Mozambique's Cahora Bassa Dam expansion plan offers Eskom a fresh clean energy option

Daily Maverick

27-07-2025

The Mozambican government-owned hydroelectric power company is looking at Eskom as a potential customer for the additional 1,245MW generation capacity that it plans to add to its existing plant at the Cahora Bassa Dam.
Eskom is already the biggest client of the Hidroeléctrica de Cahora Bassa (HCB), the company that operates the Cahora Bassa Dam plant, with about 60% of the power generated at the dam travelling more than 1,400km on two parallel power lines between Cahora Bassa in Songo, northern Mozambique and the Apollo substation near Pretoria.
Cahora Bassa has a 2,075MW generation capacity, and the Mozambican government is in discussions with the World Bank to raise money for the expansion of the dam's northern bank and the construction of a new hydropower plant at the Mphanda Nkuwa Dam. The latter dam is downstream from Cahora Bassa, also along the same Zambezi River, and is expected to generate 1,500MW of clean energy.
The expansion of the Cahora Bassa Dam scheme has received the backing of the World Bank and will increase generation capacity through the installation of three turning turbines – each generating 415MW. The projects are estimated to cost more than $6-billion.
With Eskom under pressure to keep the grid stable while trying to meet obligations to use cleaner energy sources, the power utility's spokesperson Daphne Mokwena told Daily Maverick that HCB's plans were in line with Eskom's mandate.
'One of Eskom's mandates is to ensure a reliable, sustainable and clean energy grid for the country. Eskom will review all HCB plans for future growth and give feedback once all the relevant details have been presented,' she said.
Mozambique has its own challenges as it has to meet its domestic electricity demand and has set a target of 2030 to meet this need.
According to the World Bank 2023 figures, only 36% of the Mozambican population had access to electricity, compared with 87.7% in South Africa.
In February 2024, Bloomberg reported – based on an unpublished energy transition strategy – that the Mozambican government intended to end the partnership with Eskom when the contract expired in December 2030.
Eskom said talks on the matter were yet to be concluded.
Said Mokwena: 'As the discussions are ongoing, there has been no conclusion on this matter. Eskom is therefore not able to comment on this question at this stage'.
However, Mokwena stressed that while Eskom continues to buy power from HCB, the utility 'will continue to rely on its own generation fleet'.
'Notably, the returned 800MW from Medupi Unit 4, the additional new 800MW capacity from Kusile Unit 6, and the planned return of 930MW from Koeberg Unit 1 by August 2025 will significantly boost available capacity,' she said.
The 50-year-old Cahora Bassa Dam scheme is a Mozambican government flagship and was showcased to World Bank President Ajay Banga, who visited Mozambique last week. Banga was the guest of Mozambican President Daniel Chapo, who is driving the development of Mozambique's untapped energy sources. The 48-year-old Chapo (the governing party, Frelimo's, candidate) was elected president following the disputed October 2024 elections. The development of the war-ravaged country is at the centre of his plans.
Ambitious renewable energy plans
Chapo said the main objective of the World Bank's visit was to identify areas of possible investment in the country's energy plans.
'Mozambique has a geographic location that allows for wind farms, so we are currently working with the World Bank Group, through the IFC (International Finance Corporation) which is part of the World Bank Group.
'We can have a public-private partnership, who can come and invest in this entire energy matrix we're talking about – producing electricity through hydroelectric plants, solar plants, gas plants, and also wind farms,' said Chapo.
Speaking after a tour of Cahora Bassa, Banga said Mozambique had the potential of becoming the 'energy powerhouse' of southern Africa.
'Frankly, in this part of Africa, nobody has the capacity or capability to do what can be done with the assets of this country.
'We are discussing with the government of Mozambique the idea of investing in another 1,500MW downstream from (Cahora Bassa).
'And then in the meantime, we're also doing some investing in solar capacity, 400MW. And then (Chapo) has some master plans, which I think are even more interesting in terms of adding more capacity (at Cahora Bassa) and renovating this plant and then adding further downstream,' said Banga.
Cahora Bassa is a major contributor to the Mozambican economy. It generated $547-million in revenue in 2024 and contributed $302-million to the southern African country's fiscus in the same year.
HCB CEO Tomás Matola said that while they continued to make a major contribution to the Mozambican economy, the age of the plant was a threat to its revenue plans.
He told the World Bank's Banga that they needed to refurbish Cahora Bassa's generators to future-proof the plant.
Said Matola: 'From the supply side, our big challenge is because of the age of our equipment. It is 50 years old, so all our equipment is obsolete, so now we need to do a deep rehabilitation of our power plant and substations.'
Southern Africa presently has a shortage of 10,000MW, while Mozambique plans to increase its power generation for the benefit of the domestic and the regional market.
'In Mozambique, we do have a challenge of electrification of all the country… So we have increasing demand from the domestic market, but also the regional market,' said Matola.
'As we need to diversify our power matrix, we have a project for producing 400MW of photovoltaic power. We believe that by 2027, we can start building this project,' said Matola, adding that HCB's vision was to generate 4,000MW of clean energy by 2034.
The plans for the 400MW solar power plant include the construction of two solar farms with 200MW generation capacity each.
Climate change threat to cleaner energy projects
While there is a global drive towards renewable energy and less reliance on fossil fuel energy sources, such as coal, cleaner energy sources are not without challenges.
For instance, Cahora Bassa's generation capacity has been adversely affected by the drought that has gripped countries along the Zambezi River.
The dam's levels are currently at 25%, meaning that water management techniques have to be applied to maintain the flow through the five generators – thus reducing power generation. According to engineers at HCB, that is the lowest level the dam has reached in its 50-year history.
That means Eskom has been getting less power from the plant. This was confirmed by Eskom spokesperson Daphne Mokwena, who said that the power utility had received 45% less electricity from Cahora Bassa than the previous year.
'Cyclically, southern Africa is affected by droughts, and Eskom's supply from HCB has been affected. During the droughts, Eskom relies on its own generation fleet.
'Eskom is receiving less power from HCB as compared to the previous year, due to the drought currently affecting the SADC region. The average loss of power is 45% when compared to last year,' said Mokwena.
Cahora Bassa Dam is built on the Zambezi River, which flows through six countries – namely Zambia, Angola, Namibia, Botswana, Zimbabwe and then joins the Indian Ocean in Beira, northern Mozambique.
The drought in the SADC region has seen levels at Kariba Dam – between Zimbabwe and Zambia – reach an alarming level of about 11% last year.
According to the Zambezi River Authority, the Lake Kariba water levels were sitting at 24.3% on 14 July 2025, compared with 11.5% recorded on the same date in 2025. In July 2023, Kariba's levels were at 31%.
However, while the levels have improved at Kariba, the benefits have yet to be realised downstream at Cahora Bassa, as the former is not releasing much water as it is still recovering from the lower levels.
Fast facts on Cahora Bassa
The construction of the dam took place between 1969 and 1974, resulting in the biggest hydroelectric power plant in southern Africa.
Power is generated by water passing through five vertical generator units – each producing 415MW and a total of 2,075MW.
Eskom is HCB's biggest client, buying 58% of the power generated at the plant, while 39% goes to the Mozambican state-owned energy company – 3% is sold to the Zimbabwean power utility.
The staff complement at HCB consists of Mozambican citizens, with 741 permanent workers and 685 seasonal workers.
Another 2,000 indirect workers benefit from the plant, through its suppliers.
*Source: Hidroeléctrica de Cahora Bassa (HCB)
World Bank Group structure
The World Bank Group comprises five organisations that specialise in differing areas, namely:
The World Bank, whose official name is the International Bank for Reconstruction and
Development, which lends to low- and middle-income countries;
The International Development Association, which also lends to low-income countries
The International Finance Corporation, which lends to the private sector;
The Multilateral Investment Guarantee Agency, which 'encourages' private companies to invest in foreign countries; and
The International Centre for Settlement of Investment Disputes, which mediates disputes between private investors and foreign countries.
DM
Sibusiso Ngalwa is a journalist, a cabbage farmer and a breeder of boer goats. His trip was sponsored by the Hidroeléctrica de Cahora Bassa (HCB), the company that operates the Cahora Bassa plant.