November 1, 2016 ECC Vision and Objectives Page - 2

Peak Reliability Guideline

Document name / Enhanced Curtailment Calculator (ECC) Vision and Objectives
Category / ( ) Regional Reliability Standard
( ) Regional Criteria
( ) Policy
(X) Guideline
( ) Report or other
( ) Charter
Document date / 11/1/2016
Adopted/approved by
Date adopted/approved
Custodian (entity responsible for maintenance and upkeep) / Peak Reliability
Stored/filed / Physical location:
Web URL:
Previous name/number / (if any)
Status / (X) in effect
( ) usable, minor formatting/editing required
( ) modification needed
( ) superseded by ______
( ) other ______
( ) obsolete/archived

Introduction

The purpose of this document is to outline the key objectives of the Enhanced Curtailment Calculator (ECC) tool. The information included is meant to help guide the ECC Task Force and to inform interested parties as we collaboratively work to develop the ECC to include expanded reliability and efficiency benefits for the Western Interconnection.

Vision for the ECC

The ECC will be a primary reliability and coordination tool used by all reliability entities. The ECC tool presents a wide area view of defined SOL/IROL exceedances and supports managing seams which may have other limitations beyond SOLs or IROLs. The ECC shall provide mitigation options including the management of ACE, redispatch of generation, adjustment of phase shifters, or curtailment of e-tags. The ECC will provide a method for reliability entities to initiate reliability curtailments to make the mitigation process as efficient as possible. The ECC will not be the only tool to manage SOLs and IROLs, rather it will be a tool that will fit in the current RC practices of communicate, advise, and direct.

Primary reliability objectives of the ECC

·  Improve reliability with enhanced situational awareness

The ECC tool provides reliability entities greater understanding of the pre- and post-contingency limitations on the system which will lead to improved awareness of when SOL exceedances are actually occurring. This more granular review of system conditions improves situational awareness and facilitates more efficient mitigation actions.

·  Enhance coordination through the wide area view

The wide area view provided by the ECC enhances reliability by improving coordination among reliability entities. The ECC will support entities addressing real-time exceedances who may need additional assistance from other parties to address the problem. It is important for all reliability entities to use the ECC to maximize coordination afforded by this common wide area view.

·  Identify contributing flows to SOL exceedances

The ECC provides visibility of contributing factors to congestion (e-Tags, Dynamic Transfers, ACE, Phase Shifters, DC Lines, and untagged generation serving load). This breakdown of flows into layers allows mitigation plans to be developed that are timely and appropriate for the problem being addressed.

·  Guide effective mitigation approaches

The ECC provides guidance on the development of mitigation approaches (operating plans, memos, etc.) that may include generation redispatch, e-Tag curtailments, or Phase Shifter changes. Additionally, historical ECC identified exceedances can be used as a reference to support the development of those mitigation approaches. The information provided by the ECC supports effective replacement of power when a generator is moved or an e-Tag is curtailed so that mitigation actions do not create additional issues.

·  Improve accuracy with real-time and look ahead data

The ECC provides improved accuracy of information by utilizing real-time inputs such as the Peak State Estimator solution, BA ACE values, telemetered Dynamic Transfer values, and current e-Tags. Forecasted and outage data will be incorporated into ECC look ahead functionality to provide early notification of potential future exceedances.

Roles and Responsibilities for ECC Usage

We need to first acknowledge that SOL exceedance mitigation is the responsibility of the TOP. The RC has responsibility for monitoring SOL exceedances and ensuring that SOL exceedances are being appropriately addressed. The RC will use the ECC as they would any other situational awareness tool. The TOP will provide a mitigation plan to Peak, possibly as identified by the ECC. The details of how mitigation plans are applied (redispatch, curtailments, etc.) using the ECC are to be determined with a collaborative industry process.

What is Seams Coordination

Seams coordination, in the context of ECC, has a primary objective of ensuring that exceedances on facilities which have flow contributions from external BAs, TOPs, or Market Operators are effectively and fairly managed.

There are two primary functions for seams coordination:

1.  Identify various entity responsibilities for their share of flows on a congested facility or Path.

2.  Provide a consistent method for reliability entities to monitor their obligations and to take action to address exceedances.

Seams coordination functionality within the ECC should be capable of addressing additional constraints above and beyond SOLs and IROLs. For example, if an entity has facility impacts or overloads attributable to other parties, then those entities can provide the ECC with the proper information to constrain flows on the facility and to assign the proper responsibilities.

PEAK RELIABILITY — RELIABILITY COORDINATION

7600 NE 41st STREET • SUITE 201 • VANCOUVER • WASHINGTON • 98662-6772

4850 HAHNS PEAK DRIVE • SUITE 120 • LOVELAND • COLORADO • 80538-6001