Check out the latest on OVO's Vehicle to Grid trial here

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Userlevel 2
Hi @Delboy @Hari_OVO

Thanks for this info. Concerned that the bill just shows a cash amount and no meter figures to verify against. This needs fixing as a matter of urgency otherwise there will no doubt be many queries regarding the cash amount not being correct.
Userlevel 4
Hi all,

Firstly - thank you all for being so active, and providing such valuable feedback. It's hugely appreciated and it's great to see that it helps newer trial participants like @garystokey understand things that possibly aren't made as clear as they should be up front! It's genuinely fantastic to see so many of you on here giving us useful pointers as to how we can improve.

Let me try and summarise where we are currently at with the billing process...

Currently, as @Delboy has said, you will see your export credits for the current month, when you receive your next statement.

So, if you receive your statement on the 8th of each month, you'll see a line item on that statement referring to 'Vehicle-to-grid Trial Export Credits'. These credits are for all the energy exported in the month previous, as well as the money to cover off the additional energy you would have used (so import unit rate + 6p). As @Delboy has pointed out, we have a bit of work to do here to improve what is displayed so there is more information for you. We're looking in to what we can do here.

However, in the lead up to that first statement Your consumption will rise and this will show on your graphs, as pointed out by @Leo Moran.

Because your device will be exporting, and then re-charging your car battery, you'll be using more electricity, as you'll all have quickly noticed in the first few days of having your charger up and running. In an ideal world, we would be able to show you, on the same graph as above, what the extra is that is being used by your V2G charger, and also how much you are exporting each day.

We're a little bit away from that ideal world right now, so we are looking into a couple of things in the more immediate term to see if we can make things a bit better. These are:

  • Whether we can do something up front to ease the surprise/bill anxiety from that initial rise in consumption.
  • Whether we can simplify the export rate slightly to make it easier to understand what you should expect to receive each month.
  • We want to improve on elements of our content and communications, so that as you say @piersjk, people come into the trial fully aware of what is going to happen.
Hopefully I'll be able to share more on the above 3 points soon. I would also like to re-iterate that while your graphs will show an increase in consumption, and a higher cost, your actual direct debit will not be changed, so the actual amount that you are charged will remain the same.

On E7, @Leo Moran - I don't want to make any promises or give you false hope - but we are spending a fair bit of time thinking and investigating what we can do here, once we have something more to share, we'll post something on here because we would love to get your thoughts.

Again, thanks all - really appreciate the feedback, please do keep it coming!

Userlevel 5
Mixed emotions this morning.

Checked my account and it's been credited with £25.73 though unable to see what it's for yet as there's nothing on my account to say. The last statement was on 1st August so I assume it's a credit for the power exported though not sure if it's to date or just up to the end of August, I'll have to take my shoes and socks off to work it out...

That joy was short lived when I checked the Kaluza account to see that the charger stopped working in the early hours and I now have only 52% in my battery instead of the usual 100%....not to worry though. I reset the charger in my dressing gown (an unusual place to have a charger I hear you say), pressed the boost button and it's once again filling the car at 5.86 kWh, should be ready by lunch time.

I'm not disheartened though. I realise it's part of a trial and things like this will occur. No harm done as I don't need the car and I also have my old charger which, at the flick of a switch I can bring back into service at 6.6 kWh....however it perhaps highlights another problem. What if I was intending to go somewhere today expecting a full charge to be available at 7.00am and I only have 52% available....enough for about 80 miles instead of 160 miles ( 60 instead of 120 in the 30 kW LEAF). Perhaps it may be useful to have a system where, if the charger fails it sends a text message or phones the participant to let them know of the fault. I'm sure a lot of people wouldn't mind being woken up at 2.00am when they can do something about it rather than wake up at 7.00 and realise they haven't got enough charge to get them to their destination...

I'll send an e mail to the team to let them know my charger has failed for a third time...
Userlevel 5
When I first signed up to the V2G trial I thought it would just be an hour in the morning and an hour in the evening peak periods, a couple of hours a day exporting 9-10 kWs and importing back in the early hours of the morning. But it's more than that, a lot more.

Firstly the amount exported is averaging at 20 kW a day, uploading at 3 kWh and then importing during the early hours at 6 kWh. Yes, it tends to upload in one go between 4.00pm and midnight and then download in one go between 1am and 6.30am....

But the one thing you notice is that it's both importing and exporting at all times during the day, sometimes almost simultaneously. On peak occasions it's a full flow and other times just a dribble...and the penny has dropped.

My car isn't just a battery to supply the grid, it's a bucket to catch all those drips and overspills. When the grid has to fire up a power station to meet anticipated extra demand what happens when demand doesn't meet expectation? They're now producing more electricity than required so rather than dump or waste it, they divert it to my car and all the other cars connected to save till a time when they need it and the flow is reversed.

My car isn't like I thought an extra source of joined up power, it's the polyphila to fill in all those cracks where there's not quite enough or just too much from the power stations. It may just be an extra kettle or a couple of extra TVs I'm supplying to but it's negating the necessity to fire up a massive power station and wasting vast amounts of electricity in the process.
Userlevel 7
Badge +3
That's an interesting point @Leo Moran.

And I have doubts that the times your battery is exporting are actually useful at the moment.

As I understand it, the Kaluza Platform is using National Grid stats to inform it when to draw power from your battery. But you're 3 transformers away from your Grid Supply Point.

A. Whatever you feed back to the Grid is a drop in the ocean. The best that can presently be achieved is that your EV delivers enough output to remove your own house from contributing to the early-evening peak demand.

B. Unless your export is matched to the phase imbalances on your local substation, we have no idea if you're diminishing the losses or contributing to them.

The real money to be made from managed grid supply is by Kaluza acting as an Energy Aggregator.

This would be handled by a supply contract with your local Distribution Network Operator. They could pay for a number of different services:
  • supply when Primary transformer is cannot meet local demands. In the SW Region, Western Power have designated Constraint Management Zones (CMZs) where they seek to procure power at defined times.
  • supply and/or provide a load to reduce substation losses; which can only function if you're connected to a Monitored Sub-station and it's known what phase you're on
  • supply to reduce harmonics (a requirement of the RIIO-ED1 profits cap applied by Ofgem's regulatory framework)
  • provide a load (ie charge-mode) when the local Distribution Grid is being offered a surplus of renewable generation
There's only one National Grid related payment which I think would be of use within the V2G scenario, and that's to respond to emergency power deficits, such as occurred on 9th Aug. But the mechanism to achieve that is likely to require being channeled via SMETS2 meter commands rather than across the internet. No such mechanism yet exists for Aggregators.

I don't think any of these payment systems are (yet) embedded within the Kaluza Platform software. Not only are you unlikely to be connected to any of the monitored sub-stations, but I wonder if any of the V2G sites have been checked to see what phase you're connected to.

So the 2p or 6p per kWh you are presently being offered is a notional amount, loosely based on the buy-in price which OVO would expect to pay when buying-in energy to meet their customers' requirements.

And if that's the case, I can't see what there is to gain by your V2G chargers both importing and exporting at all times during the day as @Leo Moran has just stated.

This is very early days for V2G technology. Many of the inputs which the Kaluza platform would require to access the more lucrative payments from DNOs don't even exist yet.

And just to let you know, a couple of us are discussing how Storage Devices might help to avoid a future national outage (as occurred on 9th) on this other topic about Load Shedding.

As members of this Topic have practical experience with V2G, you may want to pitch in and say what you think.
Userlevel 5
As always, Thanks Ninja for all that information. I'm still relating what you told us in Bristol, on to anyone who'll listen. The facts are brilliant to see and to work out.

That said I'm under no illusion that withdrawing my 3.2 kWh from the 32 GWh grid is hardly going to cause blackouts in the South East of England, hospitals to go without power, traffic lights to fail and planes be grounded at Newcastle Airport and that it'll probably take another 2 years before all 1,000 participants are connected to The Grid with their 3.2 MWs of power but here's some figures for you.

There are presently 32.5 million vehicles registered on the roads of the UK and if they were all EVs and just a third of them were connected to The Grid that would supply enough electricity to sustain power uninterrupted if every single generator shut down simultaneously. There are a thousand and one permutations why that couldn't possibly happen and I know you'll know most of them but the fact is when I connect my car to the grid I'm part of the grid as a whole, albeit 0.00000001% (give or take a naught) and I'm happy that when my neighbour puts his kettle on for a cup of tea it's more than likely that my car is helping to boil that kettle. I'm only a very small cog in a very large machine but if someone somewhere is getting benefit from what I'm doing then I'm more than happy to help.
Userlevel 7
Badge +3
Thanks for the response @Leo Moran .... may I be permitted to disagree?

The way that your 3.2kW is connected to the Grid at present, may not be contributing anything at all. You may actually be increasing losses rather than supplying power for your neighbour to make a cup of tea.

Let me share here one of the graphs I showed you when we met at Bristol a couple of months ago:

This is a graph on which I've plotted just four of the 146 parameters available from a monitored sub-station in Devon.

In this case we're looking at one of the three feeds from that substation. The blue, red and yellow lines are half-hourly plots of the average current (in Amps) being supplied from the 11kV Distribution Grid.

It happens to be the case that phase L2 has more photovoltaic solar panels connected to it than either L1 or L3. So on the Wednesday less power was taken from the Grid on that phase because the sun was shining.

The consequence is a phase imbalance which I've marked with an A and B. They don't exactly coincide. There is also a slight time-shift.

Three-phase transformers aren't designed to operate like this. The imbalance means that energy is being lost, which can be detected by an increased temperature in the cooling oil.

If your V2G charger was connected to L1 or L3, at point B it could provide energy to that feed and assist in reducing these losses.

Alternatively, if your V2G charger was connected to L2, it could absorb the over-generation of solar power from point A, not only reducing the sub-station losses, but giving you a payment from the DNO for your service. Thus you don't just get your EV charged for free; you actually get paid a small amount for doing so.

The problem is, we haven't a clue which phase you're on. You could actually be feeding power into the grid on phase L2 at point A and therefore increasing the losses!

The Kaluza-platform algorithm which sends instructions to your Charger is using National Grid power-demand readings. These bear little relationship to what is happening at your local substation.

It's this anomoly which means Kaluza can't operate as an effective Energy Aggregator. So there are no payments available from your DNO for the "service" you are offering.

There are solutions to this. After all, the Kaluza platform already has weather forecasting as an input, and can therefore predict when different areas of the country will receive solar radiation the following day.

Moreover there is live energy-mix data available from each Bulk Supply Point. So the pattern predicted by the Kaluza software can be verified on a per minute basis, and charge-cycles adjusted accordingly.

However, I don't believe the current iteration of the Kaluza platform uses that data stream.

And that's why you're seeing that odd sequence of charge and supply periods affecting your car's battery throughout the middle of the day.
Userlevel 5
Sorry Ninja, appreciate the effort you've put into trying to explain to me the ins and outs of the problem....but there's too many words for me to read and I have some drying paint to watch.

Can I remind you that I have problems with big words and I'm not an electro physicist...just a common-a-garden nonentity.

This forum is for people who want to get into the vehicle to Grid Trial which goes on for 2 years, not reform the way the national Grid is run. You are an expert in that field and your knowledge will prove invaluable in that forum. The vast majority on here will be like me, get the system off the ground, evaluate if it's a good or bad thing and help progress it if it is or bin it if it isn't. You seem to have written it off before we've even started.

I would never criticise the work you are doing nor the effort you put into it....but please bear in mind that the majority on this forum are not as enthusiastic as you are, just want to know the pros and cons of the V2G charger.
Userlevel 5
Ninja, out of respect for you I've actually gone back and read over what you've written and as thought, you're trying to solve the problem of where the electricity is going to after it leaves the car. This trial as I understand it is trying to develop a two way charger to export and import power from my car. It has nothing to do with The Grid or how best to use electricity. I suggest you take that one up solely with the national Grid and OVO, not on this forum.
Userlevel 7
Badge +3
That's an interesting perspective @Leo Moran

We (the population of GB) did exactly as you suggest 20 years ago when we were encouraged to install PV solar panels on our roofs.

Homeowners did so without any reference to the effect on the Distribution Grid, and were guaranteed Government-backed financial bonuses to compensate them for the capital outlay.

The result has been a doubling of technical losses in the Distribution Grid to around 10%. You and I are now paying for this in our electricity charges in addition to the 3% which goes towards the FIT payments for those with the solar panels installed.

The V2G Trial cannot be run in isolation. There are three major components which need combining in the correct way to bring about a successful uptake of V2G technology:

a. the V2G unit itself, able to operate safely and effectively without adverse effects on the EVs to which it is connected.

b. the intelligent software which operates in the background to manage the charge/discharge cycles. The Kaluza platform is heading in the right direction, but it cannot yet make the optimal decisions unless it has enough relevant data to inform it. That is a significant problem of which end-users will be largely unaware

c. a tariff structure to ensure that end-users are able to select preferences which achieve the energy efficiency, cost savings and decarbonisation balances they may be seeking

If the V2G Trial were only about achieving Point-a and half of Point-b, then we might as well stop the Trial now.

But I doubt that OVO would shift many more of their stock of V2G Chargers because there are rival companies who will notice the shortfalls and develop solutions & products to overcome them. I'm certain that @Hari_OVO won't be letting that happen!

In the last 24 hours, one of the V2G Triallists has reported a significant problem with Point-c (the tariff). Have a look here. Do you think that matters? Or should it be ignored because it's "not part of the Trial"?
Userlevel 5

I may be misreading your posts but all I can see is negative feedback. I entered this trial in good faith with an open mind. My agreement is with OVO Energy and not The National Grid, ie I'm helping OVO Energy over a 2 year period to develop a V2G charger. What they do with it is up to them. At present I'm quite happy and from what they say they're also happy with me. As for the politics of the matter....nothing to do with me so please don't bring it here, you're on the wrong forum for that.

As for the other post on chargers...who in their right mind signs up for a 2 year trial with 2 months to go on his present tariff without checking to see how much it will be onwards. Not sure what trial he's on, the V2G or just a 7 kW charger....but I made sure I had in writing exactly what I was going to be paying in July 2020 when my contract ends.
Userlevel 7
Badge +2
@Leo Moran @Transparent I guess the good learning here is that everyone is entitled to their own views and opinions, so it's great to see you both calling this out in your replies.

Let's remember no-one is here to try and get one over on anyone else, we have freedom of speech and want those with knowledge to share as it's super useful to some people, and indeed us at OVO and whilst you @Leo Moran may not want or need the in depth detail that @Transparent is able to offer, given his knowledge, him sharing this, may well be useful to others that are!

Let's continue to support and share knowledge and each take away from it what we want or need to.

And yes Leo, we are very happy with the level of feedback you and all the others on the trial are providing!! Keep up the good work!!

Userlevel 5
Thanks for that Darren and I offer my sincere apologies to Transparent if my comments were offensive, they weren't meant to be. I actually enjoy reading his posts as they give me an insight into a world I and probably most other people are unfamiliar with....however in the interests of "freedom speech" perhaps his posts on here are a bit too informative. A condensed version would be very much more appreciated. Also to bear in mind we live at 2 completely different ends of the country and with numerous on shore and offshore wind farms, a massive solar farm and a Nuclear power station and Gas Power station as well as a battery storage station within 6 miles of my house, our circumstances are probably not the same either.

As for the charger, once again it failed in the early hours, making that twice in two days and 7 times this month.....e mail already sent off...

Thanks again Darren for always the diplomat.
Userlevel 5
Just a short comment for anyone else on the trial.

I have now been monitoring my charger for a whole month and checking it every day. In that time the car has been in the garage almost none stop with only 60 miles accumulated (I don't get out much). The car charges up mainly between midnight and 6.00am and exports to the grid between 4.00pm and midnight. Initially when the trial started with a full charge I had an estimated range of roughly 160 miles. This has progressively increased and today the estimated range is 180 miles. I realise that temperature makes a difference...but the air and battery temperatures are very much the same throughout the month. I just wonder if the battery is being rejuvenated in some way.

Has anyone else noticed such a change? I'd be very interested to know your opinion on this @Transparent.....(I'm eating humble pie at the moment)

(Mod Edit - @piersjk @Delboy see Leo's comment above!)

Userlevel 7
Badge +3
That's very interesting @Leo Moran. As I don't have a Leaf (or any EV) you'll need to tell me where you obtain the "estimated range" reading from. Is it within the car's own instrumentation?

I understand the background chemistry of batteries. It's very difficult to know the state of charge by measurements on the battery itself. I surmise that the charge system actually derives this figure not just by measuring battery voltage, but also by calculation from the charge-current, battery temperature curve and charge time.

The less you use the battery, the more difficult it is for the calculation to be accurate.

So on first analysis I would expect that a battery being charged and discharged every day would tend to provide a more accurate estimate.

We really need to compare your observations with another member of the V2G Trial who actually does more road miles each day. This will enable us to assess whether Nissan are using road-miles within the calculation.

If so, then an EV which experiences most of its charging due to battery-use whilst static (plugged into the V2G charger) would be giving a different result.

Let's wait and see what others like @Delboy and @piersjk have to say.
Userlevel 5
Thanks Transparent, as always much appreciated..I may not express it well but I actually do read everything you write and try to understand.

The on board computer I believe works on the previous journeys but not sure what parameters it uses given that the journeys can be days if not weeks apart.

One thing I am doing is making sure the car is connected at every opportunity and I'm getting maximum import and export for a full month so people can see just what they may expect from one month to the other. With a maximum target it can be compared with someone who uses their cars the most and get an average.

By Tuesday I shall have exactly 30 days since the trial commenced and by next week a whole full calendar month of August. Sadly I haven't monitored the car range every day, just observed until recently.

Userlevel 5
Well it's exactly 30 days from whence I commenced the trial and it's been an interesting month. I suppose if you want to know what the maximum transfer of elecrity is, then I have probably taken that to the limit. Having only done 70 miles in 30 days and the car in the garage, connected to the grid all the rest of the time then the numbers I've collected should give a fair representation of what is involved.

Firstly this is not a scientific record and should not be quoted as true. The whole calculations have been done using LEAF Spy Pro, Kaluza charts and Nissan's own Guessomater. Now, based on the fact a watch which is 5 minutes slow tells the right time when it's midnight or noon...albeit 5 minutes out, the timing is accurate. Equally all the records taken are used with the same instruments about the same time in the same conditions and because they are recorded in a unventilated and insulated garage, they are near enough laboratory conditions....all you have to do is work out how accurate the devices and calculations are in the first place... It should also be noted that over the month I have progressively added different readings to the calculations which didn't seam important initially but became pertinent once patterns emerged, like recording the outside temperature and the range...oh, and leaving the car parked in e pedal mode also knocks about 8 miles off the predicted range.

The very base line is the first time I recored information on LEAF Spy Pro. On 1st April 2018 with 1,209 miles on the clock, the state of health of the battery was 99.24% and on the first day of the trial on 26th July 2019 it was 96%. Today that health is 95.82% meaning in 30 days the health has fallen 0.18% or on average 0.006% per day. ( I understand it's not an accurate way of measuring the state of the battery....but hey ho...) For the AHr reading it was 114.563 in April 2018, 110.820 on 26th July and 110.610 today....having fallen 2.10 in 30 days or 0.07 average per day...

In 30 days I imported 641.7 kWs from The Grid and exported 575.8 kWs to the grid, A difference of 63 kWs or 2.1 kWs average per day which is probably power that was used from the battery to run the house rather than drawing from the grid. There again it could be power that's lost to heat or converting it from AC to DC and back again to AC. The average imported was 21.39 kWs per day and the average exported was 19.2 kWs. Roughly calculated, if OVO compensate me .06p per kW that I export to the grid, that's £34.55p they will (hopefully) pay me back in September and every month. It should also point out that if the figures are correct, this will likely be the maximum I'm going to earn in a month given, once the kids are back at school I'll be going for runs out in the car and the number of evenings it will be available for exporting will be reduced.

During one of the hottest Augusts on record I recorded the battery temperature once it was fully charged to 100% every day, just after 7.00am having spent most of the evening from 4.00pm-12.00pm exporting at 3.4 kWh and 12.00am-7.00am importing at 6 kWh. On estimate the battery was 10 degrees warmer using the charger than not using it and with heat unable to dissipate from the insulated garage, this too was normally 10 degrees warmer than the ambient outside temperature. This insulation of heat had an effect on the battery which wasn't able to cool down below that of the garage, a difference of 2c-5c. Over an 8 day period with the battery average 26.2c the garage average was 21.4c. Over 30 days the battery average was 24.6C. The optimum operating temperature for a battery is estimated by some to be 26.7c but with the guesometer range varying from 172 miles to 182 miles in 8 days I'm assuming that it is also based on the relationship between the battery temperature and the air temperature as the vehicle did not move for a week.

The Charger failed to function on 7 occasions...teething problems expected in the experimental stage so it didn't bother me and as I noticed it fairly quickly it didn't cause a problem, only failing in the early hours on one occasion and a quick boost charge had the battery back to 100%. It was noticeable that the charger tended to fail two days on the trot... Wed 7th/ Thursday 8th, Wed 14th/ Thursday 15th, Sun 18th, Thur 22nd/ Friday 23rd. Not sure if it's just a coincidence or something happens on a Wednesday/ Thursday which effects the grid....

So, the conclusion. having spent the last month playing with my new toy I'll be glad when I can just get back to my old life and start using the car for long journeys again....but anticipate it will start over again when I get a 62 kW LEAF which presumably will give different results. Failure apart, I can now predict just how much energy I have left and how soon it will take to give me 100%. I can set how much I want left (25%, enough to get me to the nearest rapid charger if I'm in a hurry) and how much rebate I'm likely to get in a month. I'm not sure, just from these figures which as I said was very inaccurate...but initially the charger doesn't seem to degrade he battery any fact if anything it appears to slow the degradation slightly though long term and more accurate calculations are for someone else to judge.

Am I happy I signed up to the trial? Yes. What do I like about the trial?...well the £30ish pounds in my arse pocket every month will certainly help with the electric bills...especially as I'm also earring 4% interest on it.....but I'm looking forward to having a lovely warm garage in which to work in the winter, even without using the oil filled radiator.

This ones for @Delboy , @Transparent, @Hari_OVO, @Darran_OVO and Aaron and anyone else who can get benefit...

Userlevel 3
Great write-up Leo! Thanks for keeping track of all this!. What you've said above is pretty much on par with what I'm seeing too as far as SoH goes. Not really paid that much attention to temperature on my car. I've noticed the starting battery temperature was a bit higher than usual the other day, but that's probably got more to do with the warm weather we've been having than the charger.
Userlevel 5
Aaron, your car is on the drive and should be cooler than mine, given the air temperature is about 5 degrees cooler than in my garage which is 2-3 degrees cooler than the average battery temperature. Can you do the same and see how your battery temperature compares with that showing on the dash? The higher battery temperatures may have something to do with the nights not cooling down as much this weekend. The lowest temperature I recorded was 24.5c though that was after a night without charging when the charger failed at midnight. The highest I recorded was 28.2c.

Also did you see Tesla Bjorn's live 1000 km road test in the 62 kW LEAF yesterday. It's worrying that it's throttling to 19 kWh meaning for an hour's charge it's restricted to about 80 miles....even though he did say that consumption was better than he expected. He's on live again from 5.00pm Norway time, doing a speed test.

Thanks for your posts which are very informative but I am a newby to this area and have some questions I hope you or others may be able to answer.

I am considering getting a second EV and like the sound of V2G but want to know more about how it actually works. This forum has already provided a lot of good info so many thanks.

If I have a new 60kw Nissan Leaf, will that work or only a 40kw battery?

What if any, other EV’s will work for V2G? If no others, do you have an idea of which manufacturers will have this capability next?

We currently have a new VW E-Golf. Any chance of this working with V2G?

I have a 3 phase power supply at my house. Does this mean that I will have the abilty to charge at a faster rate than 6kw as other normal chargers have told me I can charge at up to 22kw? Any other benefits?

If we get the Leaf, we will have two EV’s so will we be able to have both plugged in at the same time or will I need two chargers? We have not bought a home charger yet as I wanted to explore V2G.

I was reading some of the OVO forum comments on V2G and wanted to ask some technical questions as follows?

How it works

When the car is plugged in and the battery has excess power stored (above the minimum I have set), what power source will be used when someone puts on the kettle in the house? Grid or Battery?

I understand that electricity prices spike in the late afternoon and evening vs the late night early hours. Will my battery charging/discharging take advantage of this and what are these rates and amounts likely to be? See link below showing the variation in wholesale electricity prices in the UK hourly.

Please explain this in detail with examples of rates I might pay/receive with a forecast of the costs I could save.

My house is large with 5 people living in it and high electricity usage. Does this mean I will save more money?

Can you send me a worked example showing some scenarios of how it might work over the course of the year?

How does the OVO offer compare to the Octopus powerloop? One of the things I don’t like about the powerloop is the condition that the car has to be plugged in by 6pm to qualify for a rebate and it is capped at £30 per month.

Does OVO have a one or two page document or website that you can send that explains how it works in detail.

My business is focused on climate change and carbon emissions so I am very interested in this area and sorry if I have asked any silly questions but I am not an expert in this area at all.

Many thanks
Userlevel 5
Hello MikeA,

Firstly I'll leave @Transparent and @Hari_OVO to explain the ins and outs to you. Although Transparent may get a bit technical for me, hence I'm somewhat sarcastic to him, I suspect you are a bit more tech savey than me and you should understand his explanations well. I've met him in person and he's very well informed and I'd take his advice anytime (but don't tell him that).

Having just concluded a full month trial of the V2G charger I'm in a position to answer some of your questions. I also have a demonstrator 62kW LEAF on loan on Wednesday so should be able to give you some answers how it compares to the 40kW...but can only speculate what it's like on the V2G. I'm going to run it from 4.00pm till 7 am (the same as the 40 kWh) just to check heat dissipation..see below for other explanation.

When I began the trial I assumed that the car was only going to be used to back up peak periods so it would take from the car for an hour in the morning and an hour in the evening and give me it back in the early hours when I normally charge the car. I was reckoning on about 9-10 kWh a day....I was wrong in so many ways.

I set the car to be ready for 7.00am every morning and the export to the grid always began at 4.00pm, at 3.4 kWh and ended about midnight. It then began importing at 6 kWh till just about 7 when the car was fully charged. Oddly enough this worked out that it took and gave back to me roughly 75% of the battery capacity or 30 kW (allow me a bit of poetic licence with the numbers here because you don't actually get 40kW out of a 40 kW battery, more like 35 kW useable as the battery won't let you take the last 2kWh out and the charger won't suck out below about 3 kWh...guestomate.).

Since the monthly trial completed this morning (it's the first calendar month I can not only compare prices with but also I can compare it with last summer when I signed up to OVO) I played around with the start time of 7am and moved it back to 2.00am tomorrow and by back calculation the vehicle has begun exporting back to the grid already, not waiting till 4.00pm. I can therefore assume that the grid will constantly take power from the battery, 24 hours a day and will calculate the time to recharge at 6 kWh (remember the last 10% throttles so takes longer to charge) and export at 3.4kWh down to 25%.

So, that gets us to the 62 kWh battery which has several advantages. Firstly it is called 62 kWh because it has a capacity of 62 kWh but an availability to use 60 kWh. (oh and yes I don't know the difference between kW and kWh so please allow me lee way in that). Secondly although it generates the same heat that a 40 kWh battery does when discharging or being used, it generates a third less heat when charging and will throttle less towards the end. That means you can take 45 kWh (probably in reality 42 kWh) out of the battery until it reaches 25% compared with about 27 kWh from a 40 kWh battery. So, doing the maths a car ready to use at 7.00am will charge a bit quicker and export a lot longer so I'm speculating the export will start about 10am instead of 4.00pm.

I can't tell you how the pennies work out till I'm billed next week. I've been told that I'll get 6p back for each kWh I export but as there's a 10% difference between how much you export and import, I suspect it won't be exactly 6p when I have to come to pay for it. There's a couple of reasons for this. Instead of using power from the grid it appears that for just the odd kettle, TV or computer, the house draws from the car battery rather than the grid and it's only when I put on the oven, hob, washer, kettle etc, which takes me over 3.4 kWh that I start drawing from the grid. Secondly the grid is AC and the car DC so when importing and exporting power is lost to the inverter changing to compatibility. There's also heat generated which also uses power. So, if OVO allow me for the extra usage or that's all included in the 6p I'll have to wait for the bill to see....incidentally the way they do it is, I believe, they charge you for how much power you draw from the grid and add that to how much you export to the grid. They then bill you for the lot. However they reimburse you the cost of every kWh you export and add 6p to they bill you at 14p kWh and reimburse you at 20p kWh....

I hope this helps you in some way.

So now we get to the stuff that I can only guess at.

Firstly I've been informed that it's only Nissan LEAFs and EV200s that are present;y compatible with the V2G trial run by OVO for two reasons. Firstly Nissan are involved in the trial and secondly it only uses CHAdeMO at the moment because it's the only system capable of two way transference....

The V2G charger imports at 6 kWh and exports at 3.4 kWh so a standard 32 amp electrical system is OK for this charger. When they installed mine they by passed the main fuse box in the garage which also runs through the house box, and installed a bigger main fuse as the power comes into the house from 80 Amp to 100 Amp and installed another fuse box which serves the charger in the garage. The advantage of this is I can use the V2G charger and my original charger at the same time, so I can charge 2 cars without crashing the fusebox. As you have 3 phase I believe you can run up to 23 kWh on that or two 6.6 kWh chargers....perhaps even 3, at the same time...but I'll let others advise you on that, I'm purely speculating.

With regards to charging 2 vehicles I'm not aware of a single unit which will charge 2 cars at the same time but I have a Type 2, Type 3 and now the V2G CHAdeMO and can use any two of the three at the same time. May be wrong but I think you need 2 separate chargers to charge.

As for Octopus, I'm not familiar with them and didn't even know anyone else was doing a V2G trial so can't comment on it. As for payments, if you're getting a set amount it's different from OVO who allow you to charge as little or as long as you want, all for 6p per kWh. By my reckoning, the most I'll make in a month is about £35 from a 40 kWh car but that's with the car being stuck in the garage all day and giving 75% every day...a 62 kWh LEAF should give a bit more, possibly a third more...

As for the costings, layouts etc, sorry but I'm just a retired person, know nothing about business plans, working models etc, I'll leave that to others to show.

I hope this has answered some of your questions and if there are any other queries you have, by all means please ask, only too willing to help....just don't rely on me for the technical stuff...

I'll be putting on comments about the 62 kWh LEAF and the bills when I've had chance to properly evaluate them both later this week.

Many thanks Leo. That is all really helpful.
Userlevel 5
Well I've had my first bill and what a shock (pardon the pun). When OVO said they were putting a bigger fuse in before my fuse box I didn't realise they were actually wiring the lights from the whole of my street into my meter as well...What OVO say I've used bears no resemblance to what I estimate I've used compared with last year once the EV charging is taken out of the equation. My daily usage is half what OVO say I'm getting...and the credit for what I've exported to the grid is about a third less than I anticipated.....not only that they've credited me too much interest for what I'm in credit....and the whole set of maths I have just doesn't correlate with the figures I'm given.

On top of that I've actually paid for all the electricity I've imported to the car and then exported to the grid. The car has done 70 miles in the month and I estimate used 17.5 kWh so hardly an impression on the with a monthly average usage of 250 kWh my figures are way South of theirs of 1090 kWh. I sincerely hope that these figures are adjusted at some time or someone can explain to me how to use a calculator properly because I can't afford to pay an electricity bill of £160 every month for the next 2 years...

Userlevel 4
Hey @Leo Moran,

I'll PM you to discuss the specifics here.

In general, just as a reminder - unfortunately your exports are applied a month in arrears, we are working to try and improve this process but it's not as straightforward as it seems.

In the meantime, your direct debit will remain the same, so your actual payments to OVO will not increase. If this is not the case for you, please do let me know and I will investigate.


Userlevel 5
Thanks Hari,

Just got the new contract...shame it isn't back dated to August because I had a good month...but still not looks good. I can sit on my hands for a month and see what the October fairy brings me....

Thanks again for your patience...

Oh by the way, the figures on the OVO App are different from the Kaluza app and don't marry up. very confusing...