Zambia’s state-owned electricity company, ZESCO, issued a warning this Wednesday (21) to Hidroeléctrica de Cahora Bassa (HCB) about the growing risks of relying almost exclusively on hydropower sources, at a time when extreme climate events are threatening the region’s energy sustainability.
The warning was delivered by ZESCO’s Director of Power Generation, Ernest Banda, during the conference marking HCB’s 50th anniversary, as he shared Zambia’s experience in dealing with the severe drought that affected the country between 2024 and 2025.
“The year 2024 was marked by one of the worst hydrology crises in our history. We went from generating over 800 GWh at the beginning of the year to less than 400 GWh in December. This drastic reduction, driven by low rainfall in our river basins, left us in a critical position,” said the engineer, referring to the Zambezi and Kafue rivers as the main water sources.
According to the official, the water shortage forced Zambia to resort to importing electricity at high costs. “We ended the year with a net bill of about 2.7 billion meticais (40 million dollars) in energy imports, a situation worsened by the fact that domestic regulated tariffs do not reflect the actual cost of procurement,” he explained.
Banda also warned that over 60% of Zambia’s installed capacity is vulnerable to climate change, which calls for urgent diversification of the energy mix and increased investment in renewable sources and transmission infrastructure.
In response to this scenario, the Zambian government adopted an Integrated Resource Plan with a horizon extending to 2050, which foresees the need for around 540 billion meticais (8 billion dollars) in investments for power generation and transmission by 2030. The plan includes the expansion of solar, wind, and geothermal energy, as well as the construction of 4,000 kilometers of new transmission lines.
“Zambia’s experience shows that relying on hydropower for more than 80% of electricity supply can be financially disastrous in the context of climate change,” Banda stressed, implying that Mozambique — where electricity production is largely dominated by HCB — faces similar risks.
ZESCO took the opportunity to strengthen ties with HCB and encourage the adoption of joint regional strategies for energy resilience, particularly within the framework of the Southern African Power Pool (SAPP).
The conference is taking place as part of the celebrations marking HCB’s 50th anniversary. HCB is one of the largest power generation infrastructures in Southern Africa. The company was established during the Portuguese colonial period, with the construction of the dam between 1969 and June 1, 1974. The reservoir began filling shortly after the completion of the structure, and commercial operations started in 1977 with the commissioning of the first three generators, delivering a capacity of 960 MW. Today, the installed capacity stands at 2,075 MW.
Located in a narrow gorge of the Zambezi River, the Cahora Bassa reservoir is the fourth largest in Africa, stretching approximately 270 kilometers in length, up to 30 kilometers in width, and covering a total area of 2,700 square kilometers. Its average depth is around 26 meters.
HCB is currently a private limited company, with 85% owned by the state-owned Companhia Eléctrica do Zambeze, 7.5% by the Portuguese company Redes Energéticas Nacionais (REN), 3.5% held as treasury shares, and 4% distributed among Mozambican citizens, companies, and institutions.
The power plant currently employs around 800 workers and is considered a key player in supplying electricity to both the country and the region, including major consumers such as Mozal, as well as power utilities in neighboring countries like South Africa and Zimbabwe, through the regional Southern African Power Pool (SAPP) network.
Source: Diário Económico
