2009 Scenario Reliability Assessment - NERC

Scenario Reliability Self-AssessmentsProjects are identified by SPP through its Balances Portfolio and/or SPP Transmission ExpansionPlan’s 10 year reliability assessment.One objective of the Balanced Portfolio and EHV Overlay study 98 is integrate wind and otherefficient generation to serve load in the SPP footprint.Operational IssuesThe variability of wind energy remains the key operating challenge within the SPP footprint. Forinstance, power output from wind generators typically peaks during the light load hours, and alarge portion of wind generators would trip as a result of high- or low- wind situations. It wouldbe critical for SPP to managing ramp rates and maintain adequate spinning reserve using fossilfuel units.The SPP WITF (Wind Integration Task Force) is conducting and reviewing studies to determinethe impact of integrating wind generation into the SPP transmission system, energy markets, andoperations system. These impacts include both planning and operational issues. Additionally,these studies should lead to recommendations for the development of any new tools required forSPP to properly evaluate requests for interconnecting wind generating resources.SPP is also participating in NERC’s Integrating Variable Generation Task Force (IVGTF), inwhich specific recommendations will be made. SPP will participate in this effort of updating ordeveloping reliability standards to reliably integrate variable generation resources into the bulkpower system.Reliability Assessment AnalysisSPP’s Reliability Criteria requires each member to sustain a 12 percent capacity margin or 13.6percent reserve margin. For 2018, the forecast reserve margin from the 2009 Reference Case is 9percent, compared to the 2009 Scenario Case capacity margin of 18.5 percent. The 18.5 percentScenario Case capacity margin is based on assumptions in the JCSP, which uses a 33 percentcapacity factor for existing and planned wind generation and a 45 percent capacity factor forconceptual wind generation. The rationale for this capacity factor is explained in the JCSP studyassumption document.The 9 percent capacity margin from the 2009 Reference Case does not take into accountdeliverable resources or 3,305 MW of conceptual resources that are forecast to be in-service in2018.There are no known unit retirements in the Scenario Case that would impact the SPP Region’sreliability. There was no difference in the amount of deliverable resources for the SPP Regionwhen the Scenario Case was compared to the Reference Case. There are no known potentialretirements from new or emerging environmental regulations.98 SPP conducted Extra High Voltage (EHV) study which is similar to Balance Portfolio in 2008-2009 to examineeconomic projects in SPP footprint2009 Scenario Reliability Assessment Page 147