The Electric Reliability Council of Texas (ERCOT) said the U.S. Environmental Protection Agency’s Cross State Air Pollution Rule (CSAPR) announced in July leaves the grid operator with "no realistic opportunity to take steps that could even partially mitigate" what it called the loss of "thousands of megawatts" of available operating capacity.
ERCOT made the statement as it released a report, “Impacts of the Cross-State Air Pollution Rule on the ERCOT System,” requested by the state's Public Utility Commission in July.
Based on information provided by the resource owners, ERCOT developed three scenarios of potential impacts from CSAPR:
The first scenario, derived from compliance plans of resource owners, indicates that ERCOT will experience a generation capacity reduction of around 3,000 MW during the off-peak months of March, April, October and November; and 1,200 to 1,400 MW during the other months of the year, including the peak load months of June, July and August.
The second scenario incorporates the potential for increased unit maintenance outages due to daily dispatch of traditionally base-load coal units and results in a generation capacity reduction of around 3,000 MW during the off-peak months of March and April; 1,200 to 1,400 MW during the remainder of the first nine months of the year; and around 5,000 MW during the fall months of October, November and possibly into December.
The third scenario includes Scenario 2 impacts and adds potential impacts from limited availability of imported low-sulfur coal. ERCOT said this scenario results in a generation capacity reduction of around 3,000 MW during the off-peak months of March and April; 1,200 to 1,400 MW during the remainder of the first nine months of the year; and around 6,000 MW during the fall months of October, November and possibly into December.
ERCOT said it had not expected to be included when the CSAPR rule was announced in July. In addition, the rule requires implementation by January 2012. ERCOT said that timeline provides an "extremely truncated period" to assess the rule's affect on reliability and offers "no realistic opportunity" to take steps to mitigate the "substantial losses of available operating capacity" it examined in its report.
The grid operator said, "In short, the CSAPR implementation date does not provide ERCOT and its resource owners a meaningful window for taking steps to avoid the loss of thousands of megawatts of capacity, and the attendant risks of outages for Texas power users."
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