Eskom systems operations and planning MD Kannan Lakmeeharan on Wednesday warned that if South Africa did not implement energy efficiency now, it would suffer a tight electricity supply during the winter period and into 2011, when Eskom restarts its maintenance period.

He told delegates at an energy conference in Johannesburg that demand was expected to return to 2007 levels this year.

While Eskom has now improved its reserve margin, it hoped to maintain this at between 9% and 12% this year, and to boost it to above 12% beyond that.

In the longer term, Eskom was hoping to get its reserve margins back above the 15% level.

In the short term, the power utility planned to sign on at least 500 MW of cogeneration capacity, as well as some renewable energy programmes and independent power producer open-cycle gas-turbine projects, subject to the enabling environments being in place.

However, energy efficiency would be a key component in South Africa's energy sector this year and beyond.

Lakmeeharan further warned that the adequacy of electricity supply between 2012/13 was of serious concern and that a worse-than-planned generation performance could result in higher risk and reduce the system adequacy between 2011 and 2013.

He added that the country had to make decisions with regard to its nuclear energy programme and renewable energy programmes this year, or it would lose out.

Eskom was hoping to complete its new Medupi and Kusile power stations by 2017/18, if funding permitted, while there could be a requirement for a third new base-load power station or smaller stations, to be run by Eskom or IPPs, but any setbacks in other infrastructure projects, like water and transport, could delay these projects.

Lakmeeharan pointed out that there was an opportunity to reduce the country's energy use by between 8% and 15% in the next five to ten years, which could delay the need for a third new base-load power station.

Nevertheless, South Africa was expected to require an additional 20 GW of generation capacity by 2010 and up to 40 GW by 2030. The power utility's current build programme and some advanced IPP projects could contribute at least 14 GW of this requirement by 2017.