What is a Renewable Energy Certificate (REC) and how does it work?

• A. RECs are physical energy meters installed at a facility.
• B. RECs are carbon credits from forestry projects.
• C. RECs certify that one unit of renewable electricity has been generated; buyers can claim green power by purchasing RECs.
• D. RECs guarantee 100% renewable energy at a site automatically.

Answer: (C)

RECs, or Renewable Energy Certificates, are a way to prove that renewable electricity has been generated. Each certificate represents the environmental attributes of one unit of energy—typically one megawatt-hour—that was produced from a renewable source and fed into the grid. The key idea is that the environmental benefit (the renewable attribute) can be separated from the physical electrons you receive.

When a renewable-energy facility generates power, the corresponding RECs are created and can be sold. A buyer can choose to purchase those RECs and retire them, which means the green attribute is claimed by the buyer. This lets individuals or organizations support renewable energy or claim to be using green power, even if the actual electricity they buy from the grid comes from a mix of sources. In short, RECs certify generation and enable green-power claims without requiring the electricity at a site to come solely from renewables.

The other options don’t fit: RECs are not physical energy meters, nor are they carbon credits from forestry projects, and owning RECs does not automatically guarantee 100% renewable energy at a site.