CECPCN for a Combined-Cycle Plant at the Canadys Site in South Carolina
Synapse provided expert testimony and analysis to support the Sierra Club in reviewing Santee Cooper and Dominion Energy South Carolina’s (Joint Applicants) application for a Certificate of Environmental Compatibility and Public Convenience and Necessity (CECPCN) for a 2.2 GW combined cycle gas plant (CC) at the Canadys site in South Carolina. The purpose of our testimony was to evaluate whether the Joint Applicants established the need for the plant, assess the extent to which large-load customers are driving this need, and discuss potential ratepayer protection measures.
Based on our analysis of Santee Cooper and Dominion’s capacity positions, we recommended that the Commission make approval of the Canadys CC contingent on a firm commitment from Santee Cooper to retire the Winyah coal plant and from Dominion to retire the Wateree and Williams coal plants once the Canadys CC comes online. We also recommended that Santee Cooper procure resources to serve large-load customers with signed contracts only, to avoid overbuilding and better allow it to use the Canadys CC as replacement capacity for retiring coal.
Given recent escalation in the cost of the Canadys CC, we also recommended that the Commission protect ratepayers by capping project cost at the amount the Joint Applicants currently estimate and requiring a separate demonstration of prudence for any costs above that amount. Finally, we recommended that the Joint Applicants focus future resource procurement on battery storage paired with renewables. Because of these resources’ modularity, lifetime, and short construction timelines, batteries paired with renewables provide much-needed flexibility for the Joint Applicants to respond to the uncertain pace and magnitude of data center load growth.