Renewable Energy Certificates 101

Renewable Energy Certificates (typically refered to as “RECs.” and also known as “green tags” and “tradable renewable certificates”) are at the heart of sales of renewable electricity. For more detail on what they are and how they work, please see the resources below.


REC Questions and Answers

For our official definition of a renewable energy certificate, see the listing in the Green-e Glossary.

See our short animated video, “What is a Renewable Energy Certificate?” released January 2015.



  • Solar Energy on Campus, a four-part series of fact sheets describing renewable energy certificates (RECs), why they are important, and what kinds of statements can be made depending on who owns them (Part I). Also solar purchasing options available to higher education institutions and communicating renewable energy use (Part II), best practices for developers marketing renewable energy products to customers (Part III), and community solar options (Part IV). (2016)
  • How Renewable Energy Certificates Make a Difference, A fact sheet explaining the impacts and benefits of buying renewable energy through renewable energy certificates (RECs). (March 2016)
  • The Legal Basis for Renewable Energy Certificates, a summary of different selected sources on the definition and function of RECs in the U.S. (June 2015)
  • Guidelines for Renewable Energy Claims: Guidance for Consumers and Electricity Providers, A description of how ownership of renewable energy attributes remains with the renewable energy certificate, and examples of claims issues between hosts, utilities, and owners. (February 2015)
  • REC Best Practices and Claims, an illustration of how renewable energy certificates (RECs) work to track ownership, best practices for using and claiming RECs, and a series of example claims for solar panel owners or leaseholders. (October 2014)
  • REC Questions and Answers, a primer on RECs, including the definition of a REC, how the REC system began, how RECs are created, tracked and verified, and how pricing works (October 2009)


101 Slideshows

Each year, CRS hosts the Renewable Energy Markets conference. As part of a pre-conference 101 session, renewable energy market participants hold a Renewable Energy 101 session. See the latest conference’s agenda on the website for the most recent set of presentations from this session. Presentations cover the basic terminology of renewables, data and growth trends, market oversight and market operation.


Other Learning Opportunities

CRS and Green-e Energy staff speak at a variety of events, discussing many aspects of RECs and the renewable energy market. See the CRS events page for details on upcoming webinars, educational sessions, conferences and presentations.