Delaware Code Title 26. Public Utilities § 307. Burden of proof;  speedy determination

(a) In any proceeding upon the motion of the Commission, or upon complaint, or upon application of a public utility, involving any proposed or existing rate of any public utility, or any proposed change in rates, the burden of proof to show that the rate involved is just and reasonable, and prudent, which requires a showing that the rate involved allows for recovery of only those costs or expenses prudently incurred, is upon the public utility.  In making the determination of whether a cost or expense was prudently incurred, the Commission must consider the objective reasonableness of the cost or expense incurred, based on what the public utility knew or reasonably should have known at the time the cost or expense was incurred.  The Commission may determine that the cost or expense incurred is only partially prudent, and may adjust the elements of rate base, operating expenses, or fuel costs accordingly to reflect that determination.

(b) The public utility shall have the burden of proof in justifying every accounting entry of record questioned by the Commission which may suspend any charge or credit pending submission of satisfactory and sufficient proof in support thereof by the public utility.

(c) The Commission shall give preference to the hearing and decision of any rate proceeding over all other proceedings and decide the same as speedily as possible.