REC stands for Renewable energy credits. It is a certificate that directs at chasing the progress and agreements with the Renewable Portfolio Standards of different states. RECs should communicate with the environmental aspects of energy generated from renewable energy sources. In a layman, a REC is a proof that the energy is being produced from renewable energy sources. A REC is issued in the following casewhen one megawatt-hour (MWh) of electricity is produced and sent to the electricity grid from a renewable energy source.