N.H. Rev. Stat. § 366:5
The department of energy shall have full power and authority to investigate any such contract, arrangement, purchase, or sale and initiate a proceeding related thereto before the commission. If the commission after notice and hearing shall find any such contract, arrangement, purchase, or sale to be unjust or unreasonable, the commission may make such reasonable order relating thereto as the public good requires. In any such investigation, the burden shall be on the public utility and affiliate to prove the reasonableness of any such contract, arrangement, purchase, or sale with, from, or to an affiliate. If the public utility shall fail to satisfy the commission of the reasonableness of any such contract, arrangement, purchase, or sale, the commission may disapprove the same and disallow payments thereunder or such part of any such payment as the commission shall find to be unjust or unreasonable. No payment disallowed by the commission shall be capitalized or included as an operating cost of the public utility in the fixing of rates or as an asset in fixing a rate base. If in any such investigation the public utility or affiliate shall unreasonably refuse to comply with any request of the commission or the department for information with respect to relevant accounts and records, whether of such public utility or any affiliate, any portion of which may be applicable to any transaction under investigation, so that such parts thereof as the commission or the department may deem material may be made part of the record, such refusal shall justify the commission in disapproving the transaction under investigation and disallowing payments in pursuance thereof.
RSA 366:5
1933, 182:1. RL 305:4. 2021, 91:254, eff. July 1, 2021.