WINTER'S TALE

Utility may have to turn to independent producers

Escom faces supply crisis

ESKOM will battle to keep the lights on this winter as plant performance and unplanned outages remain problematic.

This week, planned maintenance outages stood at 3 600MW and unplanned outages totalled 5 900MW — nearly 18% of the available capacity of 33 200MW. In February, the utility projected unplanned outages of 4 500MW for April to June.

On Monday, peak demand was 32 771MW, leaving spare capacity of just more than 1%, significantly less than the 10% to 15% that is internationally regarded as prudent.

“There is deep concern about Eskom’s maintenance. They experience problems at generators even after those have been down for extensive periods,” said energy analyst Chris Yelland.

Shaun Nel, director of the Intensive Energy User Group, said plant performance and unplanned outages remained concerning. “Either the maintenance programme is failing to achieve the required performance improvements, or the plants have reached such levels of disrepair that something is bound to go wrong when you return them to service,” he said.

Eskom has been relying heavily on expensive open-cycle gas turbines to meet peak demand. It has also re-entered into short-term power-purchase agreements with industrial customers who generate some power at their facilities, such as Sasol and Sappi. “The lights are being kept on at high cost,” it said in a statement.

Although industrial users traditionally scale down operations to do maintenance in the winter months when electricity is much more expensive, the usage of commercial and res- idential customers increases significantly between April and August.

Eskom urged customers this week to save at least 10% of their usage, particularly between 5pm and 9pm, saying unplanned outages “add more pressure to an already tight system”.

Unlike previous years, it has not received funding permission from energy regulator Nersa to buy back power from big users, such as ferrochrome smelters, to manage demand.

However, Yelland said Eskom might decide to fund this from other revenue sources if it made financial sense — for example, by limiting the use of open-cycle gas turbines and instead buying power from independent power producers or

Eskom has been relying heavily on expensive open-cycle gas turbines

large customers like smelters.

He added that the contribution from renewable energy projects had been negligible so far and that the nature of renewable projects, which largely depend on the weather, meant it was not “dispatchable power” — power that could be dispatched when needed.

“Even if Eskom does power buy-backs, it may not be able to keep the lights on. It will all depend on the coincidence of bad events, such as a generator out at Koeberg and supply disruption from Cahora Bassa in Mozambique,” said Yelland.

“We see Eskom’s availability dropping below its target of 80% and unplanned outages above 10%. The longer you run a system with such tight reserves, the higher the probability there will be outages.”