Subject to such conditions as it may impose, the State Government may, if considers it necessary in the public interest so to do, by notification in the Official Gazette, exempt, prospectively or retrospectively, the electricity duty on the consumption of energy, in the whole or any part of the State, in respect of any class of premises or purposes, in such areas and for such period as may be specified therein, or in respect of energy consumed up to a specified limit, from the payment of the whole or any part of the electricity duty payable as per the Schedules, having regard to—
(i) The availability and price of energy prevailing therein and to the state of industrial or agricultural development, educational, medical aid, facilities, social conditions; and
(ii) The various policies and need, and conditions of overall development in the areas declared by general or special order, specified in this behalf:
Provided that, nothing contained in this Act shall affect any order issued in this regard before the commencement of this Act, and such order shall continue to be in force till the period mentioned therein expires, and where such period is not mentioned, any further order is issued in that respect under the provisions of this Act.