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Abstract Annual carbon dioxide (CO2) emissions from the U.S. power sector decreased 24% from 2000 to 2018, while carbon intensity (CO2per unit of electricity generated) declined by 34%. These reductions have been attributed in part to a shift from coal to natural gas, as gas‐fired plants emit roughly half the CO2emissions as coal plants. To date, no analysis has looked at the coal‐to‐gas shift from the perspective of commitment accounting—the cumulative future CO2emissions expected from power infrastructure. We estimate that between 2000 and 2018, committed emissions in the U.S. power sector decreased 12% (six GtCO2), from 49 to 43 GtCO2, assuming average generator lifetimes and capacity factors. Taking into consideration methane leakage during the life cycle of coal and gas plants, this decrease in committed emissions is further offset (e.g., assuming a 3% leakage rate, there is effectively no reduction at all). Thus, although annual emissions have fallen, cumulative future emissions will not be substantially lower unless existing coal and gas plants operate at significantly lower rates than they have historically. Moreover, our estimates of committed emissions for U.S. coal and gas plants finds steep reductions in plant use and/or early retirements are already needed for the country to meet its targets under the Paris climate agreement—even if no new fossil capacity is added.
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Spatially Allocating Life Cycle Water Use for US Coal‐Fired Electricity across Producers, Generators, and Consumers
There are water consequences across every life cycle stage of coal‐fired electricity consumption, from production and processing to combustion, which have not been studied with regional specificity. There is often a spatial decoupling between where coal is produced and processed versus where it is combusted for power generation, complicating any analysis to estimate the life cycle water implications of electricity consumption. Furthermore, electricity generated by coal‐fired power plants can be consumed within its own balancing authority or exported to another balancing authority. This analysis spatially resolves the water consumed and water withdrawn for coal mining, coal preparation, and power plant cooling from 1) where the coal is mined to where the coal is burned for power production and 2) where the electricity is generated to where the electricity is consumed. Although the largest portion of coal consumed came from the Northern Great Plains province, coal from this region consumes the least amount of water for mining and preparation compared with other provinces. Water withdrawals for cooling power plants within each balancing authority are driven by cooling technology. Due to the interconnected grid, there can be differences between attributing water footprint at the producer level versus the consumer level.
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- Award ID(s):
- 1845931
- PAR ID:
- 10200623
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Energy Technology
- Volume:
- 8
- Issue:
- 11
- ISSN:
- 2194-4288
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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