What "Tier 1 Solar Module Maker" Means — and What It Does Not

Short answer. This guide explains one specific, published definition of "Tier 1": the BloombergNEF (BNEF) Tier 1 PV Module Makers list. Other uses of the term are not covered here. The BNEF list is a bankability list: it shows which module brands have recently been used in projects that closed non-recourse bank financing. BNEF itself says the list is not a measure of module quality and should never replace proper due diligence.

This guide explains the criteria as written in BNEF's public methodology dated 4 September 2026, what a Tier 1 label can and cannot tell a buyer, and how to check a supplier's claim.

Key terms

• Bankability — in the BNEF methodology, whether projects using a product have been offered non-recourse debt financing by banks.
• Non-recourse financing — as defined in the BNEF methodology (Section 4.2): financing where the bank has agreed to take the risk of the modules failing and will not be repaid from the developer's or equity holder's balance sheet if the project does not service the debt.
• Own-brand, own-manufacture — the module maker owns the production facilities and sells under its own brand.

The criteria, in plain English

According to the methodology, a manufacturer is Tier 1 when it has supplied own-brand, own-manufactured modules to at least six different projects, financed non-recourse by six different commercial banks — not development banks and not export-import banks — in the past two years.

Further conditions:

Table note: all rows come from BNEF, Tier 1 Solar Module Methodology, 4 September 2026.

What Tier 1 does not tell you

BNEF states that Tier 1 is "purely a measure of industry acceptance" and does not directly account for product quality or the manufacturer's financial strength, adding that there are many documented cases of quality issues or bankruptcy among Tier 1 manufacturers. The list also does not consider product quality information or environmental, social and governance (ESG) criteria.

So a Tier 1 label does not establish:

• that a specific module model, factory or production batch performs as specified;
• that the manufacturer is financially strong;
• anything about ESG or supply-chain compliance.

There is also no official "Tier 2" or "Tier 3": BNEF maintains a Tier 1 list only. If a supplier describes itself as "Tier 2", that label does not come from BNEF.

Tier 1 versus certification

Tier 1 is often confused with product certification. They answer different questions:

BNEF recommends that module buyers and banks consult a technical due-diligence firm instead of using the list as a quality measure; such firms typically look at the factory, the bill of materials and may run accelerated degradation tests on samples.

How to check a "Tier 1" claim from a supplier

BNEF says only the latest quarter's list is valid, a company can be removed in any quarter, and press releases or company claims are not evidence that a firm meets the criteria. Only BNEF clients can access the list, and copies circulating online may breach licence terms or be altered. BNEF badges are issued only to listed firms that are BNEF clients and are timestamped by quarter.

A practical checklist (CNWattHub editorial method):

1. Which quarter? Ask for the quarter of the listing. A claim without a quarter is not checkable.
2. Which entity? First identify the company by the corporate name under which BNEF lists it: BNEF's methodology says the corporate name takes precedence over branding, and the brand is added only where space allows. Then verify, separately and with documents, how that company relates to (a) the brand on your quote, (b) the legal entity that will sign the contract and (c) the manufacturer and factory that will produce your order. These can legitimately be different companies in one group; do not expect the brand to match every entity, but do expect evidence for each relationship (editorial method). The list covers manufacturers that own production facilities and sell under their own brands.
3. Who verified it? If you do not subscribe to BNEF, ask your lender or technical adviser to confirm status from the current list rather than relying on a screenshot or press release.
4. Separate quality evidence. Request model-level certificates and independent test or factory-audit reports. Tier 1 status does not substitute for them.