State-owned power utility Eskom’s ambitious plan to expand South Africa’s transmission network, which includes the roll-out of 14 000 km of new power lines over the next decade, is expected to create significant opportunities for local suppliers, such as JSE-listed Reunert, to support the project.

With a strong track record, technical expertise and black economic empowerment credentials, the company played a key role in Eskom’s last major transmission roll-out in the 2000s and expects to be a key supplier again.

The company has the necessary manufacturing capacity to meet the anticipated demand and is prepared to invest in expanded production capacity if required, says Reunert electrical engineering segment CEO Deon de Kock.

The National Transmission Company of South Africa expects to issue a long-term framework agreement to facilitate the accumulation of sufficient stock, with these agreements anticipated to be finalised this year.

De Kock says securing such agreements provides greater certainty in resource planning and ensures that the necessary materials and capacity are available to meet the country’s infrastructure expansion needs.

Reunert sees growth opportunities in South Africa’s broader energy infrastructure sector, including partnerships with State-owned enterprises, municipalities and public-private partnerships, as well as the private sector.

The company supplies power cables, circuit breakers and integrated renewable-energy solutions, which positions Reunert to benefit from ongoing investments into the transmission grid and infrastructure development.

The expected increase in infrastructure investments under the Government of National Unity also presents opportunities for Reunert.

Further, while addressing concerns about ageing municipal infrastructure, De Kock notes that Reunert provides technical expertise, products, turn-key solutions and services, with funding and financing options, to address the challenges.

“We deliver engineering design, cable installations and maintenance contracts, including fault detection and repairs, for municipalities. By offering these services, Reunert aims to improve the reliability and longevity of South Africa’s transmission and distribution networks,” he says.

The company also ensures the quality and durability of its cables by offering a comprehensive range of solutions tailored to South Africa’s conditions and grid demands.

It provides cable solutions for various voltage levels, from 600 V to 132 kV, designed to withstand a range of environmental challenges. These include high water tables that require cables to operate under water, soil conditions that affect heat dissipation, high salinity in coastal air and rocky terrain, all of which influence cable design.

Reunert has an in-house engineering team that carefully reviews customer specifications and installation conditions regarding underground high-voltage cables.

The team provides end-to-end solutions that include design, installation, testing, commissioning and ongoing maintenance.

For medium-voltage cables, the company ensures long-term reliability by adhering to international standards, including the South African National Standards, International Electrotechnical Commission standards and British Standards.

Reunert also holds certifications issued by the International Organisation for Standardisation for quality management, environmental management and occupational health and safety.

Technology Advancements

To enhance efficiency and reliability, Reunert advances its cable technology with the development of high-temperature low-sag (HTLS) conductors.

These overhead conductors increase transmission capacity while reducing the need for extensive structural modifications. Unlike traditional aluminium conductor steel-reinforced (ACSR) cables, De Kock explains that HTLS conductors feature a composite tensile core and high-temperature aluminium alloy, enabling them to operate at up to 200 °C, with minimal sagging, thereby improving safety and reliability under high-load conditions.

ACSR conductors, by comparison, reach up to 120 °C during peak demand, leading to greater sagging. Additionally, owing to its lower mass relative to ACSR, the HTLS conductor allows for an increased conductive area without adding extra weight, making it possible to reuse existing pylons and minimising the need for structural modifications.

“Reunert’s offerings also support the integration of renewable energy, spanning embedded solar energy generation, battery energy storage solutions and renewable-energy supply through licensed trading and wheeling.”

These capabilities strengthen Reunert’s role in renewable-energy investments and the infrastructure required to integrate new generation capacity into South Africa’s transmission and distribution networks, De Kock says.

Through its affiliated companies, such as solar energy business Terra Firma, energy storage solutions provider Blue Nova and green energy electricity trading supplier Apollo Africa, Reunert provides solutions that align with the country’s energy transition.

“Reunert also actively works to mitigate risk by diversifying its supply sources and maintaining comprehensive stock levels. The company’s supply chain strategy includes multiple local and international suppliers, dual sourcing for key raw materials and holding sufficient stock to offset logistical uncertainties,” he says.

Cybersecurity, meanwhile, is an emerging concern, particularly as grids become more reliant on digital systems.

While Reunert’s cable solutions can incorporate monitoring elements to track performance and detect vandalism, the cables cannot analyse data quality or identify cyberthreats.

However, fibre-optic components can be integrated to allow for data transmission, and Reunert can incorporate additional security features in line with customer requirements.