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Comment by Retric | Hacker News Reader

In aggregate total energy generation needs to increase, but last mile delivery simply isn’t a major issue. EV’s don’t need that much energy daily and they can charge at night when residential use is low. Assuming ~100% home charging, 1kW per car * 10 hours ~= 40 miles per day ~= 15,000 miles per year.

Drop that to 80% home charging and you’re at 8 hours x 1kW per car.

However, even if car sales go 100% electric it would take ~15 years before 99% of cars in use are electric. That’s a lot of time to ramp up a measly 1-2 kW of load at most houses.

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So if the French population switched to electric, we would need 38m x 800W = 30 gigawatts. We have 58 nuclear cores of ~1GW each as a comparison (80% of our energy) - with the upside that nuclear plants produce by night as much as by day, which causes a lot of issues, therefore 800W between 10pm and 6am might allow a much more efficient (and ecological) use of our nuclear energy.

Yes, this should mean much more efficient use of both the grid and nuclear power, both can provide continuous fixed supply for 24 hours but have had to be overbuilt to match up with the demand curve, which up to now has been extremely uneven.

Market-based pricing for electricity is a big thing for people who have electric cars. It'll become even bigger when vehicle-to-grid/house becomes viable in a large scale (The Ford F-150 Lightning has this feature).

Basically you can program your charger to charge the car when the electricity price is the cheapest and feed the energy back to your house (or the grid) when the price is high.

> Basically you can program your charger to charge the car when the electricity price is the cheapest and feed the energy back to your house (or the grid) when the price is high.

Taking the cost of battery wear into account, I'm not sure that would turn out profitable.

This is the exact place where used EV batteries will find a second life.

A 40kW car battery with 80% SoH might not be viable for EV use, but it's perfect as a battery for a solar cell system. Either at home or at a public charging station.

This assumes that if you have driven 160 miles, it will take 40 hours to get the full charge. It does not look like a good selling point for home charging.

To feel at ease, an electric car owner should have a fast charger at home or very nearby. A Tesla supercharger is 72 kW, which is 2-3 times more a detached house can normally receive from the grid.

The grid is also built on the assumption that maybe one in five ovens are likely to be turned on at the same time, that doesn’t mean each oven can only be used at one fifth power.

In the Netherlands the average car drives 32 kilometres per day. You can easily charge that much at home.

On average, it's like 800W. My current home charger and cars support up to 7.7 kW. It's something like 4 hours to go from near empty to full for one, and about twice that for the other one (very different sized batteries). But what that really means is that the charger will click on for a relatively short time, then sit idle for the rest of the day. It's likely that most home chargers won't exceed 40A for a while, as past that needs hard wiring. Though I suspect V2H capable chargers will all be hard wired.

The point is things average out over even hundreds of homes. A single home might be charging at 7.7kW all night long after a long trip to refill a 100kWh battery. However, everyone in the country doesn’t suddenly show up with an empty battery every Friday and then need to fully charge that night.

Which means even if people are installing 5+kW charging stations it’s little different than when everyone started installing AC.

You assume that a car needs to be fully charged each morning. If you for whatever reason drive 160 miles each day, but may only recuperate about 40 miles (in rough worst case of say ten hours at a home Level 1 [standard US electrical outlet] charge over night), you still need only need a "full charge" on a 300 mile battery every two days or so.

The economics shift even more the closer you get to the mean daily commute of 32 miles roundtrip. For instance if you travel 45 miles daily and only charge 40 each night you'd need nearly two full weeks before your range dipped below 200 miles. At that rate you'd need a full charge maybe once every month and a half (assuming of course that you have no other sources of topping up your miles in a month in a half, such as convenience chargers while shopping or work sponsored chargers during the work day).

I wouldn't be so sure about that, but I tried to look up some numbers and couldn't find any for the capacity planning of last mile delivery. 10 kWH per day is about the average electricity use per home in the Netherlands, so the aggregated impact will definitely be huge. Especially as more an more homes are switching to electric heating and cooking (until recently pretty much all homes here used natural gas). So household electricity consumption will take a huge leap in the coming decade(s), and I would think this will also affect last mile.

Also take into account standard home chargers here are 16A@230V=3.7kW, but 3 phase chargers that can do 3x16A, 10kW are gaining popularity. Only if the chargers remain 'dumb' and all start pulling max current when everyone gets home at dinner time that will be an issue here for sure

On the other hand, solar panels on the roof are also taking off. That's probably not enough for heating, but might be for everything else.

Daily electricity is highly correlated. Consider, people rarely microwave anything at 3AM. This also means houses get wired to allow multiple loads at the same time as you might only turn on the Microwave for 5 minutes a day so that’s adding 0.083kWh to your daily total, but you don’t turn off the lights just because you want to use 1.2kW heat up some leftovers.

Further, several people in a neighborhood might all microwave something during the same commercial break. Unlike most things the grid is built for peak instantaneous demand. As such distribution needs to account for huge local demand spikes. EV’s increased demand will result in some new distribution infrastructure, but it’s mostly regional not last mile.

If people get obscene bills for charging their cars during peak hours or find themselves having to adjust plans around charging that will stunt EV adoption.

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