Abstract
This research investigates cycling operations at Majuba Power Station, examining the
influence on plant performance, resource utilization, expenditure, and broader energy sector
implications. Cycling takes the form of two-shifting and load-following and is adopted to
curtail energy when electricity demand is low. The need for a flexible and adaptable
operational framework is what drives the study's imperative to address the growing
integration of renewable energy sources into the power grid. The primary objectives are to
comprehensively assess the impact of cycling operations on plant reliability, resource
consumption, and financial considerations. The relationship between annual starts and boiler
tube failures is analyzed. The costs of boiler tube leaks in 2016 were calculated. A Pearson
correlation test evaluates the relationship between starts and failures from 1996 to 2022.
Cycling costs at Majuba in 2016 were analyzed, considering fuel oil, demineralized water,
coal, and workforce. The cost of cycling the entire Eskom fleet in 2035 is calculated by
considering projections of increased energy curtailment due to cycling.
Majuba was used to stabilize the grid through frequent two-shifting in 2016. Historical data
showed high cycling was correlated with increased boiler tube failures due to temperature
and pressure fluctuations. Comparing Majuba to Matimba Power Station revealed that
Majuba's forced outage rate was ten times higher in 2016 than Matimba’s, indicating the
substantial impact of cycling on plant reliability. Resource usage analysis showed higher fuel
oil consumption during cycling, underscoring the need for efficient resource management.
Increased demineralized water and coal usage during cycling further highlighted resource
impacts. Financially, Majuba's cycling operations in 2016 cost R157 million. The study
predicted variable costs for cycling operations in 2035, based on primary energy resource
consumption rates and costs. This research provides valuable insights into the cost and
operational implications of cycling operations. The findings highlight the need for careful
consideration of cycling strategies and the exploration of alternative technologies, such as
battery storage and natural gas, to support the integration of renewable energy sources and
ensure a reliable and sustainable energy supply.