I wish we had more V1G, aka grid-interactive charging.
It's extremely unsexy, but upon further inspection it's surprisingly great. It doesn't add costly cycles to the onboard traction battery, but it still can provide similar grid services (virtual spinning inertia, demand response, distribution network balancing, etc). Better yet it should be a software update for every existing electric car, even those without bidirectional hardware.
Ideally I could tell my car, "always charge to [40]% immediately, then charge to [80]% by [8 AM] [Weekdays]." Then the car automatically participates in a fleet battery scheme, earning me money overnight by providing grid services.
Bonus points if it also knows that I have TOU metering, and automatically optimizes for minimum cost.
Our power company ("Tibber") provides this as a service in their app for a bunch of different car models. Until recently this just let you avoid hours with more expensive electricity. But now you get an extra bonus on top of that since it lets the power company provide valuable grid balancing services.
It's not sexy, but it's also not that hard to implement so I suspect this will become commonplace surprisingly quickly.
> It doesn't add costly cycles to the onboard traction battery
I guess for many people, NOT using V2G will be a net economic loss. For a big battery, and with 20%-80% limits, we are talking about extremely gentle cycles. The degradation is likely a drop in the bucket. Battery degrades with age as well as cycles. So after 20-30 years if you haven't used V2G you risk having an age-degraded battery that didn't deliver its full capability in terms of cycle life. Or the rest of your car has degraded before your battery did.
For LFP it's even more likely that V2G will get you the most value out of the battery.
If you go through a charge cycle every day or two on a Li-ion, I suspect V2G won't make sense since you're stressing the cycle life of your battery.
The problem is we don't really know how long modern EV batteries will last, so it's impossible to know what the most rational choice is. We also don't know what the value of a degraded battery is in 15 years, and what the cost of a new one is. Since the economies of scale around battery recycling will be so massive in 15 years, it's possible that you get paid a fair sum for an old battery, and that getting a new battery will be fairly cheap. Or maybe not.
I have a time of use contract with hourly pricing, based on the day-ahead electricity market. So I also wanted to schedule charging, but I was somewhat disappointed that
- my charging station has no scheduling feature built-in
- my EV does have settings for this, but they act more as a suggestion. It would often charge when I didn't want it to.
Fortunately the charging station does support being controlled over modbus tcp/ip, so I was able to write some code and run it on a Rasperry Pi to control it. My control system fetches the prices and enables charging whenever they are below the configured maximum.
However, I now find that (because of my obsession with optimizing this) it is still very far from a hands-off solution. I find myself doing this:
- check electricity prices manually
- check car state of charge manually
- if prices are going to dip very low, figure out how much time will be needed to charge to 80%
- if prices are high, figure out whether I need to do a minimal top up anyway and how much, based on how much I think I'm going to drive
- choose a maximum price such that charging will be enabled during a sufficient amount of hours, based on the above
The main thing that's missing to properly automate this is a way to retrieve the EV's state of charge. But a charging station for home use will typically only support a simple PWM signal to tell the car how much current it can draw. No other communication is possible unless the charging station supports ISO 15118. Mine doesn't :-(
Thanks! I had no trouble setting up the app with my car. This looks like it covers what most EV owners in Europe would need to optimize their electricity bill.
What I'm still missing here is a way to reserve some battery capacity to take advantage of exceptionally low prices. I'm fine with charging to 60% for daily usage. Charging to 80% could be postponed until the market offers a really good deal.
Perhaps I'm irrationally over-optimizing just to get few more euro of savings... But it also feels good to soak up renewable energy when it is plentiful.
I use home assistant to charge automatically when I want, to the level I want. Though to make it work both my charger and car are somewhat supported by hacs repos.
I live in Flanders, Belgium. Half of households here have a digital meter by now, which makes such contracts technically possible. And the government has made it mandatory for the large energy companies to offer such a "dynamisch elektriciteitscontract".
The reason for all that is to encourage more efficient usage of the grid and renewables.
> Better yet it should be a software update for every existing electric car, even those without bidirectional hardware.
Completely agree with everything you wrote, but also: It doesn't even require participation of the car!
Plain old J1772 already provides the EVSE real-time-ish control over the charge rate. Some charging stations already exploit this to split power between two ports. When one car is plugged in it gets full current. Upon detecting a second vehicle, the EVSE signals the first to reduce current draw (and it must comply).
In other words, every EV can be grid-interactive with just a software upgrade to the EVSE, or, failing that, replacement of the (much cheaper) EVSE.
They do exactly this. They charge in 30 minute chunks throughout the night - whenever suits them best. The reward is electricity at a quarter of the price during this period.
I feel that bidirectional charging is the EV feature that most consumers don't know that they want.
My current vehicle is fine, but when I'm in the market.
I want an EV/PHEV vehicle that has enough power output to entirely power up my home, and serve as energy storage for solar. It avoids the need for a IC generator, and a power wall.
They are a powerwall on wheels. When then battery age out in 10 years, you swap the vehicle.
Gensets and in-home battery storage seem very redundant, when a bidirectional charging PHEV can do both.
I've entertained the idea of picking up a Prius and hacking the electronics to act on this.
> I've entertained the idea of picking up a Prius and hacking the electronics to act on this.
All the NiMH prius' are unsuitable for this. Total energy storage is only about 1kWh and usable energy storage is more like 0.3 kWh (ie. it wouldn't even boil one kettle of water).
The hybrid-ness is still useful because it lets you get a boost of acceleration to get up a hill or overtake some cars - and the battery is very powerful - ie. it can get all that power out very fast - it just doesn't store much energy.
but remember it also has a gasoline engine - so after 12 hours you can always start the gas engine to power your house for ~a week on a tank of fuel.
The prius will do that by default with its current software if left in "ready" mode. You just need to design and add the ~300V DC to 120/240 V AC inverter.
Vehicle by definition can't be connected to the house constantly. I can imagine this lowers need for house battery size, but not need for it's existence.
House power consumption is very random.
There is typically good connectivity between houses. That means even if your EV isn't home, the other EV's in your street can send your house a lot of energy.
Unfortunately anti-islanding rules from power companies generally disallow you using the power lines between your house and a neighbours while the grid connection is disconnected elsewhere.
These rules could be adjusted though - although it would take a lot of systems design work to ensure power system stability and re-synchronizability even with every possible combination of islands.
It's more about safety than reconnection: when repairing lines, it's much more manageable to "lock and tag out" the upstream side than all the distributed generation, especially in emergencies.
Any lines being worked on will be shorted (ie. all conductors joined together and to ground).
As long as that is always done, islanding doesn't present any human safety concerns.
That is normally done anyway, because plenty of utility breakers will automatically try to reconnect every few minutes (allowing some grid scale failures to repair themselves with no human involvement).
But when the vehicle is connected, the user is typically at home. So there's a convenient relation there.
House power consumption is random because it's not designed to be predictable. It's trivial to have a washing machine and heating that prioritize energy consumption whenever the EV is connected, or grid energy is affordable.
Unless you have more than one person in the house…
But in general, yeah, when you _need_ the battery, maybe you just need to figure out that you don't need to drive that day/hour.
The other advantage of a car, is that it would allow you to bring in power "from the outside", go to somewhere where the grid is still working, charge up, then come back. Of course, you'd hope to be back on power before this was needed!
Everyone brought up really good points. My general logic is that the average American consumer gets a new car every 10 years just due to maintenance/service burden. You might as well get a "free" genset/powerwall upgrade with it anyways. The car should be viewed as an energy source that happens to move.
For me the powerwall only provides value when restoring/storing power, not for peak shaving. My logic is that eventually once all the legalities/orchestration is figured out. The net value on peak shaving will trend to zero.
Drive to work, plug into grid. You pay the grid for cheap "sun" power at work. While at work, your solar panels at home generate revenue by charging near by EV's via grid (or your second EV). Drive back home. Plug into house and supply the grid with power at night time.
PHEV's are an added bonus, since you can use it as a genset during extended power outage. If you want to go 100% "off the grid", then have 2 EV's that you cycle though. One that acts as storage/energy backup, other as a vehicle.
"you swap the vehicle" -- that's a large cost associated with the battery getting old earlier than it otherwise would have. Have you factored this into your math?
If you have a $40k EV expiring two years ahead of schedule, the added depreciation cost should be in the thousands. Remember that battery lifespan isn't measured only in years, it's primarily measured in cycles.
Dedicated LPO home batteries can be gotten for only $110 USD per kWh if you live in a place with no tarrifs or taxes on it. This makes a lot more sense to me.
The only way I can see it making sense to use EVs for this, is if the battery getting old is rarely the main reason for throwing away old EVs. If that is true, then sure, use EVs as a home battery, since you're not getting a massive depreciation cost from doing so. But is it true?
The battery chemistry used in most EV batteries are not really optimized for a lot of cycles, and they're somewhat expensive to replace, so you're much better off just buying batteries that are made for the purpose. You also have fairly limited inverter capacity in most EVs, as the inverter installed is scaled to run the cars AC and infotainment system, which doesn't really need that much.
You also have to deal with either having beefy automatic/manual transfer switch or separate isolated circuits to prevent back feeding the grid electricity in an outage or during maintenance.
There's a lot of people repurposing used Nissan Leaf-batteries for what you're describing.
The numbers in the post are 2.2 and 3.6 kW. Even 2.2kW would cover virtually all of my use.
I don't want to buy a battery for the purpose because it doesn't make sense economically. If I could get a car with this functionality though for a similar price as cars without it, that would be a big bonus.
I'm not going to pretend that there aren't edge cases and personal situations that would make it viable, but my initial comment was on consumers as a whole.
And we're talking about averages. So sure, if you have gas boiler you probably could get by with a 2,2kW or 3,6kW inverter, but just powering a simple kettle would likely trip a fuse. You can get around it with just being a little conscious about what you power up, and when you power things up, but I'd argue that most people don't want to deal with that.
And remember, if you're grid connected you either have to have a transfer switch or separate circuits if you want to use this as a backup when the grid goes down. It complicates things a whole lot.
> so you're much better off just buying batteries that are made for the purpose
Or even just used EV batteries. I personally don't think that battery recycling is as big of an issue as some people say. But, if I'm wrong, a cheap worn-out EV battery with "only" 50% capacity is still very useful as a home backup.
> When then battery age out in 10 years, you swap the vehicle.
For this use-case it'd probably be best to go with LFP so you get more lifetime out of the battery.
Though even with Li-ion, I think a modern EV with a big battery will last much longer than 10 years. My old Soul EV with a tiny 27kWh (thus several charge cycles every month) is soon over 10 years and has only gone through half of its cycles at most.
And I would expect that the price of battery replacements for a car will be reasonable in 10-20 years, so should hopefully not be necessary to replace the whole car.
is this about backup in a power outage or earning money buying when pores is cheap and selling when it is more expensive? There is a big difference as in an outage you can conserve power and watch the meter to goeto a nearby charger as needed. In a money scheme you don' know when you are low, but it isn't hard to have normal range left but no long trips
Teslas "virtual power plant" is only for Tesla Powerwall. There's no V2G capabilities in any Teslas to date, and I don't think there's even hardware support for it. The Tesla Cybertruck has V2L capability, so it might have the necessary hardware to do V2G with some software updates, but I kinda doubt it.
The Tesla "virtual power plant" does reserve some capacity for you, and technically you can charge your car with that. A single Tesla Powerwall is "only" 10kWh, and with inverter losses and such you're likely seeing closer to 8kWh of usable energy if you charge your car with it. You're probably much better off just using it to run your appliances so you mitigate some of the losses with more inverters in the mix.
Which is probably reasonable for most people, but still means if you go on a sudden road trip you are have to add power rather soon after leaving. (or you need to plan a head and go to charge only mode before leaving)
The ABSURD thing is that while we have a bi-directional CCS (DC current) standard no one produce photovoltaic hybrid systems able to direct connect to a parked car. Hybrid p.v. use since some years 400V LFP batteries, the same 400V nearly all BEV use. A direct connection means that the V2H part is already "isolating" a protected home electrical "grid" from the grid home/p.v. side, so there is nothing special to do but plug the car.
Following p.v. availability the car can chard without DC-AC-DC lossy double conversion process, with much less costly stuff in between like domestic storage, similarly can discharge to the home as needed. A simple extension to the home electricity storage piloted by the p.v. inverter/a home server. It's essentially already there p.v. inverter side since hybrid 400V p.v. systems are fairly common and it's similarly already there since most cars support DC-charging piloted by the charger connected to the car BMS.
Off topic, those prices omg, how the hell are we going to get to zero without 95% of the population just being too poor to own a car? No matter how great the tech is, this is one of those rare occasions where the price of advanced new tech goes up with time. I've been able to buy a new 150 euro laptop for decades now at about 10% the price of a decent one. Why isn't this happening with electric vehicles?
A lot of safety features are mandatory in Eu/Aus/US/NA etc, making imported Chinese cars much more expensive than first thought. Bidirectional charging does not add much cost if planned ahead, since most of the effort is in implementing ISO 15118-20 rather than hardware.
I feel like the main issue with bidirectional adoption currently is the number of groups trying to maximise their profit, everyone wants a cut of the pie: the car companies, energy companies, ev charging companies, ev charging networks, solar/inverter manufactures and government standard groups. The needle won't move until California or other countries with influence force it. In Japan, from a technology perspective CHAdeMO has allowed for EVs to do bidirectional charging for years now.
Side note - I'm all for any extra safety features but I do find that a lot of the software driven features are poorly designed and implemented. I've had bad experiences with automatic braking and lane keeping when freeways driving where I was lucky to avoid having an accidents, so not being able to disable them permanently is a major annoyance to me. It seems like these features have very little real world testing.
Charging adds TONS of cost. For start most small city cars are simply charged from wall socket. 2KW are absolutely fine to charge such small cars. You are comparing cost of power cable, with building dedicated circuits and charging station!
Second is the deprecation cost on car battery! Cycles add up quickly!
Your cheap laptop doesn't have to go through multiple rounds of destructive safety testing. It isn't recalled every time a hardware issue is found. It doesn't have to certify much of anything other than some basic electric and RF safety.
But, nevertheless, the price of EVs is coming down. You can buy a Renault AMI for 10% of the cost of a luxury EV.
The other issue is that most people buy cars on finance. £300/month gets you a decent car. Same as most people pay £50/mo for their iPhone.
Well, a cheap laptop lets me check my mail and write a document. Which I can also do on an expensive laptop. A cheap car gets me from a to b. An expensive car too.
But seriously, that's not a car. I own a Toyota IQ. Very small, but still a car. That's not a car, that's a toy. Not comparable to the cheap laptop, more comparable to a Nintendo DS or something similar. It works, but it won't let you email. Just like that "car" won't let you drive for a couple of hours on the highway without feeling you might die every moment.
If I had to guess... Because EVs are still a luxury item. All the green-deal-EVs-are-the-future talk is basically hot air. At least in my circles, all the EV owners have medium-to-high income. Its a luxury. And therefore, prices are high, because, you know, customers can and should be squeezed to the max.
The annoying thing is that there's nothing inherent about EVs that make them expensive/luxury. A budget EV is just as possible as a budget car, sure, the range may suffer (unless it's a hybrid) but it's technically possible. It's companies and maybe consumer preferences driving this. I'd guess luxury EVs just have a fatter margin.
(the underlying politics seems to be that the existing Western manufacturers are lagging deliberately, while the Chinese manufacturers are concentrating on delivering working products cheaply to consumers)
Parent comment was "how the hell are we going to get to zero without 95% of the population just being too poor to own a car?"
If people would rather walk than suffer the shame of a small cheap car that's .. fine by me? Just make sure that the small cars "nobody wants" aren't carefully kept out of the market by tariffs and non tariff barriers to avoid people discovering that they do want them.
Yeah and your comment was factually incorrect so I pointed it out. What is your response here trying to even convey? We have had small cheap EVS and small cheap ICE vehicles. They don't sell as well. I know you wish there was a conspiracy but its the average American does not want a small vehicle. Consumer demand alongside higher margin incentives on more expensive vehicles eliminate that class from the market.
The leaf and bolt were already here in the EV category and they just don't get enough demand. I think they are great but they don't sell as well as you might think.
small cars are not popular, and large cars have much more aerodynamic drag and therefore require bigger batteries. Bigger batteries dramatically increase the cost of the car.
The fact remains, in the US market small cars are not popular. Its not a conspiracy of US manufacturers "lagging deliberately". There of course is more margin to be made on bigger vehicles but its a mixture of both consumer demand and margin incentives.
Interesting seeing V2X on HN, given that I'm currently researching V2G academically.
One thing I've found in my studies is that services like frequency regulation are often described as very helpful or apt for EVs, but online discussion doesn't seem to talk much about the different electricity markets or services. I wonder if anyone here with experience either from an automotive or from an energy side as any views or opinions they'd like to share?
(If anyone wants to ask anything about V2G feel free to ask, though I am not an expert I'll try my best.)
edit: none of this seem to be true, big-ass pickup trucks are just not popular in Europe.
Isn't it for Australia only? Are those models even sold there? I know F150 are not sold in Europe because (I think) they're not road legal, because they're monstrous killing machine.
Especially as the Cupra Born (listed) is based on the same platform as ID.3 and ID.4 - maybe VW deliberately disabled this feature? Or is it just an omission?
I've only used V2L on my EV6 a few times, but the most ironic moment was when I turned off the power to my house so I could install the charger plug in the garage. It was hot, so I used my car to power a fan to keep me cool :-)
I feel like I must be missing some obvious thing because I simply don’t feel the need for a generator. Otherwise, why are whole-home generators so wildly popular, including so-called “solar generators” that are just batteries with crazy expensive solar panels and a convenient plug. And now this EV whole home generator concept taking off after the Ford F-150 Lightning made it well known.
But I’ve survived multi-day power outages with nothing more than some flashlights, a camping stove and a camping heater. The cost of replacing my frozen foods is negligible compared to the cost of generators.
What am I missing? Obviously some edge cases like CPAP, O2 concentrators, and other health things. But I have to imagine that is a small portion of the population compared to who’s buying these things.
We have a wood burning fireplace insert (vs free standing stove) and a few days each winter we lose power. The blower on the fireplace uses about 100 watts and can help keep the house comfortable in sub-zero weather. That’s why we have a small battery/inverter. We have a “generator switch” near our electrical panel that powers just the circuit that the fireplace blower is on. In normal mode the circuit is powered by mains.
>But I’ve survived multi-day power outages with nothing more than some flashlights, a camping stove and a camping heater. The cost of replacing my frozen foods is negligible compared to the cost of generators.
How are you venting the exhaust gases? It's not an issue to run them briefly, but when you're talking during a multi day outage and extended run times in a confined spacer with limited air flow, that's a problem.
>What am I missing? Obviously some edge cases like CPAP, O2 concentrators, and other health things. But I have to imagine that is a small portion of the population compared to who’s buying these things.
Obvious case I can think of is air conditioning in extremely hot climates. An extended power outage in Phoenix, AZ during the summer would probably kill a decent number of people.
0f isn’t that hard in a house. Doors compartmentalize the place pretty good. Safety is a valid concern, but one that can be mitigated in straightforward ways with just mild discipline.
110f is something I would just drive away from. So the same question in return, why would you want to do that?
No, the question is why would you stay in your house if the power is out and it’s over 98 degrees? Just leave the immediate area. Whatever caused the power outage is likely dangerous enough to justify leaving as well.
Crazy expensive solar panels? Depending on where you live they can be gotten for less than $120 USD for a half kW panel, retail cost.
It gets expensive if you insist on a hybrid inverter and battery. But even then, you can get full ROI in less than five years in some locations. ROI is highly dependent on local labor costs, tariffs, grid electricity costs, local solar irradiance, and net metering arrangements.
I am suggesting that just because its easy for you to survive does not mean its easy for others. Older people, families (especially those with young children). Areas with weather on either side of the spectrum. These are not just "edge cases".
If I had to replace every single item in my fridge I could see it easily being $500. If I lived in an area with annual outages I can see the benefit again.
A simple portable generator with a plug installed to your homes panel, probably $1500 all in. A whole house probably $10-20k. If I lived in an area that is prone to outages I can definitely see the possible benefit of installing the whole house generator. But I would say that the $1500 option is much much more common.
If you have plenty of resources, they aren't really all that expensive.
I don't have one but give it a lot of consideration just because it would be the easy way to deal with an extended winter outage where I would otherwise have to drain pipes and hope for the best.
It's extremely unsexy, but upon further inspection it's surprisingly great. It doesn't add costly cycles to the onboard traction battery, but it still can provide similar grid services (virtual spinning inertia, demand response, distribution network balancing, etc). Better yet it should be a software update for every existing electric car, even those without bidirectional hardware.
Ideally I could tell my car, "always charge to [40]% immediately, then charge to [80]% by [8 AM] [Weekdays]." Then the car automatically participates in a fleet battery scheme, earning me money overnight by providing grid services.
Bonus points if it also knows that I have TOU metering, and automatically optimizes for minimum cost.