Kelly T. Sanders

Evaluating the energy consumed for water use in the United States

This letter consists of a first-order analysis of the primary energy embedded in water in the United States. Using a combination of top-down sectoral assessments of energy use together with a bottom-up allocation of energy-for-water on a component-wise and service-specific level, our analysis concludes that energy use in the residential, commercial, industrial and power sectors for direct water and steam services was approximately 12:3 0:3 quadrillion BTUs or 12.6% of the 2010 annual primary energy consumption in the United States. Additional energy was used to generate steam for indirect process heating, space heating and electricity generation.

Spatially and Temporally Resolved Analysis of Environmental Trade-Offs in Electricity Generation

The US power sector is a leading contributor of emissions that affect air quality and climate. It also requires a lot of water for cooling thermoelectric power plants. Although these impacts affect ecosystems and human health unevenly in space and time, there has been very little quantification of these environmental trade-offs on decision-relevant scales. This work quantifies hourly water consumption, emissions (i.e., carbon dioxide, nitrogen oxides, and sulfur oxides), and marginal heat rates for 252 electricity generating units (EGUs) in the Electric Reliability Council of Texas (ERCOT) region in 2011 using a unit commitment and dispatch model (UC&D). Annual, seasonal, and daily variations, as well as spatial variability are assessed. When normalized over the grid, hourly average emissions and water consumption intensities (i.e., output per MWh) are found to be highest when electricity demand is the lowest, as baseload EGUs tend to be the most water and emissions intensive. Results suggest that a large fraction of emissions and water consumption are caused by a small number of power plants, mainly baseload coal-fired generators. Replacing 8-10 existing power plants with modern natural gas combined cycle units would result in reductions of 19-29%, 51-55%, 60-62%, and 13-27% in CO2 emissions, NOx emissions, SOx emissions, and water consumption, respectively, across the ERCOT region for two different conversion scenarios.

Clean energy and water: assessment of Mexico for improved water services and renewable energy

Vast natural resources and strained water supplies make Mexico a valuable geographic setting for studying the energy-water nexus. While Mexico has historically been a major oil producing country, it struggles with water stress, as much of its land area is experiencing or approaching physical water scarcity. Solving many of Mexico’s water issues will require energy for extracting, transporting, and treating water where it is needed most. Yet such energy use is not always possible since many people are not connected to an electricity grid or other decentralized energy infrastructure. In addition, a continuation of the almost decade-long trend of declining oil production and exports might reduce revenues and available energy to fund and operate new water systems. Consequently, there is an opportunity to improve water services through use of distributed renewable energy technologies that do not directly require fossil resources or large-scale infrastructure. Various policies and technologies are relevant to the energy-water nexus on a decentralized scale, which are covered in this manuscript. We use an integrated technology policy framework to assess the efficacy of integrating renewable energy and water systems in Mexico via case studies of technologies affecting energy-water policy objectives and choices. Particularly, important factors for technology development include consideration of performance parameters, cultural acceptance, willingness to pay, and financing.

The energy trade-offs of adapting to a water-scarce future: case study of Los Angeles

Increasing water competition, population growth and global climate change will intensify the tension between water and energy resources in arid climates of the world, since energy costs underscore the challenges facing water security in dry regions. In few places is the tension between water and energy resources more pronounced than in Los Angeles, California. This article analyzes the city’s current water supply and estimates its future energy requirements based on water supply projections from the Los Angeles Department of Water and Power. Results suggest that while increasing local water management strategies could reduce the future energy intensity of the water supply, an increased reliance on water transfers could worsen its future energy intensity.Abstract Increasing water competition, population growth and global climate change will intensify the tension between water and energy resources in arid climates of the world, since energy costs underscore the challenges facing water security in dry regions. In few places is the tension between water and energy resources more pronounced than in Los Angeles, California. This article analyzes the city’s current water supply and estimates its future energy requirements based on water supply projections from the Los Angeles Department of Water and Power. Results suggest that while increasing local water management strategies could reduce the future energy intensity of the water supply, an increased reliance on water transfers could worsen its future energy intensity.

A comparative analysis of the greenhouse gas emissions intensity of wheat and beef in the United States

The US food system utilizes large quantities of liquid fuels, electricity, and chemicals yielding significant greenhouse gas (GHG) emissions that are not considered in current retail prices, especially when the contribution of biogenic emissions is considered. However, because GHG emissions might be assigned a price in prospective climate policy frameworks, it would be useful to know the extent to which those policies would increase the incremental production costs to food within the US food system. This analysis uses lifecycle assessment (LCA) to (1)?estimate the magnitude of carbon dioxide equivalent (CO2e) emissions from typical US food production practices, using wheat and beef as examples, and (2)?quantify the cost of those emissions in the context of a GHG-pricing regime over a range of policy constructs. Wheat and beef were chosen as benchmark staples to provide a representative range of less intensive and more intensive agricultural goods, respectively. Results suggest that 1.1???0.13 and 31???8.1?kg of lifecycle CO2e emissions are embedded in 1?kg of wheat and beef production, respectively. Consequently, the cost of lifecycle CO2e emissions for wheat (i.e. cultivation, processing, transportation, storage, and end-use preparation) over an emissions price range of?

Rising Temperatures, Rising Risks: The Food-Energy-Water Nexus in the Persian Gulf

10 and

Utilizing a Unit Commitment and Dispatch Model to Temporally Resolve Water Use Data in the Western United States' Power Sector

85 per tonne CO2e is estimated to be between

Water Use in the United States Energy System: A National Assessment and Unit Process Inventory of Water Consumption and Withdrawals

0.01 and

A Quantitative Assessment of Temporally-Resolved Environmental Trade-Offs in the Power Sector

0.09 per kg of wheat, respectively, which would increase total wheat production costs by approximately 0.3?2% per kg. By comparison, the estimated lifecycle CO2e price of beef over the same range of CO2e prices is between?

Critical Review: Uncharted Waters? The Future of the Electricity-Water Nexus

0.31 and