All expenses and charges incurred by the commission in the administration of this chapter and in the performance of its duties thereunder shall be defrayed by assessments made by the Comptroller General against the electrical utilities regulated thereunder and based upon the gross revenues collected by such electrical utilities from their business done wholly within this State in the manner set out in § 58-3-100 for other corporations.

The Public Service Commission must certify to the Comptroller General annually on or before May first the amounts to be assessed in the format approved by the Comptroller General.