Executive Summary

Integrated resource planning (IRP) in the American West is the primary institutional venue where regulatory risk for clean energy projects is produced, heightened, or reduced. This paper identifies three mechanisms through which IRP process design generates such risk: assumption framing, procedural bundling, and institutional instability. A comparative analysis of Arizona and Nevada shows how institutional architecture, not geography or resource endowment, determines the regulatory risk profile for clean energy deployment. A detailed case study of NV Energy's 2026 IRP shows how conservative load forecasts, bundled procurement, and inadequate modeling of clean alternatives create risk even under Nevada's strong statutory framework. The March 2026 repeal of Arizona’s Renewable Energy Standard and Tariff provides a live case of institutional instability depressing clean energy investment signals. The paper further shows that climate-driven water scarcity in the Colorado River Basin compounds these risks by introducing physical constraints on thermal generation that current IRP processes ignore. IRP process reforms, including phased planning, explicit clean alternative modeling, water risk integration, and statutory durability, are evaluated as risk mitigation tools.

This paper will be part of the OGEL Special Issue on "Clean Energy Projects and Risk Mitigation". More information here www.ogel.org/news.asp?key=841