Using liquefied petroleum gas to reduce the operating cost of the Ankerlig peaking power plant in South Africa

Abstract

Along with the load-shedding problem that Eskom is having with the current generation system, the operator is forced to use its peaking plants at Ankerlig and Gourikwa in the Western Cape much more than planned. The two plants are set up for dual fuel operations, able to be fuelled with diesel as well as gas. As Eskom does not have access to natural gas, both plants have been fuelled with diesel. For the last three years, 2019 through 2021, Eskom has expended an average of over R4 billion per year on diesel fuel for its peaking plants, with the majority of this at Ankerlig and Gourikwa. For 2022, in their request for a rate increase, Eskom noted that their anticipated diesel fuel expenditures will increase to over R6.5 billion. This could be reduced by more than half if the plants were fuelled with natural gas. The problem Eskom faces is sourcing natural gas to fuel these plants. There has been consideration of liquefied natural gas importation into the Western Cape that could be utilised to fuel the Ankerlig plant. However, the high capital cost for this option has led to delay in the commencement of this project. There is another alternative that can be implemented in a short time-frame, using currently available gas, in the form of liquefied petroleum gas. With this fuel, the Ankerlig peaking plant could be switched to gas fuel and Eskom would have a significant reduction in the cost of fuel. In this study the economic benefit of this fuel change option is analysed.