Prime Minister Narendra Modi’s call for Indians to switch off their lights Sunday evening for nine minutes and instead use candles to "challenge the darkness” of the coronavirus outbreak will mean blackouts for some citizens as utilities take steps to safeguard their equipment.

Modi asked people to switch off lights at 9 p.m. That may result in a sudden drop of about 15 gigawatts of power demand across the nation, said S.N. Sahai, secretary in the nation’s power ministry. In Uttar Pradesh, India’s most-populated state, the state-run utility plans to switch off power in phases to stop the surge in voltage from threatening the state’s power grid and equipment, U.P. Power Transmission Corp. said in a letter sent to generators.

The country plans to switch off some of its hydropower generation capacity to deal with the sudden dip in demand, Sahai said.