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by irons 231 days ago
In the US, V2L limits your ability to output power from the car to about 1500 W. It's not going to power your house as more than a stopgap, even if you do have supplementary house batteries. V2H/V2G justify their complexity by solving that problem, along with all the ancillary grid benefits.
2 comments
torginus 231 days ago
Not sure if that's the case - however doing V2L requires the manufacturer to add an inverter to the car, and making that powerful probably adds extra cost most customers wouldn't pay. TI just looked it up and my Ioniq can only do about 2kW sustained - but since this charges the house battery, that's enough - idle load is just a couple hundred watts.
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nandomrumber 231 days ago
If the car charges the house battery, what charges the car?
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irons 231 days ago
If you have solar panels or time-of-use electrical rates, you charge the car when power is cheap/free, and spend stored power when the grid costs are high. During a protracted outage, maybe you drive the car to a fast charger.
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torginus 230 days ago
You pointed out a significant limitation of my current setup - right now there are 2 plugs - one for discharging the car through a proprietary manufacturer's V2L adapter, and one for charging.

I'm planning to make a 'box' that can switch between the 2 functionalities on the same cable.

The whole setup is a bit clunky as it is right, now, but I'm kinda more surprised that it works at all, and how well the fundamentals work.

This whole thing was more of an experiment in 'no way you can do this' to actually doing it, but I think this is HUGE, and will transform the way people think about electric cars.

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Dylan16807 231 days ago
A typical house averages less than 1500W. And most of the higher usage overlaps the sun being out. So if you have supplemental house batteries to handle bursts then 1500W of V2L can go a very long way.
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eldaisfish 230 days ago
the average hides a lot of information. the largest peak load is often an electric stove, which is regularly greater than 1,500 kW.

Also, this idea that higher usage overlap with the sun being out is laughably wrong. Solar noon is between 11 AM and 2 PM. Very few people are home at that time. There is a reason that peak grid demand in almost every country is in the early evening.

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Dylan16807 230 days ago
> the largest peak load is often an electric stove, which is regularly greater than 1,500 kW.

Does that change anything about what I said? This is specifically about "if you do have supplementary house batteries".

> Also, this idea that higher usage overlap with the sun being out is laughably wrong.

The reason we have the duck curve is that insolation and demand largely overlap (especially when we're talking about the worst case part of the summer), but then for part of the evening they really don't overlap.

The peak use is evening, but there's a significant ramp up when the sun rises and the whole day is much higher than night. https://ars.els-cdn.com/content/image/1-s2.0-S03062619173137... (This isn't the US but finding household graphs in particular is annoying, and most of the US has more summer heat than denmark)

Anyway evening is one of those bursts where you use the supplementary battery to handle the rest of the load. Even 10% of the car's capacity, 6kWh, could cover almost all use above 1500W.

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eldaisfish 230 days ago
Everything you describe is true only in some places, likely California. In much of the rest of the world, electricity demand peaks in the evening, when the sun is low in the sky and continues well into the evening, when the sun isn’t out. Notice how even the Wikipedia page about the duck curve lists mainly California. Even in Australia and the UK, daylight hours and electricity demand mostly do not overlap.
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Dylan16807 229 days ago
>> The peak use is evening

> In much of the rest of the world, electricity demand peaks in the evening

Huh?

And again my chart showing that the entire day has much higher use than at night, then an extra high peak in evening, was Denmark.

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nandomrumber 231 days ago
> And most most of the higher usage overlaps the sun being out.

Aren’t most people at work / school when the sun is out?

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Dylan16807 231 days ago
Yes but high electricity use days correlate with air conditioning, and most people don't turn that off in the middle of the day.

If you're not worrying about A/C then 1.5kW goes an extra long way. Outside of cooking you'll rarely exceed it.

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