> at full load (3kw)
Do you live in a deprived rural village in a very poor country? Because you can't even run a heater and the oven with 3kW.
No it’s quite the norm actually.
Most power contracts give you 3 kwh power supply for residential home. That’s the standard.
Bumping to 4.5 or 6kwh must be required explicitly and costs and extra on the base power supply bill