Reduced-Order Dispatch Model for Simulating Marginal Emissions Factors for the United States Power Sector

Abstract

This study develops a reduced-order power plant dispatch model and uses it to simulate marginal emissions factors (MEFs) for the 2014−2017 United States (U.S.) electric grid at the North American Electric Reliability Corporation (NERC) regional level. MEFs help quantify the health, environmental, and climate change impacts caused by changes in marginal net electricity consumption, which could result, for example, from new technologies or policies. This study develops the model, validates it against historical data, and compares its simulated MEFs against historically derived regression-based MEFs. Our method accurately reproduces CO 2 , SO 2 , and NO x emissions for multiple U.S. NERC regions and years and enables us to analyze future scenarios that are absent from the historical data. Though historically derived regression-based MEFs are generally more accurate, our simulated MEFs provide a more nuanced picture of how clusters of low-or high-emitting power plants of similar production cost create large swings in MEFs throughout the day. Policymakers could use these dynamic MEFs to target demand-reduction strategies at high-emissions portions of the power plant merit order.

Potential greenhouse gas risk led by renewable energy crowding out nuclear power

“…Such underestimation does not affect our main conclusion that VRECON causes GHG emissions increase. In addition, this simplified method is often used to study the issues related to electricity systems ( Deetjen and Azevedo, 2019 ; Fell and Linn, 2013 ; Linn and Shih, 2019 ). The lists of sets, variables, and parameters are as follow.…”

Methodology for Calculation of the Marginal Emission Rates from a ComplexCogeneration Facility compared with that of the co-located NY ISO Bus

“…The result has been a myriad of papers focused on average emissions; discussions of "Green Products" and "Green Companies." [1,2,3] In addition, one early article [4] has led to the development of a commercial product, WattTime. [5] There have been only a limited number of marginal methodologies proposed and many of those were developed by a subset of the authors of this paper or by others based on the theory developed by the authors.…”

“…To begin, consider an electrical grid as a whole and assume that at any moment that we can measure the total mass of carbon emissions released by all interconnected generators. Thus, let C(t) be total mass of CO2 emissions produced by the electrical grid measured in tons of CO2 over time period t. The MER (introduced as Marginal Carbon Intensity (MCI) in [1]) is equal to the increase or decrease in CO2 emissions in the electrical network in response to an infinitesimal increase or decrease in electricity supply or demand and measured in short tons (sh. tn/MWh).…”

“…The carbon emissions of the continental US electric power sector have been decreasing significantly in over the past decade. The electric power sector as a whole has declined from a peak of 2424 million metric tons of CO2 in 2007 to 1763 million metric tons in 2018 representing a decline in percentage of total US 1 emissions from 40.4% to 33.5%. 1 Large-scale combined heat and power installations such as institutional cogeneration facilities are being challenged to demonstrate that they too are reducing emissions, i.e., reducing their carbon footprint and, critically, that they are doing so in a manner that assures maximum economic efficiency of their operations.…”

Comparing empirical and model-based approaches for calculating dynamic grid emission factors: An application to CO2-minimizing storage dispatch in Germany

“…Deetjen and Azevedo [34] chose a different approach, by developing a simplified merit order model. The data sources are specific to some US power markets.…”