a Energy and Minerals Program , Utah Geological Survey , Salt Lake City , UT , USA.
b Department of Mathematical Sciences , Appalachian State University , Boone , NC , USA.
J Air Waste Manag Assoc. 2019 May;69(5):646-658. doi: 10.1080/10962247.2019.1578702. Epub 2019 Mar 21.
Carbon dioxide (CO) emissions from U.S. power plants are independently reported by the U.S. Energy Information Administration (EIA) and the Clean Air Markets Division (CAMD) within the U.S. Environmental Protection Agency (EPA). Differences between the CAMD and EIA emission tallies show that the amount of CO produced by an individual power plant is less certain than might be imagined or desired. These differences are attributed to systematic error and random measurement error. Random error cannot be retroactively corrected, whereas systematic error can be corrected where relevant data are available. Accordingly, this study identified and, where possible, corrected systematic error affecting the CAMD and EIA CO emission tallies for 1065 power plants that emitted more than 25,000 tons of CO during 2013. The EIA tallies were corrected by accounting for emission factor error, acid-gas sorbent consumption, and combustion of biogenic fuel. The CAMD tallies were likewise corrected by accounting for unreported unit emissions. It was not possible to objectively correct systematic error affecting about 11% of the power plants, and subjective corrections were not attempted. At these plants, the CAMD and EIA emission tallies sometimes differed by more than 20% due to missing unit error, plant identification error, temporal measurement error, or inferred reporting error. Comparisons of the CAMD and EIA emission tallies before and after correction for systematic error show the effectiveness of these corrections. The comparisons also show the persistence of random measurement error. Implications: Understanding the uncertainty of CO2 emission tallies for USA power plants might inform emission inventories, atmospheric flow models or inversions, and emission reduction policies. Knowing the cause and size of measurement errors that contribute to this uncertainty might also help to identify ways to improve the measurement methods and reporting protocols that these CO2 emission tallies are based on.
美国发电厂的二氧化碳（CO）排放量由美国能源信息署（EIA）和美国环境保护署（EPA）内的清洁空气市场司（CAMD）独立报告。CAMD 和 EIA 的排放量差异表明，单个发电厂生产的 CO 量比想象或期望的要不确定。这些差异归因于系统误差和随机测量误差。随机误差无法追溯修正，而系统误差在相关数据可用的情况下可以修正。因此，本研究确定了在 2013 年排放超过 25000 吨 CO 的 1065 个发电厂中，影响 CAMD 和 EIA CO 排放量的系统误差，并在可能的情况下进行了修正。通过考虑排放因子误差、酸性气体吸收剂消耗和生物燃料燃烧，对 EIA 排放量进行了修正。通过考虑未报告的单位排放量，对 CAMD 排放量进行了修正。大约有 11%的发电厂的系统误差无法进行客观修正，也没有尝试进行主观修正。在这些工厂中，由于缺少单位误差、工厂识别误差、时间测量误差或推断报告误差，CAMD 和 EIA 的排放量有时相差 20%以上。对系统误差修正前后的 CAMD 和 EIA 排放量进行比较，表明了这些修正的有效性。比较还表明了随机测量误差的持久性。结论：了解美国发电厂 CO2 排放量的不确定性可能会为排放清单、大气流动模型或反演以及减排政策提供信息。了解导致不确定性的测量误差的原因和大小，也可能有助于确定改进这些 CO2 排放量所依据的测量方法和报告协议的方法。
