Citation: Ndlela, N.W.; Davidson, I.E.; Moloi, K. Power Planning for a Reliable Southern African Regional Grid. Energies 2023, 16, 1028. https://doi.org/10.3390/en16031028 Academic Editor: Javier Contreras Received: 5 December 2022 Revised: 12 January 2023 Accepted: 14 January 2023 Published: 17 January 2023 Copyright: © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). energies Article Power Planning for a Reliable Southern African Regional Grid Nomihla Wandile Ndlela * , Innocent Ewean Davidson and Katleho Moloi Department of Electrical Power Engineering, Durban University of Technology, Durban 4000, South Africa * Correspondence: 21312861@dut4life.ac.za Abstract: Southern Africa has suffered from multiple power disruptions in the past decade due to inadequate electrical generation capacity, as well as load developments in locations that were not suitably planned for. Southern African countries are able to have reliable, sustainable, and efficient electrical power grids. The use of power interconnections for exchange power, especially for long-distance transmission networks, is important. Installing a suitable high-voltage alternating current (HVAC) with a high-voltage direct current (HVdc) will improve the active–reactive power compensation when transmitting electrical power over long distances (when transmitting bulk power is possible). Flexible alternating current transmission system (FACTS) devices are typically combina- tions of shunt and series converters. These approaches are capable of improving the power stability and voltage while allowing power to be transferred with minimal losses to an alternating current transmission system for the power exchange. In this article, two HVDC line-commutated converter (LCC) links, i.e., Angola–Namibia and Aggeneys–Kokerboom, were applied to minimize losses from 2657.43 to 2120.91 MW, with power setpoints of 1000 and 600 MW, respectively. The 2500 and 475 MVAr SVCs were used to control the voltage instabilities at Namibia and Mozambique substations, respectively. The use of HVdc to reduce losses and FACTS devices to enhance controllability and power transfer is extremely effective, particularly in long transmission lines transporting bulk power. Keywords: electric grid reliability; flexible AC transmission system; high-voltage direct current; power exchange; power interconnections 1. Introduction The Southern African Power Pool (SAPP) was established in August 1995 during the Southern African Development Community (SADC) summit in Johannesburg, South Africa, where SADC member governments, except Mauritius, signed an inter-governmental formal agreement for the establishment of a regional electricity power pool known as the Southern African Power Pool (SAPP) [1,2]. There are roughly 180 million inhabitants in the Southern African region [3]. Out of roughly 76 GW of installed capacity, South Africa has around 59 GW [4–6]. Access to electricity extends the useable hours of the day and improves people’s health, safety, financial inclusion, and economic activities. Regardless of the significance of electricity, according to the most recent data from [5], 771 million people do not have access to power globally. The great majority (578 million people) in Sub-Saharan Africa (SSA) lack access to electricity. At the end of 2019, only 48% of the population in SSA had access to electricity, with more than half of the region falling below this average [7,8]. In the last decade, Southern Africa has experienced electrical shortages. This was partially due to the poor electrical power supply networks in the countries involved, as well as load developments in areas that were not sufficiently planned for. This resulted in the formation of organizations (e.g., SADC and SAPP) having similar objectives in promoting regional development and economic improvement [9,10]. The SAPP’s goal is to deliver a reliable and cost-effective power supply to the customers of each SAPP member while maintaining an acceptable usage of natural resources and minimal impact on the environment [11]. Electricity demand in the SAPP’s 12 contiguous nations is expected to double by 2040. They account for almost 40 percent of the overall electrical Energies 2023, 16, 1028. https://doi.org/10.3390/en16031028 https://www.mdpi.com/journal/energies