Evaluating Environmental Governance along Cross-Border Electricity Supply Chains with Policy-Informed Life Cycle Assessment: The California–Mexico Energy Exchange

Abstract

This paper presents a "policy-informed" life cycle assessment of a cross-border electricity supply chain that links the impact of each unit process to its governing policy framework. An assessment method is developed and applied to the California-Mexico energy exchange as a unique case study. CO-equivalent emissions impacts, water withdrawals, and air quality impacts associated with California's imports of electricity from Mexican combined-cycle facilities fueled by natural gas from the U.S. Southwest are estimated, and U.S. and Mexican state and federal environmental regulations are examined to assess well-to-wire consistency of energy policies. Results indicate most of the water withdrawn per kWh exported to California occurs in Baja California, most of the air quality impacts accrue in the U.S. Southwest, and emissions of CO-equivalents are more evenly divided between the two regions. California energy policy design addresses generation-phase CO emissions, but not upstream CO-eq emissions of methane during the fuel cycle. Water and air quality impacts are not regulated consistently due to varying U.S. state policies and a lack of stringent federal regulation of unconventional gas development. Considering local impacts and the regulatory context where they occur provides essential qualitative information for functional-unit-based measures of life cycle impact and is necessary for a more complete environmental impact assessment.

Environmental Health and Policy at the Tijuana-San Diego Border

“…In response to market devaluation in the 1990s (around the same time that NAFTA was negotiated and implemented to ease trade across international borders), the U.S. contracted a few major energy plants in Baja California, Mexico and connected them to power distribution networks in San Diego. Currently, over 40% of the energy produced in Baja California is directly distributed to the U.S. (Bolorinos et al 2018).…”

“…These facilities emit several air pollutants: greenhouse gases (GHGs) which are measured through levels of methane and CO 2 , NO 2 , volatile organic compounds (VOCs), and particulate matter (PM 10 and PM 2.5 ). VOCs and NO 2 react to create ground-level ozone, and this can generate harmful consequences for surrounding communities, including asthma and other major respiratory issues (Bolorinos et al 2018).…”

“…Electric power plants are the single greatest emitters of toxic air pollutants in all of North America, and plants at the border region contributes to this (Carruthers 2007). Bolorinos et al (2018) specifically measured two U.S.-contracted plants, La Rosita and Termoeléctrica de Mexicali, to determine the effects of their air pollution. Both of these plants export electricity to San Diego's power distribution networks and are fueled by natural gas.…”

“…Both of these plants export electricity to San Diego's power distribution networks and are fueled by natural gas. Bolorinos et al (2018) discovered that GHGs are evenly distributed across both sides of the border. The health impacts of these GHGs are concentrated in the Tijuana-San Diego border region and along the remainder of the California-Mexico border (Bolorinos et al 2018).…”