Facilities remain hobbled by Russian attacks, repair work is unfinished and there is little spare equipment, although air defenses have been strengthened.
When not driving around, electric buses and other vehicles could help utilities by storing their solar and wind energy and releasing it to meet surges in demand.
The director general of the World Health Organization, Tedros Adhanom Ghebreyesus, said it was “very concerned” about the outage and reports of heavy bombardment.
As Israeli forces entered Gaza on Friday to fight Hamas, phone and internet service was severed, sowing chaos for Palestinian civilians and leaving rescuers driving blindly toward explosions.