ANALYSIS OF WATER USAGE AND GREENHOUSE GAS EMISSIONS AS TRANSITION FUEL FROM COAL TO NATURAL GAS IN SAN JUAN COUNTY, NEW MEXICO

Abstract Coal is a major contributor to various environmental issues, making the transition to alternative energy sources essential for reducing environmental impacts and combating climate change. San Juan County in New Mexico has historically depended on coal-fired power plants for producing electricity. However, due to environmental and economic pressures, there is a move to reassess energy strategies. This study explores the transition from coal to natural gas (NG) in San Juan County, with a focus on assessing changes in water usage and emissions (CO2, NOx, and SO2) at the Four Corners (coal-fired) and Afton (natural gas-fired) power plants. The research utilized linear regression to analyze historical data from the power plants. Four scenarios were analyzed: 100% coal-generated electricity, a 20% reduction in coal with a corresponding increase in NG, a 50% reduction in coal with a corresponding increase in NG, and a complete transition to NG. Regression analysis and scenario calculations indicate that switching to NG leads to significant water savings and reduction in emissions. Water saving up to 2750 gallons per MWh, valued at $0.743 per MWh when generation 100% from NG. CO2 emissions were substantially reduced, with the greatest decrease being 0.612683 metric tons per MWh, valued at $61.26 per MWh when transitioning to NG completely. NOx emissions were cut by 0.0017946 metric tons per MWh, with an economic value of $14.61 per MWh, and SO2 emissions were reduced by 0.000611 metric tons per MWh, valued at $11.91 per MWh when generation 100% from NG. The results underscore the environmental and economic advantages of moving from coal to NG. Water conservation is especially critical in the semi-arid climate of San Juan County. Moreover, lower emissions help mitigate climate change, improve air quality, and promote public health. The economic valuation of emission reductions shows significant financial benefits, positioning NG as a more viable and sustainable energy option for the region. This study emphasizes the significance of embracing cleaner energy sources for environmental sustainability and economic gain.