While energy utility Eskom’s build programme continues at pace – with the first unit (Unit 6) of the long-awaited coal-fired Medupi power station to finally be synchronised to the grid in December – Eskom senior general manager Andrew Etzinger believes this additional capacity will not be fully leveraged if the condition of existing power plants continues to decline.

The unplanned capability loss factor (UCLF) of Eskom power plants, which was measured by the time that a generator had spent out of service owing to plant failure, had increased in recent years, from 5.1% in 2010, to 11% this year, as a result of a delay in maintenance by the parastatal.

Predictable generation fleet performance had, thus, remained a challenge, as the UCLF could not be changed quickly and could only be reduced by removing or repairing each damaged component in a power station.

“Out of 87 coal-fired generating units, 32 require major ‘surgery’ and four are in a critical condition,” Etzinger reiterated.

Noting that Eskom had had “no window” to perform maintenance on its plants, he said it had long postponed these programmes to prevent power-generation capacity being taken offline over the maintenance period, and the subsequent inevitable loadshedding.

“The new plant capacity will also have to be in place of this decline in capacity of our existing plants, so new plants won’t help unless we stop this decline.

“[As a result], we’ve decided that we can’t put off maintenance any longer and have been asking our industrial clients to cut back on consumption [to accommodate this],” he told the Powering African Industry conference on Thursday.

Noting that the success of this strategy was the result of a “tightly forged” relationship with its 140 large industrial customers, Etzinger reported that Eskom’s “winter plan”,  which had seen industrial customers curtail their energy demand to enable maintenance activities, had yielded good results.

He added that the utility now had “a better handle on the system” after managing to deal with some “opportunity” maintenance over South Africa’s winter months, reducing partial load losses from an excess of 3 500 MW to 1 500 MW.

Eskom had further connected 538 MW of independent power producer (IPP) renewable energy to the grid over the period, comprising 460 MW of photovoltaics and 430 MW of wind energy capacity, bringing the total energy capacity provided by IPPs to 1 000 MW.

“We are confident that inroads are being made to arrest UCLF,” he concluded.

Presenting Eskom’s “summer plan” 2014/15 to Parliament’s Select Committee on Communications and Public Enterprises, in August, Eskom acting CEO Collin Matjila outlined that the maintenance schedule was set to be increased to over 10% for the summer season, based on the sustainable generation strategy, and the need to clear incomplete load losses, with few flexible outages.