V2G to be approved in Australia 2025

[BeamingJim]

On the back of some surprisingly progressive news here about the V2G standard to be approved in Australia, what are everyone's thoughts about the future possibilities for the MG4?

Batteries on wheels: Australia to allow vehicle to grid installations by end of year

Bowen says that agreement on new standards means that EV owners will be able to use vehicle to grid technology - effectively using their cars as batteries on wheels - by the end of the year.

thedriven.io

I realise that you can already rig up something similar today using the MG4, V2L and an inverter generator input under some circumstances, but I'm hoping this standard might mean other mainstream options may be released.

The chance of MG releasing any kind of software update to enable for V2G to existing cars is probably zero. But I'm thinking maybe in future a wall charger with V2G compliance could simulate a disconnect and reconnect as V2L to switch the existing connection over from charging to discharging?

Since here in sunny WA, the daytime solar FIT is 2c/kWh (odd how they still charge everyone else over 31c/kWh for usage at the same time of day?), it would be great to be able seamlessly shift that cheap power into the evening.

 

[ReintjeWA]

That's great news! I doubt they'll ever update these MG4's to V2G, but at least the next EV should be able to?

I wonder if you'd need a CCS2 charger at home for this to be effective? Although a Type 2 can theoretically carry 22 kW, which I guess is more than most houses use in a day...? I need smarter people to shed their light on this haha

 

[BeamingJim]

True, it's more likely something to look out for in the MG4 MK2

The AC connector can happily manage 7kW (on the Excite), though I think the official V2L output is lower than that. Even having access to just 2kW peak V2X would offset most of my evening load, even with the home A/C running, I'd probably draw less than 5kWH from the battery overnight.

 

[Coulomb]

Although a Type 2 can theoretically carry 22 kW, which I guess is more than most houses use in a day...?

You are comparing power (22 kW) with energy (what most houses use over the period of one day).

Perhaps you meant that 22 kW is more power (a faster rate of energy use) than most houses use at any time.

 

[ReintjeWA]

You are comparing power (22 kW) with energy (what most houses use over the period of one day).

Perhaps you meant that 22 kW is more power (a faster rate of energy use) than most houses use at any time.

Yeah I was sort of thinking, would you need a CCS2 connection to allow the house to pull the energy it needs, but then I thought if the car can discharge fast enough, Type 2 systems can theoretically handle up to 22 kW right? And I doubt a house would pull more than that at any given moment?

Like I said, I don't know enough about this stuff, I make connections between some very patchy knowledge haha

 

[wattmatters]

Bidirectional V2G will directly connect to the drive battery and bypass the car's onboard charger/inverter. It's like a hybrid inverter set to work with a 400 V battery.

MG4 is capable of doing so, it's been tested. Whether MG make it available is up to them. Same with most other manufacturers and very few have enabled it.

MG4 Bidirectional Charging (V2H and V2G) Successfully Trialled

Intercontrol has successfully deployed one of the first V2H (vehicle-to-home) demonstrations of the MG4 electric hatchback.

zecar.com

The bidirectional charge station is going to be expensive.

 

[Coulomb]

would you need a CCS2 connection to allow the house to pull the energy it needs, but then I thought if the car can discharge fast enough, Type 2 systems can theoretically handle up to 22 kW right? And I doubt a house would pull more than that at any given moment?

Right. Actually type 2 can go to 43 kW (around 63 A per phase from memory). But for 43 or 22 kW to flow, either in or out or both, the car's on-board charger come inverter would have to be rated for that power, and they rarely are.

That's why (nearly?) all the V2H and V2G systems do directly to the battery, via that beefy pins at the bottom of a CCS2 or even CCS1 connector. But then, you're not taking advantage of anything inside the car apart from the battery, so all the power electronics has to be external, and at house power levels, that's going to be bulky, generate a fair bit of heat, and be expensive.

 

[BeamingJim]

Bidirectional V2G will directly connect to the drive battery and bypass the car's onboard charger/inverter. It's like a hybrid inverter set to work with a 400 V battery.

MG4 is capable of doing so, it's been tested. Whether MG make it available is up to them. Same with most other manufacturers and very few have enabled it.

MG4 Bidirectional Charging (V2H and V2G) Successfully Trialled

Intercontrol has successfully deployed one of the first V2H (vehicle-to-home) demonstrations of the MG4 electric hatchback.

zecar.com

The bidirectional charge station is going to be expensive.

That's really promising, good to know the MG4 is capable at least, thanks for the link. Hopefully some competition in this space will eventually lead to lower priced options for the home.

 

[wattmatters]

Sigenergy have two bidrectional capable DC chargers, 12.5 kW and 25 kW. It's a module which fits into their battery and hybrid inverter stack and comes with a CCS2 plug/cable. They are about $7-10k a pop, and of course need to be part of their modular system, it's not a standalone option AFAIK, which might be an issue if the battery/inverter are not located near where the car is parked.

 

[AlC]

The prices of the bidirectional chargers have definitely poured water on my excitement a bit.

I'm curious though about the technical implementation details of V2G via the DC pins.

Presumably any EV should be hardware capable as it seems like all you need to do is close the contactors that are normally closed during DC fast charging. Only the energy flows in the other direction.

How does the car's BMS know the correct state of charge though? Does discharging via the DC pins bypass whatever the GOM uses to guess the state of charge? (Particularly important for LFP where between 10% and 90% the SOC is deducted by counting energy in vs energy out)

 

[wattmatters]

How does the car's BMS know the correct state of charge though? Does discharging via the DC pins bypass whatever the GOM uses to guess the state of charge? (Particularly important for LFP where between 10% and 90% the SOC is deducted by counting energy in vs energy out)

The same way it does when you use a public DC fast charger I presume. Shunts can measure current in either direction. The car is communicating with the charger, which is how it can display the SOC.

 

[Vaasref]

One way to make a MG4 do V2H on the cheap is to use a beefy entreprise grade UPS.

I tested the principle with my APC Smart-UPS C1500.
The UPS handles the dead time when you disconnect from the grid and connect the car in V2L.
The voltage from the car is kind of lowish so the UPS is grunting a bit, but since it is a UPS it accepts the new frequency and phase.

I haven't checked if there is any news in the automation of switching MG4s in V2L mode. If it it is ever possible, a V2H is achievable.

 

[wattmatters]

One way to make a MG4 do V2H on the cheap is to use a beefy entreprise grade UPS.

I can use the V2L to power a battery charger which charges my home battery. I don't use it often, mainly for extra coverage during longer power outages.

 

[agough]

One way to make a MG4 do V2H on the cheap is to use a beefy entreprise grade UPS.

I tested the principle with my APC Smart-UPS C1500.
The UPS handles the dead time when you disconnect from the grid and connect the car in V2L.
The voltage from the car is kind of lowish so the UPS is grunting a bit, but since it is a UPS it accepts the new frequency and phase.

I haven't checked if there is any news in the automation of switching MG4s in V2L mode. If it it is ever possible, a V2H is achievable.

An inline Double Conversion UPS [usually anything 3kW or over will handle the phase & frequecy issues
[ https://***********/3h94c2fu ]
Main issue then would be 400V <--> 72V/96V/… DC step up/down :-(
[ https://***********/c4ay4jdn ]
Could possibly result in automatically recharging EV battery when you go to bed !

 

[Coulomb]

[ https://***********/3h94c2fu ]
Main issue then would be 400V <--> 72V/96V/… DC step up/down :-(
[ https://***********/c4ay4jdn ]

Those aren't useable links; you've copied shortened versions.

 

[pollenface]

Since here in sunny WA, the daytime solar FIT is 2c/kWh (odd how they still charge everyone else over 31c/kWh for usage at the same time of day?), it would be great to be able seamlessly shift that cheap power into the evening.

Only true with A1 Tariff.

See midday saver & EV addon plans.

Energy plans

Description Meta Tag Compare and select an energy plan to suit your lifestyle. Choose a plan to help you save money on your electricity bill or reduce your carbon footprint.

www.synergy.net.au

 

[BeamingJim]

Only true with A1 Tariff.

See midday saver & EV addon plans.

Energy plans

Description Meta Tag Compare and select an energy plan to suit your lifestyle. Choose a plan to help you save money on your electricity bill or reduce your carbon footprint.

www.synergy.net.au

Thanks, I was aware of those plans, but ran the numbers based on my time of day usage, and even though I load shift everything I can into daytime, they both work out more expensive for me. This is mainly thanks to them slugging us with a higher daily fee, and very high evening usage charges.

Those plans might work out beneficial for someone without solar though (or someone who can only charge at night).

 

[pollenface]

Those plans might work out beneficial for someone without solar though (or someone who can only charge at night).

Yeah, i ran some numbers on a spreadsheet and decided A1 was best fitting for us.

 

[gdog]

The only way I see VTG working / being adopted is to make use of the MGs and other EVs built in inverter to output AC to home then grid. This may only be about 7kW output but adds up if many homes are connected. The trick will be providing a wall charger that can talk to Grid operator for a demand signal and can then tell EV to discharge.

All very doable and at a reasonable cost. But getting government to come up with the direction and infrastructure in collaboration with wall charger manufacturers is an ask

I would say the manufacturers would have to produce the “oven ready” chargers with this VTG facility and hope governments adopt their solution

 

[Everest]

All very doable and at a reasonable cost.

Not sure I'd agree with that.

You'd need sophisticated equipment to synchronise with grid voltage & frequencies - the MG4 outputs around 220V so that would need boosting accordingly. Then the device would need to be ENA type-tested and approved with similar disconnect parameters to a household solar or ESS inverter.

Then (in the UK at least) for any output to the DNO over 16A at nominal 230V (i.e. 3680W) you will need prior approval from the DNO and may be restricted (as many are) to the max grid export capacity - this will then need a G100 compliant export power limitation capability and failsafe detection.

Then there is the issue of efficiency. Whereas most domestic solar inverters can have a round-trip efficiency of about 85% (from AC to DC back to AC), a car with that technology using its AC inverter will be significantly less, partially due to the larger quiescent draw of the car's electronics. Likely 70% or less depending on power being drawn.

And finally, consideration must be given to battery / car's inverter longevity. Not such an issue for occasional V2L usage, but I read that VW Group will limit lifetime V2H/V2G discharge to max of 4000 hours or 10 000kWh.

It's being so cheerful that keeps me going