Will 'world's biggest' hydro power project light up Africa?

With an estimated generated power of 40,000 megawatts, the Grand Inga will have twice as much capacity as the Three Gorges dam (pictured) in China, currently the world's largest hydro project

The government of the DRC is seeking to harness the power potential of the Congo river by building Grand Inga, expected to be the world's biggest hydroelectric project when completed.

It is being hailed as the holy grail for power, the biggest hydroelectric project ever built that would harness sub-Saharan Africa's greatest river and light up half of the continent.

But will the ambitious plan to tame the mighty Congo River, a mega-project first conceived in the 1970s, finally get going and what will be its actual impact?

Last month, the government of the Democratic Republic of Congo announced in Paris that the construction of the first phase of a new set of energy projects at the country's Inga Falls would begin in October 2015. The new $12 billion development, dubbed Inga 3, is expected to have a power output of nearly 4,800 megawatts (MW), with South Africa agreeing to buy half of the electricity generated.

Grand Inga site. Click to expand

But the DRC government's bold vision ultimately involves five further stages that would complete the "Grand Inga" mega-project, giving it an astonishing capacity of 40,000 MW -- that's twice as much as the Three Gorges dam in China, currently the world's largest hydro project.

When completed, Grand Inga could provide more than 500 million people with renewable energy, say its proponents.

"A myth dreamed of for 40 years, Grand Inga is becoming a reality with an action plan spread over several plants which will be added in stages," the DRC government said in a statement after the Paris meeting.

Powerful river

With a length of 4,700 kilometers, the Congo is Africa's second biggest river, after the Nile, and the world's second largest river in terms of flow, after the Amazon. At the Grand Inga site, some 1.5 million cubic feet of water flow steadily through a network of cataracts every second, dropping about 100 meters to form the world's biggest waterfall.

Transferring power

Indeed, the pledge by energy-hungry South Africa to purchase about half of Inga 3's future power production is essential for the project to attract finance and get going.

The two countries are currently negotiating a treaty to finalize the details of a power purchasing agreement, including the construction of transmission lines to transfer 2,500 MW of Inga 3's production to South Africa. The exact routing of the energy corridor is not yet defined, but it is expected to be over land, through different countries in the southern part of the continent.

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A World Bank spokesperson told CNN that such power exports could potentially raise considerable revenues for the DRC. "With energy resources on this scale, DRC can play a pivotal role in meeting not only its future domestic energy needs for poverty reduction and economic development, but also the energy needs at regional and continental levels," said the spokesperson.