South Carolina regulators have approved Dominion Energy’s integrated resources plan, or IRP, which spells out its power development and purchasing plans for the next 15 years.
The state’s Public Service Commission (PSC) earlier this month accepted the utility’s 2020 IRP after rejecting an earlier version last December due to the company's failure to include a demand side management option. The company also failed to model for additional renewable resources or coal-plant retirements over the next five to seven years. The Sierra Club said the updated plan represented a significant turnaround.
Dominion’s modified IRP calls for shuttering its coal-fired plants in the state within the decade while also relying more on renewable sources of power. In particular, the utility plans to shut down two coal plants by 2028, while shifting a third to natural gas by 2030.
South Carolina’s PSC issued it order accepting Dominion's modified 2020 IRP on June 18.
That was a reversal from its December vote, when the commission faulted Dominion’s IRP for failing to include any renewable energy additions before 2026, and for not including a demand-side management resource option as well.
The commission, in its order published Dec. 23, also called upon the utility to explore or model the retirement of its coal-fired plants before 2028.
Will Harlan, senior representative for the Sierra Club’s Beyond Coal campaign in South Carolina, said the difference between Dominion’s original IRP and the modified plan the PSC just approved is significant.
Dominion, under one scenario the utility has presented as a favored plan in its new, modified 2020 IRP, says it would retire or modify all three of its three coal-fired plants in South Carolina within a decade.
The utility said it plans to shut down two of the plants by 2028, the Wateree Station south of Columbia, and the Williams Station north of Charleston, while the third, Cope Station near Orangeburg, would switch to gas by 2030.
Dominion’s revamped IRP also goes big on renewable energy, in contrast to its previous plan, which had no additions over the next half decade.
The utility’s preferred option would ramp up solar, adding 100 MW by 2028 and an additional 300 MW by 2032. Dominion would also add 100 MW of storage by 2032. Dominion would further bolster is solar power lineup from 2030 to 2048, potentially adding as much as 2,000 MW by mid-century. That's compared to the 973 MW of utility-scale solar power that Dominion currently has under contract.
"It is a remarkable turnaround," Sierra Club’s Harlan said. The previous plan was a "status quo plan – a do-nothing plan."
In addition, Dominion’s IRP calls for adding more gas-fired generation capacity by 2028, consisting of 523 MW of large-frame internal combustion turbines and 553 MW of combined cycle gas units.
Meanwhile, in its directive approving the IRP, the PSC also laid out the parameters of additional features it will be seeking in Dominion’s upcoming 2021 IRP and in others going forward.
Dominion will need to include "near term solar and storage in its 2021 Modified IRP Update," in order to provide a basis going forward to evaluate "potential cost savings for rate payers," the PSC said.
In addition, the PSC is ordering Dominion to "develop and implement an All Source Procurement Plan in future IRPs." This, in turn, would enable "independent power producers and developers to compete with [Dominion Energy South Carolina (DESC)] proposals in a technology neutral process" while also ensuring the "opportunity for ratepayer savings and value is enhanced."
"Future DESC IRPs should recommend a portfolio of resources that best meets the needs of the DESC system using actual bid data," according to the commission’s directive.
The PSC says it also wants to see more details on Dominion’s plans to upgrade its natural gas plants, which, according to the commission, involve replacing 10 "combustion turbines."