State-owned power utility Eskom has confirmed that its Duhva and Matla power stations, which have experienced relatively high coal-related load losses in recent years, have started receiving material in line with improved quality specifications agreed during recent contract renegotiations with suppliers.
The contracts were officially meant to come into force on April 1, 2011, but primary energy MD Dan Marokane reported on Tuesday that Eskom had decided to accelerate their implementation and had already started buying in better quality coal in a bid to improve plant operations.
He praised the cooperation received from the coal miners supplying the two power stations, and revealed that load losses at Duhva had more or less halved from the peak losses of around 850 MW to 1 000 MW. BHP Billiton Energy Coal South Africa’s Douglas/Middelburg complex supplies the Duhva facility, which has a nameplate capacity of 3 600 MW.
At Matla, it was not possible for the tied colliery, operated by Exxaro, to offer the quality of coal sought for the 3 600-MW station. Therefore, additional coal was being brought in from other mines and blended with the Matla coal to reduce losses.
Eskom has been pursuing discussions with its coal suppliers on the issue of coal volumes and quality ever since the near collapse of the power system in early 2008, which led to a period of rotational load shedding.
The utility argued at the time that much of its plant underperformance could be attributed to load losses associated with poor quality coal, exacerbated by low coal stockholdings, as well as handling difficulties associated with wet coal.
The Duvha and Matla power stations were particularly affected, with the group reporting in its latest annual report that Duvha had accounted for 40% of total system losses, or 1,6-million MWh, in 2009/10, while Matla accounted for 37,6%, or 1,5-million MWh.
“We indicated earlier that we planned to accelerate some of our solutions around buying in better quality coal . . . and we have now implemented that plan and have seen positive results,” Marokane said.
But the utility was also focusing on improving its coal handling and its stock management, with stock levels currently standing at over 40 days. In January 2008, ahead of the crisis, stock levels had fallen to below 15 days on average.
“We have also set up standard operating processes that have helped ensure that the coal remains dry throughout the process, which is also yielding results.”
For example, tarpaulins are being installed to shield portions of the coal from the rain and Marokane reports that covers should all be in place at all its stations by the end of the group’s financial year on March 31.
“But we have also been spared by the weather, with the rain having been less intense than it was in December. Therefore, the robustness of our solutions will only really be tested once there is consistent heavy rain,” he admitted.
Eskom continued to warn that the system remained “tight” with the peak evening demand having climbed to around 32 000 MW by late January.