Dominion South Carolina Resists Committing to Retirement Dates for its Coal Plants
This week, the South Carolina Public Service Commission is holding a hearing in Docket 2026-9-E to evaluate Dominion Energy South Carolina’s 2026 Integrated Resource Plan (IRP). As part of this planning cycle, Dominion has not committed to retirement dates for the Wateree and Williams coal plants. The Company’s own modeling shows that Dominion will not need the plants’ capacity once the recently approved Canadys natural gas combined-cycle plant comes online. This is concerning, because the Company is spending billions of dollars to construct Canadys. Extending the lifetime of Wateree and Williams will saddle ratepayers with substantial additional costs and is not necessary to maintain reliability.
Synapse witnesses recommend Dominion make firm commitments to retire the coal plants and implement modeling improvements to ensure a least-cost, reliable system
Synapse Witnesses Lucy Metz and Sabine Chavin submitted testimony on behalf of Sierra Club evaluating the Company’s 2026 IRP.
Lucy Metz’s testimony discussed the economic risks associated with delaying the retirement of Wateree and Williams. Both plants are already over fifty years old and will face environmental retrofit costs as well as escalating capital and operating costs if Dominion delays their retirement. She also recommended that Dominion proactively develop a large-load tariff to protect other customers and ensure that any new large-load customers pay their full cost of service. Finally, she recommended several improvements to Dominion’s modeling to ensure that it fully represents the benefits of renewable energy, battery storage and demand side management resources.
Sabine Chavin’s testimony included independent SERVM reliability analysis to evaluate the reliability impacts of retiring Wateree and Williams. She found that under the Reference load forecast, Dominion can retire Wateree and Williams by their projected retirement dates while exceeding its reliability standard. Because Dominion is exceeding its reliability standards under the Reference load forecast, it has headroom to accommodate additional load if higher-than-expected load growth materializes. Sabine also evaluated Dominion’s overall modeling framework, including how it transferred data between its capacity expansion and resource adequacy models. She found that Dominion’s current modeling framework may result in an overbuilt or suboptimal resource mix. Both outcomes would impose unnecessary costs on ratepayers.