The Ukrainian energy company "Ukrenergo":

As a result of the attack by Russian drones, several elements of the power grid that supplied electricity to parts of Kiev and the Kiev region were de-energized. Consequently, a significant number of consumers in the region are currently without electricity.

Restoration work began immediately after the security situation allowed. Currently, energy workers are working to restore power to the affected consumers. This will take some time.

@Slavyangrad