It is declared that the provision of adequate, reliable and economic sources of electrical energy is in the public interest; that there is a need to establish a means by which municipalities and public trusts operating municipal electric systems may jointly plan, finance, own and operate facilities relating to electrical energy and acquire fuel and other supplies for the generation of electrical energy through the creation of a power authority in order to achieve economies and efficiencies not possible for municipalities and public trusts acting alone; that the joint planning, financing, ownership and operation of facilities relating to electrical energy, the acquisition of fuel and other supplies for the generation of electrical energy and the issuance of revenue bonds as provided herein is for a public use and serves a valid public purpose; and that the Legislature finds it necessary and proper to provide a method for municipalities and public trusts operating municipal electric systems to jointly plan, finance, develop, own or operate, either by themselves or with other public agencies, utilities or persons, facilities appropriate to the present and projected needs of such municipalities and public trusts for electrical energy. It is further declared that the intent of this act is to consider all methods for the generation of electrical energy and to provide such energy in the most economical manner available.