Summary

Electricity transmission and distribution investment decisions are transforming due to increasing uncertainties in various parameters, driven by factors such as evolving electricity market frameworks. Notable uncertainties include the rising penetration of renewable energy sources (RES) and distributed energy resources (DER) in response to carbon neutrality targets, climate change impacts on operational planning (e.g., hydrology), and the dynamics of variable renewable energy (VRE) like wind and solar photovoltaic. Economic uncertainties, electrification of load and transport, and recent global events, such as the Covid-19 pandemic, further contribute to the complexity.

This report investigates the integration of uncertainties into transmission and distribution planning scenarios, focusing on the decision-making processes of Independent System Operators (ISOs), Transmission System Operators (TSOs), and Distribution System Operators (DSOs).

A comprehensive examination of regulatory frameworks for transmission and distribution investment across various regions reveals shared structures but limited incorporation of risk-based metrics. Notable variations are observed at the distribution level, influenced by regional governance, utility structures, and system designs.

A survey conducted by a Joint Working Group (JWG) explores how ISOs, TSOs, and DSOs integrate uncertainties into their planning processes and collaborate at their interfaces. The survey, with 43 responses from Oceania, North America, South America, Europe, and Asia, highlights historical design and regulatory influences on planning practices.

The report delves into transmission and distribution network planning methodologies under increasing energy scenario uncertainty, drawing on experiences from Portugal, Germany, and Italy. Case studies from Europe, Sweden, France, and Chile analyze investment decision-making processes and coordination between ISO/TSO and DSO.

Key learnings and recommendations for optimal investment decisions in the face of uncertainties include recognizing the impact of separate legal entities on decision-making, emphasizing the need for stronger integration among ISOs, TSOs, and DSOs, and highlighting the importance of comprehensive expansion plans that consider mutual interactions between transmission and distribution systems.

Additional informations

Publication type Technical Brochures
Reference 923
Publication year
Publisher CIGRE
Study committees
  • Power system development and economics (C1)
  • Active distribution systems and distributed energy resources (C6)
Working groups JWG C1/C6.37/CIRED
File size 9 MB
Pages number 105
Price for non member 200 €
Price for member Free

Video

Authors

J.C. ARANEDA, Convenor C1 (CL), F. PILO, Convenor C6 (IT), F. SILVESTRO, Secretary (IT)

R. PRATA (PT), J. TAYLOR (US), M. BRAUN (GE), M.C. ALVAREZ-HERAULT (FR), F. SCHAEFER (GE), F. HEYMANN (PT), A. DONNERS MUHAMMED (SE)

Corresponding Members
M. CURY (BR), S. BARRIENTOS (CL)

Keywords

Transmission planning, Distribution planning, Transmission system operators, Independent system operators, Distribution system operators, Investment decision making under uncertainties, Distributed energy resources, TDS/DSO coordinated planning

Optimal transmission and distribution investment decisions under increasing energy scenario uncertainty