Planning Information and Data

The IESO is committed to being open and transparent about information and data that inform power system plans. Data pertaining to Ontario total demand, long-term outlooks for demand and supply, and system capabilities is regularly maintained on the IESO website. Information specific to individual system plans is generally provided through the web pages the engagement pages dedicated to each region and/or bulk planning study. Other plan or system information, such as regional planning guidelines and transmission asset data (referenced below) will continue to be made accessible from this page.

Regional Planning Information and Data

The IESO developed an informational document as a guideline to the types of information and data that are made available during the regional planning process. It describes the general approach used by the IESO to make regional planning information and data available to communities, stakeholders and interested parties during the development and following completion of an Integrated Regional Resource Plan (IRRP), and provides a comprehensive list and descriptions of the information, and the timing in which it is typically made available during an IRRP. This guideline serves to set the baseline for what data and information stakeholders can expect to better enable them to provide informed feedback to the IESO and the Technical Working Group responsible for developing regional plans.

Transmission Asset Demographic Information – Available by Request

The IESO collaborated with Hydro One on a process to make transmission asset age demographic information for categories of major transmission facilities available to interested parties. This information is important for long-term planning as it informs when assets will approach their end-of-life. This information will be updated every five years. To obtain this asset demographic information, interested parties must complete the request form and submit to

Integrated Regional Resource Plans: Guide to Assessing Non-Wires Alternatives

The IESO developed a guide to the current general approach for evaluating non-wires alternatives (NWAs) during IRRPs. This guide summarizes various recent improvements made to better consider NWAs when developing an IRRP, including the process flow diagram, screening mechanism, hourly needs characterization, development of options, and economic evaluation methodology. Planning participants and stakeholders can refer to this guide to better understand what key activities to expect during the IRRP. If the approach and methodologies used to assess NWAs evolve, the IESO will update the guide.

Transmission System Losses: Evaluation Guideline

The IESO developed a guideline that describes when and how transmission system losses will be evaluated when the IESO develops power system plans. Detailed loss evaluations will quantify the economic impact of system losses for comparison between plan alternatives, when system losses can affect the choice of preferred plan alternative. By sharing this information, the IESO aims to inform stakeholders, facilitate understanding, and promote consistency in the planning and decision-making processes related to bulk transmission system and regional plans.