Eskom chief operating officer Jan Oberholzer said on Wednesday that stage 4 load shedding is needed to give the power utility enough space to build up fast-depleting emergency reserves and avoid the risk of even worse load shedding.
At the same time, he has said that the state-owned power utility is burning through nine million litres of diesel a day to support the system during the current crisis.
Stage-4 load shedding was implemented on Wednesday morning following a wide number of breakdowns and trips at power stations across the country. This included the loss of about seven units in one night, which left the power system under severe pressure.
“We again do apologise for the difficult situation we are placing the people of South Africa in and the negative impact to the economy. However, to protect and ensure the integrity of the electrical system, proactive implementation of load shedding is required,” Oberholzer said.
Challenges faced at power stations have left the power utility reliant on its emergency supplies: dams and pump storage facilities and its 14 open-cycle gas turbines at Ankerlig and Gourikwa. With reserves running low, stage-4 load shedding became critically important, Oberholzer said.
“Eskom and independent power producers have 3 000MW of open-cycle gas turbines installed on the system. Should we run out of diesel at these power stations, this capacity would not be available to supply the demand and would necessitate a further three stages of load shedding to be implemented.”
Balance
“Similarly, our pump storage generation (dam) capacity is … 2 700MW, and if the dam levels were to be completely depleted, this would require a further three stages of load shedding.
“So, it is critically important to balance these emergency resources together with load shedding to ensure we manage the power system safely while keeping the stage of load shedding as low as possible,” he said.
Oberholzer acknowledged that running the diesel-guzzling turbines extensively is not a long-term option, with diesel costs running at about R700 000 per hour per turbine.
“They were always intended to be used … early in the morning and late in the afternoon when there is a lot of demand on the country. So, it was never designed that way, but unfortunately because of the system that is not performing the way it’s supposed to, we have to use it extensively.”
We’ve already implemented the dual burners a few years ago on all our open-cycle gas turbines. So, we are looking at … moving over to gas, which is much cheaper
“Between Ankerlig and Gourikwa, we are using nine million litres of diesel a day to support the system. We all agree that it’s not sustainable and we need to get out of this situation, but this is where we find ourselves. For us, burning diesel and having a financial blood nose is much better than putting the country into a higher stage of load shedding,” he said.
He revealed Eskom is exploring alternatives to mitigate the overreliance on diesel.
“We are looking – and we will go to the market very soon – to invite the supply of gas. We’ve already implemented the dual burners a few years ago on all our open-cycle gas turbines. So, we are looking at … moving over to gas, which is much cheaper,” he said.