S.C. Code § 58-4-80
The executive director representing the regulatory staff is considered to have an interest sufficient to maintain actions for judicial review from commission orders or decisions and may, as of right and in a manner prescribed by law, intervene or otherwise participate in any civil proceeding which involves the review or enforcement of commission action that the executive director determines may substantially affect the public interest. This right includes intervention in any action for judicial review from commission orders or decisions that are pending at any stage of the action. The executive director representing the regulatory staff has the same rights of appeal from commission orders or decisions as other parties to commission proceedings. On appeal, the Office of Regulatory Staff does not represent the commission.
S.C. Code § 58-4-80
2018 Act No. 258, Section 12, provides as follows:
"SECTION 12. This act takes effect upon approval by the Governor and applies to all cases, proceedings, petitions, or matters pending before the Public Service Commission or in any other court or venue on or after the effective date of this act."