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Please can you explain the maths behind your V2G examples?

  • 19 April 2018
  • 8 replies
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As far as i can see from your examples, V2G doesn't make any sense.

Lets say I store 10kWh which at 15p ( rounding) costs me £1.50p.
You then take that back at peak times paying me 7p/kWh, so i get back 70p.
But if i want to drive somewhere i now need to charge up those 10kWh again paying an extra £1.50p.

So I've paid 80p plus £1.50p = £2.30p.
How is that better than just paying £1.50p?

What did you miss from your examples that shows how this works??
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Best answer by Tim_OVO 20 April 2018, 17:22

What did you miss from your examples that shows how this works??

Thanks for reaching out about this @ConfusedAboutV2G @Paul

I've confirmed that the stated 6p/kWh for export is the NET amount.

I.e. if we export 1 kWh from your battery back to grid, we will reimburse the import cost (the cost you pay per unit of electricity), plus 6p on top**.

What do you think of this proposition?

Tim

https://www.ovoenergy.com/electric-cars/vehicle-to-grid-charger

**Edited to ensure info is up to date - 13/06/19
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I thought exactly the same thing. An export price of 7p and a usage price of 14.93p it cant possibly work. And yes, the fault in the calculations is that they are only showing electricity to drive, not the electricity needed to replenish that exported to the grid.
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What did you miss from your examples that shows how this works??

Thanks for reaching out about this @ConfusedAboutV2G @Paul

I've confirmed that the stated 6p/kWh for export is the NET amount.

I.e. if we export 1 kWh from your battery back to grid, we will reimburse the import cost (the cost you pay per unit of electricity), plus 6p on top**.

What do you think of this proposition?

Tim

https://www.ovoenergy.com/electric-cars/vehicle-to-grid-charger

**Edited to ensure info is up to date - 13/06/19
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That makes sense then.

Still a question over how this would operate with an economy 7 tariff.

And the calculations would need to factor in a loss on recharging - I think Nissan assume a 90% efficiency in the charging.
Much better thanks but your example needs to make this clear because if you read it as written, without that key detail, , it's a losing proposition. Or, just make the export tariff 15+7
Hi, just curious as to what the charging rate of the V2G charger is, specifically with a 30kw Leaf with 3.6kw on-board charger. I know the car can only charge through the type 2 socket at 3.6kw but as the V2G charger uses the CHAdeMO pug is it able to charge (and discharge to grid) at a greater rate?

Additionally is it easy to override to your usual charge preference and request a full rate charge instantly? i.e. if you usually allow the charger to drain the battery on an evening to say 50% and recharge ready for 7am on a morning, could you press a button on the charger / in the app to say ignore settings and fully charge now if you were planning on going somewhere?

Cheers
Userlevel 4
I've moved you post here, @vespalads, you'll find the info you need.
@Amy_OVO I'm not sure this is the right thread for my post. I am asking about rate of charge in terms of the electrical charge rate, I.e. how fast the battery is charged or depleted.

This thread is talking about price rates I.e. how much you pay/ are paid for electricity used/ fed back to grid.
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Hey @vespalads the power output of the unit is 6kWh on charges and exports. Hope that helps!

You can find out more on V2G here.

Also useful to know the unit rates, so hopefully you have everything you need now? Please shout if you have any more questions and search this area of the forum as there is already a few useful topics on V2G around.

Darran

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