Zimbabwe has been short of electricity for years, but outages increased dramatically in the past two weeks. South Africa says supplies have been resumed after maintenance. But some economists say Zimbabwe was cut off for non-payment of its account.
Zimbabwe no longer generates enough power to supply demand, although it could do so for decades, even when consumption was far higher than now.
The coal-generated power plant in Hwange, in north west Zimbabwe, is massively under performing, according to the Zimbabwe Electricity Supply Authority, known as ZESA. It is short of foreign currency to fix equipment, and it is also short of coal to fire the plant, although the power station sits on some of the largest coal deposits in the world.
Foreign currency shortages are affecting productivity at the coal mine and the National Railways of Zimbabwe, which no longer has enough engines or wagons to carry coal from the mine to its destinations.
Zimbabwe also generates hydro-electricity from its vast Kariba Dam, but its generators are not working at full efficiency either.
Zimbabwe has to import about 40 percent of its electricity from South Africa, Mozambique and the Democratic Republic of Congo.
Economist John Robertson and several diplomats in Harare say Zimbabwe has failed to keep its payments to South Africa up to date. Robertson said the central bank had to go to the parallel, or black, market last week looking for U.S. dollars to try to pay its electricity bills.
ZESA Chairman Sydney Gwata told the government-controlled press recently that the authority does not generate enough revenue to pay for all its imported power.
South Africa's power authority, Eskom, says it cut power to Zimbabwe recently, while it was carrying out essential maintenance. It said it has restored full power supplies.
Meanwhile, several private importers have been told by fuel companies in South Africa that, for the moment, they cannot continue to supply Zimbabwe. One letter sent to a major industrial company in Harare cited temporary refining problems in South Africa.
Zimbabwe can no longer use the fuel pipeline from the Mozambique port of Beira, because no Zimbabwe importer can afford to buy a ship full of fuel, about 30,000 liters, to open the pipeline.
The state fuel supplier says it does not have enough foreign currency to import fuel, except for the government's pumps.
Fuel, mostly from South Africa, is available at selected gas stations. It is imported by private importers with access to foreign currency.
As the value of the Zimbabwe dollar has crashed against the U.S. dollar on the black market, the price of fuel in Zimbabwe has increased by about 30 percent in the past two weeks.