| Registries | Regional tracking systems, including PJM-GATS, M-RETS, WREGIS, NEPOOL GIS and ERCOT |
| Unit | 1 certificate = 1 MWh |
| Valid for | US consumption |
| Voluntary market, 2024 | 133.5 TWh of unbundled RECs bought by about 208,000 customers |
| Label | Green-e Energy certification is optional and widely requested by corporate buyers |
Compliance and voluntary RECs
Many states have a renewable portfolio standard that requires utilities to retire RECs, sometimes with separate classes for solar (SRECs). These compliance RECs often trade far above voluntary RECs because they are scarce under each state's rules. Companies buying for their own claims usually buy national voluntary RECs, which cost much less.
Public price references
Some state programs publish prices. For example, NYSERDA sells New York Tier 1 RECs to voluntary buyers at a published price. SREC prices for several states are published by exchanges and brokers. National voluntary REC prices are mostly bilateral or behind paid assessments.
What to check before buying
- Retirement in a registry account on your behalf, with a retirement report naming your company and year.
- Vintage and, for RE100, the plant's commissioning date.
- Green-e certification if your framework or customer requires it.
- Double counting: make sure the RECs were not also used for a state compliance obligation.