RSA 378:28: Permanent Rates.

So far as possible, the provisions of RSA 378:27 shall be applied by the commission in fixing and determining permanent rates, as well as temporary rates. The commission shall not include in permanent rates any return on any plant, equipment, or capital improvement which has not first been found by the commission to be prudent, used, and useful. Nothing contained in this section shall preclude the commission from receiving and considering any evidence which may be pertinent and material to the determination of a just and reasonable rate base and a just and reasonable rate of return thereon.