It terms of legality, it doesn't matter who the population of Gaza support .
Israel are at war with Hamas and Israel can stop Hams from receiving electrical power , same goes with food and other commodities .
Israel can legally stop supplying Gaza with commodities and everything else , but they have to allow those commodities in from other Countries , as long as its not going to Hamas .
Point being about the power station in Israel which Hamas bombed .
As Hamas bombed a power station which supplied Gaza with power , they cannot complain much when their power supply goes down .
Like Hamas bombed a power station in Israel and then Israel must fix that power station to bring the power supply back to Hamas