* System to remain constrained until next week
* Eskom working to return generating units online
(Releads with new power emergency)
By Olivia Kumwenda-Mtambo
JOHANNESBURG, Feb 21 (Reuters) - South African power utility Eskom
Eskom had declared an emergency on Thursday following outages at some of its generating units, but lifted it on Friday morning.
It then had to reintroduce the emergency measures, and said they could extend to individual households as well as large commercial consumers of electricity such as mining firm BHP Billiton
Rolling blackouts, known locally as 'load-shedding', caused misery for millions of South Africans during a severe power crunch in 2008, but spokesman Andrew Etzinger said the outages would be "better managed" this time round.
"We are working with our commercial customers," he said.
The state-owned company, which is battling to keep the lights on in Africa's largest economy, declared the first national grid emergency in five years in November.
The utility said it expected additional generating units to come back online and forecast lower demand ahead of the weekend. Eskom provides 95 percent of the electricity to Africa's biggest economy.
It urged its key industrial customers to reduce their usage by at least 10 percent.
Most mines in the platinum industry are out of action due to a strike. Workers at Anglo American Platinum
The 2008 power crunch forced the closure of mines, factories and smelters for days, costing the economy billions of dollars in lost output.
(Reporting by Olivia Kumwenda-Mtambo and Zandi Shabalala; Editing by Ed Cropley)
((Olivia.Kumwenda@thomsonreuters.com)(+27 11 775 3159)(Reuters Messaging: olivia.kumwenda.thomsonreuters.com@reuters.net))
Keywords: SAFRICA POWER/