Map by Shem Oirere/ENR Art Department

The Inga III hydro plant will harness energy from the Congo River's Inga Rapids, located some 225 kilometers from Kinshasa, the capital of the Democratic Republic of Congo.

Construction of an $8-billion to $10-billion hydroelectric plant in the Democratic Republic of the Congo may be delayed and cost more if its design remains unchanged, the African Development Bank said in late June.

The Inga III hydropower project, on the Congo River's Inga Rapids, located some 225 kilometers from the capital, Kinshasa, is likely to be bogged down by its design. That design, by SNC-Lavalin, Quebec, entails drilling 70 kilometers of tunnels into rock formations whose geology “is unknown,” according to the African Development Bank, or AfDB, a development bank that works to promote economic and social development in Africa.

The Inga III project is being executed by the government of the Democratic Republic of the Congo through the country’s public utility firm Société Nationale d'Electricité.

SNC-Lavalin’s design calls for water to be channeled through two underground tunnels to turbines that would generate 4,320 MW. An earlier design by Western Power Corridor—a joint venture of the national power firms of Namibia, South Africa, Angola and Botswana—proposed a different design using two open channels that fed a water reservoir. At one end of the reservoir, eight turbines at a power station would generate 3,600 MW. AfDB says that design should cost about $7 billion.

AfDB commissioned a $15.7-million study to examine the approaches. The results favored the Western Power Corridor design, a solution that was “cheaper, faster to implement and less risky,” says Hela Cheikhrouhou, the AfDB director of energy and environment. 

Randolphe Segla, SNC-Lavalin’s director for Africa, said he could not comment on the study because the job is currently out for request for interested developers. The government did not respond to inquiries about the study.

Inga III is the third component of a multibillion-dollar plan to generate 44,275 MW via the Congo River’s Inga Rapids. The other projects include the 351-MW Inga I hydro plant and the 1,424-MW Inga II facility, which were constructed in 1970 and 1982, respectively. A final phase after Inga III, Grand Inga, would generate 39,000 MW and is estimated to cost $80 billion.

The country expects to finance Inga III with equity and debt, and construction will not begin until financing is in place. The Democratic Republic of the Congo had an agreement with the Western Power Corridor to back the project, but that agreement collapsed in 2003.