Check out my V2G (Vehicle to grid) installation with OVO Energy!

3 days usage so far and learn't quite a lot I didn't know before...mostly good and a couple of things perhaps not so good.

Firstly the wall mounted device isn't as quiet as my other 6 kW chargers which are almost silent....it has a big fan in and if you've charged using a stand alone CHAdeMO charger in a car park or garage you'll know what to expect....perhaps not as loud as some I've heard but on a still night, if the windows are open then you may not be the most popular of neighbours....

Secondly I assumed it would be an hour at peak period in the morning and an hour at peak period in the evening.....forget that. It downloads at 6 kWh and uploads at 3 kWh. Since Friday afternoon when it was commissioned (now 7.30pm Sunday night) I've downloaded 44 kWh and uploaded 49 kWh....and that's a lot of loading....and it doesn't just do it in one go...it's off and on most of the day, sometimes for hours on end, other times a minute to two and it's both uploads and downloads. Present plug in time is 52 hours 25 mins and the charging time is 11hrs 14 mins so the time uploading or downloading is probably about 20% of the day. Now to me it's not a bother as it's in a sealed garage and completely sound proofed so no one knows it's on....and once the novelty of looking at the app to see how much I'm charging is done I'll be happy.

Thirdly and this one is aimed mainly at LEAF 2 owners.....all this uploading and down loading generates heat, not only in the battery (temperature first thing on the morning is about 25C) but also heats up the garage by a few degrees....not a problem in the winter but in the summer a warm garage prevents the battery from cooling further. The result is if you want to drive a long journey and then charge on a CHAdeMO charger the charge rate will be a lot lower in the summer than the 50 kW rate advertised .....thanks to the extra heat......but on the other hand a bit faster in the winter for the same reason.

First impressions?.....well I'm really pleased with it. The installation was brilliant and I'm really pleased with the amount i'm able to donate to the grid...for a small fee of course but not sure how much that will be yet....I'll have to wait till the end of the month to find that out...

I'm now having my first concerns about the V2G....it probably won't effect the majority of people but it's something I'm getting a little worried about.

I like to go for a run to Scotland occasionally....and when I say a run I'm talking about Edinburgh for a coffee, Aviemore for Fish and Chips and John O'Groats just for the run out. It involves some long journeys and repeated charges over a short space of time. The problem is the more I travel the warmer the battery gets. The warmer it gets the slower it charges. The more it charges the warmer it gets.....etc etc. Eventually an initial first charge of 48 kWh can reduce to as little as 13 kWh when the battery temperature rises from about 15C at start to anywhere near 56C.

Normally before I have a run there is no demand on the battery and so it has about 7 hours in the garage to cool down. Then if I have to charge it over night on Economy 7, it's finished charging by 6.30am and it has a couple of hours to cool down again. The battery temperature is usually within 1 degree of the air temperature outside, even in the garage.

Since last week the battery is in constant use either uploading to the grid or downloading from the grid and the battery has no down time to cool. The heat generated dissipates into the garage which increases the in garage air temperature and reduces the cooling effect. The result is at the time I would normally drive the car the battery is now about 10 degrees above ambient temperature. The outside temperature this morning is 17C but the battery temperature is 27C and when I travel on my journey will arrive at the first charge with an already restricted download capacity.

The only way to test my theory is to try it out and weather permitting I will probably have a run up to Aviemore tomorrow for some fish and chips. I struggled in the heat last week when I popped up and another 10 degrees on the battery is likely to aggravate it even more....I'll keep you posted.

Hi @Leo Moran - thanks for all of this really insightful feedback. It's great that we've set you up to have both chargers up and running, and thanks for sharing the pics! Love seeing another install completed nicely.

Regarding your concerns about over-heating, it may be beneficial to set a different minimum charge level and/or ready by time on the days where you're planning on making the journey up to Scotland? If you set a higher minimum charge level, it will export less but you likely have a cooler battery in the morning.

Thanks for that Hari, glad you like the photos.

I was considering having a run up to Scotland tomorrow but the weather doesn't look to promising so I think I'll give it a miss. I'll continue with the settings as they are for the moment but when I next intend a run to Scotland I'll take your advice and knock the charge level down.

Really appreciate the advice.

Leo

Let me know how it goes - just had a look at the weather forecast, don't blame you for postponing!

Likewise if you spot anything else that seems different, let us know as it's all great learning and super helpful for us!

Hari

One of the things I didn't understand before I signed up to the trial was the way we use electricity and the charger has helped me understand...I just thought you'd take an hour's worth at tea time and breakfast time and give me it back during the night...that's not quite the whole story.

Electricity has to be used when generated or it's lost. It can be stored for later use such as in reservoirs for hydro generation later or in my case, to the battery of my car.

Every time I put the kettle on, watch the TV or type on this computer the power has to be generated and rather than fire up another power station when I just want to boil a kettle, the charger taps into my car and feeds that electricity...perhaps 250 watts for a 5 minute brew of the kettle, into my domestic system without drawing anything from the grid.

Equally when the sun shines brightly and the wind blows there may be more power generated than is presently needed for the grid and so that power will be used to top up my battery even during the day time....

The charger is in constant use balancing out supply and demand both to the grid, to my house and back to the car.

The system is generally sold as a benefit to The Grid whereas it should equally be advertised as a back up supply to my house. (at present if the power goes down I cannot run the house off the car because it's still wired up to the grid and if workmen are working on the lines thinking the power is off they could get a nasty shock from my battery still connected. Obviously in time, after the trial this will change)

I couldn't understand why I couldn't use Economy 7 tariff with the system but for the time being at least I do now. Some times I draw power from the grid and sometimes from the car. Equally sometimes I'm giving power back to the grid that I downloaded at night time at 8p per kWh and some which I downloaded at 16p per kWh. Each electron isn't marked "cheap or expensive" so it's too much at the moment to calculate if I bought the electricity cheap or expensive and to compensate me accordingly. No doubt in future they'll be able to fit that in the programme but one step at a time and getting it to work is the first step...

So with 5 days done and almost 20 kW per day fed up to the grid or used in my house I'm very happy with the trial so far. I've made about £5.50 so far and if it continues this way, based on 300 days out of 365 I should make about £350 a year....enough to pay my electric bill of about £385....when you add on interest at 3/4/5%

Onwards and upwards as Buzz Lightyear says....

Latest update after 9 days....

Just thought I'd talk about some of the things they don't tell you when you sign up to the trial.

Firstly the temperature (As already mentioned). Because you start exporting to the grid about 4.00pm till just after midnight and then import to your car (mine is set to be ready by 7.00am) the battery gets warm, in my case about 10c above what it normally is without anything happening to the battery after 5.00pm. This has two effects. The first if you're on a 40/62 kW LEAF is when you travel a long distance the extra 10c will slow the rate at which you successively charge at rapid chargers, not sure how much yet till I test it. This can be addressed..... thanks to Hari above, by changing the time when you want the car to be ready, allowing the battery to cool down. Of course the good effect of having a battery start out at 26/27c is it's the optimum operating temperature which means better miles per kW if you're only doing short journeys.

Secondly degradation of the battery. I haven't been monitoring the battery since I got it but at 3 months old it was showing 99.24% SOH and 114.563 AHr. Some amongst you may know what these figures mean. At the start of the trial and with the car 18 months old, almost to the day, it was showing 96% SOH and 110.820 AHr. Today that figure is 95.94% SOH and 110.750 AHr.

I'm not sure but I think that degradation isn't as bad as I thought it would be and it's at a rate half as much as before. I'd be obliged if someone could confirm that.

Thirdly the way that the trial is priced.... having changed from Economy 7 to full rate for the trial it was confusing when I got two bills for July but realised I had a two year contract previously and the gas contract hasn't changed, only the electric so the three days electric bill was only to catch up.

Now this is where it gets interesting. The small screen I have in the kitchen for the smart meter shows the amount you're exporting to the grid as a negative value...up to 3.4 kWh. Put the kettle on and that value drops to negative 1.4 kWh indicating you are using 2 kWh from the car for the kettle and exporting 1.4 kWh to the grid.. However because the computer can't (yet) differentiate between how much you are exporting (the most I've exported so far is 22 kW) and how much you are importing, it adds the two together and charges you for both...ie my daily tariff has shot up from £1.00 to about £5.50 a day making the bill for the month £175 or for the year over £2,000. I believe...and hope...that they then credit you at the end of the month for every kW you've exported to the grid after giving it back to you with 6p each kW....but if you weren't expecting the delay of a month or so to sort this out it can come as a big shock...

As for the trial itself just one little thing. I put the car in the garage and plugged in the charger. I then switched it on and almost immediately switched it off because I wanted to move the car again. The machine froze and wouldn't do anything nor release the charger from the car. I merely switched it off at the main switch, switched it back on and like any computer, it reset and operated normally...

So, just waiting for the end of the month to see what the bill comes to...

Hi

With regards to your degradation of the battery, the SOH and AHr are both calculated guesses and they vary up and down from day to day, you'll need to check it over a long period of time before you can see any real results.
I started checking mine once a month but on numerous occasions I'd have more capacity left than the previous month, in my case when I went on a longer journey it always showed a improvement in capacity, likewise swapping to a different charging method also seamed to showed a increase in capacity, I usually charged at 3kw so either charging at a rapid or charging with a standard 13a plug socket would show a improvement. I will say that going on a long journey and using the rapid chargers is suppose to be detrimental to the battery capacity so I'm fairly sure the shown improvement isn't actually an improvement but just a little error in the algorithm used to estimate the remaining capacity.

Regards
Chris

Thanks Chris...

I had a similar view when I checked back over the 18 months and found that it didn't always decrease but on odd occasions actually went up...so, as you say, I'll take it with a pinch of salt.....oh and the Guessometer doesn't always tally with the 100% capacity either. Even when it's in the garage unused and the temperature is the same the range varies between 166 and 155...