How to Choose the Right Debt for Project Finance

Project finance deals across sectors and scale are typically structured around debt funding, given the capital-intensive nature of the underlying projects. Debt is structured so it is repaid from the project's own cash flow. Because these projects are capital intensive and long-lived, they face different risks that shift across their lifecycle. No single debt instrument absorbs all of this uncertainty, so it falls to the project sponsor to assemble a capital structure that best matches the project's risks, tenor, currency exposure, cost of capital, and repayment timeline.

This article sets out a practical framework for choosing among the main debt instruments available to project sponsors, the decision drivers that should guide the choice, and how to blend instruments into a coherent, resilient capital structure.

Choosing the Right Debt Instrument

Commercial bank debt: Commercial banks lend on a non-recourse or limited-recourse basis, secured against project assets and cash flows, with covenant packages tailored to construction and operating risk. It offers flexibility in structuring, willingness to fund during construction (the riskiest phase), and relationship-based execution. Facilities can be structured in naira, where project revenues are local, to eliminate currency mismatch risk, or in dollars where the project earns foreign currency.

Project bonds: Capital markets debt distributed to institutional investors, such as insurers, pension funds, and asset managers, who are natural buyers of long-duration, stable cash flows. Bonds can reach 10-plus year tenors and often price more competitively than bank debt once a project is operational and de-risked. The trade-off is limited post-issuance flexibility, since amending bond terms requires investor consent, and bond investors are generally reluctant to fund construction risk directly. This is why bonds are often used to refinance a construction loan once the asset is operating.

Export Credit Agency (ECA) and multilateral/DFI financing: ECAs such as Afreximbank provide cover or direct loans tied to the export of equipment or services, often at competitive pricing and long tenors of 15 to 20 years, because sovereign or quasi-sovereign backing lowers the risk. Multilaterals and DFIs, including the AfDB, World Bank, and IFC, offer similar tenor and pricing advantages, plus political risk mitigation and, in some cases, local-currency lending capacity commercial markets cannot match. The trade-off is longer due diligence, ESG requirements, and procurement conditions that can extend time to close by months.

Mezzanine and subordinated debt: Sits between senior debt and equity, taking a higher risk position in exchange for higher pricing, often a blend of cash and paid-in-kind (PIK) coupons, and sometimes equity-like upside through warrants. Mezzanine fills a funding gap when senior lenders cap leverage, or reduces the equity check without diluting sponsor returns as much as pure equity would. It costs more than senior debt but less than equity, and its subordination gives senior lenders comfort, though it adds structural complexity through intercreditor arrangements.

Green, sustainability-linked, and thematic bonds/loans: Relevant for projects with environmental or social credentials, such as renewable energy, water, and low-carbon transport. These instruments can attract a pricing benefit and broaden the investor base to ESG-mandated capital, but require ongoing reporting or KPI verification, adding administrative cost and covenant complexity.

Key Decision Drivers for Debt Selection

Risk profile of the project phase: Construction risk, including cost overruns and technology performance, is best absorbed by commercial banks and DFIs, structured to monitor drawdowns and manage contingencies. Operating-phase risk, once cash flows are stable, is where bond investors are most comfortable, which is why refinancing from bank debt to bonds post-completion is a common move.

Tenor and asset life matching: Match debt tenor as closely as possible to the useful economic life of the asset or the offtake/concession contract, to minimize refinancing risk. A 30-year toll concession financed with 10-year bullet debt creates two or three refinancing events, each exposed to market conditions the sponsor cannot control today. Where long tenor isn't available at close, sponsors should stress-test refinancing assumptions.

Currency of revenues versus currency of debt: Debt should be denominated, wherever possible, in the currency the project earns. Where foreign currency debt is unavoidable, sponsors need a view on hedging costs or should seek ECA/DFI local-currency products built to solve this problem.

All-in cost versus flexibility: Lower nominal pricing isn't always cheaper once fees, hedging, covenant tightness, and refinancing risk are factored in. A DFI loan may carry a lower coupon than a bond but come with more restrictive ESG conditions. Cost should be assessed on an all-in, risk-adjusted basis.

Execution speed and certainty of close: Bank debt and private placements generally close faster than syndicated bonds or multilateral facilities, which involve public documentation and committee approvals. Where a project has a hard close deadline, execution certainty can outweigh a modest pricing advantage elsewhere.

Covenant flexibility and future optionality: Bank facilities are the most negotiable to amend, refinance, or upsize later; public bonds the least. Sponsors expecting to expand or refinance opportunistically should weight this heavily.

Market depth and investor appetite: Some instruments aren't available at scale in every market. Sponsors should assess realistic investor appetite before designing a stack around capital.

Structuring a Blended Debt Stack

Few project finance deals are financed with a single instrument. The more common approach is to layer instruments, so each is matched to the risk and phase it suits best.

By phase: A common structure uses commercial bank debt, often with ECA cover or DFI co-financing, during construction, then refinances into project bonds or a private placement once the asset reaches commercial operations. This approach captures the flexibility of bank debt when it's needed most and the long tenor of capital markets once the project has a track record.

By seniority: Senior debt typically covers 60 to 80 percent of total capital, sized to a conservative DSCR. A mezzanine or subordinated tranche can bridge the gap between what senior lenders will underwrite and what equity is willing to fund, lowering the blended cost of capital while giving senior lenders a subordination cushion.

By currency: Where revenues are mixed, sponsors often blend foreign-currency debt, for equipment financing or ECA-linked tranches, with naira-denominated facilities for local operating costs, sometimes supplemented by partial credit guarantees or currency hedges from DFIs.

By purpose: ECA-covered tranches are sized to the value of the exported equipment or services they're tied to, with the remainder filled by commercial or multilateral debt. Green tranches can be carved out where the project has a genuine environmental profile, without forcing the whole stack into one reporting framework.

Sizing and sequencing: Test the blend against the WACC target, the minimum DSCR each lender class requires, the hedging strategy, and the intercreditor arrangements governing payment priority and enforcement across tranches. More instruments mean more intercreditor complexity, a cost to weigh against the diversification and pricing benefits blending provides.

Decision Checklist & Conclusion

Before finalizing the debt stack, sponsors and their advisors should be able to answer:

• Risk match: Does each tranche bear the risk it is priced and structured for?
• Tenor match: Does the weighted average debt tenor align with asset life, and is refinancing risk stress-tested?
• Currency match: Is debt denominated in the currency of project revenues, or is currency risk explicitly hedged?
• All-in cost: Has cost been assessed on a full, risk-adjusted basis, not headline pricing alone?
• Execution timeline: Does the mix of instruments allow the project to reach financial close on schedule?
• Flexibility: Does the stack preserve enough room to expand, refinance, or distribute later?
• Intercreditor clarity: Are payment priority, cross-default, and enforcement mechanics clearly documented across tranches?
• Market depth: Is investor appetite for each instrument realistic and confirmed?

Constructing an effective project finance debt stack is ultimately an exercise in precision alignment: matching risk to the right lender, tenor to asset life, currency to cash flow, and execution speed to project deadlines. No single instrument is inherently superior. Bank debt, project bonds, ECA facilities, and mezzanine capital are all right answers in the right context and often, the optimal solution combines several. Sponsors who treat capital structure as a deliberate engineering exercise, rather than repeating whatever closed fastest last time, position their assets to survive and thrive over decades of operations.