Civil Engineering August 2021 | Vol 29 No 7

Le t ter from the ed i tor Civil Engineering August 2021 9 T he dismal implementation of the Medupi Power Station is well known. The 4 764 MW project, which commenced in May 2007, was scheduled for completion by 2015 at a cost of R80 billion. Instead, Eskom reports that the capital cost of the project is R122 billion so far, and the utility expects to spend under R135 billion on completion of the balance of the plant (namely technical solutions related to boiler design defects). The Medupi Power Station is the fourth largest coal-fired plant and the largest dry-cooled power station in the world. Unfortunately, it has also blossomed into the most expensive coal-fired power station in the world to construct, and the price just keeps on rising. So, what have we achieved? One could argue a very heft price for dirty electricity that has not necessarily pro- vided the energy security South Africa so desperately needs. THE EXPLOSION At approximately 22:50 on 8 August, just over a week after the completion of the power station, there was an explosion at Medupi’s Unit 4, resulting in extensive damage to the generator. According to Eskom, the incident occurred during the activity to displace hydrogen with carbon dioxide and air respectively, for the purposes of finding an external leak. “Following the power station preliminary investigation, it appears that while performing this activity air was introduced into the generator at a point where hydrogen was still present in the generator at sufficient quantities to create an explosive mixture, which ignited and resulted in the explosion. It also appears that there was a deviation from the procedure for carrying out this activity,” the utility explained. Several employees have since been suspended. Eskom CEO Andre de Ruyter said the repairs are expected to take around two years and could cost between R1.5 billion and R2 billion. However, Energy analyst Ted Blom has suggested the price could be anywhere between R20 billion to R40 billion, particularly if the damage is too severe to repair and the generator unit needs to be replaced. For now, the loss of 794 MW of generating power will place added strain on the already constrained energy grid. DODGING EMISSIONS TARGETS While Eskom has hailed the completion of Medupi as a step towards achieving energy security, it is undoubtably a step back- wards for sustainability. South Africa is currently among the highest emitters of green- house gases in the world and ranks 12 th globally in terms of per capita emissions. While the country still produces significantly lower emissions than many other countries, more than 75% of our primary energy requirement is currently derived from fossil fuels. South Africa has introduced a carbon tax and emissions limits in a bid to mitigate the impacts of climate change, but Medupi has been exempted from the rules. In 2019 the indebted Eskom applied to delay complying with sulphur dioxide emission limits at its Medupi coal-fired plant until 2030. In its application, Eskom stated that the installation of flue gas desulphurisation (FGD) technologies to remove sulphur dioxide was originally scheduled to take place between 2021 and 2026. But due to lengthy project delays, this will now only happen between 2028 and 2030. The National Environmental Management Air Quality Act (39 of 2004) stipulates a sulphur dioxide emission limit of 1 000 mg/‌Nm 3 for existing plants to be achieved by 1 April 2020, while new plants are limited to 500 mg/Nm 3 . Eskom had already obtained a postponement decision granting a monthly limit of 3 500 mg/Nm 3 for sulphur dioxide until 31 May 2025. However, when 2019 rolled around, Eskom requested an alternate limit for Medupi of 4 000 mg/Nm 3 monthly from 2020 until installation of FGD in 2030, and there- after a monthly limit of 1 000 mg/Nm 3 until decommissioning of the station. This means that despite massive cost overruns and time de- lays, we have achieved a fossil fuel reliant power station that flouts our emissions standards and is costing taxpayers more money due failures. While the recently gazetted amendments to Section 2 of the Electricity Generation Act (4 of 2006) that will allow private firms to generate up to 100 MW is a positive step towards energy security, there is still a long way to go. It is clear that South Africa needs to do a lot more work to put loadshedding and its severe economic impacts behind us while achieving emissions targets and working towards a greener energy future. Danielle Petterson Editor: Civil Engineering danielle@saice.org.za Keeping the lights on Eskom celebrated recently when it announced that the last unit of the Medupi Power Station had come online, finally marking the long-awaited and overdue completion of the mega-project. Unfortunately, the optimism was short lived and the threat of loadshedding looms once more.