S.C. Code § 58-27-980
No contract charge to be made to any person, corporation or municipality by any electrical utility for electricity to be furnished for light, heat or power established subsequent to March 24, 1922, shall be exempt from alteration, control, regulation and establishment by the Commission, when in its judgment the public interest so requires, to the full extent of the powers in relation to charges conferred upon the Commission by this chapter. Nor shall any contract establishing a rate or rates or any other contract affecting the use or disposition of its product or the charges to be paid therefor be entered into by any electrical utility without prior approval by the Commission, nor unless it be subject to amendment, modification, change or annulment by the Commission, if the public interest so requires. But nothing herein contained shall be construed to require the Commission's approval of a contract fixing a rate already approved by the Commission and then effective, if such contract rate is fixed subject to subsequent amendment, modification, change or annulment by the Commission. Full power and authority is hereby conferred on the Commission to accomplish the purposes expressed in this section.
S.C. Code § 58-27-980