title: Spatially and Temporally Resolved Analysis of Environmental Trade-Offs in Electricity Generation.
abstract: The US power sector is a leading contributor of emissions that affect air quality and climate. It also requires a lot of water for cooling thermoelectric power plants. Although these impacts affect ecosystems and human health unevenly in space and time, there has been very little quantification of these environmental trade-offs on decision-relevant scales. This work quantifies hourly water consumption, emissions (i.e., carbon dioxide, nitrogen oxides, and sulfur oxides), and marginal heat rates for 252 electricity generating units (EGUs) in the Electric Reliability Council of Texas (ERCOT) region in 2011 using a unit commitment and dispatch model (UC&D). Annual, seasonal, and daily variations, as well as spatial variability are assessed. When normalized over the grid, hourly average emissions and water consumption intensities (i.e., output per MWh) are found to be highest when electricity demand is the lowest, as baseload EGUs tend to be the most water and emissions intensive. Results suggest that a large fraction of emissions and water consumption are caused by a small number of power plants, mainly baseload coal-fired generators. Replacing 8-10 existing power plants with modern natural gas combined cycle units would result in reductions of 19-29%, 51-55%, 60-62%, and 13-27% in CO2 emissions, NOx emissions, SOx emissions, and water consumption, respectively, across the ERCOT region for two different conversion scenarios.
authors.affiliation: Sonny Astani Department of Civil and Environmental Engineering, University of Southern California , 3620 S. Vermont Avenue, Los Angeles, California 90089-2531, United States.
authors.forename: Rebecca A M
authors.initials: RA
authors.lastname: Peer
authors.affiliation: Research Center for Energy Networks, ETH Zürich , Sonneggstrasse 28, SOI C 1, 8092 Zürich, Switzerland.
authors.forename: Jared B
authors.initials: JB
authors.lastname: Garrison
authors.affiliation: Department of Electrical and Computer Engineering, University of Dayton , Kettering Laboratories 341, 300 College Park, Dayton, Ohio 45469-0232, United States.
authors.forename: Craig P
authors.initials: CP
authors.lastname: Timms
authors.affiliation: Sonny Astani Department of Civil and Environmental Engineering, University of Southern California , 3620 S. Vermont Avenue, Los Angeles, California 90089-2531, United States.
authors.forename: Kelly T
authors.initials: KT
authors.lastname: Sanders
mesh_terms: D000397:Air Pollution / Q000517:prevention & control* / Q000706:statistics & numerical data; D002245:Carbon Dioxide / Q000032:analysis; D003031:Coal / Q000032:analysis; D003247:Conservation of Natural Resources / Q000706:statistics & numerical data; D004560:Electricity; D008962:Models, Theoretical; D059206:Natural Gas / Q000032:analysis; D009589:Nitrogen Oxides / Q000032:analysis; D011210:Power Plants; D015203:Reproducibility of Results; D012621:Seasons; D062211:Spatio-Temporal Analysis; D013458:Sulfur Dioxide / Q000032:analysis; D013781:Texas
chemical_list: D003031:Coal; D059206:Natural Gas; D009589:Nitrogen Oxides; D013458:Sulfur Dioxide; D002245:Carbon Dioxide