Sri Lanka announced on Tuesday that electricity would be cut to many homes, shops, offices and government buildings for three hours every day due to shortages from hydro-power stations.
The outages will be rotated across different parts of the island and begin at various times throughout the day, the energy ministry said, blaming a drought that has affected reservoirs in the central region.
"We are facing difficulties in balancing the supply and demand," the ministry said in a statement. "The only alternative is to carry out power cuts across the country until further notice."
It said two poor monsoon seasons had caused hydro-electricity generation to drop by 75 percent in the past year and added that shortages had been compounded by a new Chinese-built coal power generator breaking down.
"The main impact of the drought is on hydro-electricity reservoirs," irrigation ministry spokesman Viraj Abeysinghe said, adding that the main agricultural areas were unaffected.
Earlier this month, President Mahinda Rajapakse ordered reservoirs to be cleared of silt to increase capacity.
The state-run Ceylon Electricity Board said they were trying to restore the faulty coal power plant as well as another diesel plant to augment electricity supplies.