The Line to Apollo
Cahora Bassa dams the Zambezi in Tete province, and for the first thirty-two years of Mozambican independence it was 82 per cent owned by the Portuguese state. Mozambique bought the controlling share in 2007 for US$950 million, and what it had bought was a wall pointed the wrong way.
From the escarpment above Songo the whole apparatus is visible at once: the wall wedged into a gorge on the Zambezi, the switchyard on the terrace behind it, and two lines of pylons leaving that terrace and walking south-west out of the country. They run about 1,400 kilometres to a converter station called Apollo, outside Pretoria, and when they were commissioned in the second half of the 1970s they were the longest high-voltage direct current link in the world. They are also the explanation for everything else. Cahora Bassa was not built to light Mozambique. It was built to sell electricity to South Africa, and it was engineered around the customer rather than around the country it stands in.
Mozambique became independent on 25 June 1975, a few months after the first generator turned. It did not become the owner. Under the arrangements that followed, the company holding the dam — Hidroeléctrica de Cahora Bassa — remained 82 per cent Portuguese state property, and stayed that way for thirty-two years. The largest single piece of infrastructure in the country, sitting on the country's own river, belonged to Lisbon until November 2007, when Mozambique bought control of it for US$950 million.
What the wall was for
Construction ran from 1969 to 1974, carried out by a consortium of Portuguese, South African, West German, French and Italian firms, and it went up while a war of independence was being fought in the same province. The wall is 171 metres high. The reservoir behind it flooded roughly 2,700 square kilometres and remains one of the largest artificial lakes in Africa. Five turbines on the south bank give an installed capacity of 2,075 megawatts. Portugal's stated purpose was twofold and neither half concerned Mozambican households: an export contract with the South African utility, signed before the concrete was poured, and a settlement scheme for the Zambezi valley that was supposed to bring a million Portuguese farmers into the interior and never came close.
The pylons
Then the second war. From the early 1980s RENAMO made the transmission line a standing target, and it was an easy one — hundreds of pylons over open country with nobody living underneath most of them. They came down in numbers, repair crews were ambushed, and the link to South Africa was effectively dead for most of a decade. The general peace agreement was signed in Rome on 4 October 1992; the line did not carry power at anything like full capacity again until 1998. For those years Portugal owned a dam that earned almost nothing, Mozambique had the lake and the resettled villages, and the unpaid construction debt sat on the books growing into a number neither side seriously expected to be settled in cash.
Independence moved the border. It did not move the dam, and it did not move the contract that decided where the power went.
Nine hundred and fifty million
Armando Guebuza's government made reversion a priority from 2004 and spent three years on it. The agreement was signed in Maputo on 31 October 2007: Portugal wrote down the accumulated construction debt and accepted US$950 million for the transfer, US$250 million of it paid out of the state budget and the remaining US$700 million borrowed from a bank consortium against the dam's own future revenue. The Mozambican holding went from 18 per cent to 85, with Lisbon keeping 15. The handover ceremony was staged at Songo on 27 November 2007 and the language used was the language of independence, which in Maputo is roughly how it was received. A further tranche bought in 2012 took the Mozambican share above 92 per cent, and in 2019 part of the holding was floated on the Maputo stock exchange, putting shares in the hands of Mozambican buyers and making the dam by a distance the largest company listed in the country.
Where the power goes
HCB is now one of the largest dividend payers and taxpayers the Mozambican state has, which is the part of the purchase that has plainly worked. What ownership did not change is the direction of the wires. The bulk of the output is still contracted south to Eskom, with a share to Zimbabwe and a share bought back by the national utility, EDM, under a price structure originally written when Mozambique had no seat at the table and renegotiated only after 2007.
The awkward arithmetic sits underneath. Fewer than half of Mozambican households have a grid connection, and Maputo has historically drawn much of its supply through the South African network — buying back, at retail, power generated on the Zambezi. The reason is physical rather than political: the direct current line goes to Apollo, and no line of comparable capacity goes to Maputo. The fix now being built is a 400 kV backbone of about 560 kilometres running from Temane, near Vilankulo, down to the capital, financed with World Bank and African Development Bank money and paired with a gas plant at the northern end. It is national plumbing being installed half a century after the generation it was supposed to serve. Energia para Todos, the electrification programme launched in 2018, targets universal access by 2030 and will stand or fall on whether that kind of line gets finished.
The next wall
Sixty kilometres downstream, at Mphanda Nkuwa, Mozambique intends to build a second dam of roughly 1,500 megawatts. The project has been proposed, shelved and revived since the 1990s; it was relaunched in 2022 and a consortium of EDF, TotalEnergies and Sumitomo was selected as strategic partner in 2023. The argument against it is not scenic. Cahora Bassa flattened the Zambezi's annual flood in 1974, and the delta below Marromeu — a Ramsar wetland, a buffalo reserve and the nursery for the prawn fishery on the Sofala Bank — has been contracting ever since. Hydrologists have argued for two decades for prescribed flood releases timed to the old seasonal pulse, and the company has never made them, because water spilled is money not sold. A second wall makes that decision harder or easier depending on how it is operated. The difference from 1974 is that the decision is now taken in Maputo, by people who paid for the right to take it, and that is what the nine hundred and fifty million actually bought — not electricity, which was flowing anyway, but the argument about it.