Johannesburg - Eskom had approached this winter better resourced to keep the lights on than last year and was on track to commission its Medupi power station at the end of this year, it said yesterday.
However, Medupi’s Unit 6, whose different substations are in the process of being commissioned, would only come into full commercial operation in the first quarter of next year.
“On synchronisation, Unit 6, which is an 800 megawatts (MW) unit, will be sending power to the grid. The period between synchronisation and the achievement of full power is very delicate and is intended to ensure that all subsystems operate optimally to ensure that the maximum throughput of the unit can be maintained,” its acting executive of group capital, Dan Marokane, said.
What this means is that the unit would be in a fine-tuning process to get it to generate power at its maximum capacity.
But at least this winter, Eskom is better equipped to prevent the recurrence of rotational load shedding even though it said that could not be ruled out completely.
Units taken offline for maintenance would be reduced to 1 620MW by July compared with 2 000MW in winter last year.
“This is a deliberate reduction to meet the peak demand of winter… We have been doing a lot of maintenance since the beginning of the year. We have been able to put plants back on the grid with the confidence that they will be able to meet demand,” Eskom’s acting chief executive, Collin Matjila, said.
Besides the reduced maintenance schedule, the energy utility is going into this winter with slightly increased generating capacity.
On the supply side of its demand management, Eskom has secured 345MW of power that would be supplied under short-term contracts with independent power producers (IPPs) compared with between 200MW and 300MW last year. It is also in negotiations with a couple of other electricity generators to increase this by an extra 500MW before the end of the year.
Its target was to obtain up to 1 000MW of extra supply made up of short-term IPPs, the reduction in the company’s partial load losses and other initiatives.
During the day, there would be a further 600MW of supply from the renewable energy IPPs, an option that was not available last year.
Eskom’s hydro-electricity imports from Cahora Bassa in Mozambique will increase to 1 500MW by July. Last winter Eskom could not import the contracted 1 320MW supply capacity from Cahora Bassa.
Eskom expected the winter peak demand to reach 36 000MW. But the current demand excludes about 400MW that has been reduced in the platinum mining operations since the strike began.
Although Eskom has increased supply this winter, it is looking to sign new “interruptible load” contracts with its big industrial customers. These contracts allow Eskom to interrupt their power supplies at any point in a supply crisis.
The utility first makes use of its demand market participation, asking customers to voluntarily reduce their loads. If it still does not have enough supply, it switches on the open-cycle gas turbines.
The group executive of sustainability, Steve Lennon, said these turbines had cost Eskom more than R1 billion in diesel fuel in the first two months of this financial year.
He said the interruptible load agreements would only be used if the open-cycle gas turbines did not provide sufficient capacity to meet demand.
At the moment, Eskom has one major interruptible load agreement with BHP Billiton of 2 000MW and other smaller contracts making up 100MW. - Business Report