N.H. Rev. Stat. § 365:4
If the charges are not satisfied as provided in RSA 365:3, and it shall appear to the department of energy that there are reasonable grounds therefor, it shall investigate the same in such manner and by such means as it shall deem proper. After investigation, the department of energy may bring proceedings on its own motion before the public utilities commission, with respect to any complaint or violation of any provision of law, rule, terms and conditions of its franchises or charter, or any order of the commission. If the party bringing the complaint is unsatisfied with the disposition of the complaint by the department of energy, then they may petition the public utilities commission to resolve the matter through an adjudicative proceeding.
RSA 365:4
1911, 164:10. PL 238 :4. RL 287:4. 1951, 203:11 par. 4, eff. Sept. 1, 1951.