There's no need to be so aggressive. V2G would likely operate similar to Net Metering, which the UK (and many other countries) does have experience with: https://uk.renogy.com/blog/net-metering-for-home-solar-in-th...

According to one website that I found, the average residential electricity cost in the UK is $0.482/kWh. Simple math: 1500 cycles * 75kWh * $0.482/kWh = $54,225 in offset electric costs, which would more than cover the hypothetical battery replacement cost. It is well above the 2x break even that you requested.

However, I expect most people do not have electric bills that high, so those people would not allow that much of their battery to be used by the program, unless they were participating in this program for a very long time. They would be more than fairly compensated for whatever cycle life was used by the net metering program. Yes, I recognize that the electricity would have come from the grid at some previous point in time in most cases, so some adjustments would have to be made to the concept of Net Metering to make this a sensible proposal, but there are ways to make it work if you don't just declare that everyone is a bunch of idiots. Electricity is much more valuable to the grid at certain moments in time than others. ""Transmission costs"" are irrelevant when the grid needs more power. Any kind of V2G system would involve exporting power when the grid desperately requests it, not just at a random hours of the day when the grid doesn't even want it. Virtual distributed grid batteries are already being proven.[0] This solution can definitely be scaled up.

Also, that estimate of battery replacement cost is based on the battery magically having zero marginal value at the end of its lifecycle in your car, which is not at all how things work. A battery that people are unwilling to keep using in an EV will still have significant value if it is directly transplanted into a stationary storage application, but oftentimes, it is just a handful of cells that are causing balancing issues, so replacing those for a few dollars can restore a lot of missing capacity. Even after the battery is done in stationary storage, it will still have value in the highly concentrated resources which can easily be recycled into a new battery pack.

So, no, it would not cost that much to replace the battery. Even today, you could throw a used battery pack on eBay as a worst case scenario and get thousands of bucks for it, but in the future as more of these batteries are being cycled through the market, it will be more economically viable to have businesses built around making this as painless as possible.

If you consider V2G idiotic, then you're effectively asserting that any form of grid battery is idiotic because those have to work on very similar economics, and that is a strange position to hold when we have real world examples of grid batteries being profitable even today.

> Half of that money is distribution cost, not energy cost.

I also have no idea where you got the notion that UK electricity costs are 50% transmission fees. It is 3%.[1]

> You can extract anything from seawater, even gold.

I'm not saying seawater is absolutely the best available source of lithium, but some people claim to have proven real success with it.

"The researchers estimate that their system can extract 1 kg of lithium from seawater at a cost of $5 (Energy Environ. Sci. 2021, DOI: 10.1039/d1ee00354b). “Our process is quick, energy efficient, and scalable,” Lai says. “And the system runs continuously and is compact and easy to operate.”" https://cen.acs.org/materials/inorganic-chemistry/Can-seawat...

Using gold in your response the way you did seems intended to be an insult, which is completely unnecessary. I'm not proposing alchemy.

Maybe you know more than these researchers whose literal job is to know about lithium and seawater, and that's fine, but I have never claimed you can extract meaningful amounts of gold from seawater. It is infeasible. Lithium is far more common than gold, though, which makes a huge difference in the feasibility.

[0]: https://electrek.co/2022/09/02/tesla-virtual-power-plant-gro...

[1]: https://www.nationalgrid.com/electricity-transmission/who-we...