In its final award dated Thursday, 17 September 2026, an arbitration tribunal of the International Chamber of Commerce (ICC) in Paris rejected Sunrise Power’s claims against the Federal Republic of Nigeria. The tribunal also ordered Sunrise and its promoter, Leno Adesanya, to reimburse most of Nigeria’s legal costs.
The decision removes a significant legal obstacle surrounding one of Nigeria’s most ambitious power projects. However, it does not resolve the separate challenges of securing financing, appointing contractors and setting a construction timetable.
The three-member tribunal dismissed Sunrise Power’s claim that Nigeria had breached its obligations under a 2020 settlement agreement and a subsequent addendum. It also rejected the company’s request for US$400 million, comprising a US$200 million settlement sum and a further US$200 million in default payments.
The tribunal additionally ruled that Adesanya was personally bound by the arbitration agreement with Nigeria. It confirmed that it had jurisdiction over Nigeria’s counterclaim against him and his company. The award therefore represents a legal victory for the Nigerian government in this particular arbitration. It should not, however, be taken as confirmation that every dispute connected to the Mambilla project has been resolved.
The tribunal ordered Sunrise Power and Adesanya to reimburse 75% of Nigeria’s legal fees and expenses, amounting to US$11,819,506.51. Of that total, US$2.5 million is to be released from funds held in escrow by the ICC following formal notification of the award. Sunrise and Adesanya are responsible for the remaining US$9,319,506.51. The unpaid balance will accrue interest at 10% annually, compounded each year, from notification until full payment.
The tribunal also fixed the arbitration costs at US$1,656,500. Sunrise and Adesanya are responsible for 75% of those costs, while Nigeria bears the remaining 25%.
The award establishes the amounts payable under the tribunal’s decision, although actual recovery will depend on the implementation of its orders.
Coverage of the Mambilla dispute has referred to several different sums, reflecting what appear to be separate claims and arbitration proceedings. Vanguard and Nigerian Tribune have reported that the dismissed claim was worth approximately US$2.35 billion. A statement from the Presidency, meanwhile, referred to a US$680 million demand involving a settlement sum and interest, while noting that Sunrise had advanced claims exceeding US$2.7 billion in another arbitration. Nairametrics combined the reported figures to arrive at approximately US$3.38 billion in disputes. Other legal reports have also described multiple claims as having been rejected.
The Presidency’s statement does not fully clarify the status of the larger claim, and the headline totals should not be interpreted as a single amount confirmed by the September award. The distinction matters because the outcome of one arbitration does not automatically establish the status of every related proceeding. The scope of the award and any outstanding claims must be assessed separately.
President Bola Ahmed Tinubu welcomed the decision in a State House statement issued on 17 September 2026. He described the ruling as evidence of the government’s determination to defend Nigeria against claims it considers unjustified.
The President said Nigeria remained committed to honouring its legal obligations to genuine investors while continuing to defend itself against claims it considers opportunistic.
The Mambilla Hydroelectric Power Project is planned as a 3,960-megawatt installation in Taraba State, eastern Nigeria. Its origins date back to a 2003 contract for a 3,050-megawatt plant under a build-operate-transfer arrangement. Tinubu’s statement described the original contract as illegal. The project has since been held back by prolonged legal disputes and questions surrounding its implementation.
The September award addresses an important part of the legal uncertainty surrounding Mambilla, but it does not, by itself, move the project into construction. Nigeria still needs a workable financing structure, a clear procurement process and the contractors and other partners required to deliver a project of this scale. A credible timetable will also depend on how the government intends to organise and implement the next phase.
For expatriates, businesses and investors with interests in Nigeria, the immediate significance is fiscal and legal rather than operational. The dismissal of Sunrise Power’s claims removes the exposure associated with the amounts sought in this arbitration, subject to the precise scope of the award and any applicable legal challenges. A substantial damages payment could have added pressure to public finances, although its broader effect on the naira or government spending would depend on the circumstances.
Instead, the award directs Sunrise and Adesanya to reimburse a substantial share of Nigeria’s legal costs.
For investors in African infrastructure, the case also highlights the importance of clearly defined contractual obligations, enforceable settlement agreements and effective dispute-resolution provisions.
But Mambilla will need investment, credible execution arrangements and sustained implementation before it can contribute electricity to Nigeria’s national grid. The ruling itself adds no generating capacity and does not address the country's immediate power-supply challenges.
The first test will be whether Nigeria can recover the legal costs awarded by the tribunal and whether Sunrise pursues any further legal action. The government’s next decisions on financing, procurement and project structure will be equally important.
For Nigeria, the award marks a significant development in a long-running dispute. For investors and residents, however, the more consequential milestone will be evidence that Mambilla is moving towards construction.