Vehicle 2 Grid - octopus open

[Dillsue]

6 minutes ago, JohnMo said:

I may be wrong but everything I have read seems there are different systems and have different results.

 

Isn't V2G, basically car to grid, missing the house out all together. So ok for an export tariff, but not much else. Wouldn't you want V2H, so house could take advantage of car for self consumption via car battery.

 

There is a bidirectional inverter in both V2G and V2H, but configuration very different.

Might be mistaken but I understood V2H and V2G were the same but V2H had export limitation set to zero??

[JamesPa]

14 minutes ago, Dillsue said:

Gen 1 and 2 leafs use CHADEMO for bidirectional charging and I don't think anyone is likely to develop any more V2X kit for CHADEMO in Europe. I've been fruitlessly looking for an ex trial V2X charger but those that come up are expensive and seem to be locked to the original trial?? I think there's hacks that involve altering the car but how reliable/safe/legit they are is anyone's guess....the US one I saw wouldn't cut it over here

Interesting.  I know leafs use chademo for fast charging, but I thought that the home charger interface was universal.  Maybe it is but that doesn't preclude the v2x from not being universal.  I confess to not knowing much about vehicle electric interfaces.

[JohnMo]

17 minutes ago, Dillsue said:

Might be mistaken but I understood V2H and V2G were the same but V2H had export limitation set to zero??

I understood the V2G, the import/export is basically handed over the electricity supplier, they drag the energy from the car, when needed and put it back when there is a surplus.  V2H, is making the car similar in concept to house battery.

[Dillsue]

4 minutes ago, JamesPa said:

Interesting.  I know leafs use chademo for fast charging, but I thought that the home charger interface was universal.  Maybe it is but that doesn't preclude the v2x from not being universal.  I confess to not knowing much about vehicle electric interfaces.

The CHADEMO interface is very limited in Europe and I don't think any new cars are using it. I think any V2H/V2G development in Europe uses CCS. As I understand it any charger, home or commercial, is specifc to the interface. I think there's someone who's developed and CADEMO plug/interface that can draw on the cars battery but I think it's a Fred in a shed job and quite expensive??

[Dillsue]

10 minutes ago, JohnMo said:

I understood the V2G, the import/export is basically handed over the electricity supplier, they drag the energy from the car, when needed and put it back when there is a surplus.  V2H, is making the car similar in concept to house battery.

Could be, I don't know the details of V2G and if it's entirely regulated externally or can be forced to export by the user??

[Kelvin]

1 hour ago, JohnMo said:

I understood the V2G, the import/export is basically handed over the electricity supplier, they drag the energy from the car, when needed and put it back when there is a surplus.  V2H, is making the car similar in concept to house battery.

That’s how I expect it will work for V2G. A bit like Intelligent Octopus Go where Octopus takes over the charging of your car and charges it when it suits them although you can specify when you need it charged by and how much energy to put into the car. The user will need to have some control over export limits too. 

[Kelvin]

1 hour ago, Dillsue said:

Could be, I don't know the details of V2G and if it's entirely regulated externally or can be forced to export by the user??

The problem with this is if the purpose is to help balance the grid then  allowing users to dump energy back to the grid whenever it suits them will make that much harder to manage as people are likely to want to do that at similar times. It might be fine when it’s niche and not many are doing it but less so at scale. 

Edited July 30 by Kelvin

[JohnMo]

31 minutes ago, Kelvin said:

The problem with this is if the purpose is to help balance the grid then  allowing users to dump energy back to the grid whenever it suits them will make that much harder to manage as people are likely to want to do that at similar times. It might be fine when it’s niche and not many are doing it but less so at scale. 

I suspect it will turn like Australia did, you now pay to export, not get paid - unless it's to the benefit of the grid, i.e when it's not windy or sunny.

[Dillsue]

38 minutes ago, Kelvin said:

The problem with this is if the purpose is to help balance the grid then  allowing users to dump energy back to the grid whenever it suits them will make that much harder to manage as people are likely to want to do that at similar times. It might be fine when it’s niche and not many are doing it but less so at scale. 

Aren't we in that situation now with home batteries that can be exported whenever the user chooses?

 

Given that a V2H/G charger will either have a G98 cert or need G99 consent it's likely DNOs will be limiting or involved in what can be exported?? If thats to be a variable limit then I would guess it will be DNOs controlling chargers rather than suppliers???

[Kelvin]

Yes but it’s a scale thing. While the number of home batteries being installed is at a record high there are still relatively few out there and of them not everyone is dumping the charge to the grid so the impact is small. Scale that up significantly and it could start to be more of an issue. There will also be far more electric cars in UK households than home storage batteries so the long term potential is for millions of EVs with V2G capability. However that’s a long way away too I think. 
 

It’s unlikely the DNO will take control of the chargers. It will be the suppliers. 

Edited July 30 by Kelvin

[JamesPa]

1 hour ago, Kelvin said:

when it suits them

Which may not be when it suits the local grid so far as I understand it.

[Kelvin]

9 minutes ago, JamesPa said:

Which may not be when it suits the local grid so far as I understand it.

Exactly. If you look at how Intelligent Go works you plug the car in and Octopus charge it when it suits them and I’ve been surprised at how frequently that’s outside of the cheap window. Today, for example, it added 20kWh this afternoon. I expect V2G to operate much the same way. 

[SteamyTea]

Just had a thought about the Grid balancing capability 

At the moment there are just not enough vehicles capable of doing it to make a difference (about 1.3m BEVs).

But let's say that in 5 years there are another 2m BEVs and at any one time half if then are capable of discharging 4 kW to the grid. So 2 GW is available.

Sounds useful, but I am not so sure. If the vehicles were connected where the power shortages happen, then it could work, but I suspect that the cars are in suburban areas and the power shortages are in urban areas.

It is possible to get the local area data, but not sure if it is available as a time series.

[Dillsue]

3 hours ago, Kelvin said:

It’s unlikely the DNO will take control of the chargers. It will be the suppliers. 

Not sure about that. The DNO will know local grid demand and supply characteristics which the suppliers won't. I think its more likely the DNOs will be managing any grid balancing, maybe via suppliers, but it would be the DNOs calling the shots??

 

It's not just the total number of EVs that influence this, it's the number of EVs that support bi directional charging, and those where the owners have bought a bidirectional charger, and those where the owners have gone through G98/G99, theres more to it than just owning an EV. Whilst a growing number of EVs may support bidirectional charging I think it only going to be a (small?)proportion of owners that set themselves up for V2G, under the current framework. Maybe in a few decades once ICE cars have gone and there's greater public understanding and incentives to hook up your cars battery to the grid will things need managing differently

[JamesPa]

13 hours ago, Dillsue said:

I think it only going to be a (small?)proportion of owners that set themselves up for V2G, under the current framework. Maybe in a few decades once ICE cars have gone and there's greater public understanding and incentives to hook up your cars battery to the grid will things need managing differently

I think you are right

 

But the potential to mitigate the cost of infrastructure upgrades if done right is enormous.  A home battery can smooth out individual demand more or less completely, and its pretty much guaranteed that you are at home (and hence the car is available) when your personal demand peaks.  If we can succeed in smoothing out the demand of a significant proportion of customers, we don't have to spend anything like as much on infrastructure upgrades.  This needs (and is presumably getting) a lot of thought, although the recent (understandable - at least politically) decision not to adopt zonal pricing probably makes it more difficult.  

 

Incentivisation could be 'carrot' (eg by limiting the incoming power available to something way below the typical 23kVA (100A) or 'stick' eg some severe incentives, or a combination.  I strongly suspect, however, that  its easier just to do the infrastructure upgrades, whack our bills up and 'blame' net zero rather than have a well thought through but politically even more contentious plan.  Furthermore the infrastructure industry is incentivised to push for infrastructure upgrades.

 

Maybe there is a sweet spot to cover kettles and ovens which presumably account for the 'spikes', and switching of heating for half an hour or so when the spikes occur (some heat pumps at least specifically provide for an electricity operator shut out).  Personally Im far from convinced that the massive infrastructure upgrade needed to cover our every whim is justified or justifiable.

Edited July 31 by JamesPa

[Kelvin]

14 hours ago, Dillsue said:

Not sure about that. The DNO will know local grid demand and supply characteristics which the suppliers won't. I think its more likely the DNOs will be managing any grid balancing, maybe via suppliers, but it would be the DNOs calling the shots??

 

It's not just the total number of EVs that influence this, it's the number of EVs that support bi directional charging, and those where the owners have bought a bidirectional charger, and those where the owners have gone through G98/G99, theres more to it than just owning an EV. Whilst a growing number of EVs may support bidirectional charging I think it only going to be a (small?)proportion of owners that set themselves up for V2G, under the current framework. Maybe in a few decades once ICE cars have gone and there's greater public understanding and incentives to hook up your cars battery to the grid will things need managing differently

I didn’t say the DNO wouldn’t be involved I said the suppliers would be managing the chargers. We already have one example of that with the Octopus V2G offer. The DNOs aren’t set up to implement that. There’s a reason the Octopus Intelligent Go tariff often charges your car outside of the cheap window. 
 

On the second point. We are saying the same things so I agree. It’s a niche group of people that will do any of this for some time to come. In a generation or two of EV development they’ll likely nearly all be bi-directional capable. Bi-directional chargers will increasingly become more available at a similar price point to current chargers. 

[SteamyTea]

2 hours ago, JamesPa said:

A home battery can smooth out individual demand more or less completely

The Grid's peak and troughs are fairly well understood and very predicable, by putting in micro-balancing, at the home level, existing algorithms would change the current (pun intended) predictions somewhat.

Where balancing is really needed is near existing grid infrastructure so that unscheduled disconnects can be dealt with.  This obviously will not help when infrastructure is expectantly damaged (pylon problems), but it can help deal with cascade disconnects i.e. 2 large generators come off line together (which has happened).

 

[JamesPa]

2 hours ago, SteamyTea said:

he Grid's peak and troughs are fairly well understood and very predicable, by putting in micro-balancing, at the home level, existing algorithms would change the current (pun intended) predictions somewhat.

Doubtless so, but electrification (heat pumps and EVs) change the medium term (think periods of many hours) base load significantly.  Thus the existing peaks are layered onto a much higher base, and so the delivery capacity needs to be much higher.  This can, so far as I can see, be mitigated if the existing peaks (which are generally short term) are smeared over adjacent time periods, which a relatively modest battery can do. 

 

Thus a house, instead of requiring 90A peak to cope with kettle (say 10A), cooker (say 20A) , heat pump (say 32A), Iron (say 10A) and BEV charging (say 20A), may only need to cope with heat pump plus BEV charging plus the 400W accounted for by everything else when averaged over over a day, about 60A.  Thats means that the infrastructure as a whole needs 2/3 of the instantaneous capacity, quite a difference.

 

Of course an alternative local solution to aa battery is to turn down either the electric car charger or the heat pump when the other items are drawing their peak.  This would be less resource hungry and may actually be a better solution.  However it would require coordination between industry sectors that, at least currently, seems unlikely.  maybe that is why electricity supply company shut out is built into at least some heat pumps, so that the supplier can effect the shut down when they need to, presumably in return for a tarrif break.

 

All very rough and ready but illustrative I think of the opportunity that micro-balancing offers.  Some people are already railing against being 'controlled' or 'restricted' by the electricity companies and what everything simultaneously, but the same people will complain bitterly when they are asked to pay for the infrastructure upgrades which are necessary to give them that luxury.  Something has to give, whether its through carrot, stick, or a combination of the two.  You cant bake your cake and heat it.

Edited July 31 by JamesPa

[SteamyTea]

52 minutes ago, JamesPa said:

Some people are already railing against being 'controlled' or 'restricted' by the electricity companies and what everything simultaneously

And forget that the company fuse already limits what they can have.

Always was amazed when installing PV systems how many people thought that 3 or 4 kW_p of PV gave them independence from the electricity company. I never told them about auto disconnect.

[Kelvin]

Apart from charging the EV we are effectively self-sustaining power wise at the moment. That will change in the winter of course but the batteries are big enough that charging them overnight will massively reduce our grid demand to a relatively small amount. 
 

The bigger issue I have is with water. This long dry spell of months is definitely a worry. But a different topic. 

Edited July 31 by Kelvin

[JohnMo]

1 hour ago, Kelvin said:

self-sustaining

We generated a 3kWh today, far from self sustaining here. The joy of being north.

[SteamyTea]

2 hours ago, Kelvin said:

The bigger issue I have is with water. This long dry spell of months is definitely a worry. But a different topic. 

Start a topic on it, one of my biggest bills is for water.

[JohnMo]

16 minutes ago, SteamyTea said:

Start a topic on it, one of my biggest bills is for water.

Get a borehole? Then you stay in control of costs, not some big corporation, that passes it's fines on to you to pay.

[Dillsue]

1 hour ago, JohnMo said:

Get a borehole? Then you stay in control of costs, not some big corporation, that passes it's fines on to you to pay.

Borehole=eureka! I'm currently battling with Hafren water over a 76% rise in water only supply over the last 5 years and 100% increase if I include the current bill. A borehole sounds a dream come true but I guess there's a fair wedge of an outlay.......and regulation?

[S2D2]

4 hours ago, JamesPa said:

Of course an alternative local solution to aa battery is to turn down either the electric car charger or the heat pump when the other items are drawing their peak.  This would be less resource hungry and may actually be a better solution.  However it would require coordination between industry sectors that, at least currently, seems unlikely.

 

3 hours ago, SteamyTea said:

And forget that the company fuse already limits what they can have.

 

Yes, this is already playing out with DNOs that will not fit larger than 80A cutouts. Plenty in my opinion but it makes the local charger installers panic when you have a 32A induction hob, 2x16A ovens and a 40A heat pump. I actually had to inform the latest I had round that the premium chargers do offer a second CT clamp to limit overall household power draw and avoid blowing the cutout. Their initial solution was just to hamstring the charger to not far off a granny charger at all times despite the fact the house load never goes above ~40A.