§ 81. Approval of incorporation and franchises; certificate. No steam corporation shall begin construction of a steam plant without first having obtained the permission and approval of the commission. No such corporation shall exercise any right or privilege under any franchise hereafter granted, or under any franchise heretofore granted but not heretofore actually exercised, or the exercise of which shall have been suspended for more than one year, without first having obtained the permission and approval of the commission. Before such certificate shall be issued a certified copy of the charter of such corporation shall be filed in the office of the commission, together with a verified statement of the president and secretary of the corporation, showing that it has received the required consent of the proper municipal authorities. The commission shall have power to grant the permission and approval herein specified whenever it shall after due hearing determine that such construction or such exercise of the right, privilege or franchise is necessary or convenient for the public service.

No municipality shall build, maintain and operate for other than municipal purposes any works or systems for the manufacture and supplying of steam for purposes without a certificate of authority granted by the commission. If the certificate of authority is refused, no further proceedings shall be taken by such municipality before the commission, but a new application may be made therefor after one year from the date of such refusal.