The performance of the Eskom power supply system has improved since Monday, when it warned of a "very high" risk of rolling blackouts, the utility reported on Thursday, but it warned that the system remained constrained.

On Thursday, the capacity available to meet the evening’s peak demand was 34 618 MW, while demand was forecast at 31 168 MW.

Planned maintenance stood at 4 461 MW, with unplanned outages expected to be about 3 678 MW.

Eskom further reported that the peak demand of 31 108 MW on Wednesday was met by available capacity of 32 601 MW, while Monday’s peak demand of 30 282 MW was met by available capacity of 30 742 MW.

The peak demand for the rest of the week is forecast at 31 303 MW on Friday, 29 762 MW on Saturday and 29 205 MW on Sunday.

The parastatal also cited the temporary loss of supply from Mozambique’s Cahora Bassa hydroelectric power station, during the course of Wednesday, as a contributing factor to supply constraints.

Despite supply being restored, Eskom urged consumers to use electricity efficiently. “If all our customers could save 10% off their electricity use, it will make it significantly easier to manage the power system,” the utility stated.

Eskom spokesperson Hilary Joffe said earlier in the week that the national power distributer was working closely with its large customers to reduce their power load.

Its biggest industrial customers, mainly mining and manufacturing companies, indicated that they were willing to lower their demand to prevent rolling blackouts if the electricity situation deteriorated.

Eskom said it had warned consumers since late 2009 that the system would be tight in 2011 and that 2012 would be a particularly challenging year.