The Eskom board of directors gave approval in 2008 to develop Tubatse, until recently called by the provisional name Project Lima. (HNN 12/16/08) The pumped-storage project is planned for the escarpment between South Africa's Nebo Plateau and the Steelpoort River Valley in Mpumalanga Province.
Eskom spokesman Fani Zulu said Tubatse would be delayed because it was not required urgently as energy demand is expected to grow at a much slower pace owing to economic slowdown. Zuni said the utility would continue with construction of two coal plants, Medupi and Kusile, of 4,800 MW each.
"If we continue with Tubatse, we get into a high excess capacity situation, so we decided to move it to a later date," he said, but added that no date has been finalized.
Zulu dismissed concerns that Tubatse could be needed earlier in case there was a delay to one of the other projects.
"We've done the necessary calculations, we are comfortable with it," he said.
Eskom previously estimated the project would go on line in late 2015 for an estimated cost of 10.2 billion rand (US$1.02 billion).
The National Energy Regulator of South Africa (NERSA) has been reviewing Eskom's license application to operate Tubatse. Eskom must acquire the operating license from NERSA before proceeding to the next phase of the project, actual implementation.
Tubatse's upper reservoir would be built at the top of the Thaba ya Sekhukune escarpment near the town of Sehlakwane. The lower reservoir would be within the Steelpoort River Valley and would be fed by a pipeline from De Hoop Dam.
The upper dam is a 31-meter-tall, 3,750-meter-long concrete-faced rockfill dam. The lower dam is a 51-meter-tall, 1,600-meter-long zoned earthfill structure with an impervious core. The underground powerhouse is to contain four 375-MW pump-turbines.
Tubatse's environmental impact assessment has been completed, with the project receiving a positive environmental authorization from the Department of Environment and Tourism in October 2007. Its feasibility study was completed in November 2000.
Eskom is already developing another pumped-storage project, 1,368-MW Ingula, on the border of South Africa's Free State and KwaZulu-Natal. In September it named Voith Siemens Hydro Power Generation to supply complete electro-mechanical equipment, including four pump-turbines of 342 MW each, four motor-generators, and complete automation and control systems. (HNN 9/3/08)