The power buy-back scheme instituted for large customers by Eskom, in December, will expire at the end of May, following which the State-owned utility will rely mainly on its demand market participation (DMP) and demand response aggregator (DRA) incentives to help reduce demand from industrial customers.

In addition, 133 of its top 250 customers, including 96 of its so-called key industrial customers, have signed voluntary energy conservation scheme (ECS) commitments, under which they have pledged to try and reduce demand by 10% against an agreed baseline. Eskom is still hoping to have the scheme made mandatory as a last resort “safety net”, as the voluntary scheme currently attracts no penalties, or incentives.

Those companies with ‘signed-off baselines’ are currently saving on average 6.4% against their commitments, which is materially better than the 1.6% savings being recorded from a larger sample of customers also being targeted by the utility for savings.

CE Brian Dames has again cautioned that current savings levels are insufficient to ensure a margin large enough to enable Eskom to meet demand, while accelerating planned maintenance ahead of the introduction of some 11 000 MW of new capacity from Medupi, Kusile and Ingula between 2013 and 2019.

Eskom, which claims to be pursuing its most ambitious planned maintenance programme in its 89-year history, also plans to continue with maintenance into the winter months in a bid to eliminate its 26-unit backlog by the end of 2013.

“We have no concern about meeting capacity. But we do have a concern about having sufficient reserves in order to deal with our maintenance programmes,” Dames has reported.

Nevertheless, he remains concerned about the size of South Africa’s winter evening peak, which takes place between 17:00 and 19:00. During those hours, demand can rise by as much as 2 000 MW against the average daily draw – enough power to supply the combined demand of “Namibia, Botswana, Mozambique and Zambia”.

To create some of the space required, Eskom will lean increasingly on its DMP and DRA schemes, which offer financial incentives for those participants that are able to reduce their demand for up to two hours a day.

At its peak, the utility has been able to secure up to 1 000 MW (for differing periods) under the incentive programmes.

Such schemes, Eskom says, are deployed in many modern power markets, but the South African incentives have been associated with a stipulation that job losses should not result from the reductions.

There is no intention, though, to make buy backs, which have been drawn on extensively by the ferrochrome industry since December, resulting in a sharp fall in output, a permanent feature of South Africa’s demand management landscape.