Infrastructure for multiple electric vehicles at home

[smorgasbord]

I was thinking about a "success problem": Suppose EVs become popular and mainstream. Cool! Now, mentally raise your hand if you currently have 3 or more vehicles AND 3 or more drivers at home. Now imagine you need to charge 3 or 4 vehicles in one evening. What's the current draw?

I just installed a 50 amp outlet for my upcoming Roadster (can't wait!). I have a Model S on order. I'll probably want something along the lines of the HPC for the Model S, which puts me at 140 amps total. My whole house is only 200 amps. Many homes in the US are only 100 amps service.

So, what's the future going to be for families with 3 or more vehicles?

I'm thinking they all get plugged in to a single charger unit, which communicates with the cars to figure out which cars need what to get fully charged, and spreads the load amongst the cars and/or sequences which cars get charged when. It might be good to have a way to enter priorities for which vehicles to charge first, and/or enter anticipated mileage for the following day for each car, but that's probably more input than most people will want to give. Another possibility is that many people charge at work, which has the benefit of reducing charge times at home, but has the disadvantage of pulling electricity during prime use hours, which could be a drain on the system (I'm in CA, so we're familiar with rolling blackouts).

What I can't see happening is that all homes in the US get upgraded to 400 amp service. Any other ideas or thoughts here for a many EV future?

[dpeilow]

Well, to do average mileage (at least in the UK which is 10000 per annum) you only need to charge at 1kW overnight. So in theory, it shouldn't be a problem.

[EV_de]

no Problem in EU ... IF all cars supporting 3 phase charging ...

US 240V * 50 A = 12 KW
EU 400V * 16 A = 11 KW ... Fuses - 63A / phase ... 3 cars each 3p 16 A + Power left for the House ..

[vfx]

... Now imagine you need to charge 3 or 4 vehicles in one evening. What's the current draw?...
If they are all empty at by night, that's a lot of driving.

[smorgasbord]

If they are all empty at by night, that's a lot of driving.

Yes, not every car is going to need the full 3-4 hour charge each night, but it's easy to imagine a family where one person commutes to work, another runs errands, and another goes to school. Even if they're not all empty at night, you still have the simultaneous charging load issue for the hour or so they each need to be charged. I suppose you could program one car to start at midnight, the next to start at 2am, etc., but that assumes the each car is finished within its 2 hour window - and if it's not it's going to overload the circuit while you're sleeping. So, I think you need to do the sequencing in the charger, in which case you might as well have a smart charger that knows when each car is done, and/or reduces power to each so that the total is not more than the incoming circuit can handle.