Lender Acceptance Register India — How Solar Bankability Actually Works

India’s utility-scale solar sector closed ₹1.2 lakh crore in project financing in FY2024-25, according to Mercom India’s Q4 2024 market report. Every rupee of that financing passed through a lender’s engineering acceptance review. Yet most developers and EPC contractors treat “bankability” as a vague quality label rather than a specific, measurable set of engineering requirements that each lender applies differently. That gap in understanding is why projects reach financial close 6–12 months later than planned — and why the right engineering consultant is not a cost item but a transaction enabler.

Direct answer. Bankable solar engineering in India means the engineering package satisfies the technical acceptance criteria of the specific lender financing the project — IREDA, PFC, REC, SBI Green, or an international DFI. The India Bankability Stack presented here maps each major lender’s engineering review scope, PVsyst acceptance criteria, structural requirements, and equipment shortlist management so that developers can prepare the right engineering package for the right lender before financial close negotiations begin.

This article serves utility-scale solar developers pursuing SECI auction wins, captive IPP projects, and open-access solar projects in India. It connects to Heaven Designs’ detailed analysis of lenders’ due diligence on engineering in India and the bankable PVsyst reports guide for the specific simulation methodology required by Indian lenders.

What “Lender Acceptance” Means vs “IE Acceptance”

These two terms are used interchangeably in the market, but they represent different things. Understanding the distinction prevents costly misunderstandings about who is reviewing what and when.

Lender acceptance (also called “lender approval” or “financial close engineering clearance”) is the lender’s internal credit committee confirmation that the engineering package is adequate to support the loan. The lender’s internal technical team — or an external technical advisor appointed by the lender — reviews the engineering documents and issues an internal recommendation. This review may happen before or after an independent engineer is engaged, depending on the lender’s process.

IE acceptance is the independent engineer’s sign-off, issued separately from the lender’s internal review. The IE is a third-party technical consultant appointed by the lender to provide an objective technical opinion. The IE’s report is a key input to the lender’s credit committee decision, but the lender makes the final decision. An IE clearance letter does not guarantee financial close — the lender may still raise conditions precedent based on commercial or legal issues outside the engineering scope.

The practical implication is that developers may need to satisfy two separate technical reviews: first the lender’s LTA during credit appraisal, then the project’s IE during financial close and construction. These two reviews have overlapping but not identical scope, and preparing engineering documents that satisfy both requires understanding what each reviewer prioritizes.

India’s Major Solar Lenders and Their Engineering Context

India’s solar project finance market is anchored by five lender categories. Each operates with different organizational mandates, risk appetites, and engineering review depths.

Lender	Type	Typical deal size	Engineering review depth	Key focus
IREDA	Government DFI	₹50–2,000 Cr	High — dedicated technical wing	PVsyst methodology, ALMM compliance, DNO approval
PFC	Government DFI	₹200–5,000 Cr	High — technical appraisal team	Grid connectivity, ISTS charges, DISCOM off-taker quality
REC Limited	Government DFI	₹100–3,000 Cr	Moderate-high	SECI PPA quality, generation forecast, O&M plan
SBI Green	Commercial bank	₹100–1,000 Cr	Moderate (external LTA)	DNO approval, module/inverter shortlist, Tier-1 verification
International DFIs (ADB, AIIB, IFC)	Multilateral	$20M–$500M	High — full IE review	IFC PS compliance, P50/P90, PE-certified structural

The India Bankability Stack

The India Bankability Stack maps the engineering acceptance criteria of each major lender category, from the most accessible to the most demanding. Apply this framework before issuing your engineering brief.

PVsyst Acceptance Criteria by Indian Lender

The PVsyst energy yield report is the single most reviewed engineering document in Indian solar project finance. Every major lender reviews it. But each lender applies different acceptance criteria — and a PVsyst report calibrated for IREDA review may not pass an international DFI IE review without significant revision.

The lender-specific PVsyst acceptance criteria differ on these five dimensions:

1. Meteorological data source: IREDA and PFC accept Meteonorm 8, Solargis, and NASA POWER (cross-validated). International DFIs require Solargis or NSRDB, with NASA POWER as a secondary cross-validation source only. For sites in Gujarat and Rajasthan — where India’s largest solar parks are located — Meteonorm is generally accepted by all Indian lenders because the ground station coverage in these states is better than elsewhere.

2. Degradation rate: IREDA and PFC typically accept the module manufacturer’s declared degradation rate (0.45–0.55%/year for Tier-1 bifacial modules). International DFIs require the degradation assumption to be benchmarked against NREL’s published degradation rate database or a peer-reviewed study. A degradation assumption above 0.6%/year without peer-reviewed justification will trigger an IE query.

3. Soiling loss: Indian lenders generally accept soiling losses of 1.5–3% for Rajasthan and Gujarat, 2–4% for peninsular India, and 3–5% for dusty industrial locations, provided the loss is justified by reference to a soiling study or operational data from a nearby project. IREDA requires soiling justification for projects in high-soiling areas (industrial zones, near agricultural fields with dust-raising harvesting operations).

4. Horizon file: IREDA now requires a topographic horizon file for projects in hilly terrain — particularly Karnataka, Tamil Nadu, and the Himalayan foothills states. A flat horizon file for a project in Karnataka’s Western Ghats boundary will trigger an IREDA technical query.

5. PR calculation: IREDA and PFC review the Performance Ratio (PR) assumption against the PVsyst loss tree. A PR above 81% for a fixed-tilt project in a high-temperature zone (Rajasthan, Gujarat) without justification for the low temperature loss assumption will be queried. For tracker projects, a PR above 83% requires explicit justification of the backtracking gain assumption.

Structural Acceptance by Indian Lenders

Structural engineering acceptance for Indian solar lenders has become more rigorous after several high-profile racking failures during cyclone events in Tamil Nadu and Andhra Pradesh in 2022–2023. CEA’s Solar Power Plant Handbook 2023 now explicitly references IS 875 Part 3 wind load calculations as a requirement for grid-connected solar installations.

The current structural acceptance criteria for major Indian lenders:

• IREDA: Requires structural calculations per IS 875 Part 3 (Wind Loads on Buildings and Structures). For projects in cyclone-prone zones (Zone V in coastal Andhra, Tamil Nadu, Odisha, West Bengal), the design wind speed must use the MNRE-notified enhanced wind speed values, not just the IS 875 zonal basic wind speed. Pile pull-out test reports are required for ground-mount projects using driven piles.
• PFC: Follows IREDA’s structural requirements for new-build projects. For retrofit storage or capacity expansion projects at existing plants, PFC accepts the original structural certification plus a structural adequacy certificate from the original designer.
• SBI Green (via LTA): The LTA typically spot-checks structural calculations rather than conducting a full review. The LTA will flag projects in high-wind zones without IS 875 Part 3 compliance evidence and require the developer to provide certified calculations.
• International DFIs: Require full STAAD Pro or SAP2000 structural analysis with PE certification. For cyclone-prone coastal sites, they additionally require a site-specific wind study (not just IS 875 basic wind speed) and pile testing per IS 2911.

See also Heaven Designs’ dedicated article on solar wind load design for India for IS 875 Part 3 application guidance.

Equipment Shortlist Management and ALMM Compliance

The Approved List of Models and Manufacturers (ALMM) maintained by MNRE is the single most important equipment compliance requirement for Indian lenders. ALMM covers solar modules (Part I) and solar PV inverters (Part II). Products not on the ALMM list cannot be used in grid-connected solar projects in India as of the April 2024 MNRE notification.

Lender-specific equipment shortlist management:

• IREDA: Maintains an internal Approved Vendor List (AVL) that is more restrictive than ALMM. IREDA’s AVL includes only Tier-1 module manufacturers (by BNEF definition) and inverter manufacturers with a minimum 5-year operational track record in India. Modules from Chinese manufacturers not on Tier-1 lists — even if ALMM-listed — may trigger an IREDA technical query.
• PFC: Accepts ALMM-listed equipment without additional AVL restriction, but requires the module manufacturer to have a minimum 1 GW installed base in India. This requirement effectively limits module choices to the top 10–12 Chinese and 3–4 Indian manufacturers.
• SBI Green (via LTA): The LTA verifies ALMM compliance and Tier-1 status. For SBI deals, the developer should provide a formal equipment acceptance confirmation from the LTA before finalizing the procurement order — LTA comments on equipment after procurement orders are placed create expensive re-specification challenges.

How Lender-of-Record Differs from Construction Lender

A common point of confusion in Indian solar project finance is the distinction between the lender-of-record (the institution that holds the loan on its books) and the construction lender (the institution that provides the drawdown credit facility during the construction phase).

In large Indian utility-scale projects, it is common for multiple lenders to participate in the financing. For example: IREDA provides 40% of project debt, PFC provides 40%, and SBI Green provides 20%. IREDA is typically the “lender-of-record” or “lead lender” who coordinates the IE appointment and the engineering review process. PFC and SBI review the same engineering documents but may add their own conditions precedent based on their individual credit policies.

The practical implication for engineering is that a project with three lenders in the consortium may receive three sets of technical queries, each reflecting the reviewing institution’s priorities. The developer needs to prepare a single engineering response that satisfies all three reviewers — which requires understanding each lender’s specific focus areas, as mapped in the India Bankability Stack above.

For a deep understanding of what the independent engineer covers in Indian solar projects, see our dedicated guide on independent engineer solar DPR checklist.

How Heaven Designs Maintains Lender Acceptance Status

Heaven Designs has delivered bankable engineering packages for projects financed by IREDA, PFC, REC, SBI Green, ADB, and IFC. Our lender acceptance status is maintained through active monitoring of IREDA’s ALMM database, PFC’s technical appraisal criteria updates, and IFC’s IE framework revisions.

• Solar Ground Mount Design — bankable PVsyst, ALMM-compliant equipment schedule, IS 875 Part 3 structural, and full SLD package for IREDA and PFC-financed projects.
• Solar Rooftop Detailed Engineering Design — for C&I rooftop projects seeking SBI Green or REC financing, complete IFC-grade engineering package including structural assessment and BOQ.
• MW-Scale PMC — owner’s engineer services for projects with multiple lenders in the consortium, including IE liaison, query response management, and construction drawdown documentation.
• Download a sample IREDA-accepted PVsyst report — see the format and content that cleared IREDA’s technical review.

For a bankability assessment of your project’s current engineering status and a proposal for bringing it to lender-acceptance standard, contact us.

FAQ

What is IREDA’s primary engineering requirement for a solar project loan?

IREDA’s lending policy for solar projects requires: (1) a PVsyst energy yield report with P50 generation estimate and inter-annual variability analysis using ALMM-compliant module specifications, (2) a grid connectivity study approved by the relevant SLDC or RLDC, (3) land availability and title documentation, (4) structural calculations per IS 875 Part 3 for ground-mount projects, and (5) DNO (distribution/transmission network operator) approval for the grid connection scheme. Projects in cyclone-prone zones additionally require enhanced wind speed compliance per MNRE’s 2021 advisory.

How does the ALMM list affect project engineering and financing?

The Approved List of Models and Manufacturers (ALMM) maintained by MNRE is a mandatory compliance requirement for grid-connected solar projects in India. All modules and inverters used in projects eligible for IREDA, PFC, or REC financing must be on the ALMM list at the time of procurement. The engineering implication is that PVsyst reports must use ALMM-listed module specifications, and equipment BOQs must reference ALMM model numbers. Projects that specify non-ALMM equipment in their engineering package will not receive loan sanction from government lenders. Verify ALMM status at the time of both engineering submission and procurement order placement.

What is the difference between Tier-1 modules and ALMM-listed modules?

Tier-1 is a commercial designation assigned by Bloomberg NEF (BNEF) to module manufacturers who have successfully delivered project finance-backed projects and have strong balance sheets. It is a creditworthiness indicator, not a quality certification. ALMM is an Indian government compliance list based on BIS testing requirements. A module can be Tier-1 but not ALMM-listed (if the manufacturer has not registered with MNRE), or ALMM-listed but not Tier-1 (if it is a smaller manufacturer that meets BIS standards but lacks a large project finance track record). IREDA requires both Tier-1 status and ALMM listing for modules used in financed projects.

How long does an IREDA technical review take?

IREDA’s technical review typically takes 8–12 weeks from complete document submission to the technical wing’s recommendation to the credit committee. Incomplete submissions — missing ALMM verification, unsigned structural calculations, or a PVsyst report without the standard annexures — restart the review clock. Projects with all documentation complete at submission have achieved technical clearance in as little as 6 weeks. Projects requiring re-submission after technical queries average 16–20 weeks total review time.

Can a project use bifacial modules for IREDA financing, and how does this affect the PVsyst simulation?

Yes. IREDA accepts bifacial module specifications provided the bifacial gain assumption in the PVsyst simulation is documented and justified. The bifacial gain in PVsyst 7.4 is calculated using the ground albedo value, the module bifaciality factor (from the manufacturer data sheet), and the installation height above ground. IREDA’s technical reviewers have been increasingly querying bifacial gain assumptions above 5% without site-specific albedo measurement. For projects in sandy Rajasthan desert sites (high albedo), bifacial gains of 6–9% are defensible. For projects in darker soil or vegetated sites, gains above 4% require additional justification.

What does “open access solar” mean for project financing?

Open access solar refers to projects where the generated electricity is consumed by a captive consumer (industrial or commercial) via the grid, using the transmission and distribution network under an open access regulatory framework. Open access projects are not backed by SECI or DISCOM PPAs — the off-taker is a corporate or industrial consumer under a direct bilateral agreement. IREDA and SBI Green both finance open access projects, but the lending terms differ from SECI-backed projects: the off-taker credit risk replaces the DISCOM credit risk, and lenders require additional documentation on the corporate off-taker’s creditworthiness, power purchase agreement terms, and payment security mechanisms. Engineering requirements are the same as for other utility-scale projects, but the feasibility study must demonstrate that the open access tariff scenario is viable under the relevant state regulations.

What happens if the independent engineer rejects the PVsyst report?

A PVsyst report rejection by the IE is classified as a major objection — a condition that prevents the IE from issuing a clearance letter until resolved. The developer must engage the original PVsyst simulation author to revise the report per the IE’s specific objections, then re-submit. Common rejection reasons: meteo data source not accepted (switch from Meteonorm to Solargis required), P90 uncertainty cascade missing or incomplete, ALMM module model not found in ALMM database, and degradation assumption unsupported. Each revision cycle takes 4–6 weeks. See Heaven Designs’ bankable PVsyst reports guide for the standard report format that clears IREDA and IFC IE review.

How does Heaven Designs handle multi-lender engineering packages?

When a project has multiple lenders in the financing consortium — for example, IREDA as lead lender with SBI Green as co-lender — Heaven Designs prepares a single engineering package that meets the most demanding lender’s requirements (typically IREDA) while flagging the specific documentation that each co-lender’s LTA or IE will focus on. We maintain a living document register that tracks each lender’s engineering conditions precedent and maps them to specific deliverables. This approach has reduced the average time from engineering completion to multi-lender financial close by 6–8 weeks on projects where we serve as the engineering lead.