39 Miss. Code. R. 1-29- 106
At approximately the mid-point of the electric utility's three-year planning cycle, regulated electric utilities shall file in their respective IRP dockets a written report describing any material changes to the Integrated Resource Plan, including material changes in economic assumptions ( e.g., future natural gas price forecasts or alternative technology costs), environmental rules and regulations, regional transmission organization rules, or forecasted load requirements. Any previously undisclosed capacity needs that are identified in the Mid-Point Supply Side Update shall be supported by good cause explanation. In the event a Mid-Point Supply-Side Update identifies a previously undisclosed need for capacity in excess of 75 MW, then the Update shall also include a description of and timeline associated with the utility's plan to secure such resource. Any self-build option identified in the Mid-Point Supply-Side Update must be compared to other available market opportunities, which can be satisfied through a competitive solicitation for engineering, procurement, and construction services or long-term power purchase agreements. Submission of the Mid-Point Supply Side Update in no way affects or relieves a utility of its separate obligation to obtain regulatory approval for the acquisition of any resource(s) described therein.
39 Miss. Code. R. 1-29- 106