S.C. Code Ann. § 58-27-1550

Every electrical utility may, and may be required to, charge annually as an operating expense a reasonable sum for depreciation and credit the sum to a reserve account for such purpose. The reserve account must be charged only with plant retirements and expenditures made to restore depreciated property. But if the reserve thus created shall at any time in the judgment of the Office of Regulatory Staff be excessive, the commission, after due hearing, shall issue an order as will result in the credits to the reserve thereafter conforming to actual facts and conditions as ascertained by the commission. The commission may control or limit the depreciation reserve.