By Staff Reporter
Nigeria’s victory in the long-running international arbitration dispute over the Mambilla Hydroelectric Power Project has removed a major legal obstacle that had hung over one of the country’s most ambitious electricity projects for years.
But for millions of Nigerians struggling with unreliable electricity and the rising cost of powering homes and businesses, the bigger question is:
When will the Mambilla victory translate into actual electricity?
The International Chamber of Commerce (ICC) tribunal in Paris on September 17, 2026, ruled in Nigeria’s favour in the arbitration brought by Sunrise Power and Transmission Company Limited.
Sunrise had pursued claims that put Nigeria’s potential exposure at more than $3.38 billion across related disputes. The tribunal rejected the claims and also ordered Sunrise Power and its promoter, Leno Adesanya, to reimburse Nigeria 75 per cent of its legal fees and expenses.
President Bola Tinubu described the ruling as clearing the “single biggest legal hurdle” that had paralysed the Mambilla project for years.
But when will Nigerians actually get the electricity?
This is where the timeline becomes important.
2003 — The Mambilla controversy begins
The roots of the dispute go back to 2003, when an agreement was reached concerning development of a major hydroelectric project in Taraba State.
The original proposal envisaged a 3,050MW hydroelectric plant under a build-operate-transfer arrangement.
The disagreement surrounding the contract eventually developed into an international arbitration battle.
2017 — Arbitration begins
On October 10, 2017, Sunrise Power commenced arbitration proceedings against Nigeria at the ICC International Court of Arbitration.
The company sought approximately $2.354 billion, alleging breach of contract in relation to the Mambilla project.
The legal dispute subsequently became one of the major obstacles to progress on the project.
2020 — Settlement attempt
Nigeria and Sunrise subsequently entered into a settlement agreement in 2020.
However, another dispute emerged over the implementation of that agreement.
Sunrise later sought another $400 million, comprising a $200 million settlement sum and an additional $200 million default payment.
The latest ICC tribunal rejected that claim as well.
2021 — Project capacity reduced
There was another major change to the project itself.
The original 3,050MW proposal was subsequently reduced to approximately 1,525MW, and later rescoped to around 1,500MW, with the stated objective of making the project more financially viable and bankable.
That means Nigerians should be careful when they see old reports describing Mambilla as a 3,050MW project.
The current project being discussed by government is around 1,500MW.
September 17, 2026 — Nigeria wins the arbitration
This is the latest and most significant development.
On September 17, 2026, the ICC tribunal in Paris rejected Sunrise Power’s claims against Nigeria.
The tribunal also ordered Sunrise and Adesanya to reimburse 75 per cent of Nigeria’s $11.82 million legal expenses.
The arbitration costs were fixed at approximately $1.66 million, with Sunrise and Adesanya responsible for 75 per cent and Nigeria 25 per cent.
2026 — What happens next?
This is where Nigerians need to manage their expectations.
Winning the arbitration does not mean construction begins immediately.
The African Union’s PIDA project documentation currently describes Mambilla as a project undergoing structuring and lists 2030 as the expected year for full commercial operation. Another current project database still describes the plant as pre-construction, with 2030 as the planned commissioning year.
The remaining stages include:
- completing the project’s financial arrangements;
- finalising the technical and commercial structure;
- procurement and contracting;
- actual construction;
- construction of the dams and underground power facilities;
- construction of the necessary transmission infrastructure;
- testing and commissioning; and
- connection to the national grid.
The PIDA project documents describe the project as a 3.05GW original design but also note that the design is being reviewed to improve viability. They put the estimated project cost at about $5.8 billion and identify 2030 as the expected full commercial-operation target.
So, what does all this mean for the average Nigerian?
- Nigeria has avoided a potentially huge financial liability
This is the immediate benefit.
The government successfully defended claims that could have exposed the country to billions of dollars.
That means taxpayers are not facing the same potential liability that would have arisen if the claims had succeeded.
- The legal cloud over Mambilla has been substantially lifted
For years, the dispute was one of the major issues surrounding the project.
With the latest ICC ruling, attention can now shift from “What will happen to the arbitration?” to “How quickly can Nigeria get the project financed and built?”
That is a significant change.
- Nigerians should not expect electricity from Mambilla in 2026 or 2027
This is perhaps the most important clarification.
The September 2026 court victory is not the same thing as completion of the power plant.
Current project documentation points to 2030 as the target for commercial operation, while independent project tracking currently categorises Mambilla as pre-construction.
Therefore, Nigerians should see 2030 as the present target, rather than a guaranteed delivery date.
- If completed, Mambilla could substantially increase Nigeria’s electricity supply
The project’s current rescoping is around 1,500MW, while the original design was 3,050MW.
The project’s larger original design was expected to generate billions of kilowatt-hours of electricity annually. The African Union’s PIDA documentation says the full 3,050MW design could generate approximately 5.457 billion kWh annually.
For ordinary Nigerians, additional dependable generation could eventually mean more electricity available to the national grid.
- It could reduce generator dependence
This is where Nigerians could eventually feel the project in their pockets.
If additional Mambilla power is successfully transmitted and distributed, households and businesses could rely less heavily on petrol and diesel generators.
For small businesses such as barbers, restaurants, tailoring shops, welding workshops, salons, frozen-food sellers and other enterprises, reliable electricity could reduce operating costs.
- It could create jobs
Mambilla’s construction would require engineers, technicians, construction workers, transport operators, suppliers and other service providers.
Previous project documentation has estimated the potential for up to 50,000 local jobs during construction. That is a project estimate, not a confirmed employment figure for the eventual construction phase.
- More generation alone will not solve Nigeria’s electricity problem
This is another important reality.
Even if Mambilla generates 1,500MW, Nigeria will still need adequate transmission and distribution infrastructure to deliver that electricity to consumers.
The project therefore has to move successfully through the entire chain:
Mambilla dams → electricity generation → transmission → distribution → homes and businesses.
If any major link fails, Nigerians may not experience the full benefit of the additional generation.
The Mambilla timeline at a glance
Year| Development
2003| Original agreement concerning development of the Mambilla project
2017| Sunrise Power commenced ICC arbitration against Nigeria
2020| Settlement agreement reached, followed by another dispute
2021| Government announced reduction/rescoping of the project’s capacity
2025–2026| Legal proceedings continued while financing and project structuring remained issues
Sept. 17, 2026| ICC tribunal ruled in Nigeria’s favour
2026 onward| Focus shifts to financing, structuring, procurement and construction
2030| Current project documents identify this as the target for full commercial operation
The 2030 target comes from current PIDA project documentation, but the project is still described as being in structuring/pre-construction, so the date should be treated as a target rather than a firm commissioning date.
Concluding Part;
For the average Nigerian, the Mambilla arbitration victory means Nigeria has cleared a major legal hurdle and avoided potentially billions of dollars in claims.
But the real victory Nigerians are waiting for is different.
They want to see turbines turning, electricity entering the national grid, businesses spending less on generators and households enjoying more reliable power.
The next question is therefore no longer simply “Who won the Mambilla case?”
It is:
“Now that Nigeria has won the legal battle, how quickly can the government turn Mambilla from a decades-old promise into actual electricity?”