V2H and V2G

JKenH

Apologies for the duplication but I had posted an update on another thread of the current state of my progress to V2H.

The project is currently being reconsidered as apparently there is no signal where I live to operate a Smart meter (the joys of rural Lincolnshire- hardly any sun or network coverage).

The cost of the Wallbox Quasar bi-directional charger is £1200 (presumably plus fitting less £500 government grant). In the absence of access to a smart tariff would it still be worthwhile on E7 saving about 7.5p/ kWh (the difference between charging at night rates and discharging at day rates)?

Let’s assume the installed cost was say £1200 (ignoring any battery degradation).

At a rough guess my annual net (after solar contribution) day usage which a battery could potentially cover is about 3000kwh of which about 1800 kwh is November to February. If I was to cover all the day time usage from the EV battery that would only leave an average of 15 kWh/day available for driving during those months.
Realistically, if I could maybe save 1500 kWh of daytime usage from E7 stored in the battery over this winter period I would save £112. 50

If the sun shone consistently from 1st April to 31st August and I didn’t use the car too much I could potentially save another 900 kWh (average 6 kWh/day) by meeting all the household demand (day and night) from solar and solar charging of the battery. The sun doesn’t, however, shine consistently and some days I would empty the battery using the Leaf as a car, so perhaps a summertime saving of 500 kwh at an average (day/night rate) of 12p/kWh might be achievable - £60.

March and September would be somewhere in between- say another £30 over the two months.

The total saving per annum would be of the order of £200. Payback of the Wallbox would take 6 years. Then of course there is the battery degradation to consider - I’m not sure how to express that but maybe 120 cycles per annum for 3000 kwh from a 30 kwh battery? Then there is the warranty issue.

So I am not sure whether it is worth it at this stage. I would welcome any thoughts.

Martyn1981

EVandPV wrote: »

I would also be concerned about how much of a hammering the battery might take under V2G, especially while it's still at the trial stage and the number of participants is low.

Agree, especially with a small Leaf batt and older technology, but a few years ago there were trial results that seemed to show that V2G was actually good for your battery. I think it was because the battery is being treated far more gently than it is when driving.

This is old news but I'll have a nose around for it, and hope it's not just in my head!

Martyn1981

I think, this is what I was thinking of, so to speak, and this article photo features a Leaf, which is a nice circular touch.

V2G could help extend EV battery life

Dr Kotub Uddin, along with colleagues from WMG’s Energy and Electrical Systems group and Jaguar Land Rover, has demonstrated that vehicle-to-grid (V2G) technology can take enough energy from idle EV batteries for use in the grid and to power buildings without damaging the batteries.

In fact, this new research into the potentials of V2G shows that it could improve vehicle battery life by around ten per cent over a year.

According to the university, Dr Uddin’s team spent two years analysing some of the most advanced lithium-ion batteries used in commercially available EVs – and created one of the most accurate battery degradation models existing in the public domain – to predict battery capacity and power fade over time. They did this under various ageing acceleration factors, including temperature, state of charge, current and depth of discharge.

JKenH

Martyn1981 wrote: »

I think, this is what I was thinking of, so to speak, and this article photo features a Leaf, which is a nice circular touch.

V2G could help extend EV battery life

For the technically minded this was the actual research paper published on the battery thread last week.

http://wrap.warwick.ac.uk/88018/13/WRAP-possibility-extending-lifetime-lithium-ion-batteries-Marco-2017.pdf

Mentioned in one of the comments below the article Mart attached was the issue of round trip losses which I had forgotten about in my calculations for my V2H exercise.

EVandPV

JKenH wrote: »

So I am not sure whether it is worth it at this stage. I would welcome any thoughts.

It's a difficult one. Not sure I'd be up for it at the moment though, even if I did have a Leaf. Too many ifs and buts.

EricMears

JKenH wrote: »

So I am not sure whether it is worth it at this stage. I would welcome any thoughts.

I have got a Leaf and solar panels but really not interested in joining such a scheme.

I very seldom manage to plug Leaf in during strong sunshine and haven't been very impressed with the reports of tariffs offered for such a scheme. I manage to use most of our own consumption without dropping any into car whilst still being given the 50% deemed export rate. More than satisfied with paying 8ppu to charge car overnight or getting a free top-up at Nissan dealers when away from home.

JKenH

EricMears wrote: »

I have got a Leaf and solar panels but really not interested in joining such a scheme.

I very seldom manage to plug Leaf in during strong sunshine and haven't been very impressed with the reports of tariffs offered for such a scheme. I manage to use most of our own consumption without dropping any into car whilst still being given the 50% deemed export rate. More than satisfied with paying 8ppu to charge car overnight or getting a free top-up at Nissan dealers when away from home.

Just to clarify, I am not looking at joining a V2G scheme. I am just considering using my Leaf as a big battery to power the house using stored cheap rate electricity or stored solar, i.e. V2H. Because my panels are east and west facing I don’t generate much in winter but I can produce around 850 kWh in May, June and July. Using it at home won’t affect my deemed export and as I have been told I can’t have a smart meter because of a lack of signal I can’t see one being imposed on me.

EVandPV

JKenH wrote: »

Using it at home won’t affect my deemed export and as I have been told I can’t have a smart meter because of a lack of signal I can’t see one being imposed on me.

We just switched to Octopus and awaiting a smart meter being fitted.
I gather they use the mobile network to transmit readings to the supplier.
Seems kind of strange in this day and age that the meters don't also have wifi or ethernet capability which would solve the issue for people in areas with poor mobile coverage.
Not so "smart" after all !

1961Nick

EVandPV wrote: »

We just switched to Octopus and awaiting a smart meter being fitted.
I gather they use the mobile network to transmit readings to the supplier.
Seems kind of strange in this day and age that the meters don't also have wifi or ethernet capability which would solve the issue for people in areas with poor mobile coverage.
Not so "smart" after all !

I also live in an area with poor mobile connectivity & had to have a SMETS1 meter fitted as these are apparently are better communicators.

EVandPV

1961Nick wrote: »

I also live in an area with poor mobile connectivity & had to have a SMETS1 meter fitted as these are apparently are better communicators.

Our reception isn't fantastic downstairs either. Oddly, it's better upstairs but our meter is downstairs.
Just keeping my fingers crossed it's good enough to get us the meter required for Octopus Go.