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Proposed changes to market rules re. Ancillary Service Requirements

June 8, 2017

The IESO is proposing changes to the market rules that will increase the transparency and consistency of performance requirements for all registered facilities providing regulation ancillary service, regardless of size and where they connect.

Regulation service, like other ancillary services the IESO procures (voltage support and reactive control, operating reserve and black start capability), is necessary to maintain the reliability of the IESO-controlled grid. Regulation service is used to control power system frequency and maintain the balance between load and generation on a second-by-second basis. The IESO must maintain sufficient regulation to meet North American Electric Reliability Corporation (NERC) reliability standards. To fulfill this mandate, all resources providing regulation must meet a minimum set of performance requirements that ensures their availability over a range of expected grid conditions. 

Traditionally, regulation was supplied by synchronous generators directly connected to the grid, which are subject to a strict set of requirements to ensure their support is available when needed.  Alternative technologies now have the potential to be suppliers of regulation. Sometimes, the size, composition or location of an alternative technology regulation provider makes it more suitable for a distribution system connection, rather than being directly connected to the transmission system.

Regardless of the size or where they connect, the technical requirements of the service provided by regulation providers must satisfy the same minimum standards.  To ensure that this expectation is met by all suppliers of regulation service, the IESO will initiate a market rule amendment process through the IESO Technical Panel to clarify that certain performance requirements within Chapter 4, Appendix 4.2 of the market rules - off-nominal frequency, speed frequency regulation, and voltage ride through - are applicable to all regulation providers.

Please contact IESO Engagement for any questions or for more information about this matter. The IESO will host a webinar to provide more details if requested.

All proposed market rule amendments are brought to the IESO’s Technical Panel, which is a forum of individuals representing multiple sectors in Ontario’s electricity system. The Panel provides advice and recommendations directly to the IESO Board of Directors on market rule amendments. Email for details on how to observe Technical Panel meetings in person or via teleconference.

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