Green Power Purchasing Frequently Asked Questions (FAQ)

Who We Are

The Carbon Offset Guide is a product of the Stockholm Environment Institute (SEI) and Greenhouse Gas Management Institute (GHGMI). This initiative launched in 2011 to promote crediting programs and environmental attribute policies to maximize their potential benefits while minimizing their potential risks.

Since the initiative’s founding, the team has conducted cutting-edge research to inform policy makers and the general public about both voluntary and regulatory crediting programs as well as environmental attributes.

In 2019 The Offset Guide (First Edition) was created to update and build upon the CORE content. The Offset Guide was updated to its Second Edition in 2025.

SEI is an independent, international non-profit research institute bridging science and policy for sustainable development. SEI’s work spans climate, water, air and land-use issues, governance, the economy, gender, and health. Through stakeholder involvement, SEI aims to build capacity, strengthen institutions, and equip partners for long-term change.

SEI promotes debate and shares knowledge by convening decision-makers, academics, and practitioners while engaging with policy processes, development actions, and business practices worldwide.

GHGMI is an international non-profit organization providing expertise, training material, and courses to support a global community of experts with the highest standards of professional practice in measuring, accounting, auditing, and managing greenhouse gas emissions; meeting the needs of governments, corporations, and organizations large and small.

GHGMI’s work involves educating on the basics of GHG accounting, auditing and management, training professionals to meet the highest standards of expertise and ethics, and conducting forward-looking research into critical GHG measurement, reporting, and verification issues.

Acknowledgements

Thank you also to our many expert reviewers who helped to improve this guide. In particular, we thank Claire Carver, Craig Ebert and Max DuBuisson, Barbara Haya, Anja Kollmus, Benjamin C Pierce, Lambert Schneider, Jerry Seager, Mark Trexler, and Ruby Woodside.

Significant thanks are also in order for our volunteer translators who have facilitated the guides availability in Mandarin and Spanish.