Name of the Project
Kusile power plant project.

Location
Mpumalanga, South Africa.

Project Owner/s
State-owned power utility Eskom.

Project Description
The Kusile power station project, near the existing Kendal power station, in the Nkangala district of Mpumalanga, will comprise six units, each rated at an 800 MW installed capacity for a total capacity of 4 800 MW. Once completed, Kusile will be the fourth-largest coal-fired power station in the world.

The Kusile project will include a power station precinct, power station buildings, administrative buildings (control buildings and buildings for medical and security purposes), roads and a high-voltage yard.

The associated infrastructure will include a coal stockyard, coal and ash conveyors, temporary and permanent water-supply pipelines, temporary electricity supply during construction, water and wastewater treatment facilities, ash disposal systems, a railway line, limestone offloading facilities, access roads (including haul roads) and dams for water storage, as well as a railway siding and railway line to transport the limestone supply (sorbent).

The power station will be the first in South Africa to install wet flue-gas desulphurisation (WFGD) – a state-of-the-art technology used to remove oxides of sulphur, such as sulphur dioxide, from exhaust flue gases in power plants that burn coal or oil.

This technology abates atmospheric emissions, in line with current international practice, to ensure compliance with air-quality standards, especially since the power station is located in a priority air-shed area.

The WFGD plant is a totally integrated chemical plant using limestone as feedstock and producing gypsum as a by-product.

Each supercritical tower boiler will be about 115 m high. The air-cooled condensers will be constructed on and supported by twenty 60-m-high concrete columns.

Potential Job Creation
A comprehensive exit and outreach strategy, which aims to gradually upskill and release local labour to the job market, has been formalised in partnership with key stakeholders. This allows for project stability amid the gradual demobilisation of workers once milestones are achieved. It will further enable the project to mitigate the risk of local community disruptions.

Capital Expenditure
R161.4-billion; however, Eskom estimated the cost to completion at R145-billion, excluding WFGD, at the beginning of June 2022.

Planned Start/End Date
The last Kusile unit is expected to reach commercial operation in 2022/23, barring any delays because of, for example, contractor performance or industrial action.

Kusile Unit 1 achieved commercial operation on August 30, 2017.

Kusile Unit 2 achieved first synchronisation on March 24, 2018, and achieved full load in January 2019. Commercial operation was achieved on October 29, 2020.

Kusile Unit 3 achieved first synchronisation on April 14, 2019, eight months ahead of schedule. Commercial operation was achieved in March 2021.

Kusile Unit 4 was connected to the national grid for the first time on December 23, 2021, and was formally handed over to the generation division on May 31, 2022, following five months of testing and optimisation.

Latest Developments
Eskom’s actions to rectify major boiler defects at its newly built Medupi and Kusile power stations are improving the plants’ energy availability factor (EAF), in some cases almost doubling it, compared with the EAF when the first boiler’s fires were lit.

The major boiler defects pertain mainly to load losses, as a result of issues with the boiler’s pulse jet fabric filter (PJFF) plant, gas air heaters and mills.

To date, 80% of work to rectify the major boiler defects has been implemented. “The type of defects we have are those things that we could pick up only after you have run the plant for a long . . . [time]. They are mostly wear- [and] life-type [defects],”
Eskom new build defects senior engineering work leader Johannes van Tonder has said.

Eskom expects to complete the rectification work on major boiler defects in 2023.

The power utility started its major boiler defects rectification work by rolling out solutions, and testing their performance at Medupi’s Unit 3.  Those solutions that proved effective were then rolled out at Medupi’s other units and at Kusile.

The defect rectification scope of work covers many components around the milling plants at Medupi and Kusile.

Work on fixing mills is typically undertaken during planned outages, when a plant is refurbished or serviced, during which time the new and modified parts are installed in place of the defect items.

Undertaking these procedures during scheduled maintenance enables Eskom to rely on its spare mills, thereby not affecting boiler uptime.

To date, Eskom has implemented rectifying solutions at Kusile during outages on Units 1, 2 and 3, while the rectifying solutions were implemented on Unit 4 before it entered commercial operation.

The solutions will be rolled out on Units 5 and 6 during their ongoing construction.

The solutions to the boiler defects also serve to improve PJFF bag life, extend mill component life, reduce gas air heater erosion and improve steam preheater performance.

Eskom is also rolling out a solution at Kusile to help boilers handle low loads and load transition instability, based on a similar solution developed for Medupi. This solution serves to improve the reliability and performance of reheaters and superheaters in the boiler.

Eskom anticipates that the low load and load-transient solution will reduce economiser trips by 90% and help boilers operate at low loads (of about 40%) by using top mills more.

Together, these improvements have resulted in Eskom’s managing to decrease load losses at Kusile’s Unit 1 from a three-month average of 171 MW being lost to only 24 MW being lost on average for seven months after a 75-day outage was undertaken to implement changes and make modifications. 

Key Contracts, Suppliers and Consultants
Eskom, in partnership with Black & Veatch International (project management and engineering services); Ninham Shand Consulting Services (environmental-impact assessment, geotechnical investigation and traffic impact); AirShed Planning Professionals (air-quality impact); Jongens Keet Associates (noise impact); Strategic Environmental Focus, or SEF (visual impacts); Makecha Development Association (impacts on terrestrial fauna and flora); Golder Associates, through Ecosun (aquatic-ecosystem impact); Groundwater Consulting Services (groundwater impact); Ilitha Riscom (risk assessment); Northern Flagship Institution (archaeological impact); University of the Free State (impacts on agricultural potential); Urban-Econ (socioeconomic impacts); Seaton Thomson & Associates (planning implications); Mark Wood Environmental Consultants (process review); Mitsubishi Hitachi Power Systems Africa, or MHPSA, a subsidiary of Hitachi Power Europe, or HPE (boiler contract); Actom, formerly Alstom S&E Africa (main turbine area); ABB SA (C&I, including supply of medium-voltage switchgear and associated equipment); Mikropul, subcontracted by Alstom (axial-flow fans and auxiliary equipment for the turbine halls' ventilation); GE (EPC of six turbine islands, air-cooled condensers and WFGD); Alstom (WFGD); Murray & Roberts, or M&R (boiler construction contract); Roshcon, a subsidiary of Eskom (enabling civils, terracing construction and site services); Concrete Finishing Equipment (dust filters, and silo and environmental safety); Kusile Civil Works, or KCW, Joint Venture (JV), comprising Stefanutti Stocks, Basil Read, Group Five and WBHO Construction (main civil works); Siemens (generator transformers and electrical and auxiliary power); EsorFranki Geotechnical, formerly Franki Africa, and Stefanutti Stocks Geotechnical JV, under a subcontract to KCW JV (piling works for the turbine, boiler and air-cooled condensers); Concor Karrena JV (construction of chimney shells/structures); Tubular (engineering, supply and installation of FGD system); DSE Structural Engineers & Contractors, subcontracted by Genrec Engineering (fabrication of steel columns for boilers 1 to 3); Steel Services Direct, or SSD (steel, pipes and wax plants); GB Bearings (supplier of HSR horizontal bearing assemblies and profile bore bearings); Sulzer Pumps South Africa, subcontracted by Actom (supply of booster and boiler feed pumps); Steloy Castings, subcontracted by Sulzer Pumps South Africa (supply of chrome steel components for the pumps); Clyde Bergemann Power Group, subcontracted by MHPSA (supplier of sootblowers for boilers); Clyde Bergemann Africa (fly ash handling system); PD Naidoo & Associates, or PDNA, Industrial Projects (main water and wastewater treatment contractor); GE Water Engineered Systems, subcontracted by PDNA Industrial Projects (advanced water and wastewater treatment equipment); Bateman Africa (coal stockyard and terrace materials handling systems); Lesedi Nuclear Services (procurement and supply of the balance of plant equipment); Grinaker-LTA Metals & Minerals (supply and erection of piping, steelwork and free-issue chemicals); US Export-Import Bank, or Ex-Im Bank (loan finance); TBD (railroad construction and combustion water terrace construction phases 1 and 2); Zest WEG Group (auxiliary transformers); Aberdare Cables, a Powertech company within the JSE-listed Altron Group (cables); Konecranes (heavy duty cranes); Energy Engineered Products (supply of valves) and Turnmill Proquip Engineering (material for boiler ducting).

Contact Details for Project Information
Eskom media desk, email mediadesk@eskom.co.za.