The following timeline provides an overview of different milestones that contributed to the emergence of the U.S. voluntary green power market.

• 1978 - Public Utility Regulatory Policies Act opens wholesale power markets to non-utility power producers
• 1978 - Advent of the Investment Tax Credit (ITC) for alternative energy sources
• 1983 – First state renewable energy requirement adopted—Iowa
• 1992 - Advent of the Production Tax Credit (PTC) for wind
• 1995 - First mention of concept of certificate trading—California¹
• 1996 - First competitive retail green power pilot program—New Hampshire²
• 1997 – Some European countries introduce tradable attribute certificates¹
• 1997 - Origin of environmental disclosure electricity labels—New England¹
• 1997 – Introduction of environmental certification standards for voluntary renewable energy products—Green-e launched
• 1998 - Electricity markets in CA, MA, and RI open to retail choice¹
• 1998 - First wholesale green power market opens in CA – Automated Power Exchange (APX)¹
• 1998 - First retail REC product sold—AllEnergy Marketing Company (MA)
• 1999 - First Renewable Portfolio Standard with REC trading for compliance—Texas¹
• 2000 - EPA buys green power¹
• 2001 – EPA launches Green Power Partnership
• 2001 – EPA initiates first annual Green Power Leadership Awards
• 2001 – First REC tracking system established--TX
• 2002 - Third-party certification and verification standard introduced for tradable certificates in U.S.¹
• 2004 - First recognized EPA Green Power Community – Moab, UT
• 2004 – EPA launches first Top 25 Partners list – Air Force largest user in U.S.
• 2005 – NREL report indicates that organizations, not residences, are pacing the growth of U.S. green power markets
• 2006 - Advent of the Solar Power Purchase Agreement – SunEdison/Renewable Ventures
• 2007 - First community solar offering – SMUD, CA
• 2008 – RGGI states adopt first allowance set-aside for voluntary renewable energy purchases under cap and trade program
• 2010 – Compliance markets surpass voluntary markets in terms of total kilowatt-hours from new renewables
• 2012 – Federal Trade Commission updates Green Marketing Guidelines with clarifications for making renewable energy claims
• 2014 – Corporate Renewable Energy Buyers Principles announced
• 2015 - GHG Protocol Scope 2 Guidance finalized for reporting emissions relating to renewable energy purchases
• 2015 – Executive Order 13693 calls for 25% renewable energy use in federal agency buildings by 2025, and GHG emission reductions

Sources:

1. https://www.nrel.gov/docs/fy05osti/37388.pdf (PDF) (76 pp, 1.2 MB)
2. http://www.nrel.gov/docs/legosti/old/23446.pdf (PDF) (27 pp, 1 MB)