Published on January 4, 2024

As private solar energy experienced substantial growth in South Africa throughout 2023, a new challenge has arisen concerning peak demand spikes, placing additional strain on Eskom’s struggling power stations. Energy analyst Pieter Jordaan emphasizes the need for a comprehensive reevaluation of energy usage and storage solutions at both Eskom and national levels.

The surge in private solar installations has altered demand patterns significantly. Traditionally, peak demand occurs during morning and evening hours when people leave or return home. However, with solar power heavily reliant on sunlight and battery backups, a surge in demand is observed after sunset, impacting Eskom’s load shedding scheduling.

Eskom has resorted to peaking, primarily utilizing diesel generators, to meet the increased demand during these periods. While peaking serves as a backup, it comes at a considerable cost. Year-end data from Eskom, analyzed by Jordaan, reveals that peaking was the second-largest power generation source in 2023, slightly ahead of renewables.

Despite the notable growth of renewable energy, Eskom faced a significant supply gap in 2023, leading to heightened reliance on peaking sources. The data provided by Eskom only accounts for its energy supplies and does not incorporate the contribution of private solar installations.

By August’s end, private embedded generation, particularly solar panels capable of generating 4,481 megawatts, had significantly reduced demand on Eskom’s grid. However, the increased reliance on peaking sources, notably open-cycle gas turbines (OCGTs), resulted in substantial costs for Eskom. The financial burden on Eskom and, consequently, National Treasury has intensified, with Eskom’s use of OCGTs surpassing previous years.

Despite private solar’s initial economic benefits and its dampening effect on utility demand, it brings its own set of challenges. Jordaan highlights two risks associated with this phenomenon: a potential economic recovery in 2024 and an escalation of peak demand spikes during severe weather events as solar installations increase.

In conclusion, the boom in private solar has introduced both economic benefits and challenges, emphasizing the urgent need for a comprehensive strategy to address the evolving energy landscape in South Africa. Renewables necessitate a reevaluation of energy usage and storage practices to ensure a sustainable and reliable power supply.