As of the end of 2021, 31 states and the District of Columbia had renewable portfolio standards (RPS) or clean energy standards (CES). These polices require electricity suppliers to supply a set share of their electricity from designated renewable resources or carbon-free eligible technologies. Four states—Delaware, Oregon, North Carolina, and Illinois—updated their RPS or CES policies in 2021. In addition, Nebraska approved its first clean energy goal in December 2021, becoming the 20th U.S. state to commit to 100% clean electricity by 2050.