Renewable Electricity: How Do You Know You Have It?

When electricity is generated - either from a renewable or non-renewable power plant - the electrons added to the grid are indistinguishable. So, on what basis can a consumer of electricity claim to be using renewables? In the United States, renewable energy certificates (RECs) were developed as states passed renewable portfolio standards (RPSs) and were requiring fuel mix disclosure labels. RECs are also used in the voluntary market, where customers are buying renewables to meet sustainability goals. The concept of RECs is used most widely in the United States, but international markets also have tradable renewable electricity certificates. This fact sheet reviews how to ensure that RECs are not double-counted, roles of electricity regulators, renewable generators and purchasers. It concludes with a discussion of the international use of RECs.