We would literally have to wait until everyone starts replacing their EV batteries before we could put them to use on the grid, but yes, you made a very good point.

The use of used EV batteries is a great idea, better than V2G.

1st test market in Denmark: http://cleantechnica.com/2011/06/15/electric-vehicle-owners-to-get-cash-back-for-selling-power-to-the-electric-grid-in-denmark-10000/

researched/recommended in Switzerland: http://www.hslu.ch/181_ieee_florenz_living___mobility_assessment_of_v2g__v2h_and_stationary_storage_concepts.pdf

researched in Germany: http://www.next-energy.de/project-gridsurfer.html

at least one German company focuses on this: http://www.sgsgroup.de/en/Automotive/Electrical-Components/Power-Electronics/Charging-Stations/V2G-Communication.aspx?contactId=%7B13BD4838-13A6-4AFC-BA80-23862D34B5E6%7D

my impression, like others here, is that V2G is not cost-effective except in niche cases (if those), but it has obviously been a topic of discussion and research around the world.

i don’t get the impression that Americans are trying to force this down everyone’s throats. rather, it seems to be a topic popular with researchers (who aren’t always practical in what they decide to focus on) and perhaps also utilities (since they aren’t the ones bearing the downsides of the idea).

That would be just as reliable as the set of numbers you made up. As is your claim that the grid is silly.

There is the problem with mathematics that does not add up. One MWh electricity needs 10–20 cycles that is wasted for electricity to grid. And if you are making $20 profit by selling 1 MWh electricity back to the grid, this just is not very much if your capital cost for EV battery was $50 000.

The value of single 100 kWh EV battery is just $10 000 if you are planning to sell all the cycles back to the grid. And this does not leave any cycles for actual driving.

Selling electricity back to the grid is just silly concept, because grid as a whole is silly and old fashioned way to distribute electricity. It is always better to store the electricity locally than to sell it back to the grid.

Battery storage for PV electricity is already cheapest way to get electricity in Germany and Australia. There is just no need for EVs to meddle around.

However EVs are very good at smart charging, that they are charged (fully) only when sun is shining and wind is blowing or night time when the demand for electricity is low.

Utilities don’t have the same sort of size/weight limitations faced by EV battery applications. They will probably be able to use much cheaper flow or liquid metal batteries. And keep the profits they’d have to pay to EV owners.

Then, assuming solar whacks the midday peak and leaves us with early/late peaks like is happening in Germany, lots of those EVs would be unplugged when their stored power is most needed.

You’d be able to set a buffer of x miles over your normal driving. You could reset the limit via phone/computer if you changed your next day plans.

The amount paid by the utility should more than cover the cost of getting a rapid charge once in a while. If the owner doesn’t feel that they are making enough money for the inconvenience then they won’t sign up.

If EV batteries are assumed to be so darn cheap in some awkward distant future that selling electricity back to the grid is justified economically, then for sure households should buy an electric vehicle AND this ultra super duper cheap battery.

That is because selling electricity back to grid from the EV is redusing the value and range of the car.