This obviously can't be allowed to happen .. but I don't think there's any sign of that, as grid electricity remains cheaper than onsite generation. On a trip last month it was very noticeable that several rest stops had under-construction chargers in addition to the one or two that had previously been put in.
I would argue it SHOULD be allowed to happen, maybe even encourage it. An EV that needs a gas powered generator for 0-1% of its life is many times better than an ICE that needs a gas powered generator for 100% of its life.
If you allow gas powered generators to complement EV stations, you will have more EV charging stations in remote areas or otherwise areas that wouldn't see EV chargers. Every extra EV charger will drive up the adoption.
> If you allow gas powered generators to complement EV stations, you will have more EV charging stations in remote areas
But you don't have to do this! You can just put them on the grid. There are very few places that are truly off grid in Europe, mostly on islands, and absolutely zero on motorways.
The power requirements for charging stations are massive! A Tesla can draw 250kW. If you have 10 chargers, that is 2.5MW. You won't get that everywhere...
If you can install a 2.5MW diesel generator to cover those areas, encouraging adoption, that is a good thing.
I am not talking about 4 lane motorways, where access to megawatt power lines might not be that challenging, but more remote areas.
Can draw being a key. Cars can only sustain their max draw for a short portion of the charging curve, so it would extremely rare (if not impossible) to actually draw 2.5 MW. 10 cars with under 15% state of charge would all have to pull in within 2-3 minutes to a supercharger that started empty.
Many charging locations are getting dedicated batteries to smooth off the peaks and valleys of fast charging, turning it into a much more constant draw. When a peak is needed the battery fills in. When the site is more idle, instead of a valley, power is diverted to the battery to ready it for the next peak.
Another strategy companies like kempower are using is 25 or 50 kW modules that can be dynamically allocated across the whole site. At the peak of the curve a car gets many modules. As the power a car can take decreases deeper into the curve the extra modules can be assigned to a different plug. If everyone pulls in at low state of charge at the same time the site hits the limits and cars have the throttle. A more typical usage pattern of cars pulling in and out at different times means cars can maximize their charge curve while capping the total draw of the site.
10 cars filling up their tanks at an highway gas station is not uncommon, especially if you consider the cars waiting in lines. This may seem unfair but let me argue about that.
Filling up a gas tank and leaving takes about 5 minutes so even if you arrive there and you have to wait in a line it's not a big deal. If recharging an EV up to a reasonable level takes 15 minutes, either they 3x the number of stands or make customers unhappy and leave for the next station, if they can get there. If they can't, they are hostage of the physics of batteries and EVs and they'll have to wait.
So I think that each charging station will have more stands to recharge EVs than gas pumps now.
> I am not talking about 4 lane motorways, where access to megawatt power lines might not be that challenging, but more remote areas
That's a good use case for battery backed or battery integrated chargers. They can charge up the battery on a smaller grid connection but still deliver fast charging since you're drawing from the battery pack.
The European grid is much, much better shape than the US one. It is also luch denser, so I don't see a problem here at all, locally. Overall, the grid will be different when millions of EVs have to charged, but that will be done by the utilities because they will make money doing it. Expect a lot of whining to get EU and national subsidies to do so first, but that is business as usual.
10 250kw chargers are frequently only supplied by 1 megawatt of power supply.
They rely on the fact that it is common for some of the stalls to be empty, occupied by cars that have finished charging or can't charge at the full rate for whatever reason.
Some sites have batteries to provide a bit more power for the busiest times too. That has the benefit that those same batteries can participate in grid balancing the rest of the time (buying and selling power for profit, and getting paid for various technical grid services too).
> Maybe 2 chargers 50kW would be perfectly sufficient and much more economical outside of freeways?
That remains for the free market to decide....if the owner considers a generator is cheaper, then leave him be. Where grid power is enough, electricity will be much cheaper than a generator, so if the owner wants a generator, it's probably a choice between having a generator charger vs no charger.
> so if the owner wants a generator, it's probably a choice between having a generator charger vs no charger.
Possibly. But I would expect this to be a very uncommon scenario. Unless you’re running a car race* for instance you’d have to have a situation where somebody would both be willing to pay 2x or more per kWh and also prefer to not charge their car at all if they couldn’t do it in 5-15 minutes.
This obviously can't be allowed to happen .. but I don't think there's any sign of that, as grid electricity remains cheaper than onsite generation. On a trip last month it was very noticeable that several rest stops had under-construction chargers in addition to the one or two that had previously been put in.