South Africas grid constraints continue to slow down renewable energy integration with Eskoms latest grid connection capacity assessment showing congestion across key renewable energy development zones. The Transmission Development Plan TDP outlines 14 000 km of new lines needed by 2034 but delays, servitude limits and high costs mean new-build projects cannot solve capacity shortages fast enough.
Research presented by Independent Power Producer Office South Africas Surprise Mmako at CIGRE Southern Africa 2025 on October 15 assesses whether high temperature low sag HTLS conductors specifically aluminium conductor composite core ACCC offer a practical way to increase capacity on existing lines without replacing towers. Using a modified IEEE 9-bus system in DIgSILENT, the study compares the performance of conventional aluminium conductor steel-reinforced ACSR Zebra with ACCC Hamburg under varying load and renewable penetration conditions.
ACCC Hamburg can carry 35 more current than Zebra with significantly lower resistance and a much higher operating temperature limit 180C vs 80C. These characteristics directly improve thermal loading and system efficiency.
