V2G Analysis - Energy costs and Export Payments whilst on the V2G trial

  • 12 October 2021
  • 8 replies

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  • 9 replies

Today I was looking at my OVO account and getting cross with the incorrect data it showed for my predicted mo mthly payment and the associated graphs, suggesting I need to pay nearly £190 per month…. so I have made my own graphs which are accurate…. I thought people might be interested to see...

I have been in the V2G scheme now for 19 months and after sorting a number of issues with the smart meter (which meant I initially had little or no accurate data), I have just analysed the last 12 bills…. all of which were accurate.

FYI…. We live in a 400 year old 4 bed cottage which has been made as eco friendly as is reasonable without upsetting its character or destroying anything important…  (so far      efficient house!) however, we have a first generation 1.2Kw PV installation on the garage roof and solar water heaters on the kitchen extension. Because of lockdown, our EV mileage is relatively low at about 6K for the year, so the car has been here to plenty for V2G!

The spread sheet shows our electricity and gas bills, the export payments and the PV generation and payments, along with the various totals used on the charts...

The upper chart shows the OVO bill (gas, electric/VAT) with and without the V2G payment.

The lower chart shows the net total after the PV export payment is included….

As you can see, our net energy bills come to an average of -44p per month…. so effectively no net cost!

I think this is a very powerful advert for the future of V2G or V2H… We get the car to do work helping to balance the grid and reduce the need for carbon based power and as a payment we effectively get free fuel for house and car, complete with the added pleasure of driving a quiet and clean electric vehicle…. what’s not to like!


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Userlevel 7

A great rundown of your energy costs/V2G export payments over the past year and a half, @NeilG - We agree it’s a great advert for others who might be considering this type of charger in future!


Not sure if you’ve had a chance to check out @TomekS recent summary too:



A real insight into the amazing benefits to be had both for the V2G member and the national grid. 


Tempted to consider a V2G compatible model when you invest in the electric campervan, @Jeffus?

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@Jess_OVO Am no expert but i am sure batteries will have a role to play in the future. 

Will be interesting to see how ovo scale up to a commercial offering outside the trial


Is there anything you can share about when a mass market product will be available and whether similar savings would be possible?

We never really delved further into degradation readings experienced in this thread. @Tim_OVO did you ever find out anything about whether 6% was high? Of course it may be due to calibration?

Am sure we would be looking for our next vehicle and the charger to be ideally  compatible with v2g so we have the choice at any time. I am realistic, it may be electric campervans are outside our price range so when the time comes we may switch to an electric car and a tent although that would make any winter camping interesting... 

It is great to see so many trials generally, not only with OVO. 

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Great update, @NeilG - great ROI numbers there! A real endorsement of the technology. 


Speaking of which, @Jeffus I’ve spoken to Indra about battery degradation findings from V2G. I’m told there’s a report which covers this, with the findings available here


“This new research into the potentials of V2G shows that it could actually improve vehicle battery life by around ten percent over a year.” 


This is interesting! 


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Great update, @NeilG - great ROI numbers there! A real endorsement of the technology. 


Speaking of which, @Jeffus I’ve spoken to Indra about battery degradation findings from V2G. I’m told there’s a report which covers this, with the findings available here


“This new research into the potentials of V2G shows that it could actually improve vehicle battery life by around ten percent over a year.” 


This is interesting! 


Interesting background but the report is from 2017 and with a land rover?

I was curious about the actual ovo trial and the potential shall we say 6% degradation of the nissan leaf in the trial. This looks dramatically higher than the research paper? Of course there may be a good reason for this and perhaps the degradation isn't this high. It would be good to know the v2g team look into these real world examples and if possible give this forum some feedback? Sorry to keep pushing the point but it would be good to get some more real world degradation example figures from the trial that could be shared. It may all be fine. 

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Yep that’s a fair point, @Jeffus.


I’ve queried this with the V2G trial administrators this morning, they’ve confirmed that we don't have in depth analysis from the LEAF cars of how their battery state of health has changed, vs a control group not doing V2G. This was not the main focus of the Sciurus V2G project - it was more about proving the feasibility.

However anecdotally from customers on the trial, we've heard that people aren't seeing significant degradation above and beyond what you'd normally expect as an EV gets older. That research paper (here) sheds some light onto the possible reasons for this observation (e.g. that V2G actually means the battery spends less long at high states of charge, which is better for it). 


Don’t forget we have dozens of trailists here on the forum to speak to about this. @Jequinlan for one mentioned very low degradation on this thread:



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I have been keeping a tally of my leaf’s degradation, the car is average for age and milage.  Given 2 of it’s 5 years have been on VTG I’d say there’s been no additional degradation. If anything I think VTG has helped stop the rot, as the car was already down to 86% when purchased just before the VTG trial, it’s lost about 4% in 2 years of VTG.  It’s currently just about where Nissan predicts the battery should be…. https://flipthefleet.org/resources/benchmark-your-leaf-before-buying/

Worth mentioning that the leaf is notoriously one of the worst EV’s for battery degradation. The improved battery packs and management systems used in recent EV’s, should mean their batteries are far less likely to degrade as rapidly as a leaf.  Won't it be interesting to see how long the next generation car batteries will live for?  

Now if Ovo can sort out a VTH version of the VTG App, in 10 years time I can just leave my old leaf in the garage on bricks, and use it as the worlds largest Powerwall.

Userlevel 7

A great update this one, @jp1.


Seems to agree with the general findings on the V2G trial as well so I’m just gonna tag @Jeffus here as know he’d be interested to hear this from a trialist directly.


Interesting idea on the reuse potential of a EV battery for Home Energy Storage too - wonder what our Home Storage expert, @Transparent would make of this idea?

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At first glance @Jess_OVO a Nissan Leaf battery has enormous potential - about 360v :hugging:


More seriously, though:

If you are fortunate enough to come across a Leaf that’s been written off but still has a healthy battery, then it would serve very well as a static Storage-device.

A complete battery tray can sell on ebay for upwards of £5000.

More commonly, however, people are reporting Nissan battery trays which contain one dead battery stack out of the 48. The inbuilt software will map this out, but you then have a vehicle with reduced capacity/range.

There are numerous online blogs and YouTube videos which show how you can open the Leaf battery tray to get at the cell stacks. For example, this one describes the wiring configuration and how it might be possible to use a generic 3rd-party BMS (battery management system) to redeploy them with a Solar Inverter.

How useful such a battery-stack is to you will depend on the depth of your understanding regarding lithium-cell charging, and how to physically remove the cells from a steel casing which has been hermetically sealed!