Buying and Selling Certificates

Companies, institutions and homeowners can support clean energy by purchasing renewable energy certificates (also known as RECs, renewable energy credits, green tags, green energy certificates, or tradable renewable certificates). RECs are tradable commodities that prove 1 megawatt-hour of electricity was generated from a renewable energy source. A megawatt-hour equals 1,000 kilowatt-hours, and the average residential customer consumes about 800 kilowatt-hours a month.


RECs are bought and sold in order to provide a subsidy to encourage the development and use of renewable energy sources. For instance, a wind farm will earn RECs for the electricity it produces and can then sell those RECs on the open market.


Purchasing RECs allows companies and institutions to help the environment and at the same time help their organizations by demonstrating to others that they are environmental stewards and leaders in sustainability in their communities. 


A list of REC suppliers may be accessed through the federal Environmental Protection Agency (EPA):


A list of Connecticut organizations that are buying RECs may be accessed through the EPA: