4 Photos: S.Africa: Black Failure at it’s finest: Electricity: Medupi Generator explodes – long term damage – My Comments

Eskom’s grid will have to run for another two years and four months without one of the big coal-powered generation units at its Medupi Power Plant that suffered a devastating explosion in August 2021.

Medupi Unit 4 first achieved commercial operation in November 2017 and is one of the utility’s biggest units by generating capacity.

The 720 MW unit was wrecked during a short-term outage shortly before 23:00 on 8 August 2021.

The incident was caused by operator errors when plant workers attempted to identify the source of a hydrogen leak.

An investigation found the workers had failed to purge the generator of hydrogen before it mixed with oxygen, resulting in a massive blast.

Miraculously, no one was injured during the explosion, but the resulting damage was evident in several shocking pictures and videos shared by energy expert Chris Yelland.

These showed that almost the entire roof above the generator had been ripped apart, with pieces of the generator spread across a field of debris.

In the explosion’s immediate aftermath, Eskom CEO André de Ruyter initially said it would take more than two years to repair the unit.

The power utility now only estimates a return to service for the unit by 31 August 2024 — three years after it blew up.

For reference, it took Eskom more than seven years to bring the first unit at Medupi online from the start of the plant’s construction in July 2008. It was also more than six years after work on that unit’s boiler began.

While the revised repair time is slower than initially anticipated, Eskom said it had made notable progress.

Eskom told MyBroadband the property damage assessment had been completed, and the original manufacturer submitted a proposal for the refurbishment to Eskom on 3 May 2022.

Previously, it was suggested that Eskom could use the Kusile power plant’s equipment to speed up the process, but this was ruled out as technically and economically unviable.

Eskom said it is evaluating the manufacturer’s proposal before submitting it to relevant governance structures to decide on the way forward.

The power utility said it could not divulge information on the repair cost as it will first have to conclude negotiations with the manufacturer.

De Ruyter previously estimated the cost of the repair at around R2.5 billion.

Medupi only a drop in the ocean

Eskom said its assurance and forensics department had conducted the common cause investigation and made recommendations which are being implemented, including “consequence management”.

Eskom needs every ounce of generation it can muster in light of the dire state of its generation system.

When asked about the impact of Unit 4’s absence in the grid regarding load-shedding, Eskom said the system would be “less constrained” if it were available.

The 720 MW maximum capacity of the unit is equivalent to about 72% of the load shed during stage 1 rotational power cuts, or 36% of stage 2.

However, Eskom has had breakdowns exceeding 15,000MW on repeated occasions in recent weeks, highlighting its problems go well beyond Medupi.