LONGi strengthens solar supply chain ESG compliance through supplier training

LONGi’s 2025 Sustainability Report highlights the company’s efforts to strengthen ESG standards across its supplier network. Its supplier training programme helps upstream partners meet growing expectations for responsible sourcing in the European solar market.

Solar manufacturers depend on extensive supply chains, and the environmental and social footprint of a finished module is strongly influenced by how its materials are produced. For companies such as LONGi, understanding these upstream processes is essential to assessing supplier performance and providing reliable information about their products.
An audit can establish whether a supplier meets certain requirements at a particular point in time. Maintaining those standards requires functioning management systems and employees who understand their responsibilities. This is the focus of LONGi's Supplier ESG Capacity Building programme.

LONGi expands ESG training across its supplier network

LONGi introduced its 2024–2028 Supplier ESG Capacity Building Plan to help suppliers strengthen their environmental and social management practices. The programme focuses on developing the capabilities suppliers need to meet ESG requirements and demonstrate compliance during independent assessments.

The programme has expanded its reach across LONGi's supply chain. In 2025, suppliers participating in ESG capacity-building activities represented 76% of the company's total material procurement by value, up from 73% in 2024. This reflects growing participation among suppliers that account for a significant share of LONGi's material purchases.

During 2025, LONGi conducted 52 supplier ESG training sessions with 1,798 attendees. The sessions addressed requirements under the Solar Stewardship Initiative (SSI) ESG Standard and helped suppliers improve their internal management systems. All LONGi procurement personnel also completed sustainable procurement training.

LONGi also embeds ESG requirements in its supplier management processes. According to its 2025 Sustainability Report, all 3,298 suppliers had signed the company's Supplier Code of Conduct. ESG due diligence audits covered 90% of procurement by value, with additional on-site assessments of 24 key suppliers. Twelve suppliers in the silicon supply chain underwent third-party ESG audits.

Together, these measures allow LONGi to assess supplier compliance and identify areas where further development is needed.

Supplier certifications show progress in ESG management

LONGi's efforts to strengthen supplier ESG practices are also reflected in the certifications suppliers have obtained. Carbon accounting is one area of progress, as more suppliers are measuring and documenting the emissions associated with their production. In 2025, LONGi supported carbon verification activities across 97 supply chain enterprises. Among them, 23 obtained ISO 14067 certification for product carbon footprints and 20 obtained ISO 14064 certification for greenhouse gas accounting.

More suppliers are also meeting internationally recognised environmental and social standards. In 2025, 88% of LONGi's Tier 1 material suppliers held ISO 14001 certification for environmental management, including all polysilicon suppliers. Another 38 Tier 1 suppliers obtained SA8000 certification, demonstrating their commitment to recognised standards for labour rights and working conditions.

Suppliers are also making improvements directly at their production sites. In 2025, 61 of LONGi's key material suppliers took steps to reduce their environmental impact, for example through their own solar installations or more efficient use of resources.

Better supplier data help LONGi measure and reduce carbon emissions

The progress suppliers are making in carbon accounting has direct implications for LONGi's own emissions reporting. In 2025, Scope 3 accounted for approximately 90.4% of the company's total reported greenhouse gas emissions. A significant share of these indirect emissions originates in the production of purchased materials, making reliable supplier data essential to understanding their impact.

Much of this impact occurs before materials reach LONGi's factories. To calculate emissions more accurately, the company needs reliable information about upstream production. This is where suppliers' carbon accounting capabilities become valuable. Assessments under ISO 14067 help suppliers quantify the carbon footprint of their products and can provide more precise data for LONGi's own lifecycle assessments.

Better information also helps identify opportunities to reduce emissions. LONGi's 2025 Sustainability Report shows that the company has already achieved a 39.2% reduction in Scope 3 emissions intensity per tonne of purchased goods and services compared with 2020. Its target is a 52% reduction by 2030, making continued improvements in upstream production an important part of its sustainability efforts.

European sourcing requirements increase the need for supplier training

European market requirements are making it increasingly important for solar manufacturers to demonstrate responsible sourcing. This places greater responsibility on upstream suppliers, who must be able to document their practices and provide reliable information about the origin of materials.

The Solar Stewardship Initiative (SSI) has introduced new certification targets for manufacturer members. From January 2027, at least 80% of the modules they place on the market in the European Economic Area, the UK and Switzerland must come from sites certified against both the SSI ESG Standard and the SSI Supply Chain Traceability Standard. This share rises to 100% in 2028.

LONGi's Chuzhou manufacturing site received SSI ESG Gold certification in January 2026. However, compliance across the wider supply chain also depends on suppliers understanding the relevant standards and maintaining records that can support independent assessments. LONGi's ESG training programme helps suppliers develop these capabilities.

The EU Forced Labour Regulation, which will apply from 14 December 2027, further increases the importance of reliable supplier information. It prohibits products made with forced labour from being placed or made available on the EU market. Supplier training can help companies understand responsible sourcing expectations and improve the internal processes needed to document their practices.

For LONGi, investing in supplier capabilities and training therefore has practical value beyond individual certifications. It helps strengthen the quality of information available across the supply chain and supports the company's ability to respond to evolving European market requirements.

Stronger supplier capabilities support responsible sourcing

For LONGi, continued investment in supplier training strengthens the ability of upstream partners to meet ESG requirements and provide reliable evidence of their practices. This gives European customers greater transparency into the production of their solar modules and supports responsible sourcing as market expectations evolve.

For more info, visit our ESG pages at LONGi.