On August 1, 2016, the New York Public Service Commission issued an Order Adopting a Clean Energy Standard, the most comprehensive and ambitious clean energy mandate in the state’s history. The CES Order adopts the goal that fifty percent of New York’s electricity is to be generated by renewable sources by 2030 as part of a strategy to reduce statewide greenhouse gas emissions by forty percent by 2030. As expected, fossil fuel generation interests mounted challenges to the CES Order, touting concerns over, among other issues, eligibility standards, procedural deficiencies, and jurisdictional competency. On December 15, 2016, the PSC issued an Order on Petitions for Rehearing that summarily dismissed these concerns. This Field Report focuses on the challenge to the PSC’s jurisdictional competency in enacting the CES Order in Coalition for Competitive Electricity v. Zibelman.