer. In particular it requires Plug and Charge with secure communication between vehicle and grid which it defines. It doesn't handle V2H for grid outages, nor the transition period to/from grid connection. It doesn't define the "local" wiring standards for Earthing, load shedding, etc.
In theory OPCC compliance means that an EVSE is "ISO15118 ready" as the communication will be done via either the existing pilot connections digitally or wirelessly via another device owned by the power company. So the onus is on the car manufacturers and the grid to resolve the difficult part of the certificates which isn't popular when talking about the Chinese Government having access to critical UK infrastructure.
"Minor details" such as the inverter synchronisation, keeping the vehicle awake enough to respond, grid disconnection, V2H etc. are left to individual countries and manufacturers.
A useful starting point, if a bit out of date is this article.

What is ISO 15118? | Switch

Personally I can't see it happening anytime soon, particularly for our Chinese cars.

 

[Coulomb]

ISO15118 is a family of standards regarding V2G communication to allow bidirectional charging for both AC and DC transfer.

Thanks! You obviously know a lot more about this than I do.

In theory OPCC compliance means that an EVSE is "ISO15118 ready" as the...

Did you mean OCPP? I'm not trying to snipe, I honestly want to know. I haven't read up on OCPP, but I know that Openevse supports it, and it seems relevant.

 

[BugEyed]

You obviously know a lot more about this than I do.

Probably not.

Did you mean OCPP?

Yes! Not a clever mistake on my part.