Dominion Energy's plan to retire two coal plants in South Carolina will save ratepayers millions while maintaining grid stability, according to expert analysis filed with state regulators this week.
The analysis examined Dominion's long-range energy strategy and found the utility would generate substantially more electricity than needed by 2033 if it continues operating the Wateree and Williams coal plants. The redundancy creates a straightforward economic case for closure.
Dominion serves nearly 2.7 million customers across the Carolinas, Virginia, and West Virginia. The Wateree plant operates in Moncks Corner, South Carolina. The Williams plant sits near Smithfield, Virginia. Both are aging facilities facing rising maintenance costs and stricter environmental compliance requirements.
The expert filing came to South Carolina regulators, who oversee Dominion's operations within the state. The analysis projects customer savings from avoiding continued coal plant investments, which include pollution control upgrades, staff retention, and fuel procurement. Replacing this generation with renewable energy and natural gas resources costs less per megawatt-hour while meeting peak demand.
Dominion's 2033 projection assumes strong solar and wind deployment across its service territory. The utility has committed to net-zero emissions by 2050 under state clean energy mandates. Retiring coal capacity accelerates that timeline while reducing compliance risk from federal and state environmental rules.
Grid reliability concerns often surface when utilities retire baseload generation. The analysis directly addressed this by modeling load forecasts, reserve margins, and transmission constraints. The findings show Dominion maintains adequate capacity reserves even without the coal plants. Alternative resources, including battery storage projects now under development, provide the dispatchability coal plants currently supply.
Coal plant retirements in the Southeast have accelerated over the past five years. Duke Energy, another major regional utility, retired multiple coal units in the Carolinas and closed plants in Kentucky and Ohio. American Electric Power and Southern Company have announced similar timelines. This shift reflects both economics and policy. Coal generation now costs more than renewables in most markets, and state regulations increasingly penalize carbon emissions.
South Carolina's Integrated Resource Plan requires utilities to minimize ratepayer costs while meeting reliability standards. The state has no explicit carbon target but adopted a 70% reduction in carbon intensity by 2030 under the South Carolina Energy Freedom Act.
Dominion faces a decision point in its 2027 regulatory filing cycle. State officials will review the long-range plan and potentially mandate coal retirements through rate case proceedings. Customer advocacy groups have already filed comments supporting the closures. Industry groups representing coal workers have opposed rapid retirement timelines.
The timing matters. If Wateree and Williams close by 2030, Dominion reduces fixed costs during a period when solar and battery prices continue declining. Delayed retirements lock in higher operational expenses and defer needed infrastructure investment in transmission and storage.
Expert analyses like this one influence rate cases. Utilities must prove their generation choices minimize total cost of service. Dominion's filing demonstrates closure reduces that cost metric. Regulators typically weigh expert testimony heavily in deciding whether to approve utility capital plans.
The South Carolina Public Service Commission will review this analysis during Dominion's next formal rate case. The commission has historically approved coal retirements when economic evidence supports them. A decision could arrive within 18 months.