Vehicle to Grid (V2G) Technology for next LEAF

Did anyone else see this article and video?

http://thinkprogress.org/romm/2011/07/15/270456/july-15-news-how-to-electric-cars-owners-can-get-paycheck-bp-oil-still-washing-ashore-in-gulf/

I remember hearing that Nissan executives are already talking about integrating V2G technology into their cars at a future date, which is a great sign... I sincerely hope that they follow through, soon!

In a power outage, wouldn't it be nice to have backup household electricity available from the LEAF? And for all of the other days... Charge in the early morning off-peak hours and then sell what you don't need back to the grid, at high demand periods. Buy low, sell high, and add an extra few dollars to your pocket, while it serves as a load-leveler for the electrical network. Everyone's a winner... Brilliant!

Electrons are so versatile. Amazing. We should all be taking full advantage of them...

There's nothing about today's LEAF that prevents doing this, except the Warranty terms that forbid it.

I suspect that will continue to be the greatest impediment going forward, but an inverter that can "power your home" from the Leaf's high voltage DC is not cheap either. It's almost identical in function to a solar panel inverter, actually.

GroundLoop said:

There's nothing about today's LEAF that prevents doing this, except the Warranty terms that forbid it.

I suspect that will continue to be the greatest impediment going forward, but an inverter that can "power your home" from the Leaf's high voltage DC is not cheap either. It's almost identical in function to a solar panel inverter, actually.

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With existing equipment (J1772 plug or the QC port) in a Leaf, how do you "give back" to the grid whilst plugged in to your EVSE? Doesn't one need special equipment ?

Ohmie said:

In a power outage, wouldn't it be nice to have backup household electricity available from the LEAF? And for all of the other days... Charge in the early morning off-peak hours and then sell what you don't need back to the grid, at high demand periods. Buy low, sell high, and add an extra few dollars to your pocket, while it serves as a load-leveler for the electrical network. Everyone's a winner... Brilliant!

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Probably a good idea to supplement the system with a standby generator, but the Leaf would give you a few hours if the gasoline runs out during the night.. plus handle starting surges. You could use a smaller more efficient genset.

The 24kwh (usable) pack of the Leaf is probably good for 1500 cycles, at a rebuild cost of about $12k for the cells, perhaps to go down to $6k in a few years.. thus the pack stores the juice at a cost of $0.33 to $0.15 per kwh. What is the cost differential of on-peak and off-peak electricity where you live?

Its possible the pack will last longer if you limit SOC to about 15kwh.. not sure. Usually total coulomb count determines the maximum life of a lithium-ion battery, when not abused.

Dont forget that even without V2G your Leaf could help the local grid immensely.. just by throttling up/down charging power instantly (on command from the power company).

mxp said:

With existing equipment (J1772 plug or the QC port) in a Leaf, how do you "give back" to the grid whilst plugged in to your EVSE? Doesn't one need special equipment ?

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It would be possible with the CHAdeMO port since that has a direct connection to the battery pack. You would need some type of grid-tied inverter that could do something useful with the 400 volts from the battery though.

DarkStar said:

mxp said:

With existing equipment (J1772 plug or the QC port) in a Leaf, how do you "give back" to the grid whilst plugged in to your EVSE? Doesn't one need special equipment ?

Click to expand...

It would be possible with the CHAdeMO port since that has a direct connection to the battery pack. You would need some type of grid-tied inverter that could do something useful with the 400 volts from the battery though.

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If you have solar panels, you probably have exactly what you need.
My inverter takes anywhere from 235 to 550v DC and pushes up to 4kW back into the grid.

You would have to get a CHAdeMO plug, the proper communication software to keep the battery contactor closed, and some form of external charger if you want to flow current both ways.

All in all, it would take a really long time to pay off any such investment purely on power TimeOfUse arbitrage. (buy low, sell high)

GroundLoop said:

If you have solar panels, you probably have exactly what you need...

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Yes, and a healthy percentage of LEAF driver homeowners already have or will have solar panels, especially as PV system prices continue their drop...

GroundLoop said:

All in all, it would take a really long time to pay off any such investment purely on power TimeOfUse arbitrage. (buy low, sell high)

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The article states that the participants in Kempton's study made $2,000-5,000 a year... I would have assumed this was for the entire group of seven participants, but then why the range? It must be the range of earnings per person (?). This is a pretty substantial sum!

I don't know how much a CHAdeMO plug, software, and external charger would run... of course, it has DIY written all over it at this point, but if Nissan became more involved, I could see it become simplified for greater convenience and savings...

I'm now considering installing solar panels while I wait for my Leaf. Part of the issues I'm dealing is that in Georgia - there is new electric car rates of only 0.0125 per KWH from 11 pm to 7 am and 20.5 cents from 2-7pm. My interest is for the days I'm at the house = or in the event of a power blackout - is to disconnect from the utility and exclusively use the Leaf battery to power the house for those 5 hours. If I'm not in the house, the need for solar is to power my 1kwh basic power needs (no a/c running). If I'm on vacation I would like to make the meter run backward for those 5 hours..... any suggestions on equipment needed or things I should consider?

Storing electricity in the Leaf's battery wears it out, it would become very expensive electricity once you took that into consideration.

braineo said:

...is to disconnect from the utility and exclusively use the Leaf battery to power the house for those 5 hours. ..... any suggestions on equipment needed or things I should consider?

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You might consider that using the LEAF battery as a power source is one of the specific disqualifications mentioned in the battery warranty. A number of threads talk about doing so in the abstract, but it probably isn't worth the risk at this point. If you went ahead with it, you would be in DIY territory as far as equipment goes.

DarkStar said:

You would need some type of grid-tied inverter that could do something useful with the 400 volts from the battery though.

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With a totally naive dismissal of "the details", I note that each Leaf's drive electronics already HAS an inverter: for manufacturing the AC that runs the car's motor. If you flipped a switch that substituted the AC mains powerline for the AC motor (perhaps through a suitable voltage-matching transformer), why wouldn't the Leaf's regular motor driver be able to "drive" the grid?

For that matter, why should the Leaf need a separate "charging" equipment, given that it can regenerate electrical energy from the kinetic energy of the car and store it in the battery? Seems like the same simpleminded "connect the AC mains instead of the motor to the drive electronics" operation should answer the needs of battery charging as well.

OK; I know the drive motor is (I would fervently hope) 3-phase, vs. most home power being just single phase. I'd be willing, though, to pay for a 3Phase power drop if it would help things out