Getting Your SAF Project Financed: A Bankability Guide for Engineering Directors and Plant Owners

What lenders, equity investors, and airlines actually require from a sustainable aviation fuel project before committing capital in 2026 - and what engineering can do to de-risk the conversation.

Key Takeaway

A SAF project that cannot be financed will not be built. The engineering deliverables produced in pre-FEED and FEED are not just technical documents. They are the foundation of the bankability case. Lenders want an AACE Class 3 cost estimate, a technology guarantee from the licensor, a committed feedstock supply, and a creditworthy offtake structure. Engineering directors who understand what lenders need from the very start of pre-FEED build projects that close faster and cheaper.

Why SAF Project bankability starts at Pre-FEED, not at Financial close

Many plant owners treat project financing as a commercial task that happens after engineering is complete. That is a costly mistake. The decisions made in pre-FEED, including technology licensor selection, feedstock strategy, plant scale, and utility integration approach, directly determine whether a project is financeable. Getting these decisions right at the pre-FEED stage saves months of remediation later and avoids the risk of spending 10 to 20 million US dollars on a FEED that lenders cannot accept.

Engineering directors who have navigated project finance know that lenders do not just read the cost estimate. They read the assumptions behind it, question the technology risk, and stress test the feedstock and offtake economics. Every aspect of the FEED package is scrutinized.

5-15%	Typical CAPEX saving achieved when pathway and licensor selection is right at pre-FEED, versus late-stage scope changes after FEED is complete.
AACE CLASS 3	Cost estimate class most project finance lenders require for final investment decision. Class 5 and 4 are sufficient for pre-FEED and early FEED stages.
70%	Minimum feedstock supply contract coverage (as a share of plant capacity) that most lenders require for first five years. Source: industry lender guidance

The Five Bankability Pillars for SAF projects.

Pillar 1: Feedstock security

No lender will advance funds for a SAF plant without a documented feedstock supply strategy. For HEFA, this means traceable UCO or animal fat supply contracts. For ATJ, ethanol purchase agreements. For Fischer-Tropsch, biomass aggregation contracts or waste processing agreements including tipping fee arrangements. For PtL, power purchase agreements with defined pricing and term.

The minimum threshold most project finance banks apply is a contracted supply covering 70 percent of plant nameplate capacity for the first five years of operation. Offtake from a counterparty with an investment grade credit rating carries significantly more weight than a contract with a smaller or unrated supplier.

Pillar 2: AACE Class 3 cost estimate

The AACE International cost estimate classification system defines five levels of estimate accuracy. Class 5 has accuracy of minus 50 to plus 100 percent, used in very early screening. Class 1 is the final contractor cost estimate with accuracy of minus 3 to plus 10 percent.

AACE	Accuracy range	Project Phase	What it covers
Class 5	-50% to +100%	Concept screening	Order of magnitude from published data and analogies
Class 4	-30% to +50%	Pre-FEED	Preliminary equipment list, flow diagrams, factored estimate
Class 3	-20% to +30%	Early FEED	Detailed equipment list, sized major items, vendor quotes for long leads
Class 2	-15% to +20%	Late FEED / AFD	Definitive estimate with vendor quotes for most equipment
Class 1	-3% to +10%	EPC bidding	Full contractor cost basis

Most project finance lenders for SAF require a Class 3 estimate or better at the time of final investment decision. Class 3 requires a detailed equipment list with preliminary sizing, vendor enquiries for long lead items such as gasifiers, Fischer-Tropsch reactors, and electrolyzers, and a process basis developed to at least 30 percent engineering completion.

 

Pillar 3: Technology licensor guarantee

For ATJ, Fischer-Tropsch, and PtL plants, lenders require a process performance guarantee from the technology licensor. This guarantee typically covers production yield, energy consumption, and product quality for a defined feedstock specification. It shifts technology risk from the project company to the licensor, which is essential for lender comfort.

For HEFA plants based on proven refinery hydrotreating technology, the guarantee structure is less formal, but equipment vendor warranties and a detailed design basis with operating data from analogous plants serve a similar function.

Pillar 4: Creditworthy offtake

SAF plants need long term offtake agreements to service project finance debt. The strongest offtake structure is a fixed price or price-indexed contract with a major airline or fuel aggregator for at least 10 years, covering 70 to 100 percent of plant SAF output. Airlines such as United, American, Delta, and Southwest have all signed multi-year SAF supply agreements in 2024 and 2025.

For projects in mandated markets such as the EU, SAF mandate compliance obligations create a floor demand that is treaty-level durable and easier to model in a project finance structure. For US projects, airline voluntary commitments and corporate travel buyer demand through book-and-claim add to the demand stack alongside 45Z credit eligibility.

Pillar 5: Policy credit eligibility

Incentive	Market	Value	Eligibility criteria
US 45Z Clean Fuel Production Credit	United States	Up to 1.75 USD per gallon SAF (varies by CI score)	Lifecycle CI below 50 gCO2e per MJ; plant must be in the US
UK RTFO Certificates	United Kingdom	Variable market price; currently 0.30 to 0.60 GBP per litre	SAF meeting ASTM D7566 and 70% GHG reduction threshold
EU ReFuelEU Aviation	European Union	Indirect: creates mandatory demand rather than direct subsidy	ASTM D7566 certified SAF used at EU airports
ICAO CORSIA	Global	Offsets value; estimated at 5 to 20 USD per tonne CO2 equivalent	SAF meeting CORSIA sustainability criteria

A common mistake engineering directors make is building project economics that only work if every credit is received at the maximum value. Lenders require sensitivity analysis showing the project remains viable at 50 percent credit value and with feedstock cost 20 percent above base case.

What a Bankable FEED package looks like

A bankable FEED package for a SAF project contains more than just engineering deliverables. It is a document suite that allows an independent engineer, working on behalf of the lender, to verify the technical basis of the project. A complete bankable FEED package typically includes the following.

• Process design basis: Full description of the feedstock specification, process technology basis, operating conditions, and product specification.

• Heat and material balance: Complete steady-state simulation results for all operating cases including design, turndown, and startup.

• Piping and instrumentation diagrams (P&IDs): Issued for design or issued for approval; minimum 60 percent complete for most project finance purposes.

• Equipment list and datasheets: All major and minor equipment with preliminary sizing and vendor enquiry status documented.

• AACE Class 3 cost estimate: Full estimate with basis of estimate document, contingency analysis, and exclusions list.

• Project schedule: Level 3 schedule from FEED completion through mechanical completion and startup.

• Licensor documentation: Process guarantee, basic engineering package, and any licensor warranties.

• Independent engineer report: Third party technical review commissioned by the lender covering technology risk, construction risk, and operating risk.

Common Bankability mistakes in SAF Pre-FEED

• Selecting a technology licensor based on cost rather than lender credibility. A licensor with no commercial references, even at a lower license fee, adds technology risk that lenders price heavily.

• Developing a Class 5 estimate and presenting it as Class 4 by changing the label. Lenders will identify this in independent engineer review and it damages credibility.

• Signing a feedstock MOU instead of a binding supply agreement. MOUs do not satisfy the supply security requirement for project finance.

• Underestimating working capital and contingency. SAF FEED packages that show tight contingencies are viewed as optimistic and trigger lender adjustments upward.

• Not engaging the independent engineer early. Waiting until after FEED to invite the independent engineer creates late-stage rework. The best projects engage the IE during FEED, not after.

Frequently Asked Questions

How long does SAF project financing typically take?

From the start of FEED to financial close typically takes 18 to 36 months for a SAF project, depending on project size and complexity. This includes FEED completion of 10 to 14 months, independent engineer review of 3 to 6 months, legal documentation of 6 to 12 months, and syndication if required. Starting the lender relationship early in FEED compresses this timeline.

What is an independent engineer in project finance?

An independent engineer, sometimes called a lenders engineer or technical advisor, is a third party firm appointed by the project finance lenders to review the technical basis of the project, assess construction risk, and monitor progress through construction and commissioning. IE selection is typically led by the lead arranger bank.

Do SAF projects need project finance or can they use corporate balance sheet?

Both structures work. Corporate balance sheet financing is faster and simpler but requires the project sponsor to have sufficient credit capacity. Project finance allows higher leverage and ring-fences project risk from the corporate balance sheet, which is why it is common for first-of-a-kind or large scale SAF plants where the sponsor does not want to take full balance sheet exposure.

What CAPEX level triggers a requirement for project finance versus balance sheet?

There is no absolute threshold, but most sponsors start evaluating project finance structures for SAF projects above 200 to 300 million US dollars of total CAPEX. Below that threshold, corporate debt or equity is typically faster and cheaper.

About Author:

Ragavan Vaidyanathan is a Chemical Engineer (Ph.D., Auburn University) with 25+ years leading capital projects up to $3B TIC across Power, Petrochemical, Refining, and Renewable Fuels. Former Sr. Director of Process Engineering at Jacobs/Worley, he now leads RVN Inc., delivering high-value engineering solutions from Houston, TX.

About RVN:

RVN Inc. is a Houston-based engineering firm specializing in pre-FEED, FEED, detailed engineering, and AACE Class 3 cost estimation for capital projects across the Power, Petrochemical, Polymer, Refining, and Renewable Fuels industries. With a global network of high-value engineering centers, RVN delivers rigorous technical execution — from process design through commissioning — for clients navigating complex, large-scale energy transitions including Sustainable Aviation Fuel.

📩 To learn more or discuss your SAF project, contact us at admin@rvninc.com

Sources

• IATA. SAF Handbook. May 2024. iata.org

• IATA. Finance Net Zero CO2 Emissions Roadmap. September 2024. iata.org finance roadmap

• S&P Global. Global SAF supply to slow in 2026 on high costs. December 2025. spglobal.com

• ResourceWise. 2026 SAF Market Outlook. January 2026. resourcewise.com

• OIES. Drop In Decarbonization: Techno-Economic Benchmark for SAF and Renewable Diesel. December 2025.

• White and Case LLP. Sustainability Trends in Aviation in 2026. April 2026. whitecase.com

• AACE International. Cost Estimate Classification System. aace.org