press releases

Study Finds Risk Analysis Key to Improved Transmission Planning


For Immediate Release: April 27, 2015
Contact: Regina L. Davis, 202-898-9382,


WASHINGTON—A recent study funded by the Department of Energy offers new approaches to address the challenges of maintaining reliable electricity systems through transmission planning. Electric power systems depend on transmission planning to link generation and distribution systems. The research paper, led by the Electric Power Research Institute (EPRI), incorporates risk analysis as a framework for better understanding the risks facing transmission planners.

Along with EPRI, Astrape Consulting, General Reliability, Advanced Grounding Concepts and other independent contractors produced the white paper and a related case report with case studies, commissioned by the Eastern Interconnection States’ Planning Council and the National Association of Regulatory Utility Commissioners (NARUC). These reports will help States incorporate risk analysis into transmission and other resource planning.

Through in-depth analysis, researchers identify weaknesses in current models of transmission planning, detail key uncertainties faced by States and offer a more effective framework for transmission planning. Researchers noted that because of “unprecedented changes in the electric power industry and the pressure to ensure system reliability at a minimum cost, transmission planning is becoming more complex than ever.” The research provides:

  • A framework to categorize factors and uncertainties impacting transmission planning;
  • Risk-based transmission planning approaches for reliability and economic assessments;
  • Practical case studies using risk-based transmission planning concepts;
  • Current status of tools for performing risk-based transmission analyses;
  • Impediments to wide-scale integration of risk-based approaches;
  • Regulatory and jurisdictional considerations in incorporating risk-based planning concepts; and
  • An augmented transmission planning framework and recommendations to states moving forward

“Transmission planning is a critical aspect in ensuring reliable utility service,” said NARUC President Lisa Edgar. “We at NARUC appreciate the hard work that went into developing this framework, and I urge State regulators and interested stakeholders to review the research, its recommendations and its conclusions.”

This research is a valuable primer on risk-based transmission planning to States in the Eastern Interconnection and is also useful to North American transmission planners, independent State operators, transmission owners, federal regulators, academia and other research organizations.

The related report reviewed the results of four case studies on the benefits of using probabilistic risk assessment for bulk power system planning. Three planning authorities provided relevant network models and advise for this research: the Tennessee Valley Authority, the Midcontinent Independent System Operator and the Southwest Power Pool.

The risk analysis report can be found here.

The case study results can be found here.


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NARUC is a non-profit organization founded in 1889 whose members include the governmental agencies that are engaged in the regulation of utilities and carriers in the fifty States, the District of Columbia, Puerto Rico and the Virgin Islands. NARUC's member agencies regulate telecommunications, energy, and water utilities. NARUC represents the interests of State public utility commissions before the three branches of the Federal government.

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