The one thing I always wonder about these schemes, is reimbursing the battery owner for the wear and effective use of charge cycles. Batteries are (very expensive) consumables, so pulling power from idle batteries comes with a background cost to the owner.
This is probably the one redeeming quality of electric cars. We can’t convince people to put batteries in their home that most likely will cost more money than they save, but for a car people are willing to shell out tens if not hundreds of thousands.
The home battery provides a backup source of limited power if the grid goes down, like a giant UPS. If one also has solar panels and/or wind generation capabilities on site, they have access to distributed domestically/locally sourced energy that isn’t subject to things like embargoes, war, and other supply issues that can affect traditional energy sources. In an off-grid application, that battery is the only way to use these sourced of energy when it’s night or the wind isn’t blowing. Unfortunately, these capabilities are more expensive than utility-scale grid power which can leverage economies of scale. An EV is able to inject many different sources of energy into the task of transportation, depending on how and where the electricity is sourced. This is an excellent way of diversifying the energy input portfolio instead of putting all of one’s eggs in one basket. Nuclear, hydroelectric, wind, geothermal, solar, natural gas, and coal come to mind. An ICE has much less choice and is therefore more beholden to economic fluctuations and vulnerabilities. I see a range of used EVs and PHEVs with costs equivalent or less to traditional ICE vehicles in my country. Certainly cheaper than many SUVs and pickups at least.
If utilities have to pay car owners an realistic amount for prematurely degrading their batteries this would be uneconomical. Thus this is either hoping for car-owners being ignorant and only realizing it a few years later or it will never take off.
Usually it is no problem for utilities to get a loan for installing grid tied batteries, as it is nearly an guaranteed payback and they can either buy better suited battery technology or recycled car batteries in bulk for it.
Maybe if the technology allows running them completely separate from the grid for personal battery backup and utilities finally pass through off-peak electricity prices to customers so that it makes sense for home owners to use their batteries during peak hours…
I don’t think it’ll be economical for a daily cycle, but there’s a good chance this comes out as a reasonable choice for the 10-15 highest-peak-demand hours per year.
What is the use case for an EV to provide power to the grid?
Peak times vs. off peak.
This makes sense to me.
Charge car overnight offpeak costs, power house during peak hours
Here’s one scenario: Go to work with a partial charge, charge during the day using excess solar production when electricity is super cheap, drive home fully charged, sell some power to the grid during peak domestic use hours, keep enough to safely get back to work, repeat.
The use case (as opposed to public transit and stationary grid batteries) is that rich people get to feel good about themselves while still being subsidized by and separated from the working class.
The highest few hours of peak demand each year. It can make sense to use relatively expensive storage for that because you’re using it infrequently.