An electric membership corporation may serve any one or more of the following purposes:

(1) To furnish electrical energy and service;

(2) To assist its members in the efficient and economical use of energy;

(3) To engage in research and to promote and develop energy conservation and sources and methods of conserving, producing, converting, and delivering energy; and

(4) To engage in any lawful act or activity necessary or convenient to effect the foregoing purposes.