South Africa, known for its vast coal reserves, is increasingly exploring renewable energy sources to diversify its electricity mix and reduce carbon emissions.

While hydropower contributes a smaller portion of the country’s energy compared to coal and solar, hydro turbines play a critical role in providing clean and reliable electricity.

This article examines hydro turbines in South Africa, key hydroelectric plants, the benefits and challenges of hydropower, and the future outlook for the sector.

The Role of Hydroelectric Power in South Africa

Hydropower accounts for around 3% of South Africa’s total electricity generation, making it a relatively small but essential part of the country’s energy infrastructure.

The country has both conventional hydroelectric plants and pumped-storage schemes, which help balance the national power grid, especially during peak demand periods.

Given South Africa’s semi-arid climate and limited large rivers, hydropower is not as dominant as in other countries.

However, the government is investing in small-scale and cross-border hydro projects to expand its renewable energy capacity.

Major Hydroelectric Plants in South Africa

Several hydroelectric facilities in South Africa use advanced hydro turbines to generate power efficiently.

The most notable ones include:

1. Gariep Hydroelectric Plant – Located on the Orange River, this plant has an installed capacity of 360 megawatts (MW) and utilizes Francis turbines to generate electricity.

2. Vanderkloof Hydroelectric Plant – Also on the Orange River, this facility has a capacity of 240 MW and is equipped with Kaplan turbines, which are suitable for varying water flow conditions.

3. Drakensberg Pumped Storage Scheme – This 1,000 MW facility in KwaZulu-Natal uses reversible Francis turbines, allowing water to be pumped back into an upper reservoir during off-peak hours and released to generate electricity during peak demand.

4. Ingula Pumped Storage Scheme – One of the most important hydro projects in South Africa, Ingula has a 1,332 MW capacity. It consists of four Francis turbines, providing much-needed grid stability.

5. Steenbras Pumped Storage Scheme – Located near Cape Town, this 180 MW facility is the oldest pumped-storage scheme in South Africa and plays a crucial role in managing power demand in the Western Cape.

How Hydro Turbines Work

Hydro turbines convert the kinetic energy of moving water into mechanical energy, which is then transformed into electricity using generators.

The most common types of hydro turbines in South Africa include:

• Francis Turbines – Used in medium to high-flow hydro plants, including Gariep and Vanderkloof.
• Kaplan Turbines – Efficient for variable water flow conditions, often found in run-of-river hydro plants.
• Reversible Francis Turbines – Used in pumped-storage schemes like Ingula and Drakensberg, allowing water to be stored and reused for electricity generation.

Advantages of Hydro Turbines in South Africa

1. Renewable and Low-Carbon Energy

Hydropower is a sustainable energy source that reduces South Africa’s reliance on coal and helps lower greenhouse gas emissions.

2. Grid Stability and Energy Storage

Pumped-storage schemes, such as Ingula and Drakensberg, act as massive “batteries” that store energy and release it when needed, helping to stabilize the national grid.

3. Cost-Effective and Long-Lasting

Once built, hydroelectric plants have low operational costs and can last for several decades with proper maintenance.

4. Supports Economic Growth and Jobs

The hydropower sector creates jobs, supports infrastructure development, and contributes to economic growth.

Challenges Facing Hydropower in South Africa

1. Limited Water Resources

Unlike countries with abundant rivers, South Africa’s semi-arid climate restricts large-scale hydro development, making it difficult to expand the sector significantly.

2. High Initial Investment Costs

Hydroelectric and pumped-storage projects require substantial financial investment, making them costly to develop.

3. Environmental and Social Concerns

Dams and reservoirs can disrupt ecosystems, affect biodiversity, and displace local communities. Sustainable planning is essential to minimize negative impacts.

4. Dependence on Regional Hydropower Imports

South Africa imports hydroelectric power from Mozambique (Cahora Bassa Dam) and Lesotho (Lesotho Highlands Water Project), increasing its reliance on external energy sources.

Future of Hydropower in South Africa

To maximize its hydro potential, South Africa is focusing on:

• Small-Scale Hydropower Projects – Developing mini and micro-hydro plants to provide electricity to rural areas.
• Cross-Border Hydro Projects – Expanding collaborations with Mozambique, Lesotho, and Zambia to import clean energy.
• Upgrading Existing Infrastructure – Improving the efficiency of existing hydro plants with modern turbine technology.

Conclusion

Hydro turbines play a vital role in South Africa’s renewable energy mix, particularly in pumped-storage schemes that help balance the national power grid.

While large-scale hydropower expansion is limited due to water scarcity, ongoing investments in small hydro projects and regional collaborations will help South Africa strengthen its clean energy transition.

With a strategic approach, hydropower can continue to support the country’s long-term energy security and sustainability goals.