In most urbanised industrialised economies, the current focus on renewable energy growth is on wind and solar. Lacking untapped river resources, major hydroelectric projects are rare. However, in larger and more rural countries, especially those still industrialising, large-scale hydro is still an option. Cameroon, which is finalising construction of a new 420 MW project by damming the Sanaga River, the Central African country’s largest watercourse, 70 km north-east of the capital Yaoundé, is a case in point.

Its new Nachtigal hydroelectric dam will be 1,455 km long, with turbines being fuelled by a 3.3 km headrace channel, according to France’s EDF, which owns 40% of Cameroonian operator the Nachtigal Hydro Power Company (NHPC). ‘Nachtigal will be the most powerful electricity generating facility in Cameroon when it is commissioned,’ says EDF, a major fillip for the country’s power production, which the International Renewable Energy Agency (IRENA) estimates currently amounts to 1.5 GW.

Once this $1.3bn project is fully operational next year, it will also shift Cameroon’s power generation profile towards green energy, with renewables (98% of which is hydro) currently delivering 54% of the country’s electricity capacity, the rest depending on fossil fuels, according to IRENA.

‘The dam will provide around 30% of the electricity consumption of the interconnected network in Southern Cameroon. It will produce green, competitive electricity available all year round,’ says EDF.

The NHPC reports construction is on track, with 92% of construction works completed as of November 2023.

Electrical constraints 
The plant’s regional importance is accentuated by the fact that Cameroon (population 27.2 million) operates three independent grids: a Southern Interconnected Grid; Northern Interconnected Grid; and the Eastern Isolated Grid. A 2023 report in Frontiers in Sustainable Cities commented: ‘Presently, electric power transfer among the three grids does not exist; but there are, however, imminent plans within the timeframe of 2030–2035 to connect the three grids to form a common network.’

Cameroon experiences periodic acute shortages of electricity supply, with power cuts being especially common during the dry season (November to March) because of the country’s reliance on hydroelectric power. This leads to electricity rationing in major cities, including the capital Yaoundé and its major economic centre Douala (the country’s two largest cities). Neighbourhoods in Yaoundé can go for days without electricity supply, so the Nachtigal project is a focus of optimism for the future.

Cameroon’s Minister of Energy and Water Resources, Gaston Eloundou Essomba, believes the Nachtigal dam will transform the country’s electricity system. ‘We will have more stability in electricity production to satisfy actual and future demands. Take, for example, the industrial cities of Douala and Kribi, there is a supplementary demand of 250 MW of electricity which is not satisfied,’ said Essomba during a December 2023 visit to the site. The project would help Cameroon’s industries which are currently generating 450 MW of their electricity through their own generators because the country lacks sufficient and stable electricity supplies.

The dam should also reduce the overall cost of grid power, added Essomba, who stressed that the government currently spends €0.30 per kW of electricity produced using fossil fuel sources (such as diesel) compared to just €0.06 per kW at the Nachtigal dam. ‘This dam will enable us to substantially reduce government subvention [subsidies] which the state pays for all Cameroonians to have electricity. Between 2012 and 2022, the government spent over €457mn to subsidise electricity production in the country,’ he said.

It is also a key plank of rolling out the Cameroon government’s National Development Strategy 2020–2030, which targets producing energy in abundant quantities to boost industrialisation, even turning the country into an energy exporter. This development blueprint foresees an increase in installed power generation capacity to 5,000 MW by 2030.

As a result, the Cameroonian government and partner EDF are developing another hydropower dam project in Kikot, also on the Sanaga River, but downstream from Nachtigal, 6 km north-west of Yaoundé. The plant could cost €1bn to build, with EDF saying its capacity would be larger than Nachtigal, at between 450 MW and 550 MW, with construction beginning in 2025 and commissioning in 2030.

Plant commissioning 
In the meantime, the NHPC has been announcing final steps towards the Nachtigal plant’s operational launch. Its first turbine unit, generating 60 MW, was due to be commissioned by the end of 2023, with power then injected into the southern interconnected network grid. The second and third units will be commissioned in March and May 2024 respectively, and the others will follow suit.

The NHPC notes that the 3.3 km long and 14 metre deep headrace canal, funnelling water from the reservoir created by the dam, will comprise 28mn m³ and a surface area of 4.21 km². The Cameroon government intends to create a commercial fishery within the reservoir.

Last November (2023), testing began for the two 51 km, 225 kV lines connecting the plant’s substation to the southern Cameroon grid. That month also saw the installation of the seven penstocks carrying water from the canal to the power station’s seven turbines, which contain 32-tonne Francis-type wheels. A 4.5 MW mini power hydro station has also been built, which will power the plant’s auxiliary buildings and local communities.

NHPC was created in 2016 and was granted a 35-year government concession for power generation in 2017. It is owned by the Cameroon state, EDF, the World Bank’s International Finance Corporation (IFC), French government development fund STOA and African public investment platform AFRICA50.

One key beneficiary of the project will be Cameroonian aluminium manufacturer ALUCAM, which operates a smelter at Edéa, downstream from the hydro plant. An initial aim of the dam was to aid the industry with more reliable power, and Rio Tinto Alcan, ALUCAM’s former owner, was an initial NHPC shareholder, although it subsequently withdrew. The Cameroon government, as ALUCAM’s 93% owner, now represents the industry’s interests on the hydro project.

This hydro plant is a milestone for the Cameroonian energy transition, argues EDF: ‘When commissioned in 2024, Nachtigal will be the most powerful power plant in Cameroon and a real asset for the sustainable development of the country,’ it said in a note.

The IFC added that it would: ‘increase access to energy by providing clean, reliable, low-cost base load energy and help meet the fast-growing demand; improve the country’s power sector financial sustainability by displacing more expensive thermal power generation... and promote renewable energy and carbon emissions reductions’.

Turbines under construction at the end of the Nachtigal project’s headrace canal
Photo: Nachtigal Hydro Power Company

Local impacts 
The project has not been without its critics, however. For example, the IFI Synergy Group lodged formal concerns with the African Development Bank (AfDB), which has supported Nachtigal through its links to AFRICA50.

It claimed in June 2022 that more than 1,000 people living and working near the project are facing multiple associated environmental and social difficulties. These include the loss of income by local fishermen, sand extractors and fishmongers through the creation of the reservoir; insufficient and late compensation; unsatisfactory physical resettlement; displacement and destruction of sacred sites; and the loss of more than 2,000 ha of forest which contained medicinal plants, food and other non-timber forest products.

An inquiry liaising with these local communities, the government and the power company has been launched by the AfDB, which is still ongoing.

Responding, the NHPC tells New Energy World that it has always taken care to mitigate any harm to communities living near the project. The company’s communication department says that six families immediately affected by construction and resulting flooding have been resettled, with new modern homes constructed for them. It stresses that financial compensation has also been paid to local farmers, fishermen and fishmongers, with around 1,000 farmers receiving new fields and seedlings, with agricultural engineers appointed to provide technical assistance.

The NHPC says it has compensated 200 fishermen financially while waiting for the operation of the project’s fishery development plan.

Meanwhile, the NHPC says two tonnes of archaeological artefacts have been collected from construction and flooding and were given to the Cameroonian Ministry of Arts and Culture. The company has also improved local potable water supplies, health and education services, setting up schools, health centres and boreholes.

The company claims that it is reforesting 100 ha of tree cover to replace biodiversity lost to the project. When work started, a database of identified species was created along with a nursery of some local species. The NHPC says it is working with officials from Cameroon’s Mpem and Djim National Park, north of Nachtigal, to preserve plants and animal species.

Should these contingency measures gain local acceptance, and the hydro plant and dam’s operations be rolled out efficiently, the NHPC may have developed good practice which can be used at the larger and future Kikot project downstream.