A framework for assessing the CO2 mitigation options for the electricity generation sub-sector

Abstract

The primary objective of this work is to develop an approach for evaluating GHG mitigation strategies that considers the detailed operation of the electricity system in question and to ascertain whether considering the detailed operation of the electricity system materially affects the assessment. A secondary objective is to evalute the potential benefit of flexible CO2 capture and storage.

An electricity system simlator is developed based upon a deregulated electricity system containing markets for both real and reserve power. Using the IEEE RTS ’96 as a test case, the performance of the electricity system is benchmarked with GHG regulation. Two different implementations of CO2 capture are added to the electricity system — fixed CO2 capture and flexible CO2 capture — and the impact of having CCS is assessed.

The results indicate that: - the assessment of GHG mtigation strategies for the electricity generation subsector should consider the detailed operation of the electricity system in question, - cost of generation alone is not necessarily a good indicator of the economic impact of GHG regulation or the deployment of a GHG mitigation strategy, - adding CCS, at even a single generating unit, can significantly reduce GHG emissions and moderate the ecnomic impact of GHG regulation relative to the cases where CCS is not present, and - a generating unit with a flexible CCS processes participates preferentially in the reserve market enabling it to increase its net energy benefit.

It is conclued that there is a significant potential advantage to generating units with flexible CCS processes. The flexibiity of existing and novel CCS process should be an assessment and design criterion, respectively, and the development of novel CCS processes with optimial operability is a suggested area of future research activity.

A reduced-order model of a coal-fired generating unit with flexible CO2 capture is developed and integrated into the MINLP formulation of an economic dispatch model. Both of these efforts, not observed previously in the literature, constitute an important contribution of the work as the methodology provides a template for future assessmments of CCS and other electricity mitigation strategies in the electricity generation subsector.