2009 Scenario Reliability Assessment - NERC

Scenario Reliability Self-Assessmentsconducted by PJM and MISO for their respective RTOs. The reserve margins in both thereference and Scenario Cases are 23 percent. These reserves do not require a reliance on externalresources to satisfy Regional demand. They are also sufficient to satisfy demand levels above thebase 50/50 demand forecast.However, there would be an expected increase in net imports, as the amount of renewable energyneeded to satisfy Renewable Portfolio Standards (RPS) is likely to create a need to import windand other renewable resources.Generating unit retirements between the Reference Case and the Scenario Case are identical.However, as mentioned in the operations section above, when wind generation penetrationreaches a level where many of these older and less efficient baseload fossil-fueled facilitiesbecome sporadically dispatched day-in and day-out, owners may contemplate an early retirementof those baseload facilities.The JCSP study did not address the issue of deliverability since this was a first-ever conceptualtypestudy. Both MISO and PJM have detailed deliverability criteria and conduct studies on aregular basis to determine the deliverability of generation resources. These detaileddeliverability studies would need to be performed prior to the new generation coming on-line inthe future.It is assumed that new wind facilities that may be integrated into the system would comply withFERC Order 660-1A, which addresses the need for low-voltage ride-through capabilities andreactive power capabilities of individual wind turbines. In both the Midwest ISO and PJM,reactive power analysis is one integrated part of every individual Generation InterconnectionSystem Impact Study. No wind plant can be granted interconnection services without mitigatingthe incremental reactive support problem it would cause. The PJM Ancillary Service Market, theMidwest ISO Ancillary Service Market and the Midwest Contingency Reserve Sharing Groupprovide financial incentives and legal obligations to ensure that the entire Midwest ISO systemhas adequate frequency response support in both the short term and long term. The Midwest ISObelieves that wind forecast accuracy is critical to minimizing unexpected ramps in windproduction which in turn would minimize the requirement for additional reactive and frequencysupport requirements. Generator characteristics would be reviewed to identify more responsiveunits, which also may alleviate reactive or frequency response issues.The Midwest ISO and PJM are actively working with their stakeholders to determine the bestsolution to be able to incorporate large amounts of wind. Accurate wind forecasts for the DayAhead market process and accurate and timely updates during the operating day would need tooccur in order to incorporate wind generation into the Day Ahead market. Equitably allocatingcosts for reserve sharing would need to be developed, also. In addition, it may be necessary tochange operating reserve requirements, regarding the amount of operating reserves, the type ofoperating reserves, and the deployment of operating reserves.Fuel supply vulnerability was not analyzed in these cases. There is no significant changeexpected to the resulting fossil fuel mix as a result of the Scenario Case. The significant increase2009 Scenario Reliability Assessment Page 133