Feasibility of Wind Power for Brackish Groundwater Desalination: A Case Study of the Energy-Water Nexus in Texas

2010 ◽  
Author(s):  
Ashlynn S. Stillwell ◽  
Michael E. Webber
Keyword(s):  
Drinking Water ◽  
Energy Consumption ◽  
Wind Power ◽  
Wind Turbines ◽  
Carbon Emissions ◽  
Groundwater Resources ◽  
Water Sources ◽  
Additional Energy ◽  
West Texas ◽  
Membrane Treatment

With dwindling water supplies and the impacts of climate change, many cities are turning to water sources previously considered unusable. One such source for inland cities is brackish groundwater. With prolonged drought throughout Texas, cities such as El Paso, Lubbock, and San Antonio are desalinating brackish groundwater to supplement existing water sources. Similar projects are under consideration elsewhere in Texas. While brackish groundwater contains fewer total dissolved solids than seawater, desalination of brackish groundwater is still an energy-intensive process. Brackish water desalination using reverse osmosis, the most common desalination membrane treatment process, consumes 20 to 40 times more energy than traditional surface water treatment using local water sources. This additional energy consumption leads to increased carbon emissions when using fossil fuel-generated electricity. As a result of concern over greenhouse gas emissions from additional energy consumption, some desalination plants are powered by wind-generated electricity. West Texas is a prime area for desalination of brackish groundwater using wind power, since both wind and brackish groundwater resources are abundant in the area. Most of the Texas Panhandle and Plains region has wind resource potential classified as Class 3 or higher. Additionally, brackish groundwater is found at depths less than 150 m in most of west Texas. This combination of wind and brackish groundwater resources presents opportunities for the production of alternative drinking water supplies without severe carbon emissions. Additionally, since membrane treatment is not required to operate continuously, desalination matches well with variable wind power. Implementing a brackish groundwater desalination project using wind-generated electricity requires economic feasibility, in addition to the geographic availability of the two resources. Using capital and operating cost data for wind turbines and desalination membranes, we conducted a thermoeconomic analysis for three parameters: 1) transmission and transport, 2) geographic proximity, and 3) aquifer volume. Our first parameter analyzes the cost effectiveness of tradeoffs between building infrastructure to transmit wind-generated electricity to the desalination facility versus pipelines to transport brackish groundwater to the wind turbines. Secondly, we estimate the maximum distance between the wind turbines and brackish groundwater at which desalination using wind power remains economically feasible. Finally, we estimate the minimum available brackish aquifer volume necessary to make such a project profitable. Our analysis illustrates a potential drinking water option for Texas (and other parts of the world with similar conditions) using renewable energy to treat previously unusable water. Harnessing these two resources in an economically efficient manner may help reduce future strain on the energy-water nexus.

Implementation of Brackish Groundwater Desalination Using Wind-Generated Electricity as a Proxy for Energy Storage: A Case Study of the Energy-Water Nexus in Texas

2011 ◽  
Author(s):  
Mary E. Clayton ◽  
Ashlynn S. Stillwell ◽  
Michael E. Webber
Keyword(s):  
Drinking Water ◽  
Energy Storage ◽  
Wind Power ◽  
Groundwater Resources ◽  
Compressed Air ◽  
Energy Sources ◽  
Low Carbon ◽  
West Texas ◽  
Storage Technologies ◽  
Low Carbon Energy

With a push toward renewable electricity generation, wind power has grown substantially in recent U.S. history and technologies continue to improve. However, the intermittency associated with wind-generated electricity without storage has limited the amounts sold on the grid. Furthermore, continental wind farms have a diurnal and seasonal variability that is mismatched with demand. To increase the broader use of wind power technologies, the development of systems that can operate intermittently during off-peak hours must be considered. Utilization of wind-generated electricity for desalination of brackish groundwater presents opportunities to increase use of a low-carbon energy source and supply alternative drinking water that is much needed in some areas. As existing water supplies dwindle and population grows, cities are looking for new water sources. Desalination of brackish groundwater provides one potential water source for inland cities. However, this process is energy-intensive, and therefore potentially incongruous with goals of reducing carbon emissions. Desalination using reverse osmosis is a high-value process that does not require continuous operation and therefore could utilize variable wind power. That is, performing desalination in an intermittent way to match wind supply can help mitigate the challenges of integrating wind into the grid while transforming a low-value product (brackish water and intermittent power) into a high-value product (treated drinking water). This option represents a potentially more economic form of mitigating wind variability than current electricity storage technologies. Also, clean energy and carbon policies under consideration by the U.S. Congress could help make this integration more economically feasible due to incentives for low-carbon energy sources. West Texas is well-suited for desalination of brackish groundwater using wind power, as both resources are abundant and co-located. Utility-scale wind resource potential is found in most of the region. Additionally, brackish groundwater is found at depths less than 150 m, making west Texas a useful geographic testbed to analyze for this work, with applicability for areas with similar climates and water supply scarcity. Implementation of a wind-powered desalination project requires both economic and geographic feasibility. Capital and operating cost data for wind turbines and desalination membranes were used to perform a thermoeconomic analysis to determine the economic feasibility. The availability of wind and brackish groundwater resources were modeled using geographic information systems tools to illustrate areas where implementation of a wind-powered desalination project is economically feasible. Areas with major populations were analyzed further in the context of existing and alternative water supplies. Utilization of wind-generated electricity for desalination presents a feasible alternative to energy storage methods. Efficiency, economics, and ease of development and operation of off-peak water treatment were compared to different energy storage technologies: pumped hydro, batteries, and compressed air energy storage. Further economics of compressed air energy storage and brackish groundwater desalination were examined with a levelized lifetime cost approach. Implementation of water desalination projects using wind-generated electricity might become essential in communities with wind and brackish groundwater resources that are facing water quality and quantity issues and as desires to implement low carbon energy sources increase. This analysis assesses the economic and geographic feasibility and tradeoffs of such projects for areas in Texas.

scholarly journals Design Aspects, Energy Consumption Evaluation, and Offset for Drinking Water Treatment Operation

Water ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1772
Author(s):  
Saria Bukhary ◽  
Jacimaria Batista ◽  
Sajjad Ahmad
Keyword(s):  
Drinking Water ◽  
Energy Consumption ◽  
Water Treatment ◽  
Carbon Emissions ◽  
Water Distribution ◽  
Net Present Value ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Solar Pv ◽  
Pv System

Drinking water treatment, wastewater treatment, and water distribution are energy-intensive processes. The goal of this study was to design the unit processes of an existing drinking water treatment plant (DWTP), evaluate the associated energy consumption, and then offset it using solar photovoltaics (PVs) to reduce carbon emissions. The selected DWTP, situated in the southwestern United States, utilizes coagulation, flocculation, sedimentation, filtration, and chlorination to treat 3.94 m3 of local river water per second. Based on the energy consumption determined for each unit process (validated using the plant’s data) and the plant’s available landholding, the DWTP was sized for solar PV (as a modeling study) using the system advisor model. Total operational energy consumption was estimated to be 56.3 MWh day−1 for the DWTP including water distribution pumps, whereas energy consumption for the DWTP excluding water distribution pumps was 2661 kWh day−1. The results showed that the largest consumers of energy—after the water distribution pumps (158.1 Wh m−3)—were the processes of coagulation (1.95 Wh m−3) and flocculation (1.93 Wh m−3). A 500 kW PV system was found to be sufficient to offset the energy consumption of the water treatment only operations, for a net present value of $0.24 million. The net reduction in carbon emissions due to the PV-based design was found to be 450 and 240 metric tons CO2-eq year−1 with and without battery storage, respectively. This methodology can be applied to other existing DWTPs for design and assessment of energy consumption and use of renewables.

scholarly journals An Analysis of Energy Consumption and the Use of Renewables for a Small Drinking Water Treatment Plant

Water ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 28 ◽  
Author(s):  
Saria Bukhary ◽  
Jacimaria Batista ◽  
Sajjad Ahmad
Keyword(s):  
Drinking Water ◽  
Energy Consumption ◽  
Water Treatment ◽  
Carbon Emissions ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Battery Storage ◽  
Drinking Water Treatment Plant ◽  
Modeling Study

One of the pressing issues currently faced by the water industry is incorporating sustainability considerations into design practice and reducing the carbon emissions of energy-intensive processes. Water treatment, an indispensable step for safeguarding public health, is an energy-intensive process. The purpose of this study was to analyze the energy consumption of an existing drinking water treatment plant (DWTP), then conduct a modeling study for using photovoltaics (PVs) to offset that energy consumption, and thus reduce emissions. The selected plant, located in southwestern United States, treats 0.425 m3 of groundwater per second by utilizing the processes of coagulation, filtration, and disinfection. Based on the energy consumption individually determined for each unit process (validated using the DWTP’s data), the DWTP was sized for PVs (as a modeling study). The results showed that the dependency of a DWTP on the traditional electric grid could be greatly reduced by the use of PVs. The largest consumption of energy was associated with the pumping operations, corresponding to 150.6 Wh m−3 for the booster pumps to covey water to the storage tanks, while the energy intensity of the water treatment units was found to be 3.1 Wh m−3. A PV system with a 1.5 MW capacity with battery storage (30 MWh) was found to have a positive net present value and a levelized cost of electricity of 3.1 cents kWh−1. A net reduction in the carbon emissions was found as 950 and 570 metric tons of CO2-eq year−1 due to the PV-based design, with and without battery storage, respectively.

scholarly journals Optimal Peak Shifting of a Microgrid Load Based on Deep Q-Learning Network

2020 ◽  
Author(s):  
Mostafa Algabalawy ◽  
Nesreen Hosny
Keyword(s):  
Reinforcement Learning ◽  
Energy Consumption ◽  
Carbon Emissions ◽  
Optimization Problem ◽  
Optimization Problems ◽  
Energy Requirement ◽  
Future Research ◽  
Multi Objective Optimization ◽  
Additional Energy ◽  
Multi Objective

Abstract Background: Peak periods are a result of consumers generally using electricity at similar times and periods as each other, for example, turning lights on when returning home from work, or the widespread use of air conditioners during the summer. Without peak shifting, the grid’s system operators are forced to use peaked plants to provide the additional energy, the operation of which is incredibly expensive and dangerous to the environment due to their high levels of carbon emissions.Methods: Battery storage system (BSS) has been used to allow for the purchase the energy during off-peak periods for later use, with the primary objective of achieving peak shifting, is explored. In addition, reduction in energy consumption and the lowering of consumer’s utility bills are also sought, making this a multi-objective optimization problem. Reinforcement learning methods are implemented to provide a solution to this problem by finding an optimal control policy which defines when is best to purchase and store energy with the objectives in mind.Results: This achieves over a 20% reduction in energy consumption and consumers’ energy bills, as well as achieving perfect peak shifting, thereby removing peaking plants from the equation entirely. This result was obtained using a simulator that the author has developed specifically for this task, which handles the model training, testing, and evaluation process. Secondly, the development of a novel technique, automatic penalty shaping, was also found to be crucial to the success of the learned model. This technique enabled the automatic shaping of the reward signal, forcing the agent to pay equal attention to multiple individual signals, a necessity when applying reinforcement learning to multi-objective optimization problems. The policy does, however, attempt to overcharge the battery about 7% of the time, and promising methods to address this has been proposed as a direction for future research.Conclusion: The aim of this task was to verify that reinforcement learning is a suitable solution method to the peak demand problem. That is, can reinforcement learning be used in conjunction with a BSS to purchase energy at off-peak periods, in order to flatten the energy requirement profile of consumers. Such an achievement would prevent the grid’s system operators from needing to use peaked plants to provide additional energy during peak periods, lowering carbon emissions and energy prices for the consumer. This peak-shifting would allow the grid’s system operators to be able to more easily predict electricity demand, thereby reducing their need to generate more energy than necessary, again lowering the tariffs for energy for the consumer. Secondary aims of directly reducing the energy consumption and utility bills were also sought, making this a multi-objective optimization problem. The used data, in conjunction with the created simulator which performs the full training and testing phases of the models, to find an optimal policy using the deep Q-network (DQN) and Proximal Policy Optimization (PPO) reinforcement learning algorithms. Finally, the proposed algorithm is able to achieve perfect peak shifting, a reduction in the monthly utility bill by 21% and also a reduction in energy consumption by 23%, achieving all of the aims of the task.

Hygiene Aspects of Drinking Water Sources Used in Primary Milk Production

2016 ◽  
Vol 1 (6) ◽  
pp. 311-317
Author(s):  
Nada Sasakova ◽  
Gabriela Gregova ◽  
Jan Venglovsky ◽  
Ingrid Papajova ◽  
Bozena Nowakowicz-Debek ◽  
...  
Keyword(s):  
Drinking Water ◽  
Milk Production ◽  
Water Sources ◽  
Drinking Water Sources

EXPERIMENTAL AND ANALYTICAL STUDIES OF VERTICAL AXIS WIND TURBINES

2018 ◽  
pp. 51-58
Author(s):  
B. P. Khozyainov
Keyword(s):  
Wind Turbine ◽  
Flow Velocity ◽  
Wind Power ◽  
Wind Turbines ◽  
Power Efficiency ◽  
Air Flow ◽  
Geometrical Parameters ◽  
Wind Speeds ◽  
Analytical Studies ◽  
Air Flow Velocity

The article carries out the experimental and analytical studies of three-blade wind power installation and gives the technique for measurements of angular rate of wind turbine rotation depending on the wind speeds, the rotating moment and its power. We have made the comparison of the calculation results according to the formulas offered with the indicators of the wind turbine tests executed in natural conditions. The tests were carried out at wind speeds from 0.709 m/s to 6.427 m/s. The wind power efficiency (WPE) for ideal traditional installation is known to be 0.45. According to the analytical calculations, wind power efficiency of the wind turbine with 3-bladed and 6 wind guide screens at wind speedsfrom 0.709 to 6.427 is equal to 0.317, and in the range of speed from 0.709 to 4.5 m/s – 0.351, but the experimental coefficient is much higher. The analysis of WPE variations shows that the work with the wind guide screens at insignificant average air flow velocity during the set period of time appears to be more effective, than the work without them. If the air flow velocity increases, the wind power efficiency gradually decreases. Such a good fit between experimental data and analytical calculations is confirmed by comparison of F-test design criterion with its tabular values. In the design of wind turbines, it allows determining the wind turbine power, setting the geometrical parameters and mass of all details for their efficient performance.

Resorcinarene Cavitand Polymers for the Remediation of Halomethanes and 1,4-Dioxane

2019 ◽  
Author(s):  
Luke Skala ◽  
Anna Yang ◽  
Max Justin Klemes ◽  
Leilei Xiao ◽  
William Dichtel
Keyword(s):  
Drinking Water ◽  
Activated Carbon ◽  
High Capacity ◽  
The United States ◽  
Water Sources ◽  
Disinfection Byproducts ◽  
Porous Polymer ◽  
Organic Micropollutants ◽  
Executive Summary ◽  
Regulatory Limits

<p>Executive summary: Porous resorcinarene-containing polymers are used to remove halomethane disinfection byproducts and 1,4-dioxane from water.<br></p><p><br></p><p>Disinfection byproducts such as trihalomethanes are some of the most common micropollutants found in drinking water. Trihalomethanes are formed upon chlorination of natural organic matter (NOM) found in many drinking water sources. Municipalities that produce drinking water from surface water sources struggle to remain below regulatory limits for CHCl<sub>3</sub> and other trihalomethanes (80 mg L<sup>–1</sup> in the United States). Inspired by molecular CHCl<sub>3</sub>⊂cavitand host-guest complexes, we designed a porous polymer comprised of resorcinarene receptors. These materials show higher affinity for halomethanes than a specialty activated carbon used for trihalomethane removal. The cavitand polymers show similar removal kinetics as activated carbon and have high capacity (49 mg g<sup>–1</sup> of CHCl<sub>3</sub>). Furthermore, these materials maintain their performance in real drinking water and can be thermally regenerated under mild conditions. Cavitand polymers also outperform activated carbon in their adsorption of 1,4-dioxane, which is difficult to remove and contaminates many public water sources. These materials show promise for removing toxic organic micropollutants and further demonstrate the value of using supramolecular chemistry to design novel absorbents for water purification.<br></p>

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