In the pursuit of a sustainable future, the leading role of grid expansion cannot be overstated. To reach net-zero emission targets, nations are channeling resources into expanding electricity generation and modernizing infrastructure on a global scale.
HVDC (High-Voltage Direct Current) technology excels in efficiently transmitting massive power over long distances and integrating renewables, enabling a carbon-neutral energy future.Hitachi Energy, a leader since the 1950s, drives innovation with Ultra-High-Voltage (UHV) advancements, minimizing losses and connecting remote wind farms to energy-hungry cities. Globally, nations are investing in HVDC projects to expand grids and meet rising energy demands. In South Africa, HVDC is set to revolutionize power distribution as infrastructure grows.
Breaking records, Hitachi Energy has tested 1,100 kV converter transformers—the world’s highest DC voltage level.
Grid expansion toward net-zero
As part of South Africa’s grid expansion and strengthening plan, two massive HVDC power lines connect Apollo Substation (near Pretoria in South Africa) to Songo (near Cahora Bassa Dam in Mozambique).
The HVDC power from Cahora Bassa flows through these lines, is converted to AC power, and is integrated into Eskom’s national power grid via the Apollo inverter station.
The Apollo – Songo HVDC line is approximately 1414 km with a single PLC repeater station at Pietersburg. The section of the HVDC line length from Pietersburg to Songo covers approximately 1146 km, making it one of the longest PLC links in the world.
Hitachi Energy collaborates with Eskom to support South Africa’s infrastructure expansion. Amid the global surge in energy infrastructure development, component manufacturers like Hitachi Energy support their customers in finding optimal solutions, considering timing requirements and the massive production demands that impact the delivery periods of products like transformers.
A certainly common challenge in such a market scenario is dealing with emergency situations in the event of a breakdown when the production of new units cannot be executed rapidly. Spare units play a crucial role in such conditions, ensuring uninterrupted operations.
Back-up transformers for enhanced grid reliability
Specifically for the Apollo Converter Substation in Johannesburg, Hitachi Energy has supplied three 90.8 MVA HVDCs, a critical component of the Cahora Bassa/Apollo HVDC scheme. As a key hub within the national grid, the Apollo substation interfaces seamlessly with both the 400 kV and 275 kV networks.
Delivered in January 2024, these three transformers serve as backup units. During breakdowns or maintenance, they step in without disrupting operations to ensure an uninterrupted power supply. As the older transformers retire, these new units will take over the critical task of converting 533 kV DC to 275 kV AC. Their mission: connect clean, renewable energy to industries and communities, providing stability to the grid.
The flawless execution of this project owes much to meticulous planning, vigilant oversight, and continuous monitoring at every stage during the entire design phase, right up to Factory Acceptance Testing (FAT) compliance. Each HVDC transformer is meticulously designed to precise client specifications, adhering to the highest engineering, quality, and sustainability standards.
Our long-standing partnership with the Apollo Substation underscores our commitment to providing advanced transformers for uninterrupted power supply in the country. Together, we facilitate the seamless integration of renewable energy into the national grid
Enabling South Africa's clean energy future
Apollo Converter Substation has a strategic importance for the national grid. As a trusted partner of our customers, it is our duty to help them ensure a continuous energy supply throughout the country.
It is not the first time that Hitachi Energy has supplied products for Apollo Substation, underlining a long history with its customers characterized by adherence to stringent manufacturing and installation standards.
Together with our partners, we are steering South Africa toward a sustainable energy future—a future where reliable, clean energy effortlessly serves industries and communities.
“HVDC technology stands out for its remarkable efficiency in transmitting substantial power over long distances and catering for specialized applications. As a key enabler for a carbon-neutral energy system based on renewables, HVDC is shaping the grid of the future,” comments Abel Gilbert, South Africa Market Manager of Hitachi Energy Transformers Business.
