Nigeria has secured a major legal victory in the long-running dispute over the Mambilla Hydroelectric Power Project in Taraba State, after an International Chamber of Commerce arbitration tribunal in Paris rejected claims by Sunrise Power and Transmission Company Limited that could have exposed the country to more than $3.38bn.
The tribunal’s final award, issued on September 17, 2026, dismissed Sunrise Power’s claims arising from disputes over the development of the long-delayed project. The ruling removes a major legal obstacle that has hindered efforts to move the 1,500-megawatt project forward.
President Bola Tinubu announced the development in a statement issued by his Special Adviser on Information and Strategy, Bayo Onanuga. The President described the ruling as a significant victory for Nigeria, saying it had cleared what he called the biggest legal hurdle that had paralysed the Mambilla project for years.
The dispute dates back to a 2003 agreement concerning the development of the Mambilla hydroelectric project. Sunrise later commenced arbitration proceedings against Nigeria at the ICC in October 2017, alleging breaches of contractual obligations and seeking billions of dollars in compensation.
The claims involved two related disputes. In one, Sunrise sought more than $2.7bn in compensation and interest over disagreements connected with the project. In another, the company demanded $680m, including a settlement sum and interest. Combined, the claims created potential financial exposure of more than $3.38bn for Nigeria.
The tribunal also rejected Sunrise’s demand for $400m arising from a 2020 settlement agreement. That claim comprised a $200m settlement sum and another $200m allegedly arising from a default under the agreement.
The ruling has financial consequences beyond the rejection of the claims. According to details reported on the award, Sunrise and its promoter, Leno Adesanya, were ordered to reimburse Nigeria for 75 per cent of its legal fees and expenses. Nigeria’s legal costs were put at about $11.82m, with $2.5m expected to be recovered from funds held in escrow by the ICC. The remaining $9.32m is payable by Sunrise and Adesanya, with interest accruing at 10 per cent annually until payment.
The tribunal also fixed arbitration costs at approximately $1.66m, with Sunrise and Adesanya responsible for 75 per cent and Nigeria for the remaining 25 per cent.
Tinubu commended Attorney-General of the Federation and Minister of Justice, Lateef Fagbemi, officials of the Federal Ministry of Justice and Nigeria’s external legal team for their handling of the case.
He also acknowledged the roles played by former President Olusegun Obasanjo and the late former President Muhammadu Buhari, who testified during the proceedings. Former ministers Babatunde Fashola and Suleiman Adamu were also among witnesses recognised by the President.
The Mambilla project has been under development for more than two decades and has undergone several changes in scope. Initially conceived as a 3,050MW hydroelectric facility, the project was later reduced to about 1,525MW and subsequently rescoped to approximately 1,500MW as the government sought to make it more financially viable and acceptable to lenders.
The project has faced repeated delays caused by legal disputes, financing challenges and disagreements over its implementation. Its completion is regarded as potentially significant for Nigeria’s electricity supply because of its proposed generation capacity.
However, the arbitration victory does not mean the power plant is immediately ready for construction or generation. Financing arrangements, project implementation and other technical and administrative requirements still have to be addressed before the facility can become operational.
Meanwhile, Sunrise Power promoter Leno Adesanya said on Friday that the company’s legal team was reviewing the tribunal’s decision and would consider its available lawful options. He said it would be premature to make extensive comments until the review had been completed.
Adesanya also said Sunrise remained committed to protecting its interests in relation to the Mambilla project and expressed hope that the longstanding dispute could eventually be resolved in a way that supports the project’s development.
For the Federal Government, the arbitration outcome removes a potentially costly financial liability and creates a clearer legal environment for efforts to revive the long-delayed 1,500MW Mambilla power project. The next challenge will be turning the legal victory into concrete progress toward financing, construction and eventual electricity generation.
