https://www.tesla.com/sites/default/files/downloads/tesla-ne...
> Warranty Limitations
> This New Vehicle Limited Warranty does not cover any vehicle damage or malfunction directly or indirectly caused by, due to or resulting from normal wear or deterioration, abuse, misuse, negligence, accident, improper maintenance, operation, storage or transport, including, but not limited to, any of the following:
> ...
> Using the vehicle as a stationary power source
https://www.theverge.com/2022/9/12/23349971/nissan-leaf-bidi...
> Ideal for companies with fleet vehicles, the Fermata Energy Demand Charge Management application, along with the FE-15 charger, continuously monitors a building’s electrical loads, and may draw on the Nissan LEAF’s energy to provide power to the building during more expensive high-demand periods. In states with utility demand response programs, bi-directional-enabled Nissan LEAF vehicles (MY2013 and later) are able to safely send energy stored in the battery to the grid during peak energy demand times, such as in summer months.”
> The downsides to V2G tech are that it must degrade your battery (to some extent or another) to be discharging and charging more frequently, and it leaves your battery with less charge at times when you may wish you hadn’t discharged at all. Some people will always take that tradeoff, though, and it is great to simply have an option on the table for consumers who really want V2G tech. Stay tuned and watch this space.
> The article on the Fermata Energy/Nissan announcement is not quite correct. It’s for commercial use only – not residential. The Nissan-approved FE-15 bidirectional charger is available for commercial and government fleet owners. https://www.fermataenergy.com/fe15-sales
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The other part is that this is grid supplemental charging where there is already a steady main current to be matched. If you are using it to power an island (home or similar disconnected from the grid), it is a different situation and would require completely disconnecting from the grid with safety cutouts to make sure that when the grid comes back on that the systems are not out of phase and damage equipment.
Grid storage is a different (and arguably easier) problem than home backup in the case of a blackout.
There needs to be a specialized charging (and discharging) setup in the garage. People who charge using a regular extension cord without installing additional hardware will not be able to do V2H or V2G.
The charging setup needs to be able to cut off power from the grid to the home. This involves a more extensive modification to the home's electrical setup. Note that there's a different culture with housing in Japan.
https://en.wikipedia.org/wiki/Housing_in_Japan
> An unusual feature of Japanese housing is that houses are presumed to have a limited lifespan, and are generally torn down and rebuilt after a few decades, generally twenty years for wooden buildings and thirty years for concrete buildings – see regulations for details. Refurbishing properties, rather than rebuilding them, is a relatively uncommon practice in Japan, though its prevalence is increasing, indicating that attitudes towards older houses may be changing.
> ...
> The taxable value of a house is controlled by its building material. Wooden houses are considered to have a lifespan of twenty years, and concrete ones to have a lifespan of thirty years, and the assessed price depreciates each year contrary to housing markets in other nations.
This means that basically every 20 years the house is rebuilt and you've got more recent electrical setup. If you're building/buying a new house in Japan and had an EV, the incremental addition to the cost of building the house isn't significant.
The house I am living in was built before electricity was available, had gas pipes to each room for lighting (though not in use), and had functioning knob and tube wiring as recently as 2010.
I do look at a home generator (and the corresponding changes to the electrical wiring needed) - but that's not a small change. If I was getting an EV, and considering V2H as an add on, it would likely not be something I'd do.
Simple delayed charging with a timer is common, yes. The grid interactivity part? Much less so.
The few V1G pilot programs out there have been very encouraging.
>better to use dedicated batteries as part of the grid itself than to use car batteries
Fortunately, it's not an either/or. We can better optimize the total system cost by doing both.
Why? Every kwh we can store using car batteries is a kwh of dedicated grid storage we don't need to purchase. It can increase the speed we add new storage on the grid. It is a more efficient use of lithium and other precious metals. This "smart charge" or "flex EV" is the type of incentive utility companies can push, and something that would decrease the amount of capital investments they need to make.
I can imagine a few counter arguments for why dedicated batteries are better, but nothing that convinces me. This claim that dedicated batteries are better than car batteries has little support in your comment and I would like to understand why you believe this claim.
Then there are the efficiency downsides. Storage "at the edge" means more transmission infrastructure is needed, on average, compared to more centralized storage. Also, grid batteries can be optimized for number of charge cycles, not for charge amount per unit weight. Finally, servicing individual cars is probably more expensive than replacing batteries in a storage facility.
And this is before going into inconvenience aspects, such as risking that your car doesn't have a near-full charge when you need to go on an unexpected trip, or the hazzle of handling the payment agreements, etc, just for a couple of dollars per day in potential revenue.
In computer terms, it's kind of running mining software on your computer GPU at night. For those especially interested, it may be fun, but for the average consumer, probably not worth bothering with.
So you can forget about your car (or even most solar inverters) to work during blackouts unless a couple of things are present:
- a automatic grid disconnection switch (aka a transfer switch)
- special firmware to allow the inverter to operate in 'off grid' mode
Both Xantrex and Victron have inverters that can do this but they are not normally deployed for such installations and they wouldn't know what to do with your car battery (voltage much higher than the ones that they require, typically 48V max).
Growatt has some off-grid units too, but those still won't satisfy the impedance requirements of your cars inverter (the grid is 'too small' so it will fluctuate too much due to high impedance).
Personally having an EV and a Victron inverter with batteries and same vendor car charger I HATE the fact I can't even adapt charging amps depending on p.v. available power in AC charging.
With HA and a bunch of scripts you can actually get quite far in automating all this, but when the grid fails everything will shut down.
I'd love to see these babies become more easily (and cheaper!) to source:
https://en.wikipedia.org/wiki/Lithium-titanate_battery
The energy density isn't super but for stationary applications that's fine. 6K+ cycles, fast charging, what's not to like?
Beside modern water heater nothing else is available on sale and even to simply "trigger switches by software" means pay not marginal prices for IoT devices like Shelly ones, who have simply too much stuff, starting from a webui, to justify their costs.
Even the simple, decades old modbus, is BADLY spoken just by few devices, MQTT even less...
I can definitely recommend the 'Shelly' stuff, it's been absolutely problem free and super reliable, they have a nice range of sensors and controllers.
Some actually have happened, like minisplit with optional remote control module to be installed easily lifting the front top and some hot water heater, but such controls are still very rare and damn limiting...
A small example, I cite it because it's not on sale anymore (there is a slightly updated version, with a different name) my home hot water is made with a Daikin/Rotex M2O EKHHP it feature a "renewable integration" witch consist in two dry contacts who allow just to tell the machine:
- do not run
- run as you want
- run full power (heat pump, if possible PLUS classic resistive stick)
- run for an hour with heat pump only, then full power.
Those who design such logic have NO IDEA about domestic p.v. self consumption. Why the hell such logic instead of:
- do not run, except antifreeze
- do run full power (heat pump and resistance)
- do run ONLY in heat pump mode if possible
- do run ONLY with resistance
My actual "solution" is:
- knowing the outside temperature in HA, so being able to decide if I can run the heat pump or not
- decide to trigger the "run for an hour with heat pump only, then full power", switching to "do not run", switch again to "run for an hour with heat pump only, then full power"
just to limit the load to ~600-800W of the heat pump, BUT for instance sometimes I can use more, like the 2kW resistive stick BUT NOT 2kW+600-800W and for that I have no option. Sure it does not change my life, but it's absurd. Why not give such simple controls?
My VMC is even nicer: it have a range of ModBUS controls, with some registers badly enough documented I can't understand what they mean, some not documented but understandable through observation manually command the machine via it's own keyboard/display.
I've decided to buy an absurdly expensive EV domestic charger from the same vendor of my main home inverter, a Victron EVC. It claim formally to be integrated. Actually in p.v. mode all it do is staring a charge at 6A if there is at least them available from p.v. of course if there is room to more amps no way to change them, it seems to be hardcoded. Only option use the manual mode driven via ModBUS from Home Assistant. At that point I do not even understand the dams logic, the only thing better than a far cheaper charger is that it's three-phase, I have a 3-phase 36kVA domestic contract so if I need a quicker charge I can run around 7*3kW from grid. But that's all. Other domestic chargers for EVs are not better and still with absurdly high price for a simple metered socket with some extras on a mini-board computer, something who can cost around 30€...
Your generator is not allowed to feed a non-functioning grid for safety reasons. It can't distinguish between a blackout and a utility worker disconnecting to service something. Your inverter would kill that unsuspecting person by surprising them with a generator on the side they're touching.
This functionality is already there.
> So each kwh cycled into and out of the battery costs 8 cents.
This is quite much. If you add other infra overhead, feeding power back into the grid is not going to produce much revenue for the individual unless the selling price is maybe 20 cents above the price when charging.
On the other hand, something that MAY make more sense, is if the car battery can be used to provide power to the owner's own house during short price peaks. This might allow some savings even in stable grids, but the killer app would be in grids that have rolling blackouts during high demand periods.
And even for grids where blackouts are infrequent, if your car can serve as large UPS for your house (combined with a large capacitor to keep the power stable), such functionality in the charger may be worth the cost of the hardware for many people. (Bringing the number of units up and hence the cost per unit down over time.)
Still, though, for grid stability it is probably much better to use dedicated batteries as part of the grid itself than to use car batteries.