Spatially Allocating Life Cycle Water Use for US Coal‐Fired Electricity across Producers, Generators, and Consumers

Abstract

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 This analysis spatially resolves the water consumed and water withdrawn for coal mining, coal preparation, and power plant cooling from 1) where the coal is mined to where the coal is burned for power production and 2) where the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.

Monthly virtual water transfers on the U.S. electric grid

“…As previously alluded to, most were multi-year and single year studies, and only three focused on sub-annual timescales scale [31][32][33]. Additionally, most studies investigated virtual water for energy trade in China, and only 9 investigated virtual water transfers associated with energy trade in the United States [21][22][23][24][25][26][27][28][29]. Of these 9 studies, only 8 investigate virtual water for electricity trade and most focus on a limited region in the United States.…”

“…Understanding this network of virtual water transfers allows regulators and planners to identify the burden shift between consumers and producers. The virtual water trade of energy is an established focus in the literature [21][22][23][24][25][26][27][28][29]. Figure 1 provides an illustration of the sources of virtual water of electricity and depicts how this water is transferred to end users, sometimes significant distances, within and between balancing authorities.…”