Section 1. The following words as used in this chapter shall, unless the context otherwise requires, have the following meanings:

''Department'', the department of public utilities.

''Domestic electric utility'', an electric utility organized under the laws of, or having its principal place of business in the commonwealth, including the Massachusetts Bay Transportation Authority for the purposes specified in chapter one hundred and sixty-one A.

''Electric power facilities'', or ''electric power facility'', generating units rated twenty-five megawatts or above and transmission facilities rated sixty-nine kilovolts or above which have been designated in writing as pool or pool-planned facilities under the New England power pool agreement, when provision is made for such designation in said agreement, and which, if to be financed in whole or in part under the provisions of sections eleven to twenty-two, inclusive, are approved by the department, after notice and opportunity for hearing, as consistent with the power needs of the commonwealth. A copy of the designation shall be placed on file with the department.

''Electric utility'', any individual or entity or subdivision thereof, private, governmental or other, including a municipal electric department, wherever resident or organized, primarily engaged in the generation and sale or the purchase and sale of electricity, or the transmission thereof, for ultimate consumption by the public.

''Foreign electric utility'', any electric utility other than a domestic electric utility.

''Member of the New England power pool'', an electric utility which is a participant in the New England power pool created by a New England power pool agreement.

''Municipal electric department'', an electric department or lighting plant of a city or town of the commonwealth, which department or plant is subject to the provisions of chapter one hundred sixty-four. Except where otherwise specifically provided, a municipal electric department may exercise any of its powers or authority contained in this chapter through its municipal light board. Before such a municipal electric department exercises any power under this chapter, this chapter shall be accepted by a majority vote, as defined in section one of chapter forty-four of the municipality.

''Municipal light board'', the municipal light board or commission, municipal gas and electric commission or similar body; the mayor or city manager, as the case may be, of a city having no such body; or the selectmen of a town having no such body.

''New England power pool agreement'', a contractual agreement between electric utilities which is open to all electric utilities operating in New England, which provides for cooperation and joint participation in developing and implementing a regional bulk power supply of electricity, which constitutes the central dispatching and primary pooling arrangement for electric utilities in the New England states, which has been signed by eligible electric utilities whose annual peak loads in the year preceding the year in which the agreement is executed aggregate more than seventy-five per cent of the annual peak loads for all of New England, and which has been placed on file with the department for informational purposes and permitted to become effective under the Federal Power Act by the Federal Power Commission.

''New England power pool'', the relationship or organization created by a New England power pool agreement.