Five problem power stations to blame for power cuts

● Eskom’s latest devastating load-shedding cycle can be attributed to five problematic power stations — Kendal, Tutuka, Majuba, Medupi and Duvha.

According to the ailing power utility, the five stations contributed “about 55% of the total breakdowns” last month.

“Boiler, turbine, draught plant and generator were the main contributors to the breakdowns, totalling 64% for August,” according to the utility.

Eskom said from the end of August, five of the six units at Kendal, totalling 640MW each, all six Tutuka units totalling 585MW and all six at Arnot amounting to 350MW each were offline at least once.

The five have contributed to Eskom implementing stage 6 load-shedding after the power stations were collectively forced to go offline frequently.

Some are part of Eskom’s ageing powergenerating fleet. Duvha, at 42 years old, is one of the oldest and scheduled to be decommissioned in the next 12 years. Kendal and Tutuka are 34 and 37 years old respectively and are scheduled for mothballing in about 20 years.

Experts say a toxic combination of factors, including lack of skills, corruption and poor maintenance over the years, has resulted in the dire situation. Eskom COO Jan Oberholzer on Monday blamed ageing generators.

“We understand our mandate and that is to supply sustainable electricity to the country, which we unfortunately sometimes, and as we speak, are not able to do,” he said. “Until new projects are realised we will need to rely on the old, unreliable coal fleet which continues to deteriorate due to insufficient opportunity to perform maintenance.”

Prof Mark Swilling, from the Centre for Sustainability Transitions at Stellenbosch University, said some of the stations should have been closed or will close soon and that their age is not the only determining factor for their impending closure.

Corruption, he said, was one of the contributing factors accelerating power stations’ shortened lifespans.

“Look at Tutuka. It is a relatively new power plant, so age is not the only driver. In Tutuka’s case, it is corruption,” he said.

Eskom has 15 coal-fired power stations which generate 80% of the country’s electricity. It is expected to shut down about 22,000MW of coal plants that are reaching the end of their life cycles by 2035, which will almost halve its 46,000MW of capacity.

According to Swilling’s research, the only way to increase generation capacity is through renewable power generation.

“This will take only two years and that means load-shedding will last until then,” said Swilling.

He said it was technically and scientifically incorrect to blame Eskom’s maintenance programme for load-shedding because broken machines can be fixed only if they are taken offline.

“Eskom is doing a good maintenance job, but the machines were abused for many years and maintenance was neglected to keep the lights on. As a result, machines trip often and unexpectedly. To fix that, Eskom needs to take some power stations off the grid for extended periods to fully rehabilitate them. However, it cannot do that until there is new additional generation capacity on the grid,” said Swilling.

Hilton Trollip, associate at the Electricity Systems Research Group of UCT, said the problem lies with the fleet itself as SA’s 15 stations have a total of 90 generation units. Each consists of two huge machines plus boilers and coal-supply and ash removal.

He said about 10 of these at a time were removed from service for planned maintenance and fewer than this should break down, ideally two or three. Hence, if the machines were at an acceptable state of reliability, at any time Eskom would only have to maintain about 10 and fix another two or three.

“However, recently it has had more than 10 on planned maintenance because of their old and unreliable state, and 30 unplanned outages.”