CAISO Finds Duke Did Not Withhold Power
LCG, Oct. 28, 2001--An analysis of generators' available capacity during May 8, 2001, a day on which rolling blackouts were ordered in California, has found that while earlier California Public Utilities Commission (CPUC) conclusions concerning generators' withholding of power were substantially correct, Duke Energy did not withhold capacity on that day.The California Independent System Operator (ISO) issued a report Friday in response to a request from state Sen. Joe Dunn (D-Santa Ana), who is investigating last year's energy crisis. The grid operator said that outage data provided by the ISO, which was used as the basis for a report last month by the CPUC, may have led the commission to make conclusions about specific generators' reasons for outages which may or may not be correct. The ISO stated in its report that Unit 3 of Duke's Morrow Bay plant was on scheduled outage on May 8, 2001, and that the ISO had asked some of Duke's other generators to reduce output, meaning no remaining capacity was available from the company.According to the ISO, generators did have power available that was not bid into the market and were not always responsive to the grid operators' emergency orders. These behaviors did contribute to a difficult situation when the ISO required power in particular areas, according to its report. The ISO said however, that in discussing the usage of its outage data with the CPUC that the commission "may have used outage data that was useful for depicting outages on a macro level but which was not appropriate for investigation of unit-specific behavior during a specific subset of hours."Among the considerations that the ISO said were not explicitly accounted for in the earlier CPUC report were generating units' ability to increase output at a certain rate, the units' actual capacity as opposed to their rated capacities, and the need to have units back down their output to provide more power later if necessary. Transmission constraints and ISO's need to maintain stable conditions on the grid were also cited by the ISO as not appearing in the CPUC findings.
Copyright © 2006 LCG Consulting. All rights reserved.