scholarly journals Analysis of a Wave-Powered, Reverse-Osmosis System and its Economic Availability in the United States

Author(s):  
Yi-Hsiang Yu ◽  
Dale Jenne

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to permeate saltwater through the reverse-osmosis membrane to generate clean water. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production in the United States. The model was developed by coupling a time-domain radiation-and-diffraction-method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis process. To evaluate the feasibility of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The annual water production was estimated based on the wave resource at a reference site on the coast of northern California to investigate the potential cost of water in that area, where the cost of water and electricity is high compared to other regions. In the scenario evaluated, for a 100-unit utility-scale array, the estimated levelized cost of energy for these WECs is about 3–6 times the U.S.’s current, unsubsidized electricity rates. However, with clean water as an end product and by directly producing pressurized water with WECs, rather than electricity as an intermediary, it is presently only 12% greater than typical water cost in California. This study suggests that a WEC array that produces water may be a viable, near-term solution to the nation’s water supply, and the niche application of the WPDS may also provide developers with new opportunities to further develop technologies that benefit both the electric and drinking water markets.

2018 ◽  
Vol 6 (4) ◽  
pp. 132
Author(s):  
Yi-Hsiang Yu ◽  
Dale Jenne

A wave energy converter (WEC) system has the potential to convert the wave energy resource directly into the high-pressure flow that is needed by the desalination system to pump saltwater to the reverse-osmosis membrane and provide the required pressure level to generate freshwater. In this study, a wave-to-water numerical model was developed to investigate the potential use of a wave-powered desalination system (WPDS) for water production. The model was developed by coupling a time-domain radiation-and-diffraction method-based numerical tool (WEC-Sim) for predicting the hydrodynamic performance of WECs with a solution-diffusion model that was used to simulate the reverse-osmosis (RO) process. The objective of this research is to evaluate the WPDS dynamics and the overall efficiency of the system. To evaluate the feasibility of the WPDS, the wave-to-water numerical model was applied to simulate a desalination system that used an oscillating surge WEC device to pump seawater through the system. The hydrodynamics WEC-Sim simulation results for the oscillating surge WEC device were validated against existing experimental data. The RO simulation was verified by comparing the results to those from the Dow Chemical Company’s reverse osmosis system analysis (ROSA) model, which has been widely used to design and simulate RO systems. The wave-to-water model was then used to analyze the WPDS under a range of wave conditions and for a two-WECs-coupled RO system to evaluate the influence of pressure and flow rate fluctuation on the WPDS performance. The results show that the instantaneous energy fluctuation from waves has a significant influence on the responding hydraulic pressure and flow rate, as well as the recovery ratio and, ultimately, the water-production quality. Nevertheless, it is possible to reduce the hydraulic fluctuation for different sea states while maintaining a certain level of freshwater production, and a WEC array that produces water can be a viable, near-term solution to the nation’s water supply. A discussion on the dynamic impact of hydraulic fluctuation on the WPDS performance and potential options to reduce the fluctuation and their trade-offs is also presented.


Author(s):  
Diana Bull ◽  
Ann Dallman

A detailed methodology was used to select the sea states tested in the final stage of the Wave Energy Prize (WEPrize), a public prize challenge sponsored by the U.S. Department of Energy [1]. The winner was selected based on two metrics: a threshold value expressing the benefit to effort ratio (ACE metric) and a second metric which included hydrodynamic performance-related quantities (HPQ). HPQ required additional sea states to query aspects of the techno-economic performance not addressed by ACE. Due to the nature of the WEPrize, limited time was allotted to each contestant for testing and thus a limitation on the total sea states was required. However, the applicability of these sea states was required to encompass seven deployment locations representative of the United States West Coast and Hawaii. A cluster analysis was applied to scatter diagrams in order to determine a subset of sea states that could be scaled to find the average annual power flux at each wave climate for the ACE metric. Four additional sea states were selected, including two highly energetic sea states and two bimodal sea states, to evaluate HPQ. These sea states offer a common experimental testing platform for performance in United States deployment climates.


2021 ◽  
Vol 172 ◽  
pp. 1212-1224
Author(s):  
Seongho Ahn ◽  
Vincent S. Neary ◽  
Mohammad Nabi Allahdadi ◽  
Ruoying He

1988 ◽  
Vol 20 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Rebecca W. Hanmer

The pulp, paper, and paperboard industry in the United States is the larqest industrial user of water with half of the facilities discharging wastewater directly to our Nation's waters. The major pollutants of concern have historically been the conventional pollutants: biochemical oxygen demand (BOD5), total suspended solids (TSS), and pH. Biological treatment systems are currently employed to reduce these pollutants. Sludges generated by these treatment systems have been categorized as nonhazardous and are generally landfilled. Under the Clean Water Act, the Environmental Protection Agency (EPA) has promulgated all the reguired regulations for this industry. The national regulations are applied to individual pulp and paper mills through permits issued by EPA Regional or State staff. Permit limits can be written that are more restrictive than the national regulations to protect local water guality. In its current projects concerning the pulp and paper industry, EPA is focusing on the reduction of toxic pollutants. The Agency is conducting a joint EPA/industry program to study dioxin discharges at bleached kraft mills. The Agency will also undertake a comprehensive review of the pulp and paper regulations in 1988.


Author(s):  
Terry L. Dickson ◽  
Shah N. Malik ◽  
Mark T. Kirk ◽  
Deborah A. Jackson

The current federal regulations to ensure that nuclear reactor pressure vessels (RPVs) maintain their structural integrity when subjected to transients such as pressurized thermal shock (PTS) events were derived from computational models that were developed in the early to mid 1980s. Since that time, there have been advancements in relevant technologies associated with the physics of PTS events that impact RPV integrity assessment. Preliminary studies performed in 1999 suggested that application of the improved technology could reduce the conservatism in the current regulations while continuing to provide reasonable assurance of adequate protection to public health and safety. A relaxation of PTS regulations could have profound implications for plant license extension considerations. Based on the above, in 1999, the United States Nuclear Regulatory Commission (USNRC) initiated a comprehensive project, with the nuclear power industry as a participant, to re-evaluate the current PTS regulations within the framework established by modern probabilistic risk assessment (PRA) techniques. During the last three years, improved computational models have evolved through interactions between experts in the relevant disciplines of thermal hydraulics, PRA, human reliability analysis (HRA), materials embrittlement effects on fracture toughness (crack initiation and arrest), fracture mechanics methodology, and fabrication-induced flaw characterization. These experts were from the NRC staff, their contractors, and representatives from the nuclear industry. These improved models have now been implemented into the FAVOR (Fracture Analysis of Vessels: Oak Ridge) computer code, which is an applications tool for performing risk-informed structural integrity evaluations of embrittled RPVs subjected to transient thermal-hydraulic loading conditions. The baseline version of FAVOR (version 1.0) was released in October 2001. The updated risk-informed computational methodology in the FAVOR code is currently being applied to selected domestic commercial pressurized water reactors to evaluate the adequacy of the current regulations and to determine whether a technical basis can be established to support a relaxation of the current regulations. This paper provides a status report on the application of the updated computational methodology to a commercial pressurized water reactor (PWR) and discusses the results and interpretation of those results. It is anticipated that this re-evaluation effort will be completed in 2002.


Author(s):  
Padmanabha J. Prabhu ◽  
Damian A. Testa

The Steam Generator Asset Management Program (SGAMP) is a long term program designed to maximize the performance and reliability of the steam generators. The SGAMP focuses on plant specific conditions and hence is applicable to the original or the replacement steam generators. It is recommended that the utility and the vendor form a joint steam generator management team (SGMT) to develop, monitor and implement a long-term plan to address steam generator operation, maintenance and life extension goals. The SGMT will consist of representatives from operations, chemistry, maintenance and engineering functions and will be responsible for making decisions related to the steam generators. The charter of the SGMT is to develop a steam generator strategic plan that will cost-effectively manage steam generator options. The strategic plan is consistent with the Steam Generator Program Guidelines (NEI 97-06 in the United States). The strategic plan is a living document and is revised periodically to incorporate inspection results, new technology developments, lessons learned and industry experience. Cost-benefit analyses of strategies may be performed to prolong steam generator operability through steam generator performance modeling (tube degradation, fouling, etc.), diagnostic tools, regulatory strategy, condition monitoring and operational assessment strategy, and maintenance strategy. The SGMT will provide input regarding potential maintenance of the steam generators with schedule and cost impacts for each outage. It will also recommend engineering evaluations to be performed in support of program goals and will develop short- and long-term recommendations. These recommendations will address action plans, performance measures and results. Secondary side inspection and cleaning strategy should be developed (techniques and frequency) to maximize performance cost-effectively. This paper is based on Westinghouse experience gained by working with several pressurized water reactor (PWR) plant operators in the United States (US).


1994 ◽  
Vol 26 (1) ◽  
pp. 80-89 ◽  
Author(s):  
Roy R. Carriker

AbstractThe federal government program for wetlands regulation is administered by the United States Army Corps of Engineers pursuant to Section 404 of the Clean Water Act. Proposals for amending and/or reforming the Section 404 program are included in Congressional deliberations regarding Clean Water Act reauthorization. Specific issues of public policy include the definition of “waters of the United States”, criteria for delineation of jurisdictional wetlands, definition of activities exempt from regulation, mitigation and classification of wetlands, and issues of property rights.


2016 ◽  
Vol 113 (27) ◽  
pp. 7575-7579 ◽  
Author(s):  
Dean R. Paini ◽  
Andy W. Sheppard ◽  
David C. Cook ◽  
Paul J. De Barro ◽  
Susan P. Worner ◽  
...  

Invasive species present significant threats to global agriculture, although how the magnitude and distribution of the threats vary between countries and regions remains unclear. Here, we present an analysis of almost 1,300 known invasive insect pests and pathogens, calculating the total potential cost of these species invading each of 124 countries of the world, as well as determining which countries present the greatest threat to the rest of the world given their trading partners and incumbent pool of invasive species. We find that countries vary in terms of potential threat from invasive species and also their role as potential sources, with apparently similar countries sometimes varying markedly depending on specifics of agricultural commodities and trade patterns. Overall, the biggest agricultural producers (China and the United States) could experience the greatest absolute cost from further species invasions. However, developing countries, in particular, Sub-Saharan African countries, appear most vulnerable in relative terms. Furthermore, China and the United States represent the greatest potential sources of invasive species for the rest of the world. The analysis reveals considerable scope for ongoing redistribution of known invasive pests and highlights the need for international cooperation to slow their spread.


2017 ◽  
Vol 74 ◽  
pp. 1300-1313 ◽  
Author(s):  
Marcus Lehmann ◽  
Farid Karimpour ◽  
Clifford A. Goudey ◽  
Paul T. Jacobson ◽  
Mohammad-Reza Alam

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