Power utility Eskom on Wednesday called on consumers to switch off geysers, pool pumps and all non-e.
"We will do an investigation and talk to the Department of Science and Technology on what is the cause of the lightning," Dube said.
She was visiting Makhimba, near Mpumazi in Eshowe, where seven people from two families died after being struck by lightning on Sunday.
"Scientists from the department could perhaps help us and come up with instruments that could help community members protect themselves against lightning."
Four members of the Cele family - Samke, 2, Lindani, 12, Zandile, 37, and Edith, 57, - were killed when lightning struck their rondavel and burnt it to ashes.
The other victims belong to the Mahaye family.
They were identified as Velephi, 60, Aphiliswa, 2, and Senamile, 3.
Eight people were killed by lightning in the Eastern Cape on New Year's Day.
Dhlomo, a medical doctor, stopped his convoy to assist a paramedic who was attending to the hurt woman.