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.