Stage 4 load shedding, which calls for 4000MW to be removed from the grid, is as bad as it gets in terms of load shedding. The country hasn’t reached this stage since 2008, but Stage 4 was implemented as a result of Eskom struggling to meet electricity demand amid tube failures and breakdowns at its ageing fleet of power stations, as well as damaged lines from the Cahora Bassa hydroelectric facility in Mozambique.
Eskom has said its employees were “working around the clock to restore stability to operations and supply”. Five units were restored since Friday morning, which had “positively shifted system performance” and led to suspension of load-shedding on Sunday.
Despite this, some industry commentators believe that the situation at Eskom is more dire than the utility would have us believe. While Public Enterprises Minister Pravin Gordhan has said an independent enquiry into the current situation would take up to 14 days to complete, South Africans have seen various suppositions and educated guesses in the media – and none of them are good.
Writer Hilton Tarrant, for example, did some simple calculations in a recent column, and reached the conclusion that Eskom is currently just not capable of generating enough electricity to power the country’s needs. While this comes as no surprise to South Africans who have spent weeks without regular power, if his maths is correct, this is not just a crisis that has been caused by failure at plants due to lack of maintenance and loss of additional power from Cahora Bassa, but the daily reality for the utility.
Eskom’s pumped storage schemes, Drakensberg, Ingula and Palmiet, together (nominally) produce 2.7GW. Tarrant points out that these are not intended to produce base-load power for the simple reason that they are net users of electricity. In other words, they use more power than they produce.
Reports indicate that Eskom had somewhere between 26.3GW and 28.1GW available to fulfil peak demand at the beginning of March. “We do not know the performance of various plants (or even types of plants), but we do know that given the demand/supply mismatch, Eskom is relying heavily on its pumped storage schemes, and its gas/diesel peaking plants. Strip this out of the equation (as well as imports and Koeberg) and it is highly probable that Eskom has less than 19GW available from its coal fleet,” he writes.
In addition to the 20-odd GW available to fulfil peak demand, there is an additional 700MW in hydroelectric and wind power, with use of the former at the Gariep and Vanderkloof dams “restricted to periods of peak demand”. Factor this in, and the total starts looking a lot closer to 18GW, Tarrant says.
“Whether or not renewables and other independent producers are included remains unknown. But with 1GW accessible from Avon and Dedisa, it wouldn’t be a stretch to imagine that these very much form part of ‘available generation’. A well-placed source suggests that Avon (670MW) has often been running for 24 hours a day in recent weeks. Even at a generous 20GW, the electricity available from Eskom’s coal fleet is barely 52% of the about 38.6GW nominal capacity. At 19GW available from coal, it drops below 50%.”
In light of this, it’s no wonder that Eskom has burned through 20 - 25 million litres of diesel within three weeks. And yet, the Western Cape government is still involved in a costly court case to gain the rights to purchase power from IPPs, which current regulations do not allow. While South Africans suffer appliance failures and income losses, the monolithic state apparatus is too busy putting out Eskom’s fire to look at the genuine alternatives IPPs and renewables offer.