The water implications of generating electricity: water use across the United States based on different electricity pathways through 2050

Abstract

The power sector withdraws more freshwater annually than any other sector in the US. The current portfolio of electricity generating technologies in the US has highly regionalized and technology-specific requirements for water. Water availability differs widely throughout the nation. As a result, assessments of water impacts from the power sector must have a high geographic resolution and consider regional, basin-level differences. The US electricity portfolio is expected to evolve in coming years, shaped by various policy and economic drivers on the international, national and regional level; that evolution will impact power sector water demands. Analysis of future electricity scenarios that incorporate technology options and constraints can provide useful insights about water impacts related to changes to the technology mix. Utilizing outputs from the regional energy deployment system (ReEDS) model, a national electricity sector capacity expansion model with high geographical resolution, we explore potential changes in water use by the US electric sector over the next four decades under various low carbon energy scenarios, nationally and regionally.

The impact of climate change mitigation on water demand for energy and food: An integrated analysis based on the Shared Socioeconomic Pathways

“…The combination of the calibrated baseyear data on electricity final energy demand with the water withdrawal and consumption coefficients from Macknick et al (2012Macknick et al ( , 2011 and the cooling shares from , result in a good fit of our water demand baseyear values (496 km 3 /year for withdrawal, 26 km 3 /year for consumption excluding hydropower, and 50 for hydropower consumption, Figure 2) …”

“…Water withdrawal and consumption coefficients per electricity output are based on Macknick et al (2012Macknick et al ( , 2011 and shown for the REMIND technologies in SM Table 1. These coefficients have been utilized by numerous studies in the literature analyzing water demand for electricity generation (e.g.…”

“…. The electricity output-based coefficients from Macknick et al (2012Macknick et al ( , 2011 are static in time and have been converted into the coefficients for excess heat for the thermal power plant technologies (cheat) by back calculating the respective value for the US for 2005. Assuming that the cooling efficiency of a technology per unit of excess heat is constant across regions and time, the estimated value is then applied to all regions and time steps.…”

“…Also, since it is associated to large amounts of water, it can highlight more noticeably water scarcity risks associated to the security of electricity supply. The water consumption indicator reflects water that is not directly returned into the water systems, and can have impacts in cases with low water availability (Macknick et al, 2012). …”

Water Impacts of a Low-Carbon Electric Power Future: Assessment Methodology and Status

“…The results show that the water-use constraint could also impact the generation mix and the choice of cooling technology. & Different levels of reductions in energy-system-wide CO 2 emissions Cameron et al evaluated the effects of reducing the energy-system-wide CO 2 emissions by 10 %, 25 %, and 50 % on water use for the US electric power sector [24•]. For the 10 % and 25 % reduction scenarios, the electric power sector account for nearly all of the systemwide reductions.…”