[tgsovlerkhgsel]

It's unclear if he means Alternating Current or Air Conditioning with AC. I hope it's the former, because the latter needs kilowatts, not the 270 W they have.

"Concrete" can also mean "the cement based building material" or "specific", as in "this specific building needs power to be habitable, because <unusual detail>" (pumping drinking water for example, which is mentioned).

The comment "because Russia and America are busy in Ukraine" indicates OP is not in Ukraine.

[gizmo686]

What else would they need power for? Heating and cooling are the only appliances I can think of that would be necessary for habitability.

[evan_]

sump pump or well pump, which would also need quite a bit of power but not as much as HVAC

maybe just lighting if there are no windows or they have to keep the windows covered

[jstarfish]

The device they're asking the question from ;)

[jccooper]

Ventilation and/or lighting.

[Nition]

OP has now said:

"Water evaporative coolers are very effective in Sudan because of the dry weather and they consume little energy and also use ceiling fans for cooling and other things like split units but I'm not planning to turn that power hungry device those days."