(2) Without prejudice to the provisions of section 47, the Grid Tariff shall apply to sales of electricity by the Board to licensees where so required under any of the First, Second and Third Schedules, and shall, subject as herein 821 after provided, also be applicable to sales of electricity by the Board to licensees in other cases: Provided that if in any such other case it appears to the Board that, having regard to the extent of the supply required, the transmission expenses involved in affording the supply are higher than those allowed in fixing the Grid Tariff, the Board may make such additional charges as it considers appropriate,. . . " The first contention urged before us by the City Board is that in the absence of any regulations framed by the Electricity Board under section 79 of the Act regarding the principles governing the fixing of Grid Tariffs, it was not open to the Electricity Board to issue the impugned notifications.