Image credit: Bill McLaugh
Client: Mountain Association (MA), Kentuckians for the Commonwealth (KFTC), Kentucky Solar Energy Society (KYSES), and Metropolitan Housing Coalition (MHC)
Authors: Joshua R. Castigliego, Elizabeth A. Stanton, PhD
March 2025
On behalf of the Mountain Association (MA), Kentuckians for the Commonwealth (KFTC), Kentucky Solar Energy Society (KYSES), and Metropolitan Housing Coalition (MHC) (collectively, the “Joint Intervenors”), Senior Researcher Joshua R. Castigliego and Principal Economist Elizabeth A. Stanton, PhD prepared a white paper that sets out best practices for IRP modeling and reporting, and assesses the Louisville Gas and Electric Company (LG&E) and Kentucky Utilities Company (KU) (collectively, LG&E-KU) 2024 IRP filed on October 18, 2024 in Case No. 2024-00326 based on those criteria.
AEC’s best practices are organized into five categories: (A) Demand-Side Analysis; (B) Supply-Side Analysis; (C) Modeling Structure; (D) Selection of Recommended Plan; and (E) Stakeholder Input. Through its best-practices assessment, AEC finds that LG&E-KU’s 2024 IRP is missing critical components and includes errors in forecasting key assumptions, resulting in an overall flawed least-cost resource plan selection. LG&E-KU’s failure to follow IRP best practices results in resource decisions that are not properly informed (or justified) by comprehensive IRP modeling, leading to possible adverse effects on ratepayers. In particular, the flawed IRP findings may result in support for uneconomic resource additions in near-term CPCN applications.