Tier 1 gives buyers evidence of recent acceptance in bank-financed projects, not a module quality rating. Non-Tier 1 means the manufacturer is not on BNEF’s current list; it does not establish poor quality. For either group, compare the exact module, test evidence, warranty costs and service arrangements before choosing.
What Tier 1 Measures
BloombergNEF bases its solar module classification on completed financing deals. Its September 2026 methodology requires own-brand, own-manufacture modules supplied to at least six qualifying projects financed without recourse by six different commercial banks during the previous two years. Development and export-import banks do not count. The list is reviewed quarterly, and BNEF publishes no Tier 2 or Tier 3 list.[1]
For individual project financings, the capacity threshold is over 10MW. Defined project portfolios can also qualify under separate rules, including at least 10MW supplied by the manufacturer across the portfolio and debt secured across its assets. Small installations are therefore not automatically excluded when financed as a qualifying portfolio. The threshold is not a minimum order size for buyers.
| Buying question | Tier 1 manufacturer | Non-Tier 1 manufacturer |
|---|---|---|
| What evidence does the label provide? | The manufacturer meets BNEF’s current financing-based criteria. | Its current inclusion is not established. The reason needs to be checked. |
| Are its modules more efficient or reliable? | The classification does not establish either. | Absence from the list does not establish lower performance. |
| Will a lender accept the product? | The lender still reviews the proposed supplier, module and project. | Ask whether the lender will consider it and which supporting documents are required. |
| Is a long warranty secure? | Check the responsible legal entity, financial position and claim terms. | Carry out the same checks. |
When the Classification Matters
If a tender names the BNEF Tier 1 list, confirm the required quarter and manufacturer name before ordering. A supplier’s announcement from last year cannot establish current status. Ask for a current BNEF record or verification through an authorized subscriber, rather than relying on a cropped marketing screenshot.
For financed projects, send the lender the manufacturer name, module code and proposed factory early in the process. Obtain written acceptance or a list of outstanding checks before paying a non-refundable deposit. Tier 1 does not guarantee approval, a lower interest rate or a shorter review period.
A manufacturer may not be on the list because it lacks enough qualifying financing records, focuses on a specialist market or uses a production model outside BNEF’s criteria. Financial distress is another possibility, but it should not be assumed. If a company has dropped off the list, check its disclosures and ask why.
Check the Module Behind the Brand
Certification and Test Coverage
Match the quoted module code to the certificate’s covered models, manufacturer and production locations. IEC 61215 addresses design qualification and type approval for outdoor operation. It does not turn a laboratory result into a guaranteed service life.[2] IEC 61730 addresses module safety, including electrical shock, fire and mechanical hazards; local requirements still apply.[3]
For extended reliability tests, request the report date, test sequence, sample count, power loss and covered bill of materials (BOM). Compare results from equivalent test conditions. A result for one glass, cell or encapsulant combination should not be applied to another without documented coverage.
A Published Specification Check
Tongwei’s residential module specifications provide a useful worked example. The page lists a TNC-G12R 48 Bifacial option at 455W, with dimensions of 1,762 × 1,134 × 30mm, a weight of 22.4kg and a maximum-power current of 14.95A at standard test conditions.
Using those published figures, 22 modules total 10.01kW and 492.8kg. Their combined face area is about 44m², before spacing, access routes and roof setbacks. The weight excludes rails, fixings and any ballast. These calculations help check a quote; they are not a roof design or a forecast of annual generation.
The current rating also gives the designer something specific to check against the inverter’s input limits. String voltage, low-temperature open-circuit voltage, short-circuit current, connectors and mounting positions need separate checks. A small difference in module size or voltage alone does not establish compatibility.
Confirm the exact version against the quotation and the applicable module datasheet. A public product page does not establish that a particular shipment has been certified, inspected or supplied to the same specification.
Warranty Costs and Responsibility
Read the product warranty separately from the power warranty. Check the remedy, evidence required for a claim, exclusions, and responsibility for testing, removal, transport and reinstallation. Record the name of the company that owes the warranty—not just the distributor taking the order. Tongwei lists its warranty documents separately from product specifications.
Warranty calculation example: assume a contract allows a 1% first-year reduction and 0.4 percentage points per year for the next 24 years. Its year-25 minimum is 99% − (24 × 0.4%) = 89.4% of initial rated power. This is an illustrative contract floor, not measured degradation or an annual energy forecast.
If warranty insurance is offered, check the insurer, beneficiary, term, exclusions and what happens if the manufacturer fails. Insurance is not included in every warranty. For service, ask who handles the claim locally, what response time is written into the agreement and how discontinued models are replaced.
Compare Quotes on Equal Terms
There is no fixed Tier 1 price premium. Compare the same capacity, delivery terms, taxes, mounting scope and warranty services. For an illustrative 10,000W order, a module price difference of US$0.02/W equals US$200. It does not establish a saving on the inverter, the installation or the whole system.
Price replacement work separately. Ask for module supply, transport, roof access, removal, electrical testing and reinstallation costs. Do not assume that five failed modules require replacing an entire string, or that a cheaper brand will fail while a more expensive one will not.
Documents to Request Before Ordering
- Supplier identity: manufacturer, factory, seller and warranty provider, with their roles stated in the order.
- Product evidence: exact module code, datasheet revision, applicable certificates and relevant reliability reports.
- Project acceptance: lender or tender approval where required, plus the designer’s electrical and structural checks.
- Claim procedure: covered costs, exclusions, contact details and a replacement plan for discontinued modules.
- Delivery records: serial numbers, labels, invoices and agreed inspection results. For Tongwei modules, the module authenticity query can form part of the identity check; it does not replace condition inspection.
If a supplier leaves the Tier 1 list after installation, that alone does not mean the modules need replacing. Review the reason, any lender or insurance obligations, and the actual system condition. Leave electrical inspection and replacement to qualified personnel: solar work carries electric-shock and arc-flash hazards.[4]
Check the Tongwei module documents for your project
Include your destination market, project capacity, proposed module code and any lender or tender requirements in your inquiry. Ask Tongwei’s module team which datasheet, certificate coverage and warranty terms apply to the proposed supply.
Send a module document inquiryEvidence note: This guide uses BNEF’s September 4, 2026 methodology, IEC’s public standard descriptions, OSHA guidance and published Tongwei product information. The specification check is a desk review, not a factory audit, installation case study or independent product test. Calculations are labeled as examples. No current manufacturer listing or product endorsement is asserted.