Chapter 164 of the General Laws is hereby amended by inserting after section 1B the following section:-

        Section 1B½. (a) For the purposes of this section, the term rate increase shall mean any upward adjustment to any rates or charges of any ancillary service, basic service, cogeneration, default service, distributed generation, distribution, electric service, generation, generation service or transmission by an electric company to either a distribution company or a retail customer.

        Notwithstanding any other provision of this chapter, an electric company shall not institute a rate increase or other change in its rates, charges or retail access except upon approval by the department and after 30 days’ notice to the department and to the public published pursuant to this section, which shall plainly state the changes proposed to be made to the schedule then in force, and the time when the changed rates or charges will go into effect.

        Whenever the department receives notice of any rate increase to be made by an electric company, the department shall first hold a public hearing and make investigation as to the propriety of the proposed change or changes. After notice of any investigation, the department shall have power to suspend the taking effect of the change or changes, pending the decision of the department. Each hearing and investigation shall be conducted as expeditiously as may be practicable and with a minimum of delay.

        Within 90 days after the completion of the last hearing, the department shall make such order in reference to any proposed rate increase as may be proper; provided, that if the department makes an upward adjustment to any current or prior rates or charges by an electric company, the department shall periodically hold a public hearing and make investigation as to the continued propriety of such rates charged by an electric company and shall make such order in reference to the rate or charge as may be just, which may include decreasing the rate or charge.

        (b) Upon receipt from an electric company of a notice of any rate increase proposed to be made pursuant to subsection (a), the department shall give notice as it may prescribe of the pendency of the proposal and of the time and place of the hearing thereon to the chief executive officer of any city or town containing a retail customer affected by such proposed rate increase. The department shall also publish a notice of the hearing at least 10 days prior to the date thereof in a newspaper of general circulation in each such city or town. The department, upon request of the chief executive officer of any such city or town, shall hold a public hearing on the matter within each such town or city; provided; however, that the requesting city or town shall provide suitable accommodation for the public hearing.