Good news for Kusile Power Station

Eskom says its temporary solution at Kusile Power Station is proving effective and it is on track to complete the repairs to the permanent flue-gas duct stack by December 2024.

The state-owned power utility published an update on the use of temporary stacks at the power station, which South Africa’s National Air Quality Officer approved through a postponement of the Minimum Emission Standards (MES) policy in June 2023.

“The postponement allows Eskom to operate units 1, 2, and 3 without utilising the Flue Gas Desulphurisation (FGD) plant,” said Eskom.

“This plant is equipped with emission-abatement technology for SO2. The allowance extends until 31 March 2025, during which time the flue gas ducts in the permanent stack are being repaired.”

It said using these three units is critical to the Generation Operational Plan, as they contribute “a much-needed 2,400MW to the national grid”.

However, the postponement is subject to several conditions, including requirements for Eskom to mitigate the impact of SO2 emissions on air quality and public health in the region.

The power utility was also required to inform nearby communities of the potential environmental risks.

“To this end, several engagements have taken place and will continue until the permanent stacks are in place,” said Eskom.

Eskom’s Kusile power plant flue gas duct failed

Eskom Group executive for generation, Bheki Nxumalo, says the power utility has been doing its utmost to adhere to these conditions, adding that the emissions from the three units remain lower than its atmospheric emission license and ambient air quality limits.

“We have implemented robust health screening initiatives within the surrounding areas and have installed additional ambient quality monitoring equipment to specifically monitor SO2 emissions. This ensures that we safely and responsibly operate Kusile while minimizing any potential impact on public health,” said Nxumalo.

“The health and safety of our employees, contractors and neighbouring communities remains Eskom’s top priority. We will continue taking proactive measures to manage and mitigate any potential risks.”

Eskom revealed that Kusile Power Plant’s unit one had suffered a catastrophic failure of its flue gas duct in October 2022.

Part of the flue duct had collapsed, taking units two and three offline, in addition to Kusile unit one.

Eskom explained that a section of the duct exiting the sulphur dioxide absorber failed on the horizontal rubber expansion joint and compensator.

“[The compensator] is a bend to direct flue gas up the [duct] and allow for thermal expansion of the chimney,” Eskom said at the time.

All three units are now back in service, providing 2,400MW to the grid using a temporary solution while the permanent stacks are repaired.