Reliable Power Reliable Markets Reliable People RAS Guideline Initiative March 23, 2009

2 RAS Initiative Background Proposed Transmission Constraint Management (TCM) rules manage real time congestion through system controller action –AUC decision pending –If TCM rules approved, OPP’s will follow and system controller tools will be built –In the interim, OPP revisions or additions will align with TCM proposal as far as practical

3 RAS Initiative Background A Remedial Action Scheme (RAS) is designed to protect system facilities without the need for system controller intervention – AESO committed to provide more formal documentation of RAS policies and procedures –RAS initiative will explore the need for RAS rules and discuss the content of the RAS guideline seeking stakeholder feedback on improvements to or clarification of the policies and procedures

4 What is RAS? ISO Rule RAS Definition: RAS means a control system that makes automatic adjustments to power system elements in order to preserve system reliability RAS can be categorized into two broad types: –Interconnection RAS A RAS requirement that arises from a customer interconnection application which is usually removed when needed facilities are built The potential RAS rules are expected to be directed toward interconnection RAS only –System RAS A RAS requirement that arises from changes to the AIES that develop over time System RAS requires a more flexible approach to creating solutions as it is more unique, often permanent and is generally paid for by load RAS Guideline will provide some discussion and examples of system RAS

5 RAS Legislative Authority Transmission Regulation requirements: plan for 100% in merit energy under normal conditions non-wires solutions (RAS) allowed as a temporary solution EUA duties: safe, reliable and economic operation Supports technical RAS requirements FEOC market Influences RAS polices and procedures RAS must be used in a manner which is consistent with the Act, any other obligations set out for the ISO in legislation, the ISO rules and any other applicable Authoritative Document.

6 RAS Documentation Format Potential RAS rules: Some aspects of RAS policy and procedure may belong in an ISO rule Regulatory authority Technical requirements Operational implementation Supporting RAS documentation: Most aspects of RAS policy and procedure are informational and may not belong in the rules Some RAS policies may either be addressed in rules or outlined in an informational format The term “guideline” may be too formal for the information document as the contents may be best maintained outside the rules process

7 RAS Policy Issues Interconnection RAS and transmission rights Constraints caused by interconnections often can not be dealt with by the system controller in real time RAS is intended to be proactive allowing early interconnection RAS is assigned to and generally paid for by the interconnecting customer Alternatively, system operating limit derates may be required which manage the constraint in advance among existing and new generation sources Early interconnection needs to balanced with fairness to existing generators in the area and the AESO duties to operate the system

8 RAS Policy Issues Interconnection RAS and real time operation Interconnection RAS operates automatically at preset levels to protect system facilities Under the proposed Transmission Management Constraint rules, after a RAS has been activated, the system controller will apply the TCM protocol using RMO and pro-rata to allocate the constraint mitigation among effective generators in the area; this is a change from past practises Interconnection RAS generators have on occasion requested that whenever possible the system controller issue curtailment instructions to proactively prevent RAS activation; the AESO will need to consider whether it is still appropriate to offer this service

9 Energy Market Life Cycle Stage RAS Guideline

10 Next Steps Market Services stakeholder meeting March 23 Discussion paper Complete internal reviews and publish in April Stakeholder comments will be requested Recommendation paper Discussion paper stakeholder comments will be reviewed and a set of recommendations put forward for further comment ISO Rule process Potentially promote RAS rules thru the October rules process RAS guideline document would be developed in a parallel work stream

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