Uhhh, GoodCheeer, they already do that, read the article:

Having demand based pricing is obvious, it might be 20c / Kwh, 10c at night and 50c - 1e for peak (5-7pm) times.

You barely need to meter it - you could just put in a 1 or 2 euro coin to charge it for a day's driving (@20c/kwh).

- Your car should be able to tell you how much power it needs and you "feed the meter" to pay for it - this way you eliminate the complexity of getting charging stations to talk to various makes of cars.

I would be cautious about letting anyone drain my expensive and cycle limited LiOn battery.

I would only use V2G for my own house in a power out emergency - unless you could prove a very large number of battery discharge cycles ( say > 2000 ).

Batteries are very expensive currently and you don't want the utility to exhaust yours for a few Euros / night.

A network of charging stations, especially at people's places of work and shopping could really help - you would need half the battery capacity if you could charge at work. If there were lots of charging stations around, you would have less to worry about if you were running low on juice - just pop in for a few KwH and a cup of coffee.
The AA might also have to have a service to get people moving in the case of dead batteries.
Or is there some kind of long life chemical battery that you could keep for emergencies that would give you say 5-10 Kwh?

Orrrrr, if you're like mahonj, skip the V2G and just use intelligent charging.

check out these cool new evs http://www.youtube.com/watch?v=j_laBPi9wbA

A few million PHEVs and BEVs charging at night will contribute to even up power consumption and should potentially make the average power cheaper.

Much the same could be accomplished with an intelligent timer (such as a $30 baseboard heater electronic programmable thermostat) on our electric hot water heaters.

anne:

Hope you are correct about shallow discharging of our e-car batteries by the power grid operators.

The time has come for stardardized connectors and associated tools.

Harvey,
Any programmable parameters can be designed into the EV.
The program is as required by the vehicle system and equally importantly by the consumer who after all as they pay gets the say.
(the customer is always right and comes first.)
The power co is then a grateful recipient.
This correct priority and programmability will be as necessary for marketing as for function.

Not likely that V2G option will be popular with car owners, at least first 5-6 years of mass EV introduction.
V2G capable EV would require a more expensive invertor, with interface to the grid, and some extra protection.
Even if very shalow discharge can be programmed in EVs (say up to 15%, that practically won't shorten cycle life), there is additional risk of something going bad at 380V (3 phase) interface to the grid.
In the worst case some spikes (during lightening), or a short on the grid can do significant dammage to entire car electronics.
And the protection that limits discharge to say 15% sometimes won't work, or can be set wrong way by mistake.

To me (from perspective of a future EV owner) the V2G looks too much risk for minimal gain.

A better way to even up the power consumption (or to smooth the peak demand) would be to introduce more smart high power devices (including car battery chargers) at households that could interpret some overload signal from power lines and turn itself off for a short time. Also some algorithms should be implemented so that not all devices come back up at the same time, ie have some back off mechanism, like on ethernet cables.

Dear Sirs
The idea of getting an Electric Car is quite a thrill to me. I hope one will be available at a price I can afford, and the sooner the better. Obviously I want a recharge system available that is standard for all cars and capable of handling a 40kWh battery recharge in an hour or less. (Recommend 220v 100a 3ph)

One of the most expensive parts of such a vehicle is the battery. So far, all high density batteries are high cost and have limited life (sufficiently long to be useful, but still limited).

The idea of using MY transport battery to modulate the grid is not going to fly. Sorry, I need MY car when I need it, not when the grid feels like making it available. I have ZERO interest in being a part of V2G technology or of using an expensive transport battery frivolously. I suspect most drivers will feel similarly when making the real choice. The idea is fine for others, but not for me. (NIMBY - Not In My Battery Youfukers )

However, the Battery 2 Grid idea is not necessarily dead. Many homes (including mine) have installed or will install home generating systems with battery storage. Home generated power storage batteries would be PERFECT for modulating grid power, they will be cheap heavy old tech batteries that no one will worry about replacing when necessary. If a system for selling power when needed is made available most any homeowner will jump at the opportunity.

The idea is H2G (Home to Grid) ... I install solar panels, or wind machine and a battery bank, *(recommend 5 kW generating capacity as a normal home benchmark) then H2G systems connect and monitor how much extra power I produce and decide when to sell it to the grid. This interface needs to be “plug in capable” so home power can easily get plugged into it, as can a battery pack and power generator, and phone/cable line for intelligent control. This H2G system should be cheaper than the silly V2G requirements, and far more useful. The system would have the added advantage of making home generating systems more affordable and more attractive, and reduce grid loading ... Win Win Win. 

Meanwhile, If I decide to go out at 3 pm one afternoon, my car is still ready to go the distance.

Please reconsider V2G and consider H2G as a “better idea” grid modulating feature.

Thank you
John

ps... if anyone is interested in helping develop such a system as H2G, please have them contact me.

Come on...

Turn off your V2G if you dont want it in your car, but it really needs to be an option for motorists who can help out and make a small buck at the same time. V2G research, development and deployment need to happen at the same time as charging grids and EVs.

ai_vin > Well John as long as you are at home when you make that decision you're free to go anywhere/anytime, but if you're at work that afternoon I think your boss will insist you and your car stay put. [mine does]

> I'm happy that you are such an understanding employee who never ever has personal emergencies.
Most of us do have contingency plans for emergency situations (family member gets in accident, damn bursts and will flood our workplace) and our car is a big part of the transportation plan to deal with these.

It may be that some day they will make an ideal transportation battery that is also ideal for grid stabilization, but so far we don't have such a thing available. One reasonable part of the V2G plan that can be done is to use load shedding on charge up ports during peak times to even the grid loading, and this would only extend recharge by a minimal time factor.