V2G your lessons learnt

[Thebaggers]

Hi all,

I have a solar install at home, 8kWh, (Solaredge inverter) and we are on a 3 phase supply and Octopus Flux.

I have had quotes for a battery install and it doesn't stack up against getting a v2g compatible car, such as a leaf, post 2013, and using that as a run around and house battery.

Battery and inverter quotes are £11k for 9kWh capacity and a leaf can be had for just over £5k for 24 or 30 kWh capacity.

Can those with learnt experience of doing this help me understand whether there are any gotchas please?

Who has trodden this path before? Are there limitations on the vehicle, or charger type, or solar installation?

Thanks

[SWoll]

Is there not a significant cost for the installation required to support V2G from the Leaf though, and do they support powering your home as well as V2G?

As an example the Octopus Powerloop only appears to send power back to the grid.

https://octopusev.com/powerloop

[OutInTheShed]

The leaf will be nearly shagged out, its battery will have done a lot of cycles.
It will be a Li-Ion chemistry not ideal for high numbers of cycles.
It will also have had a long life already in terms of calendar months.

Quite likely you will soon reduce the range to the point where you've lost a lot of value, in relation to the few shillings you've saved on electricity.

You need to have a serious look at how depleting a car's battery to run your house fits in with the car being useful for transport.

[SWoll]

A 2013 62k mile 24kWh Leaf here for £4k with 9 bars and a 70-80 mile range (very easy to confirm)

https://www.autotrader.co.uk/car-details/202305257...

[TheDeuce]

SWoll said:

A 2013 62k mile 24kWh Leaf here for £4k with 9 bars and a 70-80 mile range (very easy to confirm)

https://www.autotrader.co.uk/car-details/202305257...

And even with it's used and limited capacity battery... It's pretty much enough for what the average UK home consumes a day isn't it?

Certainly seems a better value proposition than spending additional thousands on a separate battery for the house - one which can't also fuel a car.

[Thebaggers]

SWoll said:

Is there not a significant cost for the installation required to support V2G from the Leaf though, and do they support powering your home as well as V2G?

As an example the Octopus Powerloop only appears to send power back to the grid.

https://octopusev.com/powerloop

Exact the sort of questions I hope we can raise and answer with this thread.

[Evanivitch]

I'm pretty sure that V2G is in the next round of trials, and that the Indra chargers are not publicly available or approved by the DNO outside of trials. I understood that the chargers were circa £5k. They are a grid tied Inverter after all.

So yes, it sounds like it makes sense but no it's not practical right now.

[TooLateForAName]

SWoll said:

A 2013 62k mile 24kWh Leaf here for £4k with 9 bars and a 70-80 mile range (very easy to confirm)

https://www.autotrader.co.uk/car-details/202305257...

There is no way a 9 bar gen 1 leaf is going to do 80 miles in any normal driving.

That is going to be around 66-70% of original capacity. so maybe 17kwh?

[Thebaggers]

TooLateForAName said:

There is no way a 9 bar gen 1 leaf is going to do 80 miles in any normal driving.

That is going to be around 66-70% of original capacity. so maybe 17kwh?

If a 9kWh battery installation is going to cost £11k tbh I don't care about the range of the EV, it is good for local journeys and that's fine, it will have some residual value as a usable car / house battery.

[DonkeyApple]

Thebaggers said:

If a 9kWh battery installation is going to cost £11k tbh I don't care about the range of the EV, it is good for local journeys and that's fine, it will have some residual value as a usable car / house battery.

Yup. A house battery on wheels in the garage has more logic than one bolted to the garage wall, if the numbers stack.

Why V2G though, the price the Grid pays is so dismal that system efficiency stems from using everything you generate on site and infilling with the cheapest grid power.

I completely get V2H but when I've looked at this the V2G payments have always made it a plaster to try and make a set up error not as bad.

[Thebaggers]

I found this through some research, looks like one of the only commercially available products right now at £6k.

https://wallbox.com/en_uk/quasar-dc-charger


Re rates, on octopus flux the export rates are excellent, 11p less than the import rate with a dip overnight for charging and a peak 4-7pm where I can sell for 35p per kWh, so it does stack up if the charger prices come down.

[DonkeyApple]

It's still a huge number of units that need to be traded to recoup the capex on the battery and infrastructure and within a relatively limited time frame.

Octopus does exist to make money and has a professional energy trading team so one always needs to consider whether the free money that looks to be being left on the table actually exists.

This is why a house battery that's on wheels seems a good idea as it brings a utility benefit that helps offset the capex losses etc.

[OutInTheShed]

Thebaggers said:

TooLateForAName said:

There is no way a 9 bar gen 1 leaf is going to do 80 miles in any normal driving.

That is going to be around 66-70% of original capacity. so maybe 17kwh?

If a 9kWh battery installation is going to cost £11k tbh I don't care about the range of the EV, it is good for local journeys and that's fine, it will have some residual value as a usable car / house battery.

If a battery has dropped to 2/3 of its original capacity, you'd probably expect the decline to accelerate from there.
It's a ten year old battery.

If you cycle it heavily on a daily basis, it might not last long.

You can get 9kW useable capacity in Lead/acid for under £2k. That will be less efficient though.

Say you managed to time-shift all your domestic use, 10kWh per day and you saved 20p per kWh. That would save you £2 a day.
2000 days to break even? 5 1/2 years.

The inverter to take power from the car and feed into the mains should only be a few hundred pounds, it's essentially similar to a solar inverter.
But because few are sold, the costs are much higher.

Personally, if we were in the market for a runabout, I would consider buying a Leaf like this.

[oop north]

I believe there is some evidence that the relatively gentle use of leaf battery as a home energy source (the discharge rate is way slower than at least the peak in use as a car and charge speeds also slower) is not bad for the battery life.

As others have said you need a compatible charger - I had discussions with indra (I got a regular smart charger from them just over a year ago) and they were talking £6k for any vehicle to home compatible charger. Then they invited me to take part in their v2h trial but you needed a leaf or Nissan van to take part and it seemed a bit daft to buy one just for that.

I am hopeful that v2x will be fully in play when I next change my car - and that will be a useful addition to the home battery and suggests to me it isn’t worth going mad on batteries for home now - having three pylontech 5000 batteries fitted today with solar as it happens (we already have a share in a wind turbine).

The charger prices need to come down a lot before it’s worth thinking about

[superpp]

It's really surprising the market isn't pushing V2H really hard on all new car development.

We have a 61kWh battery sat there doing nothing most of the time.

[Evanivitch]

superpp said:

It's really surprising the market isn't pushing V2H really hard on all new car development.

We have a 61kWh battery sat there doing nothing most of the time.

What's the benefit to the car manufacturers? It's hard to tell.

VW have said some of their cars are V2x ready. I thought the standard was published and clear at the start of the year but there appears to still be a delay, internationally and in the UK.

[TheDeuce]

Evanivitch said:

superpp said:

It's really surprising the market isn't pushing V2H really hard on all new car development.

We have a 61kWh battery sat there doing nothing most of the time.

What's the benefit to the car manufacturers? It's hard to tell.

VW have said some of their cars are V2x ready. I thought the standard was published and clear at the start of the year but there appears to still be a delay, internationally and in the UK.

As I understand it making the car V2G 'ready' is actually a fairly easy consideration - given that all the power switching hardware is to be found in the V2G charger, not the car. So it's more like a minor extra effort to be ready to take part if it becomes a big deal from the manufacturers POV.

Feel free to correct me if I've misunderstood something - but it seems to me the expense is pretty much bumped to the expensive V2G charger.

[DMZ]

According to people I know in the energy sector, the manufacturers are on it and want to build the eco system together with energy companies. They probably see a monetisation opportunity by being the middle man. It’s obviously a big paradigm shift that cars provide battery storage essentially as part of the grid. I guess a V2G fleet would be a nice partner to a set of wind farms on windy and not so windy days.

Some mumbo jumbo about it here, as an example: https://www.eenewseurope.com/en/vw-teams-for-vehic...

[Evanivitch]

TheDeuce said:

As I understand it making the car V2G 'ready' is actually a fairly easy consideration - given that all the power switching hardware is to be found in the V2G charger, not the car. So it's more like a minor extra effort to be ready to take part if it becomes a big deal from the manufacturers POV.

Feel free to correct me if I've misunderstood something - but it seems to me the expense is pretty much bumped to the expensive V2G charger.

Correct, the hardware solution is fairly straightforward with some exceptions.

But the CCS standard has historically had a lot more issues than Chademo, with some car brands being (temporarily) incompatible with some rapid charger hardware. Then add the increased complexity of domestic installs with different electrical properties and you start getting into the weeds of how good standards are authored and reviewed.

[TheDeuce]

Evanivitch said:

TheDeuce said:

As I understand it making the car V2G 'ready' is actually a fairly easy consideration - given that all the power switching hardware is to be found in the V2G charger, not the car. So it's more like a minor extra effort to be ready to take part if it becomes a big deal from the manufacturers POV.

Feel free to correct me if I've misunderstood something - but it seems to me the expense is pretty much bumped to the expensive V2G charger.

Correct, the hardware solution is fairly straightforward with some exceptions.

But the CCS standard has historically had a lot more issues than Chademo, with some car brands being (temporarily) incompatible with some rapid charger hardware. Then add the increased complexity of domestic installs with different electrical properties and you start getting into the weeds of how good standards are authored and reviewed.

Standardisation is always going to improve in the longer term I guess. As with all new tech solutions, at the start there are a lot of good ideas - none of which are as compatible or as well thought as they should be in terms of how they make sense in the rest of the developing ecosystem.