I don't understand what 50 kW could possibly be needed for.
Part of the electricity bill here in Flanders is based on monthly power peak. I charge an EV at home, and by setting up the charging station to take into account consumption data from the meter, I have no problem staying below 7 kW. Okay, that's averaged over 15 minute time slots, but even the connection for my house is only rated 13.8 kW!
> Okay, that's averaged over 15 minute time slots, but even the connection for my house is only rated 13.8 kW!
In the US we have single-phase (split-phase) 120/240v 200A service drops for houses, 48kW. Houses over 3,000 square feet with electric heating, electric ovens, electric water heaters, and electric air conditioning can push 150A peak demand, and a 200A service drop is not much more expensive for the utility than a 100A service drop. Most houses in my state have gas water heaters and furnaces so 200A is overkill for most people in my state.
A 7kW 240V single-phase load draws (7000/240) 29.1A
IIRC most of Europe gets 230V or 400V three-phase power for houses, so here’s both calculations.
A 7kW 230V three-phase load draws (7000/(230*1.732) 17.57A
A 7kW 400V three-phase load draws (7000/(400*1.732) 10.1A
The reasoning behind a 50kW for a house in the US is (probably a 48kW) generator is you can fully back up your 200A service (240V times 200A = 48kW) and not split out the generator loads into a subpanel.
Older houses in the US might have a 100A service, I’ve even seen 60A house services.
Not needing a sub-panel is almost certainly the reason.
The North American residential electrical code limits how many circuits you can put onto a generator based on the circuit capacity, not the expected use. You aren't allowed to pinky swear that you won't run your electric oven and dry laundry at the same time. It doesn't matter that your generator will just trip its breaker or die.
So if you want to have most of your house on a permanently wired standby generator you need to wildly oversize that generator such that it can entirely replace utility power.
Alternatively, you put in load shed devices. They're basically fancy self-resetting circuit breakers that trip when the generator begins to be under too much load. They all trip at the same time and then come back up in a pre-determined sequence.
I have 2 wells, irrigation, a big shop and a smallish house. I live on the eastern crest of the North Cascades mountains in Washington State US and it can be -30c in the winter and 40c in the summer. Heat pump system with wood backup for the house and woodstove in the shop. When looking at the costs to put in the genset the difference to go big was de minimus.
Startup spikes; AIUI anything with a motor will initially sink way more power than you expect it to use, then settle to a more reasonable level. So you need to overspec a generator to handle that without a brownout.
I think that's it, anyways; this is not my strong suit.
Part of the electricity bill here in Flanders is based on monthly power peak. I charge an EV at home, and by setting up the charging station to take into account consumption data from the meter, I have no problem staying below 7 kW. Okay, that's averaged over 15 minute time slots, but even the connection for my house is only rated 13.8 kW!