For several years now, public EV charging points in Amsterdam have also been used to provide temporary power supplies for construction projects and events, for example. The city is now actively promoting this as an alternative to diesel generators on construction sites.

https://www.amsterdam.nl/leefomgeving/openbare-stroompunten/

@burger_jaap what a wonderful idea! I do not know if this is used in Luxembourg; I have never personally heard of it.