Eskom maintains that recent Cape power outages were “abnormal”, but the signs are there that delays and about‒turns in transforming the electricity sector are pushing supply capacity to the limit.
Trevor Gaunt, an electrical engineering professor at the University of Cape Town, said procrastination over restructuring has meant years of inadequate planning and infrastructure investment.
“We’re too close to the bone. When something goes wrong, the system falls over. Experts forecast six years ago that new capacity was needed to be available and working in 2006,” he said. “Blackouts are still rare events, but they won’t be rare when the system doesn’t have the spare capacity it needs.”
South Africa’s peak demand this winter stood at 33 600MWe (megawatt electrical) from an overall capacity of 38 000MWe, including a 10% safety margin. But, by July 2002, there was already little room to manoeuvre. Peak-time demand was 31 500MWe from a 37 000MWe capacity. The Department of Minerals and Energy’s 2003 Integrated Energy Plan said: “South Africa will be short on capacity by 2005, 2007 unless demand side management [brings down consumer usage] or a new plant is built.”
The department and Eskom say there will be sufficient electricity supply until 2007, although they disagree on the month.
Much is made of the government’s R84billion allocation for Eskom infrastructure expenditure. But, until the government’s decision last year to use state-owned entities to lead infrastructure investment, the power sector was earmarked for partial privatisation. Caught on the wrong foot, Eskom had no new plants planned and environmentally unfriendly coal-powered stations had been mothballed.
Independent engineer Andrew Kenny has warned that it will be difficult to catch up, pointing out that it takes up to eight years to build a power plant. The electricity grid is already struggling to cope with the increase in demand, which is linked to the country’s economic expansion, said Kenny.
Eskom has applied for an above-inflation tariff increase from the National Energy Regulator of South Africa, partly to help fund infrastructure projects.
Eskom national spokesperson Fani Zulu said the increase would be pegged slightly above inflation, but would only come into force on April 1 next year.
Last week’s four huge power blackouts, which engulfed an area from Cape Town to Grahamstown, cost Cape Town businesses millions of rands, said the Cape Chamber of Commerce. Unlike Johannesburg blackouts, which are the council’s responsibility, Cape blackouts relate to dwindling national grid capacity in the region.
While the department insisted that the cuts were “no reflection on the level of investment”, last Friday’s outage highlights the difficulties in maintaining the grid. There was sufficient electricity parked in Mpumalanga to offset the Koeberg cut-off, but high-voltage lines could not carry it.
The blackout followed a “controlled shut-down” when the concentration of chemicals used in the safety system was found to be out of kilter.
The first outage, on November 11, was triggered when the transmission network tripped following maintenance work. While back-up systems — gas turbines at Cape Town’s Acacia Park and Port Elizabeth’s Port Rex, and the hydro plant at Palmiet — were brought on line immediately, it still took hours for the grid to recover.
Eskom’s Carin de Villiers said the outages were “abnormal” and linked to unusually long maintenance work at Koeberg. One unit was shut down while the other was being worked on and both should be running by mid-December.
While Koeberg only supplies around 6,5% of the national demand, it is essential to the Cape. Cape Town’s power demand and supply at peak times are at stretching point. The city demand is 5 000MWe, of which Koeberg’s two units generate 1 800MWe (900MWe each) and 3 700MWe are imported from Mpumalanga, according to Die Burger. The available 5 500MWe is just enough to cover demand and a 10% safety margin.
Eskom’s planned gas-power plants at Atlantis, near Cape Town, and in Mossel Bay — and a R2billion upgrade of high-tension lines to carry up to 765 000 volts from Mpumalanga — are meant to stabilise supplies. But these developments are only expected to be on line in 2007, leaving a potential gap.
Transformation of the electricity sector — first discussed in 1997 and adopted as strategy by Cabinet in February 2001 — is a piecemeal procedure. Yet the department defended the pace, saying transformation was complex because 187 municipalities also have a stake in the R25billion industry and charge their own tariffs.
Early next year, the Electricity Distribution Industry Restructuring Bill, aimed at consolidating the sector, will be tabled in Parliament. Delays have also been related to complaints that local government powers were being unconstitutionally infringed.
Despite delays beyond the initial May 2005 deadline, one of the six proposed regional electricity distributors was established as a municipal entity in Cape Town. EDI Holdings, the government-owned electricity distribution company, was established in the city in 2003.
Independent power producers have been invited to build new power plants in KwaZulu-Natal and the Eastern Cape. These will be commissioned in 2008, according to the department.
Lights out Cape power outages
Friday, November 11: No electricity for more than five hours after Unit 2 at Koeberg tripped after maintenance work. The Cape Peninsula, Stellenbosch, Paarl, Hermanus and Swellendam are affected. Power was “imported” from Mpumalanga.
Wednesday, November 16: Outages for several hours across Cape Town and all the way to George on the Cape south coast. Eskom says it was caused by a fire under a supply line in Wellington.
Thursday, November 24: “Controlled shut down” at Koeberg affects Cape Town, parts of the Eastern Cape, including Port Elizabeth, East London and Bisho. Eskom re-routes power from Durban to meet demand. Instituted because of “the chemical concentration in the safety injection system being slightly below specifications”.
Friday, November 25: “Rolling power outages” affect the Western and Northern Cape, as far as Springbok, and parts of the Eastern Cape. On November 24 and 25, Eskom uses the gas turbines at Acacia and Port Rex, and the hydroelectric units at Gariep, Vanderkloof and Palmiet to compensate for shortages.