| Summary: | <p> The Regional Greenhouse Gas Initiative (RGGI) is a regionally based carbon dioxide (CO<sub>2</sub>) cap and trade policy. A potential weakness of regional emissions trading policies is that they can incur "leakage" if emission reductions in the targeted area are accomplished by relying more on imports, thereby causing offsetting emission increases in the regions supplying the imports. The member state of New York shares a long electrically interconnected border with non-member state Pennsylvania. Pennsylvania is a source of many coal plants and statewide emissions may increase if coal power is exported to New York. RGGI Leakage is empirically tested for using several models.</p><p> A method is demonstrated to empirically estimate emission and fuel use functions for fuel-burning electric generation units in Texas. Emission functions are necessary for estimating emissions and fuel use when measurements are not available such as in power system simulation scenarios, unit commitment and dispatch decisions, and when measurement equipment is absent, turned off, or malfunctioning. Commonly, the "functions" used assume that emissions of a generation unit are simply a constant multiple of its output. The functions include the impacts of ramping, startup, and shutdown on emissions. The method of their estimation is described and can be extended to any fuel-burning generator in the U.S. that reports hourly generation and emissions via the EPA's Continuous Emissions Monitoring System (CEMS). The accuracy of the emission functions in predicting in-sample and forecasting out-of-sample is shown.</p><p> The regulations governing the reporting requirements for emissions under various EPA mandates offer a possible loophole by way of a calibration exemption. Generators that report emissions from CEMS equipment must calibrate the equipment once every 24 hours. During the hour of calibration generators can take advantage of different emission rates during that hour to under-report emissions. This has potential cost savings due to the need for generators to hold allowances for NO<sub>x</sub> and SO<sub>2</sub> emissions. CEMS data containing the additional information of the hour in which generators calibrate is analyzed to determine if generators are utilizing this loophole.</p><p> The emission functions, which can estimate the impact of calibration on reported emissions, are then used to determine the magnitude of unreported emissions. The emission functions are then used to address a controversy about the emission effects of wind power. Because wind power increases the frequency of startups, shutdowns, and ramping by fuel-burning generators, some have claimed that wind power actually increases emissions. Some have also claimed that emissions reductions may not be as large as constant emissions rates would indicate. Emission functions are calculated for all of the combustion-based generators in Texas, and applied to the output of differing wind power penetration scenarios to carefully estimate the emission impacts of increased wind power penetration.</p>
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