The Solar Stewardship Initiative (SSI) collaborates with manufacturers, developers, installers and purchasers across the global solar value chain to foster responsible production, sourcing and material stewardship.
The SSI is the first-ever supply chain sustainability assurance scheme devoted to the solar photovoltaic (PV) sector and the needs of its customers.
The SSI Standards unite international standards and industry, civil society and political expertise. The SSI Secretariat assigns an independent assessor, such as SGS, to evaluate your organization’s compliance with robust sustainability and environmental, social and governance (ESG) criteria.

As an SSI-approved Assessment Body (AB), we can assess SSI members against the SSI Standards, including the ESG Standard to enhance supply chain sustainability, instilling confidence in solar manufacturing practices and setting the bar for the sector’s ESG performance.
Successful completion of an assessment enables you to:
Combining decades of sustainability and supply chain assurance leadership, we can guide you through the entire SSI process, whatever your needs and aims. Our expert auditors will establish and verify information on current transparency levels, ESG performance and other aspects at solar value chain production sites.
Contact us today to discuss your SSI assessment needs.

The Solar Stewardship Initiative (SSI) collaborates with manufacturers, developers, installers and purchasers across the global solar value chain to foster responsible production, sourcing and material stewardship.
The SSI’s mission involves:
The SSI was set in motion by SolarPower Europe and Solar Energy UK in March 2021, as part of a workstream established in 2015 to promote sustainable production in the solar value chain.
Published in October 2023, the SSI ESG Standard was the organization’s first standard. It uses key criteria to enhance supply chain sustainability, instilling confidence in solar manufacturing practices and setting the bar for the sector’s ESG performance.
Independent Assessment Bodies (ABs), like SGS, establish and verify information on current transparency levels and ESG performance at solar value chain production sites.
SSI members from manufacturing sites must complete an ESG assessment of two sites within 12 months by an SSI-approved AB. The assurance process is at site level. A “site” comprises several activities in the same geographic area, under the same management control.
The key principles of the SSI ESG Standard
Governance and business ethics:
Environmental:
Human and labor rights:
The SSI Standards’ assurance process involves a stringent site-level assessment by a compliant, independent Assessment Body (AB), such as SGS, within 8 to 10 months of becoming an SSI member. This encompasses all sites and activities for procuring raw materials and manufacturing polysilicon, ingots, wafers, cells, modules and other components under the participant’s control.
Each site is reassessed every three years. Detailed expectations and timelines are defined in the SSI assurance process.
The assurance process steps:
Solar value chain manufacturers, developers, installers and purchasers are welcome to become SSI members. Other stakeholders are welcome to join the Stakeholder Advisory Group (SAG).
Membership allows your organization to get involved in these sector-defining standards from their inception and helps you prepare for upcoming legislation.
SSI membership signifies your commitment to the SSI Principles. Members are only considered certified after undergoing an independent assessment within 12 months.
You can join here.
As of 2024, over 40 organizations active in the solar industry and/or supply chain responsibility have joined the SSI. View the current members’ list here.
Since its inception, the SSI has secured global financial community endorsement, particularly through the International Finance Corporation (World Bank Group) and the European Investment Bank.