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Comment by kuro68k | Hacker News Reader

Not really a problem. Putting chargers in every space in a car park is pretty cheap, they are basically just circuit breakers or even just ordinary domestic style sockets.

Throw in a few fast ones for the people who need them and you are sorted. The fast chargers can be multi-head too, so even if someone finishes charging and doesn't come back someone else can still use it. Most rapid chargers are like that.

Also, if it's still a problem with a five minute charge, why doesn't it affect petrol pumps?

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Charging a car requires a nontrivial amount of electricity, so it's not sufficient to add a circuit breaker / socket, you also need a payment infrastructure unless e.g. the municipality is willing to sponsor the energy costs of everyone driving.

Parking spaces in dense areas already act as a huge subsidy toward cars, so I don't think electrical cost is a deal-breaker.

Or you glue on half a parking meter to turn the electricity on and off.

> I don't think electrical cost is a deal-breaker.

Do you have any numbers, or are you guessing?

If you are talking about pure electrical cost, the average cost per kwh in the US is about 12 cents according to NPR.

An average Nissan Leaf battery is about 24kwh (although some cars have much smaller or larger batteries). So if you assume an average Leaf is totally empty, and charging to completely full, that would be a little less than $3 of electricity for roughly 84 miles of range.

To charge a car quickly takes a lot of electricity. But to trickle charge a car takes very little electricity. You can charge cars on as little as 120 volts at 8 amps -- that's less electricity than the average plug-in space heater.

A small parking lot could easily handle 20+ cars simultaneously charging overnight, with just a single standard US household circuit. (100 - 150 amps).

That's interesting, thanks.

But why didn't you consider other costs, such as equipment installation and maintenance?

And what about the grid? Can the grid sustain the equivalent amount of energy that the nation's cars burn every day in gasoline?

It costs $1 to put 8kW (30miles) into a car, and takes about an hour (for a level 2 charger) so the cost of electricity is less than the land value (unsubsidized meter rate) of the parking space itself, in any urban area.

Why didn't you consider other costs, such as equipment, installation, maintenance, etc? Why did you reduce the value to the parking meter rate?

no because carparks don't have the electrical power availed to support charging hundreds or cars at at a time - they will have enough to run the lights but not enough to service hundreds of high amperage car chargers

They won't need to charge hundreds of cars immediately.

When car parks need to charge hundreds of cars at a time, it will be proditable for them to they will build power providing structures.

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