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Centralized Forecasting

The IESO has implemented a new Centralized Forecasting Service that will more accurately predict the generation output from wind and solar facilities (variable generators) in Ontario. All existing and future transmission-connected wind and solar facilities, and distribution-connected wind and solar facilities with an installed capacity equal to or greater than 5 MW are required to register and participate in this new service.

Variable generators were once a minor contributor to meeting Ontario’s generation needs and now represent an increasing portion of the province’s generation fleet. Centralized Forecasting will be implemented to more accurately predict variable wind and solar generation output, and is an essential tool for the IESO to maintain system reliability and market efficiency. This Centralized Forecasting service is similar to services implemented in most jurisdictions with comparable amounts of this generation.


This Training Guide for all distribution-connected wind and solar generators may help you better understand the technical requirements and process necessary to register for the Centralized Forecasting service.

For information on the requirements please review:

Market Manual 1: Market Entry, Maintenance, and Exit – Part1.2: Facility Registration, Maintenance, and De-registration

   Section 5 – Variable Generation
     •  Section 5.1: Responsibilities
     •  Section 5.2: Facility Data
     •  Section 5.3: Operational Monitoring
           •  Section 5.3.1: Operational Monitoring – Wind Generation Facilities
           •  Section 5.3.2: Operational Monitoring – Solar Generation Facilities
     •  Appendix E: Data Requirements – Wind
     •  Appendix F: Data Requirements – Solar

Transmission connected facilities must complete the Centralized Forecasting registration process prior to first connection.

Distribution connected facilities must complete the Centralized Forecasting registration process prior to reaching commercial operation.

Operators of existing embedded wind or solar facilities that are 5MW or greater should contact IESO Customer Relations to begin the Centralized Forecasting registration process.

All variable generators that are transmission-connected or are distribution-connected and greater than 5 MW are required to submit facility data and provide operational monitoring to the IESO.

Registration Forms
Please contact the IESO at prior to completing any documents for registration.

Form 10 - Register an Organization
Form 1736 – Wind Generation Facility Data
Form 1737 – Solar Generation Facility Data

Participant Technical Reference Manual

The Participant Technical Reference Manual outlines all the communication methods and protocols available to variable generators to send data/information to the IESO.

Contact Information

Market Entry –
Customer Relations – or 905-403-6900 or toll-free at 1-888-448-7777


Customer Relations | e-mail: | Telephone: 905-403-6900 | Toll-free: 1-888-448-7777 | Fax: 905-403-6921
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