Nigeria has defeated Sunrise Power and Transmission Company Limited in a long-running international arbitration dispute linked to the Mambilla Hydroelectric Power Project, potentially shielding the country from claims exceeding $3.38bn.
The International Chamber of Commerce arbitration tribunal in Paris issued its final award on September 17, 2026, ruling in favour of Nigeria and rejecting claims brought by Sunrise over the stalled Taraba State project.
The Presidency said Sunrise had sought $680m as a settlement sum and interest in the latest arbitration, while a separate related claim involved more than $2.7bn in compensation and interest.
President Bola Tinubu described the ruling as the biggest legal hurdle to the project’s progress being removed.
“Today’s ICC ruling clears the single biggest legal hurdle that has paralysed the Mambilla hydro power project for years,” Tinubu said.
The tribunal also rejected Sunrise’s claim arising from a 2020 settlement arrangement, including a demand for $400m comprising a $200m settlement sum and a further $200m default payment.
It further ordered Sunrise and its promoter, Leno Adesanya, to reimburse 75 per cent of Nigeria’s legal fees and expenses. Nigeria’s legal costs were put at about $11.82m.
The dispute dates back to a 2003 agreement for the development of the Mambilla project. Sunrise later commenced ICC arbitration proceedings against Nigeria on October 10, 2017, after disputes emerged over the project and subsequent government arrangements.
The Mambilla project has undergone several changes since its conception.
It was originally designed as a 3,050MW hydropower project in Taraba State. In 2021, then Power Minister Saleh Mamman said the government had rescoped the scheme to about 1,500MW to make it financially viable and acceptable to lenders.
The project was estimated at about $5bn-$5.8bn in its original form, while the rescoped version was put at roughly $4bn.
The project was also expected to rely heavily on Chinese financing, with China’s Export-Import Bank previously identified as a major source of funding. Financing conditions and unresolved legal disputes contributed to repeated delays.
The terminology surrounding the project’s capacity has varied over the years, including references to 3,050MW, 1,525MW and 1,500MW. The current project commonly referred to by the Federal Government is the approximately 1,500MW version.
Tinubu said former presidents Olusegun Obasanjo and the late Muhammadu Buhari testified during the arbitration. He also commended former ministers Babatunde Fashola and Suleiman Adamu, Attorney-General of the Federation Lateef Fagbemi and Nigeria’s legal team.
The President said the government would continue to honour legitimate contractual obligations while defending what it considers unjustified claims against Nigeria.
The arbitration victory removes a major legal obstacle to the project, but it does not automatically restart construction.
Funding, final project structuring, lender requirements and implementation arrangements must still be resolved before the 1,500MW scheme can move into construction.
Sunrise promoter Leno Adesanya said the company’s lawyers were reviewing the tribunal’s decision and would advise on the next legal steps.
For Nigeria’s power sector, the ruling represents a significant legal development. The bigger challenge now is converting the cleared legal position into financing, construction and eventual electricity generation.
