Maryland Code, Public Utilities § 3-112

(a) In a proceeding before the Commission where a person applies for the approval of the Commission under § 5-104, §§ 5-201 through 5-203, or §§ 6-101 through 6-103 of this article, the person shall show by clear and satisfactory evidence that granting the application complies with the requirements of this division and, as the case may be, is required by the public interest or is consistent with the public interest.

(b) In a proceeding involving a temporary or permanent new rate, or a temporary or permanent change in rate, the burden of proof is on the proponent of the new rate or change in rate.