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Sample records for surface renewal model

  1. A heat transfer correlation based on a surface renewal model for molten core concrete interaction study

    International Nuclear Information System (INIS)

    Tourniaire, B. . E-mail bruno.tourniaire@cea.fr

    2006-01-01

    The prediction of heat transfer between corium pool and concrete basemat is of particular significance in the framework of the study of PWR's severe accident. Heat transfer directly governs the ablation velocity of concrete in case of molten core concrete interaction (MCCI) and, consequently, the time delay when the reactor cavity may fail. From a restricted hydrodynamic point of view, this issue is related to heat transfer between a heated bubbling pool and a porous wall with gas injection. Several experimental studies have been performed with simulant materials and many correlations have been provided to address this issue. The comparisons of the results of these correlations with the measurements and their extrapolation to reactor materials show that strong discrepancies between the results of these models are obtained which probably means that some phenomena are not well taken into account. The main purpose of this paper is to present an alternative heat transfer model which was originally developed for chemical engineering applications (bubble columns) by Deckwer. A part of this work is devoted to the presentation of this model, which is based on a surface renewal assumption. Comparison of the results of this model with available experimental data in different systems are presented and discussed. These comparisons clearly show that this model can be used to deal with the particular problem of MCCI. The analyses also lead to enrich the original model by taking into account the thermal resistance of the wall: a new formulation of the Deckwer's correlation is finally proposed

  2. Surface renewal as a significant mechanism for dust emission

    Directory of Open Access Journals (Sweden)

    J. Zhang

    2016-12-01

    Full Text Available Wind tunnel experiments of dust emissions from different soil surfaces are carried out to better understand dust emission mechanisms. The effects of surface renewal on aerodynamic entrainment and saltation bombardment are analyzed in detail. It is found that flow conditions, surface particle motions (saltation and creep, soil dust content and ground obstacles all strongly affect dust emission, causing its rate to vary over orders of magnitude. Aerodynamic entrainment is highly effective, if dust supply is unlimited, as in the first 2–3 min of our wind tunnel runs. While aerodynamic entrainment is suppressed by dust supply limits, surface renewal through the motion of surface particles appears to be an effective pathway to remove the supply limit. Surface renewal is also found to be important to the efficiency of saltation bombardment. We demonstrate that surface renewal is a significant mechanism affecting dust emission and recommend that this mechanism be included in future dust models.

  3. Surface renewal model for heat transfer calculation between a porous solid wall and an internally heated bubbling pool

    International Nuclear Information System (INIS)

    Tourniaire, B.

    2005-01-01

    Full text of publication follows: This work has been performed in the frame of the study of severe accident of LWR involving core meltdown and failure of the reactor vessel with molten corium relocation in the reactor pit. One of the main issue in nuclear safety is the estimation of the time when the reactor cavity may fail due to the erosion of the basemat since it would lead to the contamination of the groundwater. The calculation of the basemat erosion velocity requires the knowledge of the heat transfer between the corium pool and the concrete. Due to the gas release (mainly CO 2 and H 2 O) resulting from the concrete erosion, two-phase flow heat transfers occur during molten core concrete interaction (MCCI). Two-phase flow heat transfer between a porous horizontal wall and an internally heated bubbling pool has been already extensively investigated on the experimental side by several authors (Kutateladze and Malenkov, Duignan et al, Bonnet et al, Bilbao y Leon et al). The effect of various parameters such as the physical properties of the fluid or the pool aspect ratio has been studied so that many experimental data are available. From dimensional analysis (Kutateladze-Malenkov, Bonnet et al) or theoretical approach (Konsetov) and from these experimental data, heat transfer correlations have been proposed based on usual non-dimensional groups as Nu, Pr, Ra, etc. Today, the most widely used correlation in MCCI study are those proposed by Konsetov and by Kutateladze and Malenkov. Comparisons of the results of these correlations with available experimental data show that not all tendencies are well reproduced. The main purpose of this paper is to present an alternative heat transfer correlation that can be used in MCCI study. This correlation has been proposed by Deckwer in the frame of the study of heat transfer in bubble column reactors dedicated to chemical engineering. This correlation has been deduced from a theoretical analysis based on a surface renewal

  4. Modeling renewable energy company risk

    International Nuclear Information System (INIS)

    Sadorsky, Perry

    2012-01-01

    The renewable energy sector is one of the fastest growing components of the energy industry and along with this increased demand for renewable energy there has been an increase in investing and financing activities. The tradeoff between risk and return in the renewable energy sector is, however, precarious. Renewable energy companies are often among the riskiest types of companies to invest in and for this reason it is necessary to have a good understanding of the risk factors. This paper uses a variable beta model to investigate the determinants of renewable energy company risk. The empirical results show that company sales growth has a negative impact on company risk while oil price increases have a positive impact on company risk. When oil price returns are positive and moderate, increases in sales growth can offset the impact of oil price returns and this leads to lower systematic risk.

  5. SURFACE ENERGY BALANCE OVER ORANGE ORCHARD USING SURFACE RENEWAL ANALYSIS

    Directory of Open Access Journals (Sweden)

    Salvatore Barbagallo

    2009-12-01

    Full Text Available Reliable estimation of surface sensible and latent heat flux is the most important process to appraise energy and mass exchange among atmosphere and biosphere. In this study the surface energy fluxes were measured over an irrigated orange orchard during 2005-2008 monitoring periods using a Surface Renewal- Energy Balance approach. The experimental area is located in a representative orchard growing area of eastern Sicily (Italy. The performance of Surface Renewal (SR analysis for estimating sensible heat flux (H was analysed and evaluated in terms of correlation with H fluxes from the eddy covariance (EC method. Study revealed that the mean available energy (RN- G and latent heat flux (LE were of about 300 W m-2 and 237 W m-2, respectively, during dry periods and unstable-case atmospheric conditions. The estimated crop coefficient Kc values for the orchard crop averaged close to 0.80, which is considerably higher than previous FAO studies that found the value to be 0.65 for citrus with 70% of ground cover. The intercepted photosynthetically active radiation (LI PAR by the crop was measured and relationships between LAI and crop coefficient (Kc were established.

  6. Modeling of renewable hybrid energy sources

    Directory of Open Access Journals (Sweden)

    Dumitru Cristian Dragos

    2009-12-01

    Full Text Available Recent developments and trends in the electric power consumption indicate an increasing use of renewable energy. Renewable energy technologies offer the promise of clean, abundant energy gathered from self-renewing resources such as the sun, wind, earth and plants. Virtually all regions of the world have renewable resources of one type or another. By this point of view studies on renewable energies focuses more and more attention. The present paper intends to present different mathematical models related to different types of renewable energy sources such as: solar energy and wind energy. It is also presented the validation and adaptation of such models to hybrid systems working in geographical and meteorological conditions specific to central part of Transylvania region. The conclusions based on validation of such models are also shown.

  7. Surface renewal method for estimating sensible heat flux | Mengistu ...

    African Journals Online (AJOL)

    For short canopies, latent energy flux may be estimated using a shortened surface energy balance from measurements of sensible and soil heat flux and the net irradiance at the surface. The surface renewal (SR) method for estimating sensible heat, latent energy, and other scalar fluxes has the advantage over other ...

  8. Surface Renewal Application for Estimating Evapotranspiration: A Review

    Directory of Open Access Journals (Sweden)

    Yongguang Hu

    2018-01-01

    Full Text Available The estimation of evapotranspiration (ET is essential for meteorological modeling of surface exchange processes, as well as for the agricultural practice of irrigation management. Hitherto, a number of methods for estimation of ET at different temporal scales and climatic conditions are constantly under investigation and improvement. One of these methods is surface renewal (SR. Therefore, the premise of this review is to present recent developments and applications of SR for ET measurements. The SR method is based on estimating the turbulent exchange of sensible heat flux between plant canopy and atmosphere caused by the instantaneous replacement of air parcels in contact with the surface. Additional measurements of net radiation and soil heat flux facilitate extracting ET using the shortened energy balance equation. The challenge, however, is the calibration of SR results against direct sensible heat flux measurements. For the classical SR method, only air temperature measured at high frequency is required. In addition, a new model suggests that the SR method could be exempted from calibration by measuring additional micrometeorological variables. However, further improvement of the SR method is required to provide improved results in the future.

  9. PECULIARITIES OF THE RENEWABLE ENERGY BUSINESS MODELS

    Directory of Open Access Journals (Sweden)

    BĂLOI Ionut-Cosmin

    2014-07-01

    Full Text Available By exploring the competitiveness of industries and companies, we could identify the factors whose importance is likely to generate competitive advantage. An inventory of content elements of the business model summarizes the clearest opportunities and prospects. The objectives developed throughout the paper want to identify the pillars of a renewable business model and to describe the strategic dimensions of their capitalisation in regional and national energy entrepreneurship. The trend of increasing the renewable energy business volume is driven by the entrepreneurs and company’s availability to try new markets, with many unpredictable implications and the willingness of these players or their creditors to spend their savings, in various forms, for the concerned projects. There is no alternative to intensive investment strategies, given that the small projects are not able to create high value and competitiveness for interested entrepreneurs. For this reason, the international practice shows that the business models in energy production are supported by partnerships and networks of entrepreneurs who are involved in the development of large projects. The most important feature of renewable business initiatives is on attracting the latest clean emerging technologies, and obviously the investors who can assume the risk of such great projects. The benefits of a well developed business model recommend a prudent approach in the launching in the investment strategies, because the competitive contexts hide always some dissatisfaction of the partners that endanger the business concept’s success. The small firms can develop a profitable business model by exploring the opportunity of the alliances, namely the particular joint ventures (association between Romanian and foreign firms. The advantages of joint venture's partners are considerable; they include access to expertise, resources and other assets that the partners could not achieve on their own

  10. Modelling of Integrated Renewable Energy System

    Science.gov (United States)

    Akella, A. K.; Saini, R. P.; Sharma, M. P.

    2007-10-01

    Energy is supplied in the form of electricity, heat or fuels and an energy supply system must guarantee sufficient production and distribution of energy. An energy supply system based on renewable energy can be utilized as integrated renewable energy system (IRES), which can satisfy the energy needs of an area in appropriate & sustainable manner. Given the key role of renewable energy in rural electrification of remote rural areas, the IRES for a given area can be modeled & optimized for meeting the energy needs. In the present paper, Jaunpur block of Uttaranchal state of India has been selected as remote area. Based upon the data collected, the resource potential and energy demand has been calculated & presented. The model on the basis of unit cost of the energy has been optimized using LINDO software 6.10 version. The results indicated that the optimized model has been found to the best choice for meeting the energy needs of the area. The results further indicated that for the above area, either an IRES consisting of the above sources can provide a feasible solution in terms of energy fulfillments in the range of EPDF from 1.0 to 0.75.

  11. Surface renewal analysis for estimating turbulent surface fluxes

    International Nuclear Information System (INIS)

    Castellvi, F.

    2009-01-01

    A decade ago, the need for a long-term surface monitoring was recognized to better understand the soil-vegetation-atmosphere scalar exchange and interaction processes. the AmeriFlux concept emerged in the IGBP workshop (La Thuile, IT, 1995). Continuous acquisition of surface fluxes for different species such as temperature, water vapour, CO x , halocarbon, ozone, etc.,) and momentum allows determination of the influence of local (canopy) exchanges, fossil fuel emission, large-scale biotic exchange on ambient concentrations which are crucial to take decisions for protecting natural environments and water resources, to develop new perspective for modern agriculture and forest management and to better understand the global climate change. (Author)

  12. Modelling renewable energy economy in Ghana with autometrics

    Energy Technology Data Exchange (ETDEWEB)

    Ackah, Ishmael; Asomani, Mcomari [Africa Centre for Energy Policy, Accra (Ghana); Kwame Nkrumah Univ. of Science and Technology, Kumasi (Ghana)

    2015-04-15

    Renewable energy consumption has been identified as a potential solution to the intermittent power supply in Ghana. Recently, a Renewable Energy Act has been passed which has a target of 10% of renewable energy component in Ghana's energy mix by 2020. Whilst effort is been made to enhance supply through feed in tariffs, education and tax reduction on renewable energy related equipment, there is the need to understand the drivers of renewable energy demand. In this study, the general unrestricted model through Autometrics is used to estimate the determinants of renewable energy demand in Ghana. The results indicate that both economic factors and non-economic affect the demand for renewable energy. In addition, the underlying energy demand trend exhibits energy using behaviour. The study recommends that economic factors such as consumer subsidies should be considered when promoting renewable energy demand.

  13. Modelling renewable energy economy in Ghana with autometrics

    International Nuclear Information System (INIS)

    Ackah, Ishmael; Asomani, Mcomari

    2015-01-01

    Renewable energy consumption has been identified as a potential solution to the intermittent power supply in Ghana. Recently, a Renewable Energy Act has been passed which has a target of 10% of renewable energy component in Ghana's energy mix by 2020. Whilst effort is been made to enhance supply through feed in tariffs, education and tax reduction on renewable energy related equipment, there is the need to understand the drivers of renewable energy demand. In this study, the general unrestricted model through Autometrics is used to estimate the determinants of renewable energy demand in Ghana. The results indicate that both economic factors and non-economic affect the demand for renewable energy. In addition, the underlying energy demand trend exhibits energy using behaviour. The study recommends that economic factors such as consumer subsidies should be considered when promoting renewable energy demand.

  14. Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model)

    Science.gov (United States)

    2017-09-01

    ARL-TR-8155 ● SEP 2017 US Army Research Laboratory Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model... Energy Research, Volume 5 (Solar Radiation Flux Model) by Clayton Walker and Gail Vaucher Computational and Information Sciences Directorate, ARL...2017 June 28 4. TITLE AND SUBTITLE Atmospheric Renewable Energy Research, Volume 5 (Solar Radiation Flux Model) 5a. CONTRACT NUMBER ROTC Internship

  15. Hybrid Hydro Renewable Energy Storage Model

    Science.gov (United States)

    Dey, Asit Kr

    2018-01-01

    This paper aims at presenting wind & tidal turbine pumped-storage solutions for improving the energy efficiency and economic sustainability of renewable energy systems. Indicated a viable option to solve problems of energy production, as well as in the integration of intermittent renewable energies, providing system flexibility due to energy load’s fluctuation, as long as the storage of energy from intermittent sources. Sea water storage energy is one of the best and most efficient options in terms of renewable resources as an integrated solution allowing the improvement of the energy system elasticity and the global system efficiency.

  16. Determining of the Optimal Device Lifetime using Mathematical Renewal Models

    Directory of Open Access Journals (Sweden)

    Knežo Dušan

    2016-05-01

    Full Text Available Paper deals with the operations and equipment of the machine in the process of organizing production. During operation machines require maintenance and repairs, while in case of failure or machine wears it is necessary to replace them with new ones. For the process of replacement of old machines with new ones the term renewal is used. Qualitative aspects of the renewal process observe renewal theory, which is mainly based on the theory of probability and mathematical statistics. Devices lifetimes are closely related to the renewal of the devices. Presented article is focused on mathematical deduction of mathematical renewal models and determining optimal lifetime of the devices from the aspect of expenditures on renewal process.

  17. Modeling renewable energy resources in integrated resource planning

    Energy Technology Data Exchange (ETDEWEB)

    Logan, D.; Neil, C.; Taylor, A. [RCG/Hagler, Bailly, Inc., Boulder, CO (United States)

    1994-06-01

    Including renewable energy resources in integrated resource planning (IRP) requires that utility planning models properly consider the relevant attributes of the different renewable resources in addition to conventional supply-side and demand-side options. Otherwise, a utility`s resource plan is unlikely to have an appropriate balance of the various resource options. The current trend toward regulatory set-asides for renewable resources is motivated in part by the perception that the capabilities of current utility planning models are inadequate with regard to renewable resources. Adequate modeling capabilities and utility planning practices are a necessary prerequisite to the long-term penetration of renewable resources into the electric utility industry`s resource mix. This report presents a review of utility planning models conducted for the National Renewable Energy Laboratory (NREL). The review examines the capabilities of utility planning models to address key issues in the choice between renewable resources and other options. The purpose of this review is to provide a basis for identifying high priority areas for advancing the state of the art.

  18. Solar radiation practical modeling for renewable energy applications

    CERN Document Server

    Myers, Daryl Ronald

    2013-01-01

    Written by a leading scientist with over 35 years of experience working at the National Renewable Energy Laboratory (NREL), Solar Radiation: Practical Modeling for Renewable Energy Applications brings together the most widely used, easily implemented concepts and models for estimating broadband and spectral solar radiation data. The author addresses various technical and practical questions about the accuracy of solar radiation measurements and modeling. While the focus is on engineering models and results, the book does review the fundamentals of solar radiation modeling and solar radiation m

  19. Renewable Energy Resources With Smart Microgrid Model In India

    Directory of Open Access Journals (Sweden)

    Manikant Kumar

    2015-08-01

    Full Text Available Along with the development of civilization is increasing energy consumption. Due to which India is facing an energy crisis. It is estimated that global energy demand will double in 2030. India Trhurga other developing countries will face a crisis. Returning to the problem Fall growth of renewable energy resources will increase. Even for electricity generation from renewable sources. Naturally replenished renewable energy such as sunlight wind rain tides and geothermal heat as will have to depend on natural resources. High energy demand and environmental concerns in the papers smart microgrid is forced to change the existing power grid. This paper dynamic demand response and smart microgrid for residential and industrial consumption in the context of renewable energy production including the proposed management approach. The objectives of this research renewable energy resources with a smart microgrid has played an important role. Power system in rural areas in India to meet growing energy demand. The model deployed PLC networks data management system sensors Switchgears Transformers and other utility tools to integrate Smart Grid Smart homes are used together. Analytical results Residential renewable energy generation and smart meters show the effectiveness of the proposed system to optimize control of the electrical grid and is designed to improve energy conservation.

  20. AN INTELLIGENT HYBRID NEURAL NETWORK MODEL IN RENEWABLE ENERGY SYSTEMS

    Directory of Open Access Journals (Sweden)

    K. Gnana Sheela

    2012-07-01

    Full Text Available This paper presents a hybrid neural network approach to predict wind speed automatically in renewable energy systems. Wind energy is one of the renewable energy systems with lowest cost of production of electricity with largest resources available. By the reason of the fluctuation and volatility in wind, the wind speed prediction provides the challenges in the stability of renewable energy system. The aim is to compute predicted wind speed based on hybrid model which integrates a Self Organizing Map (SOM and Back propagation (BP neural network. The simulation result shows that the proposed approach provides significant result of wind speed prediction with less error rates. Due to seasonality, single computing models have some disadvantages such as fluctuality, randomness and unstable. These disadvantages are rectified by using hybrid computing neural network models. Wind speed prediction is an important in the field of wind power plants.

  1. Model for optimum design of standalone hybrid renewable energy ...

    African Journals Online (AJOL)

    An optimization model for the design of a hybrid renewable energy microgrid supplying an isolated load has been developed. This is achieved in two steps. The first step developed a linear programming model that uses the average pattern of demand, wind, and solar energy to determine the optimal configuration.

  2. Forecasting US renewables in the national energy modelling system

    International Nuclear Information System (INIS)

    Diedrich, R.; Petersik, T.W.

    2001-01-01

    The Energy information Administration (EIA) of the US Department of Energy (DOE) forecasts US renewable energy supply and demand in the context of overall energy markets using the National Energy Modelling System (NEMS). Renewables compete with other supply and demand options within the residential, commercial, industrial, transportation, and electricity sectors of the US economy. NEMS forecasts renewable energy for grid-connected electricity production within the Electricity Market Module (EM), and characterizes central station biomass, geothermal, conventional hydroelectric, municipal solid waste, solar thermal, solar photovoltaic, and wind-powered electricity generating technologies. EIA's Annual Energy Outlook 1998, projecting US energy markets, forecasts marketed renewables to remain a minor part of US energy production and consumption through to 2020. The USA is expected to remain primarily a fossil energy producer and consumer throughout the period. An alternative case indicates that biomass, wind, and to some extent geothermal power would likely increase most rapidly if the US were to require greater use of renewables for power supply, though electricity prices would increase somewhat. (author)

  3. Modeling of an autonomous microgrid for renewable energy sources integration

    DEFF Research Database (Denmark)

    Serban, I.; Teodorescu, Remus; Guerrero, Josep M.

    2009-01-01

    The frequency stability analysis in an autonomous microgrid (MG) with renewable energy sources (RES) is a continuously studied issue. This paper presents an original method for modeling an autonomous MG with a battery energy storage system (BESS) and a wind power plant (WPP), with the purpose...

  4. Supporting Renewable energies in Europe - The German Model

    International Nuclear Information System (INIS)

    Kreuzer, Karin

    2013-01-01

    This document presents some key information and figures about Germany's energy transition (Energiewende), the leading up to the Renewable energy Sources Act (EEG) and its amendments, the Current EEG Act: push to direct marketing and the market premium model, and the future challenges and the planned EEG reform in 2014

  5. Evaluation of surface renewal and flux-variance methods above agricultural and forest surfaces

    Science.gov (United States)

    Fischer, M.; Katul, G. G.; Noormets, A.; Poznikova, G.; Domec, J. C.; Trnka, M.; King, J. S.

    2016-12-01

    Measurements of turbulent surface energy fluxes are of high interest in agriculture and forest research. During last decades, eddy covariance (EC), has been adopted as the most commonly used micrometeorological method for measuring fluxes of greenhouse gases, energy and other scalars at the surface-atmosphere interface. Despite its robustness and accuracy, the costs of EC hinder its deployment at some research experiments and in practice like e.g. for irrigation scheduling. Therefore, testing and development of other cost-effective methods is of high interest. In our study, we tested performance of surface renewal (SR) and flux variance method (FV) for estimates of sensible heat flux density. Surface renewal method is based on the concept of non-random transport of scalars via so-called coherent structures which if accurately identified can be used for the computing of associated flux. Flux variance method predicts the flux from the scalar variance following the surface-layer similarity theory. We tested SR and FV against EC in three types of ecosystem with very distinct aerodynamic properties. First site was represented by agricultural wheat field in the Czech Republic. The second site was a 20-m tall mixed deciduous wetland forest on the coast of North Carolina, USA. The third site was represented by pine-switchgrass intercropping agro-forestry system located in coastal plain of North Carolina, USA. Apart from solving the coherent structures in a SR framework from the structure functions (representing the most common approach), we applied ramp wavelet detection scheme to test the hypothesis that the duration and amplitudes of the coherent structures are normally distributed within the particular 30-minutes time intervals and so just the estimates of their averages is sufficient for the accurate flux determination. Further, we tested whether the orthonormal wavelet thresholding can be used for isolating of the coherent structure scales which are associated with

  6. Surface solar radiation from geostationary satellites for renewable energy

    Science.gov (United States)

    Laszlo, Istvan; Liu, Hongqing; Heidinger, Andrew; Goldberg, Mitchell

    With the launch of the new Geostationary Operational Environmental Satellite, GOES-R, the US National Oceanic and Atmospheric Administration (NOAA) will begin a new era of geostationary remote sensing. One of its flagship instruments, the Advanced Baseline Imager (ABI), will expand frequency and coverage of multispectral remote sensing of atmospheric and surface properties. Products derived from ABI measurements will primarily be heritage meteorological products (cloud and aerosol properties, precipitation, winds, etc.), but some will be for interdisciplinary use, such as for the solar energy industry. The planned rapid observations (5-15 minutes) from ABI provide an opportunity to obtain information needed for solar energy applications where frequent observations of solar radiation reaching the surface are essential for planning and load management. In this paper we describe a physical, radiative-transfer-based algorithm for the retrieval of surface solar irradiance that uses atmospheric and surface parameters derived independently from multispectral ABI radiances. The algorithm is designed to provide basic radiation budget products (total solar irradiance at the surface), as well as products specifically needed for the solar energy industry (average, midday and clear-sky insolation, clear-sky days, diffuse and direct normal radiation, etc.). Two alternative algorithms, which require less ABI atmosphere and surface products or no explicit knowledge of the surface albedo, are also explored along with their limitations. The accuracy of surface solar radiation retrievals are assessed using long-term MODIS and GOES satellite data and surface measurements at the Surface Radiation (SURFRAD) network.

  7. Strategy renewal through business model innovation

    DEFF Research Database (Denmark)

    Holm, Anna; Ulhøi, John Parm

    2011-01-01

    by leading newspapers. More specifically, we review how changes introduced during the on-going development of digital platforms have affected the dominant business model and its key components at the leading newspaper industry players in Denmark, and whether those changes have improved their situation...

  8. Renewed mer model of integral management

    Directory of Open Access Journals (Sweden)

    Janko Belak

    2015-12-01

    Full Text Available Background: The research work on entrepreneurship, enterprise's policy and management, which started in 1992, successfully continued in the following years. Between 1992 and 2011, more than 400 academics and other researchers have participated in research work (MER research program whose main orientation has been the creation of their own model of integral management. Results: In past years, academics (researchers and authors of published papers from Austria, Belgium, Bosnia and Herzegovina, Bulgaria, Byelorussia, Canada, the Czech Republic, Croatia, Estonia, France, Germany, Hungary, Italy, Poland, Romania, Russia, the Slovak Republic, Slovenia, Switzerland, Ukraine, and the US have cooperated in MER programs, coming from more than fifty institutions. Thus, scientific doctrines of different universities influenced the development of the MER model which is based on both horizontal and vertical integration of the enterprises' governance and management processes, instruments and institutions into a consistently operating unit. Conclusions: The presented MER model is based on the multi-layer integration of governance and management with an enterprise and its environment, considering the fundamental desires for the enterprises' existence and, thus, their quantitative as well as qualitative changes. The process, instrumental, and institutional integrity of the governance and management is also the initial condition for the implementation of all other integration factors.

  9. CFD simulation of direct contact condensation with ANSYS CFX using surface renewal theory based heat transfer coefficients

    Energy Technology Data Exchange (ETDEWEB)

    Wanninger, Andreas; Ceuca, Sabin Cristian; Macian-Juan, Rafael [Technische Univ. Muenchen, Garching (Germany). Dept. of Nuclear Engineering

    2013-07-01

    Different approaches for the calculation of Direct Contact Condensation (DCC) using Heat Transfer Coefficients (HTC) based on the Surface Renewal Theory (SRT) are tested using the CFD simulation tool ANSYS CFX. The present work constitutes a preliminary study of the flow patterns and conditions observed using different HTC models. A complex 3D flow pattern will be observed in the CFD simulations as well as a strong coupling between the condensation rate and the two-phase flow dynamics. (orig.)

  10. Thermal infrared remote sensing of surface features for renewable resource applications

    Science.gov (United States)

    Welker, J. E.

    1981-01-01

    The subjects of infrared remote sensing of surface features for renewable resource applications is reviewed with respect to the basic physical concepts involved at the Earth's surface and up through the atmosphere, as well as the historical development of satellite systems which produce such data at increasingly greater spatial resolution. With this general background in hand, the growth of a variety of specific renewable resource applications using the developing thermal infrared technology are discussed, including data from HCMM investigators. Recommendations are made for continued growth in this field of applications.

  11. The Role of Controlled Surface Topography and Chemistry on Mouse Embryonic Stem Cell Attachment, Growth and Self-Renewal.

    Science.gov (United States)

    Macgregor, Melanie; Williams, Rachel; Downes, Joni; Bachhuka, Akash; Vasilev, Krasimir

    2017-09-14

    The success of stem cell therapies relies heavily on our ability to control their fate in vitro during expansion to ensure an appropriate supply. The biophysical properties of the cell culture environment have been recognised as a potent stimuli influencing cellular behaviour. In this work we used advanced plasma-based techniques to generate model culture substrates with controlled nanotopographical features of 16 nm, 38 nm and 68 nm in magnitude, and three differently tailored surface chemical functionalities. The effect of these two surface properties on the adhesion, spreading, and self-renewal of mouse embryonic stem cells (mESCs) were assessed. The results demonstrated that physical and chemical cues influenced the behaviour of these stem cells in in vitro culture in different ways. The size of the nanotopographical features impacted on the cell adhesion, spreading and proliferation, while the chemistry influenced the cell self-renewal and differentiation.

  12. Advanced Modeling of Renewable Energy Market Dynamics: May 2006

    Energy Technology Data Exchange (ETDEWEB)

    Evans, M.; Little, R.; Lloyd, K.; Malikov, G.; Passolt, G.; Arent, D.; Swezey, B.; Mosey, G.

    2007-08-01

    This report documents a year-long academic project, presenting selected techniques for analysis of market growth, penetration, and forecasting applicable to renewable energy technologies. Existing mathematical models were modified to incorporate the effects of fiscal policies and were evaluated using available data. The modifications were made based on research and classification of current mathematical models used for predicting market penetration. An analysis of the results was carried out, based on available data. MATLAB versions of existing and new models were developed for research and policy analysis.

  13. Mathematical modelling of electricity market with renewable energy sources

    International Nuclear Information System (INIS)

    Marchenko, O.V.

    2007-01-01

    The paper addresses the electricity market with conventional energy sources on fossil fuel and non-conventional renewable energy sources (RESs) with stochastic operating conditions. A mathematical model of long-run (accounting for development of generation capacities) equilibrium in the market is constructed. The problem of determining optimal parameters providing the maximum social criterion of efficiency is also formulated. The calculations performed have shown that the adequate choice of price cap, environmental tax, subsidies to RESs and consumption tax make it possible to take into account external effects (environmental damage) and to create incentives for investors to construct conventional and renewable energy sources in an optimal (from the society view point) mix. (author)

  14. Marketing of renewable energies. Foundations, business models, case studies

    International Nuclear Information System (INIS)

    Herbes, Carsten; Friege, Christian

    2015-01-01

    How to market green electricity or biomethane? What is the right price for renewable energy and how do you design the optimal use of social media? What impact have the EEG or electromobility to the Green Power Marketing? Does direct marketing works or is online marketing the guarantee of success? Answers to these and many other basic questions provides the band with contributions from leading scientists and renowned practitioners. For the first time they describe in a structured form the basics of marketing of renewable energies, provide an introduction to the legal and market-based features and present new business models. The book is based on the latest research results, treats all questions of marketing issues important for practitioners, provides case studies and specific recommendations. [de

  15. Modelling Renewable Energy Economy in Ghana with Autometrics

    OpenAIRE

    Ackah, Ishmael; Asomani, Mcomari

    2015-01-01

    Renewable energy consumption has been identified as a potential solution to the intermittent power supply in Ghana. Recently, a Renewable Energy Act has been passed which has a target of 10% of renewable energy component in Ghana’s energy mix by 2020. Whilst effort is been made to enhance supply through feed in tariffs, education and tax reduction on renewable energy related equipment, there is the need to understand the drivers of renewable energy demand. In this study, the general unrestri...

  16. Advanced mechanisms for the promotion of renewable energy-Models for the future evolution of the German Renewable Energy Act

    International Nuclear Information System (INIS)

    Langniss, Ole; Diekmann, Jochen; Lehr, Ulrike

    2009-01-01

    The German Renewable Energy Act (EEG) has been very successful in promoting the deployment of renewable electricity technologies in Germany. The increasing share of EEG power in the generation portfolio, increasing amounts of fluctuating power generation, and the growing European integration of power markets governed by competition calls for a re-design of the EEG. In particular, a more efficient system integration and commercial integration of the EEG power is needed to, e.g. better matching feed-in to demand and avoiding stress on electricity grids. This article describes three different options to improve the EEG by providing appropriate incentives and more flexibility to the promotion mechanism and the quantitative compensation scheme without jeopardising the fast deployment of renewable energy technologies. In the 'Retailer Model', it becomes the responsibility of the end-use retailers to adapt the EEG power to the actual demand of their respective customers. The 'Market Mediator Model' establishes an independent market mediator responsible to market the renewable electricity. This model is the primary choice when new market entrants are regarded as crucial for the better integration of renewable energy and enhanced competition. The 'Optional Bonus Model' relies more on functioning markets since power plant operators can alternatively choose to market the generated electricity themselves with a premium on top of the market price instead of a fixed price

  17. Renewable energy systems the choice and modeling of 100% renewable solutions

    CERN Document Server

    Lund, Henrik

    2009-01-01

    How can society quickly convert to renewable energy? Can worldwide energy needs ever be met through 100% renewable sources? The answers to these questions rest largely on the perception of choice in the energy arena. It is of pivotal importance that engineers, researchers and policymakers understand what choices are available, and reasonable, when considering the design and deployment of new energy systems. The mission of this new book, written by one of the world's foremost experts in renewable power, is to arm these professionals with the tools and methodologies necessary to make smart choic

  18. GMLC Extreme Event Modeling -- Slow-Dynamics Models for Renewable Energy Resources

    Energy Technology Data Exchange (ETDEWEB)

    Korkali, M. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Min, L. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-03-30

    The need for slow dynamics models of renewable resources in cascade modeling essentially arises from the challenges associated with the increased use of solar and wind electric power. Indeed, the main challenge is that the power produced by wind and sunlight is not consistent; thus, renewable energy resources tend to have variable output power on many different timescales, including the timescales that a cascade unfolds.

  19. Advancing the Frontiers in Nanocatalysis, Biointerfaces, and Renewable Energy Conversion by Innovations of Surface Techniques

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.; Frei, H.; Park, J.Y.

    2009-07-23

    The challenge of chemistry in the 21st century is to achieve 100% selectivity of the desired product molecule in multipath reactions ('green chemistry') and develop renewable energy based processes. Surface chemistry and catalysis play key roles in this enterprise. Development of in situ surface techniques such as high-pressure scanning tunneling microscopy, sum frequency generation (SFG) vibrational spectroscopy, time-resolved Fourier transform infrared methods, and ambient pressure X-ray photoelectron spectroscopy enabled the rapid advancement of three fields: nanocatalysts, biointerfaces, and renewable energy conversion chemistry. In materials nanoscience, synthetic methods have been developed to produce monodisperse metal and oxide nanoparticles (NPs) in the 0.8-10 nm range with controlled shape, oxidation states, and composition; these NPs can be used as selective catalysts since chemical selectivity appears to be dependent on all of these experimental parameters. New spectroscopic and microscopic techniques have been developed that operate under reaction conditions and reveal the dynamic change of molecular structure of catalysts and adsorbed molecules as the reactions proceed with changes in reaction intermediates, catalyst composition, and oxidation states. SFG vibrational spectroscopy detects amino acids, peptides, and proteins adsorbed at hydrophobic and hydrophilic interfaces and monitors the change of surface structure and interactions with coadsorbed water. Exothermic reactions and photons generate hot electrons in metal NPs that may be utilized in chemical energy conversion. The photosplitting of water and carbon dioxide, an important research direction in renewable energy conversion, is discussed.

  20. Stochastic Modeling and Analysis of Power System with Renewable Generation

    DEFF Research Database (Denmark)

    Chen, Peiyuan

    . With the increasing number of wind turbines (WTs) connected to distribution systems, network operators are concerned about how such a stochastic generation affects power losses of the network. Furthermore, the operators need to estimate how much and when the stochastic generation can reduce the loading of substation...... be achieved through a probabilistic analysis that takes into account the stochastic behavior of wind power generation (WPG) and load demand. Such a probabilistic analysis may help network operators to cut down the cost associated with system planning. Thus, the objective of this thesis is to develop...... stochastic models of renewable generation and load demand for the optimal operation and planning of modern distribution systems through a probabilistic approach. On the basis of statistical data, stochastic models of WPG, load and combined heat and power (CHP) generation are developed. The stochastic wind...

  1. Hydrological land surface modelling

    DEFF Research Database (Denmark)

    Ridler, Marc-Etienne Francois

    and disaster management. The objective of this study is to develop and investigate methods to reduce hydrological model uncertainty by using supplementary data sources. The data is used either for model calibration or for model updating using data assimilation. Satellite estimates of soil moisture and surface......Recent advances in integrated hydrological and soil-vegetation-atmosphere transfer (SVAT) modelling have led to improved water resource management practices, greater crop production, and better flood forecasting systems. However, uncertainty is inherent in all numerical models ultimately leading...... hydrological and tested by assimilating synthetic hydraulic head observations in a catchment in Denmark. Assimilation led to a substantial reduction of model prediction error, and better model forecasts. Also, a new assimilation scheme is developed to downscale and bias-correct coarse satellite derived soil...

  2. Hydrological land surface modelling

    DEFF Research Database (Denmark)

    Ridler, Marc-Etienne Francois

    Recent advances in integrated hydrological and soil-vegetation-atmosphere transfer (SVAT) modelling have led to improved water resource management practices, greater crop production, and better flood forecasting systems. However, uncertainty is inherent in all numerical models ultimately leading...... and disaster management. The objective of this study is to develop and investigate methods to reduce hydrological model uncertainty by using supplementary data sources. The data is used either for model calibration or for model updating using data assimilation. Satellite estimates of soil moisture and surface...... hydrological and tested by assimilating synthetic hydraulic head observations in a catchment in Denmark. Assimilation led to a substantial reduction of model prediction error, and better model forecasts. Also, a new assimilation scheme is developed to downscale and bias-correct coarse satellite derived soil...

  3. Research on the decomposition model for China’s National Renewable Energy total target

    International Nuclear Information System (INIS)

    Liu, Zhen; Shi, Yuren; Yan, Jianming; Ou, Xunmin; Lieu, Jenny

    2012-01-01

    It is crucial that China’s renewable energy national target in 2020 is effectively decomposed into respective period targets at the provincial level. In order to resolve problems arising from combining the national and local renewable energy development plan, a total target and period target decomposition model of renewable energy is proposed which considers the resource distribution and energy consumption of different provinces as well as the development characteristics of various renewable energy industries. In the model, the total proposed target is comprised of three shares: basic share, fixed share and floating share target. The target distributed for each province is then determined by the preference relation. That is, when total renewable energy target is distributed, the central government is more concerned about resources potential or energy consumption. Additionally, the growth models for various renewable energy industries are presented, and the period targets of renewable energy in various provinces are proposed in line with regional economic development targets. In order to verify whether the energy target can be achieved, only wind power, solar power, and hydropower are considered in this study. To convenient to assess the performance of local government, the two year period is chosen as an evaluation cycle in the paper. The renewable energy targets per two-year period for each province are calculated based on the overall national renewable energy target, energy requirements and resources distribution. Setting provincial period targets will help policy makers to better implement and supervise the overall renewable energy plan. - Highlights: It is very importance that the national target of renewable energy in 2020 can be effectively decomposed into the stages target of various province. In order to resolve the relation the plan between the national and local renewable energy development planning, a total target and phase target decomposition model

  4. Cancer Modeling: From Optimal Cell Renewal to Immunotherapy

    Science.gov (United States)

    Alvarado Alvarado, Cesar Leonardo

    Cancer is a disease caused by mutations in normal cells. According to the National Cancer Institute, in 2016, an estimated 1.6 million people were diagnosed and approximately 0.5 million people died from the disease in the United States. There are many factors that shape cancer at the cellular and organismal level, including genetic, immunological, and environmental components. In this thesis, we show how mathematical modeling can be used to provide insight into some of the key mechanisms underlying cancer dynamics. First, we use mathematical modeling to investigate optimal homeostatic cell renewal in tissues such as the small intestine with an emphasis on division patterns and tissue architecture. We find that the division patterns that delay the accumulation of mutations are strictly associated with the population sizes of the tissue. In particular, patterns with long chains of differentiation delay the time to observe a second-hit mutant, which is important given that for many cancers two mutations are enough to initiate a tumor. We also investigated homeostatic cell renewal under a selective pressure and find that hierarchically organized tissues act as suppressors of selection; we find that an architecture with a small number of stem cells and larger pools of transit amplifying cells and mature differentiated cells, together with long chains of differentiation, form a robust evolutionary strategy to delay the time to observe a second-hit mutant when mutations acquire a fitness advantage or disadvantage. We also formulate a model of the immune response to cancer in the presence of costimulatory and inhibitory signals. We demonstrate that the coordination of such signals is crucial to initiate an effective immune response, and while immunotherapy has become a promising cancer treatment over the past decade, these results offer some explanations for why it can fail.

  5. Model documentation Renewable Fuels Module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-01-01

    This report documents the objectives, analaytical approach and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the 1996 Annual Energy Outlook forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs, and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described.

  6. Predictive Surface Complexation Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Sverjensky, Dimitri A. [Johns Hopkins Univ., Baltimore, MD (United States). Dept. of Earth and Planetary Sciences

    2016-11-29

    Surface complexation plays an important role in the equilibria and kinetics of processes controlling the compositions of soilwaters and groundwaters, the fate of contaminants in groundwaters, and the subsurface storage of CO2 and nuclear waste. Over the last several decades, many dozens of individual experimental studies have addressed aspects of surface complexation that have contributed to an increased understanding of its role in natural systems. However, there has been no previous attempt to develop a model of surface complexation that can be used to link all the experimental studies in order to place them on a predictive basis. Overall, my research has successfully integrated the results of the work of many experimentalists published over several decades. For the first time in studies of the geochemistry of the mineral-water interface, a practical predictive capability for modeling has become available. The predictive correlations developed in my research now enable extrapolations of experimental studies to provide estimates of surface chemistry for systems not yet studied experimentally and for natural and anthropogenically perturbed systems.

  7. Renewable Energy Deployment in Colorado and the West: A Modeling Sensitivity and GIS Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Barrows, Clayton [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Haase, Scott [National Renewable Energy Lab. (NREL), Golden, CO (United States); Melius, Jennifer [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mooney, Meghan [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-03-01

    The Resource Planning Model is a capacity expansion model designed for a regional power system, such as a utility service territory, state, or balancing authority. We apply a geospatial analysis to Resource Planning Model renewable energy capacity expansion results to understand the likelihood of renewable development on various lands within Colorado.

  8. Modeling sustainability in renewable energy supply chain systems

    Science.gov (United States)

    Xie, Fei

    This dissertation aims at modeling sustainability of renewable fuel supply chain systems against emerging challenges. In particular, the dissertation focuses on the biofuel supply chain system design, and manages to develop advanced modeling framework and corresponding solution methods in tackling challenges in sustaining biofuel supply chain systems. These challenges include: (1) to integrate "environmental thinking" into the long-term biofuel supply chain planning; (2) to adopt multimodal transportation to mitigate seasonality in biofuel supply chain operations; (3) to provide strategies in hedging against uncertainty from conversion technology; and (4) to develop methodologies in long-term sequential planning of the biofuel supply chain under uncertainties. All models are mixed integer programs, which also involves multi-objective programming method and two-stage/multistage stochastic programming methods. In particular for the long-term sequential planning under uncertainties, to reduce the computational challenges due to the exponential expansion of the scenario tree, I also developed efficient ND-Max method which is more efficient than CPLEX and Nested Decomposition method. Through result analysis of four independent studies, it is found that the proposed modeling frameworks can effectively improve the economic performance, enhance environmental benefits and reduce risks due to systems uncertainties for the biofuel supply chain systems.

  9. Plasma-Assisted Synthesis and Surface Modification of Electrode Materials for Renewable Energy.

    Science.gov (United States)

    Dou, Shuo; Tao, Li; Wang, Ruilun; El Hankari, Samir; Chen, Ru; Wang, Shuangyin

    2018-02-14

    Renewable energy technology has been considered as a "MUST" option to lower the use of fossil fuels for industry and daily life. Designing critical and sophisticated materials is of great importance in order to realize high-performance energy technology. Typically, efficient synthesis and soft surface modification of nanomaterials are important for energy technology. Therefore, there are increasing demands on the rational design of efficient electrocatalysts or electrode materials, which are the key for scalable and practical electrochemical energy devices. Nevertheless, the development of versatile and cheap strategies is one of the main challenges to achieve the aforementioned goals. Accordingly, plasma technology has recently appeared as an extremely promising alternative for the synthesis and surface modification of nanomaterials for electrochemical devices. Here, the recent progress on the development of nonthermal plasma technology is highlighted for the synthesis and surface modification of advanced electrode materials for renewable energy technology including electrocatalysts for fuel cells, water splitting, metal-air batteries, and electrode materials for batteries and supercapacitors, etc. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Renewable Energy and Efficiency Modeling Analysis Partnership: An Analysis of How Different Energy Models Addressed a Common High Renewable Energy Penetration Scenario in 2025

    Energy Technology Data Exchange (ETDEWEB)

    Blair, N.; Jenkin, T.; Milford, J.; Short, W.; Sullivan, P.; Evans, D.; Lieberman, E.; Goldstein, G.; Wright, E.; Jayaraman, K.; Venkatech, B.; Kleiman, G.; Namovicz, C.; Smith, B.; Palmer, K.; Wiser, R.; Wood, F.

    2009-09-30

    The Renewable Energy and Efficiency Modeling and Analysis Partnership (REMAP) sponsors ongoing workshops to discuss individual 'renewable' technologies, energy/economic modeling, and - to some extent - policy issues related to renewable energy. Since 2002, the group has organized seven workshops, each focusing on a different renewable technology (geothermal, solar, wind, etc.). These workshops originated and continue to be run under an informal partnership of the Environmental Protection Agency (EPA), the Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy (EERE), the National Renewable Energy Laboratory (NREL), and the American Council on Renewable Energy (ACORE). EPA originally funded the activities, but support is now shared between EPA and EERE. REMAP has a wide range of participating analysts and models/modelers that come from government, the private sector, and academia. Modelers include staff from the Energy Information Administration (EIA), the American Council for an Energy-Efficient Economy (ACEEE), NREL, EPA, Resources for the Future (RFF), Argonne National Laboratory (ANL), Northeast States for Coordinated Air Use Management (NESCAUM), Regional Economic Models Inc. (REMI), ICF International, OnLocation Inc., and Boston University. The working group has more than 40 members, which also includes representatives from DOE, Lawrence Berkeley National Laboratory (LBNL), Union of Concerned Scientists (UCS), Massachusetts Renewable Energy Trust, Federal Energy Regulatory Commission (FERC), and ACORE. This report summarizes the activities and findings of the REMAP activity that started in late 2006 with a kickoff meeting, and concluded in mid-2008 with presentations of final results. As the project evolved, the group compared results across models and across technologies rather than just examining a specific technology or activity. The overall goal was to better understand how and why different energy models give similar

  11. Reconciling Reinforcement Learning Models with Behavioral Extinction and Renewal: Implications for Addiction, Relapse, and Problem Gambling

    Science.gov (United States)

    Redish, A. David; Jensen, Steve; Johnson, Adam; Kurth-Nelson, Zeb

    2007-01-01

    Because learned associations are quickly renewed following extinction, the extinction process must include processes other than unlearning. However, reinforcement learning models, such as the temporal difference reinforcement learning (TDRL) model, treat extinction as an unlearning of associated value and are thus unable to capture renewal. TDRL…

  12. Renewal processes

    CERN Document Server

    Mitov, Kosto V

    2014-01-01

    This monograph serves as an introductory text to classical renewal theory and some of its applications for graduate students and researchers in mathematics and probability theory. Renewal processes play an important part in modeling many phenomena in insurance, finance, queuing systems, inventory control and other areas. In this book, an overview of univariate renewal theory is given and renewal processes in the non-lattice and lattice case are discussed. A pre-requisite is a basic knowledge of probability theory.

  13. Model documentation: Renewable Fuels Module of the National Energy Modeling System

    Science.gov (United States)

    1994-04-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it related to the production of the 1994 Annual Energy Outlook (AEO94) forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs, and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. This documentation report serves two purposes. First, it is a reference document for model analysts, model users, and the public interested in the construction and application of the RFM. Second, it meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. The RFM consists of six analytical submodules that represent each of the major renewable energy resources -- wood, municipal solid waste (MSW), solar energy, wind energy, geothermal energy, and alcohol fuels. Of these six, four are documented in the following chapters: municipal solid waste, wind, solar and biofuels. Geothermal and wood are not currently working components of NEMS. The purpose of the RFM is to define the technological and cost characteristics of renewable energy technologies, and to pass these characteristics to other NEMS modules for the determination of mid-term forecasted renewable energy demand.

  14. Weather Driven Renewable Energy Analysis, Modeling New Technologies

    Science.gov (United States)

    Paine, J.; Clack, C.; Picciano, P.; Terry, L.

    2015-12-01

    Carbon emission reduction is essential to hampering anthropogenic climate change. While there are several methods to broach carbon reductions, the National Energy with Weather System (NEWS) model focuses on limiting electrical generation emissions by way of a national high-voltage direct-current transmission that takes advantage of the strengths of different regions in terms of variable sources of energy. Specifically, we focus upon modeling concentrating solar power (CSP) as another source to contribute to the electric grid. Power tower solar fields are optimized taking into account high spatial and temporal resolution, 13km and hourly, numerical weather prediction model data gathered by NOAA from the years of 2006-2008. Importantly, the optimization of these CSP power plants takes into consideration factors that decrease the optical efficiency of the heliostats reflecting solar irradiance. For example, cosine efficiency, atmospheric attenuation, and shadowing are shown here; however, it should be noted that they are not the only limiting factors. While solar photovoltaic plants can be combined for similar efficiency to the power tower and currently at a lower cost, they do not have a cost-effective capability to provide electricity when there are interruptions in solar irradiance. Power towers rely on a heat transfer fluid, which can be used for thermal storage changing the cost efficiency of this energy source. Thermal storage increases the electric stability that many other renewable energy sources lack, and thus, the ability to choose between direct electric conversion and thermal storage is discussed. The figure shown is a test model of a CSP plant made up of heliostats. The colors show the optical efficiency of each heliostat at a single time of the day.

  15. Business models for model businesses: Lessons from renewable energy entrepreneurs in developing countries

    International Nuclear Information System (INIS)

    Gabriel, Cle-Anne; Kirkwood, Jodyanne

    2016-01-01

    Against the background of mounting research suggesting entrepreneurship as a means of increasing the uptake of renewable energy technologies (RETs) in developing countries, this paper presents the findings of an exploratory investigation into the business models used by renewable energy entrepreneurs in such countries. Forty-three entrepreneurs were interviewed in 28 developing countries and secondary information about country and regional conditions was analysed. We chose the Business Model Canvas as an analytical tool and the findings shed new light on established renewable energy business types. Three different types of businesses were identified – Consultants, Distributors, and Integrators; yet, there is also some overlap between these types. These business types appeared to parallel the life cycle progression of the business, but this requires further research. A key component of the study was to assess whether the types of businesses were related to country-level conditions to assess the impact of regional differences. These comparisons revealed consistencies between country-level characteristics and the entrepreneurs’ choice of business model. Conclusions suggest that different regions may support certain business models more than others due to differing levels of government interest in renewables, governance and policy support and the relative ease of doing business. - Highlights: •Business model canvas used to analyse renewable energy entrepreneurs’ businesses. •Consultants, distributors and integrators are the main business models used. •Business model characteristics are related to country and regional conditions. •Entrepreneurs in least favourable policy environments likely to be Consultants. •Energy entrepreneurship policy should focus on promoting specific business models.

  16. RE-Europe, a large-scale dataset for modeling a highly renewable European electricity system.

    Science.gov (United States)

    Jensen, Tue V; Pinson, Pierre

    2017-11-28

    Future highly renewable energy systems will couple to complex weather and climate dynamics. This coupling is generally not captured in detail by the open models developed in the power and energy system communities, where such open models exist. To enable modeling such a future energy system, we describe a dedicated large-scale dataset for a renewable electric power system. The dataset combines a transmission network model, as well as information for generation and demand. Generation includes conventional generators with their technical and economic characteristics, as well as weather-driven forecasts and corresponding realizations for renewable energy generation for a period of 3 years. These may be scaled according to the envisioned degrees of renewable penetration in a future European energy system. The spatial coverage, completeness and resolution of this dataset, open the door to the evaluation, scaling analysis and replicability check of a wealth of proposals in, e.g., market design, network actor coordination and forecasting of renewable power generation.

  17. RE-Europe, a large-scale dataset for modeling a highly renewable European electricity system

    Science.gov (United States)

    Jensen, Tue V.; Pinson, Pierre

    2017-11-01

    Future highly renewable energy systems will couple to complex weather and climate dynamics. This coupling is generally not captured in detail by the open models developed in the power and energy system communities, where such open models exist. To enable modeling such a future energy system, we describe a dedicated large-scale dataset for a renewable electric power system. The dataset combines a transmission network model, as well as information for generation and demand. Generation includes conventional generators with their technical and economic characteristics, as well as weather-driven forecasts and corresponding realizations for renewable energy generation for a period of 3 years. These may be scaled according to the envisioned degrees of renewable penetration in a future European energy system. The spatial coverage, completeness and resolution of this dataset, open the door to the evaluation, scaling analysis and replicability check of a wealth of proposals in, e.g., market design, network actor coordination and forecasting of renewable power generation.

  18. Microgrid planning based on fuzzy interval prediction models of renewable resources

    NARCIS (Netherlands)

    Morales, R.; Sáez, D.; Marín, L.G.; Nunez Vicencio, Alfredo; Cordon, O.

    2016-01-01

    Microgrids are sustainable solutions for electrification of rural zones that can make use of their local renewable resources. In this paper, we propose a new method for microgrid planning which includes the effect of the uncertainties of the renewable resources explicitly. Fuzzy interval models are

  19. Solar radiation modeling and measurements for renewable energy applications: data and model quality

    International Nuclear Information System (INIS)

    Myers, Daryl R.

    2005-01-01

    Measurement and modeling of broadband and spectral terrestrial solar radiation is important for the evaluation and deployment of solar renewable energy systems. We discuss recent developments in the calibration of broadband solar radiometric instrumentation and improving broadband solar radiation measurement accuracy. An improved diffuse sky reference and radiometer calibration and characterization software for outdoor pyranometer calibrations are outlined. Several broadband solar radiation model approaches, including some developed at the National Renewable Energy Laboratory, for estimating direct beam, total hemispherical and diffuse sky radiation are briefly reviewed. The latter include the Bird clear sky model for global, direct beam, and diffuse terrestrial solar radiation; the Direct Insolation Simulation Code (DISC) for estimating direct beam radiation from global measurements; and the METSTAT (Meteorological and Statistical) and Climatological Solar Radiation (CSR) models that estimate solar radiation from meteorological data. We conclude that currently the best model uncertainties are representative of the uncertainty in measured data

  20. Model documentation renewable fuels module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-06-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the 1995 Annual Energy Outlook (AEO95) forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs, and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. The RFM consists of six analytical submodules that represent each of the major renewable energy resources--wood, municipal solid waste (MSW), solar energy, wind energy, geothermal energy, and alcohol fuels. The RFM also reads in hydroelectric facility capacities and capacity factors from a data file for use by the NEMS Electricity Market Module (EMM). The purpose of the RFM is to define the technological, cost and resource size characteristics of renewable energy technologies. These characteristics are used to compute a levelized cost to be competed against other similarly derived costs from other energy sources and technologies. The competition of these energy sources over the NEMS time horizon determines the market penetration of these renewable energy technologies. The characteristics include available energy capacity, capital costs, fixed operating costs, variable operating costs, capacity factor, heat rate, construction lead time, and fuel product price.

  1. Variable Renewable Energy in Long-Term Planning Models: A Multi-Model Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frew, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bistline, John [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Blanford, Geoffrey [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Young, David [Electric Power Research Inst. (EPRI), Knoxville, TN (United States); Marcy, Cara [U.S. Energy Information Administration, Washington, DC (United States); Namovicz, Chris [U.S. Energy Information Administration, Washington, DC (United States); Edelman, Risa [US Environmental Protection Agency (EPA), Washington, DC (United States); Meroney, Bill [US Environmental Protection Agency (EPA), Washington, DC (United States); Sims, Ryan [US Environmental Protection Agency (EPA), Washington, DC (United States); Stenhouse, Jeb [US Environmental Protection Agency (EPA), Washington, DC (United States); Donohoo-Vallett, Paul [Dept. of Energy (DOE), Washington DC (United States)

    2017-11-01

    Long-term capacity expansion models of the U.S. electricity sector have long been used to inform electric sector stakeholders and decision-makers. With the recent surge in variable renewable energy (VRE) generators — primarily wind and solar photovoltaics — the need to appropriately represent VRE generators in these long-term models has increased. VRE generators are especially difficult to represent for a variety of reasons, including their variability, uncertainty, and spatial diversity. This report summarizes the analyses and model experiments that were conducted as part of two workshops on modeling VRE for national-scale capacity expansion models. It discusses the various methods for treating VRE among four modeling teams from the Electric Power Research Institute (EPRI), the U.S. Energy Information Administration (EIA), the U.S. Environmental Protection Agency (EPA), and the National Renewable Energy Laboratory (NREL). The report reviews the findings from the two workshops and emphasizes the areas where there is still need for additional research and development on analysis tools to incorporate VRE into long-term planning and decision-making. This research is intended to inform the energy modeling community on the modeling of variable renewable resources, and is not intended to advocate for or against any particular energy technologies, resources, or policies.

  2. Modeling conoid surfaces

    OpenAIRE

    Velimirović Ljubica S.; Stanković Mića S.; Radivojević Grozdana

    2002-01-01

    In tins paper we consider conoid surfaces as frequently used surfaces in building techniques, mainly as daring roof structures. Different types of conoids are presented using the programme package Mathematica. We describe the generation of conoids and by means of parametric representation we get their graphics. The geometric approach offers a wide range of possibilities in the research of complicated spatial surface systems.

  3. Growth and renewable energy in Europe: A random effect model with evidence for neutrality hypothesis

    International Nuclear Information System (INIS)

    Menegaki, Angeliki N.

    2011-01-01

    This is an empirical study on the causal relationship between economic growth and renewable energy for 27 European countries in a multivariate panel framework over the period 1997-2007 using a random effect model and including final energy consumption, greenhouse gas emissions and employment as additional independent variables in the model. Empirical results do not confirm causality between renewable energy consumption and GDP, although panel causality tests unfold short-run relationships between renewable energy and greenhouse gas emissions and employment. The estimated cointegration factor refrains from unity, indicating only a weak, if any, relationship between economic growth and renewable energy consumption in Europe, suggesting evidence of the neutrality hypothesis, which can partly be explained by the uneven and insufficient exploitation of renewable energy sources across Europe.

  4. Renewable Energy and Efficiency Modeling Analysis Partnership (REMAP): An Analysis of How Different Energy Models Addressed a Common High Renewable Energy Penetration Scenario in 2025

    Energy Technology Data Exchange (ETDEWEB)

    Blair, N.; Jenkin, T.; Milford, J.; Short, W.; Sullivan, P.; Evans, D.; Lieberman, E.; Goldstein, G.; Wright, E.; Jayaraman, K. R.; Venkatesh, B.; Kleiman, G.; Namovicz, C.; Smith, B.; Palmer, K.; Wiser, R.; Wood, F.

    2009-09-01

    Energy system modeling can be intentionally or unintentionally misused by decision-makers. This report describes how both can be minimized through careful use of models and thorough understanding of their underlying approaches and assumptions. The analysis summarized here assesses the impact that model and data choices have on forecasting energy systems by comparing seven different electric-sector models. This analysis was coordinated by the Renewable Energy and Efficiency Modeling Analysis Partnership (REMAP), a collaboration among governmental, academic, and nongovernmental participants.

  5. An Integrated Multiperiod OPF Model with Demand Response and Renewable Generation Uncertainty

    DEFF Research Database (Denmark)

    Bukhsh, Waqquas Ahmed; Zhang, Chunyu; Pinson, Pierre

    2015-01-01

    stage realizes generation from the renewable resources and optimally accommodates it by relying on the demand-side flexibilities and limited available flexibilities from the conventional generating units. The proposed model is illustrated on a 4-bus and a 39- bus system. Numerical results show......Renewable energy sources such as wind and solar have received much attention in recent years, and large amount of renewable generation is being integrated to the electricity networks. A fundamental challenge in a power system operation is to handle the intermittent nature of the renewable...... generation. In this paper we present a stochastic programming approach to solve a multiperiod optimal power flow problem under renewable generation uncertainty. The proposed approach consists of two stages. In the first stage, operating points for the conventional power plants are determined. The second...

  6. Modelling land surface - atmosphere interactions

    DEFF Research Database (Denmark)

    Rasmussen, Søren Højmark

    related to inaccurate land surface modelling, e.g. enhanced warm bias in warm dry summer months. Coupling the regional climate model to a hydrological model shows the potential of improving the surface flux simulations in dry periods and the 2 m air temperature in general. In the dry periods......The study is investigates modelling of land surface – atmosphere interactions in context of fully coupled climatehydrological model. With a special focus of under what condition a fully coupled model system is needed. Regional climate model inter-comparison projects as ENSEMBLES have shown bias...

  7. RE-Europe, a large-scale dataset for modeling a highly renewable European electricity system

    DEFF Research Database (Denmark)

    Jensen, Tue Vissing; Pinson, Pierre

    2017-01-01

    Future highly renewable energy systems will couple to complex weather and climate dynamics. This coupling is generally not captured(R2.8) in detailby the open models developed in the power and energy system communities, where such open models exist. To enable modeling such a future energy system......, we describe a dedicated large-scale dataset for a renewable electric power system. The dataset combines a transmission network model, as well as information for generation and demand. Generation includes conventional generators with their technical and economic characteristics, as well as weather......-driven forecasts and corresponding realizations for renewable energy generation for a period of 3 years.(R2.9) These may be scaled according to the envisioned degrees of renewable penetration in a future European energy system.(R2.10) The spatial coverage, completeness and resolution of this dataset, open the door...

  8. Alternative model of random surfaces

    International Nuclear Information System (INIS)

    Ambartzumian, R.V.; Sukiasian, G.S.; Savvidy, G.K.; Savvidy, K.G.

    1992-01-01

    We analyse models of triangulated random surfaces and demand that geometrically nearby configurations of these surfaces must have close actions. The inclusion of this principle drives us to suggest a new action, which is a modified Steiner functional. General arguments, based on the Minkowski inequality, shows that the maximal distribution to the partition function comes from surfaces close to the sphere. (orig.)

  9. Biodegradable polyester films from renewable aleuritic acid: surface modifications induced by melt-polycondensation in air

    Science.gov (United States)

    Jesús Benítez, José; Alejandro Heredia-Guerrero, José; Inmaculada de Vargas-Parody, María; Cruz-Carrillo, Miguel Antonio; Morales-Flórez, Victor; de la Rosa-Fox, Nicolás; Heredia, Antonio

    2016-05-01

    Good water barrier properties and biocompatibility of long-chain biopolyesters like cutin and suberin have inspired the design of synthetic mimetic materials. Most of these biopolymers are made from esterified mid-chain functionalized ω-long chain hydroxyacids. Aleuritic (9,10,16-trihydroxypalmitic) acid is such a polyhydroxylated fatty acid and is also the major constituent of natural lac resin, a relatively abundant and renewable resource. Insoluble and thermostable films have been prepared from aleuritic acid by melt-condensation polymerization in air without catalysts, an easy and attractive procedure for large scale production. Intended to be used as a protective coating, the barrier's performance is expected to be conditioned by physical and chemical modifications induced by oxygen on the air-exposed side. Hence, the chemical composition, texture, mechanical behavior, hydrophobicity, chemical resistance and biodegradation of the film surface have been studied by attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR), atomic force microscopy (AFM), nanoindentation and water contact angle (WCA). It has been demonstrated that the occurrence of side oxidation reactions conditions the surface physical and chemical properties of these polyhydroxyester films. Additionally, the addition of palmitic acid to reduce the presence of hydrophilic free hydroxyl groups was found to have a strong influence on these parameters.

  10. Renewable energy systems a smart energy systems approach to the choice and modeling of 100% renewable solutions

    CERN Document Server

    Lund, Henrik

    2014-01-01

    In this new edition of Renewable Energy Systems, globally recognized renewable energy researcher and professor, Henrik Lund, sets forth a straightforward, comprehensive methodology for comparing different energy systems' abilities to integrate fluctuating and intermittent renewable energy sources. The book does this by presenting an energy system analysis methodology and offering a freely available accompanying software tool, EnergyPLAN, which automates and simplifies the calculations supporting such a detailed comparative analysis. The book provides the results of more than fifteen comprehensive energy system analysis studies, examines the large-scale integration of renewable energy into the present system, and presents concrete design examples derived from a dozen renewable energy systems around the globe. Renewable Energy Systems, Second Edition also undertakes the socio-political realities governing the implementation of renewable energy systems by introducing a theoretical framework approach aimed at ...

  11. Model documentation renewable fuels module of the National Energy Modeling System

    International Nuclear Information System (INIS)

    1997-04-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the 1997 Annual Energy Outlook forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs. and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. This documentation report serves three purposes. First, it is a reference document for model analysts, model users, and the public interested in the construction and application of the RFM. Second, it meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. Finally, such documentation facilitates continuity in EIA model development by providing information sufficient to perform model enhancements and data updates as part of EIA's ongoing mission to provide analytical and forecasting information systems

  12. Model documentation renewable fuels module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the 1997 Annual Energy Outlook forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs. and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. This documentation report serves three purposes. First, it is a reference document for model analysts, model users, and the public interested in the construction and application of the RFM. Second, it meets the legal requirement of the Energy Information Administration (EIA) to provide adequate documentation in support of its models. Finally, such documentation facilitates continuity in EIA model development by providing information sufficient to perform model enhancements and data updates as part of EIA`s ongoing mission to provide analytical and forecasting information systems.

  13. Modelling of Diesel Generator Sets That Assist Off-Grid Renewable Energy Micro-grids

    Directory of Open Access Journals (Sweden)

    Johanna Salazar

    2015-08-01

    Full Text Available This paper focuses on modelling diesel generators for off-grid installations based on renewable energies. Variations in Environmental Variables (for example, Solar Radiation and Wind Speed make necessary to include these auxiliary systems in off-grid renewable energy installations, in order to ensure minimal services when the produced renewable energy is not sufficient to fulfill the demand. This paper concentrates on modelling the dynamical behaviour of the diesel generator, in order to use the models and simulations for developing and testing advanced controllers for the overall off-grid system. The Diesel generator is assumed to consist of a diesel motor connected to a synchronous generator through an electromagnetic clutch, with a flywheel to damp variations. Each of the components is modelled using physical models, with the corresponding control systems also modelled: these control systems include the speed and the voltage regulation (in cascade regulation.

  14. Modelling land surface - atmosphere interactions

    DEFF Research Database (Denmark)

    Rasmussen, Søren Højmark

    The study is investigates modelling of land surface – atmosphere interactions in context of fully coupled climatehydrological model. With a special focus of under what condition a fully coupled model system is needed. Regional climate model inter-comparison projects as ENSEMBLES have shown bias...

  15. A global renewable energy system: A modelling exercise in ETSAP/TIAM

    DEFF Research Database (Denmark)

    Føyn, Tullik Helene Ystanes; Karlsson, Kenneth Bernard; Balyk, Olexandr

    2011-01-01

    This paper aims to test the ETSAP2-TIAM global energy system model and to try out how far it can go towards a global 100% renewable energy system with the existing model database. This will show where limits in global resources are met and where limits in the data fed to the model until now are met...

  16. The surface renewal method for better spatial resolution of evapotranspiration measurements

    Science.gov (United States)

    Suvocarev, K.; Fischer, M.; Massey, J. H.; Reba, M. L.; Runkle, B.

    2017-12-01

    Evaluating feasible irrigation strategies when water is scarce requires measurements or estimations of evapotranspiration (ET). Direct observations of ET from agricultural fields are preferred, and micrometeorological methods such as eddy covariance (EC) provide a high quality, continuous time series of ET. However, when replicates of the measurements are needed to compare irrigation strategies, the cost of such experiments is often prohibitive and limits experimental scope. An alternative micrometeorological approach to ET, the surface renewal (SR) method, may be reduced to a thermocouple and a propeller anemometer (Castellvi and Snyder, 2009). In this case, net radiation, soil and sensible heat flux (H) are measured and latent heat flux (an energy equivalent for ET) is estimated as the residual of the surface energy-balance equation. In our experiment, thermocouples (Type E Fine-Wire Thermocouple, FW3) were deployed next to the EC system and combined with mean horizontal wind speed measurements to obtain H using SR method for three weeks. After compensating the temperature signal for non-ideal frequency response in the wavelet half-plane and correcting the sonic anemometer for the flow distortion (Horst et al., 2015), the SR H fluxes compared well to those measured by EC (r2 = 0.9, slope = 0.92). This result encouraged us to install thermocouples over 16 rice fields under different irrigation treatments (continuous cascade flood, continuous multiple inlet rice irrigation, alternate wetting and drying, and furrow irrigation). The EC measurements with net radiometer and soil heat flux plates are deployed at three of these fields to provide a direct comparison. The measurement campaign will finish soon and the data will be processed to evaluate the SR approach for ET estimation. The results will be used to show better spatial resolution of ET measurements to support irrigation decisions in agricultural crops.

  17. Energy models for commercial energy prediction and substitution of renewable energy sources

    International Nuclear Information System (INIS)

    Iniyan, S.; Suganthi, L.; Samuel, Anand A.

    2006-01-01

    In this paper, three models have been projected namely Modified Econometric Mathematical (MEM) model, Mathematical Programming Energy-Economy-Environment (MPEEE) model, and Optimal Renewable Energy Mathematical (OREM) model. The actual demand for coal, oil and electricity is predicted using the MEM model based on economic, technological and environmental factors. The results were used in the MPEEE model, which determines the optimum allocation of commercial energy sources based on environmental limitations. The gap between the actual energy demand from the MEM model and optimal energy use from the MPEEE model, has to be met by the renewable energy sources. The study develops an OREM model that would facilitate effective utilization of renewable energy sources in India, based on cost, efficiency, social acceptance, reliability, potential and demand. The economic variations in solar energy systems and inclusion of environmental constraint are also analyzed with OREM model. The OREM model will help policy makers in the formulation and implementation of strategies concerning renewable energy sources in India for the next two decades

  18. Nuclear energy, renewable energy, and economic growth in developed and developing countries : A modelling analysis from simultaneous-equation models

    OpenAIRE

    Anis Omri; Anissa Chaibi

    2014-01-01

    This paper investigates the causal relationship among two types of energy consumption (nuclear energy and renewable energy) and economic growth using dynamic simultaneous-equation panel data models for 17 developed and developing countries. Our results in

  19. Variable Renewable Energy in Long-Term Planning Models: A Multi-Model Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Cole, Wesley J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Frew, Bethany A. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mai, Trieu T. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sun, Yinong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bistline, John [Electric Power Research Inst., Palo Alto, CA (United States); Blanford, Geoffrey [Electric Power Research Inst., Palo Alto, CA (United States); Young, David [Electric Power Research Inst., Palo Alto, CA (United States); Marcy, Cara [Energy Information Administration, Washington, DC (United States); Namovicz, Chris [Energy Information Administration, Washington, DC (United States); Edelman, Risa [Environmental Protection Agency, Washington, DC (United States); Meroney, Bill [Environmental Protection Agency; Sims, Ryan [Environmental Protection Agency; Stenhouse, Jeb [Environmental Protection Agency; Donohoo-Vallett, Paul [U.S. Department of Energy

    2017-11-03

    Long-term capacity expansion models of the U.S. electricity sector have long been used to inform electric sector stakeholders and decision makers. With the recent surge in variable renewable energy (VRE) generators - primarily wind and solar photovoltaics - the need to appropriately represent VRE generators in these long-term models has increased. VRE generators are especially difficult to represent for a variety of reasons, including their variability, uncertainty, and spatial diversity. To assess current best practices, share methods and data, and identify future research needs for VRE representation in capacity expansion models, four capacity expansion modeling teams from the Electric Power Research Institute, the U.S. Energy Information Administration, the U.S. Environmental Protection Agency, and the National Renewable Energy Laboratory conducted two workshops of VRE modeling for national-scale capacity expansion models. The workshops covered a wide range of VRE topics, including transmission and VRE resource data, VRE capacity value, dispatch and operational modeling, distributed generation, and temporal and spatial resolution. The objectives of the workshops were both to better understand these topics and to improve the representation of VRE across the suite of models. Given these goals, each team incorporated model updates and performed additional analyses between the first and second workshops. This report summarizes the analyses and model 'experiments' that were conducted as part of these workshops as well as the various methods for treating VRE among the four modeling teams. The report also reviews the findings and learnings from the two workshops. We emphasize the areas where there is still need for additional research and development on analysis tools to incorporate VRE into long-term planning and decision-making.

  20. Dynamic Modeling of Networks, Microgrids, and Renewable Sources in the dq0 Reference Frame

    DEFF Research Database (Denmark)

    Baimel, Dmitry; Belikov, Juri; Guerrero, Josep M.

    2017-01-01

    to simplify the analysis of dynamic phenomena, among them are models based on the dq0 transformation. Many recent works present dq0-based models of various power system components, ranging from small renewable sources to complete networks. The purpose of this paper is to review and categorize these works......With increasing the penetration of distributed and renewable sources into power grids, and with increasing the use of power electronics-based devices, the dynamic behavior of large-scale power systems is becoming increasingly complex. These recent developments have led to several models attempting...

  1. Model documentation, Renewable Fuels Module of the National Energy Modeling System

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-01-01

    This report documents the objectives, analytical approach, and design of the National Energy Modeling System (NEMS) Renewable Fuels Module (RFM) as it relates to the production of the Annual Energy Outlook 1998 (AEO98) forecasts. The report catalogues and describes modeling assumptions, computational methodologies, data inputs, and parameter estimation techniques. A number of offline analyses used in lieu of RFM modeling components are also described. For AEO98, the RFM was modified in three principal ways, introducing capital cost elasticities of supply for new renewable energy technologies, modifying biomass supply curves, and revising assumptions for use of landfill gas from municipal solid waste (MSW). In addition, the RFM was modified in general to accommodate projections beyond 2015 through 2020. Two supply elasticities were introduced, the first reflecting short-term (annual) cost increases from manufacturing, siting, and installation bottlenecks incurred under conditions of rapid growth, and the second reflecting longer term natural resource, transmission and distribution upgrade, and market limitations increasing costs as more and more of the overall resource is used. Biomass supply curves were also modified, basing forest products supplies on production rather than on inventory, and expanding energy crop estimates to include states west of the Mississippi River using information developed by the Oak Ridge National Laboratory. Finally, for MSW, several assumptions for the use of landfill gas were revised and extended.

  2. Greening the Grid: Advances in Production Cost Modeling for India Renewable Energy Grid Integration Study

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, Jaquelin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Palchak, David [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2017-07-12

    The Greening the Grid: Pathways to Integrate 175 Gigawatts of Renewable Energy into India's Electric Grid study uses advanced weather and power system modeling to explore the operational impacts of meeting India's 2022 renewable energy targets and identify actions that may be favorable for integrating high levels of renewable energy into the Indian grid. The study relies primarily on a production cost model that simulates optimal scheduling and dispatch of available generation in a future year (2022) by minimizing total production costs subject to physical, operational, and market constraints. This fact sheet provides a detailed look at each of these models, including their common assumptions and the insights provided by each.

  3. Modeling Feasibility of a Proposed Renewable Energy System with Wind and Solar Resources and Hydro Storage in Complex Terrain

    Science.gov (United States)

    Jiang, J.; Koracin, D.; Hamilton, R.; Hagen, D.; King, K. C.

    2012-04-01

    High temporal and spatial variability in wind and solar power brings difficulties in integrating these resources into an electricity grid. These difficulties are even more emphasized in areas with complex topography due to complicated flow patterns and cloudiness evolution. This study investigates the feasibility and efficiency of a proposed renewable energy system with wind and solar resources and hydro storages in western Nevada, U.S.A. The state-of-the-art Weather Research and Forecasting (WRF) model was used for the prediction of wind fields and incoming solar radiation at the ground surface. Forecast winds and solar radiation were evaluated with observational data from four wind masts and four meteorological towers in two months, July 2007 and January 2010. Based on a hypothetical wind farm and an assumed neighboring solar power plant both located near the hydro storage facility, as well as considering local power demand, the efficiency of the renewable energy system is projected. One of the main questions was how to optimize a schedule of activating pump storages according to the characteristics of several available hydro pumps, and wind and/or solar power predictions. The results show that segmentation of the pump-storage channel provides improved efficiency of the entire system. This modeled renewable energy system shows promise for possible applications and grid integration.

  4. Surface renewal: an advanced micrometeorological method for measuring and processing field-scale energy flux density data.

    Science.gov (United States)

    McElrone, Andrew J; Shapland, Thomas M; Calderon, Arturo; Fitzmaurice, Li; Paw U, Kyaw Tha; Snyder, Richard L

    2013-12-12

    Advanced micrometeorological methods have become increasingly important in soil, crop, and environmental sciences. For many scientists without formal training in atmospheric science, these techniques are relatively inaccessible. Surface renewal and other flux measurement methods require an understanding of boundary layer meteorology and extensive training in instrumentation and multiple data management programs. To improve accessibility of these techniques, we describe the underlying theory of surface renewal measurements, demonstrate how to set up a field station for surface renewal with eddy covariance calibration, and utilize our open-source turnkey data logger program to perform flux data acquisition and processing. The new turnkey program returns to the user a simple data table with the corrected fluxes and quality control parameters, and eliminates the need for researchers to shuttle between multiple processing programs to obtain the final flux data. An example of data generated from these measurements demonstrates how crop water use is measured with this technique. The output information is useful to growers for making irrigation decisions in a variety of agricultural ecosystems. These stations are currently deployed in numerous field experiments by researchers in our group and the California Department of Water Resources in the following crops: rice, wine and raisin grape vineyards, alfalfa, almond, walnut, peach, lemon, avocado, and corn.

  5. Renewable Energy Cost Modeling. A Toolkit for Establishing Cost-Based Incentives in the United States

    Energy Technology Data Exchange (ETDEWEB)

    Gifford, Jason S. [Sustainable Energy Advantage, LLC, Framington, MA (United States); Grace, Robert C. [Sustainable Energy Advantage, LLC, Framington, MA (United States); Rickerson, Wilson H. [Meister Consultants Group, Inc., Boston, MA (United States)

    2011-05-01

    This report serves as a resource for policymakers who wish to learn more about levelized cost of energy (LCOE) calculations, including cost-based incentives. The report identifies key renewable energy cost modeling options, highlights the policy implications of choosing one approach over the other, and presents recommendations on the optimal characteristics of a model to calculate rates for cost-based incentives, FITs, or similar policies. These recommendations shaped the design of NREL's Cost of Renewable Energy Spreadsheet Tool (CREST), which is used by state policymakers, regulators, utilities, developers, and other stakeholders to assist with analyses of policy and renewable energy incentive payment structures. Authored by Jason S. Gifford and Robert C. Grace of Sustainable Energy Advantage LLC and Wilson H. Rickerson of Meister Consultants Group, Inc.

  6. Development of SWITCH-Hawaii model: loads and renewable resources.

    Science.gov (United States)

    2016-08-01

    This report summarizes work done to configure the SWITCH power system model using data for the Oahu power system. SWITCH is a planning model designed to choose optimal infrastructure investments for power systems over a multi-decade period. Investmen...

  7. Analysis of Modeling Assumptions used in Production Cost Models for Renewable Integration Studies

    Energy Technology Data Exchange (ETDEWEB)

    Stoll, Brady [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Gregory [National Renewable Energy Lab. (NREL), Golden, CO (United States); Townsend, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bloom, Aaron [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2016-01-01

    Renewable energy integration studies have been published for many different regions exploring the question of how higher penetration of renewable energy will impact the electric grid. These studies each make assumptions about the systems they are analyzing; however the effect of many of these assumptions has not been yet been examined and published. In this paper we analyze the impact of modeling assumptions in renewable integration studies, including the optimization method used (linear or mixed-integer programming) and the temporal resolution of the dispatch stage (hourly or sub-hourly). We analyze each of these assumptions on a large and a small system and determine the impact of each assumption on key metrics including the total production cost, curtailment of renewables, CO2 emissions, and generator starts and ramps. Additionally, we identified the impact on these metrics if a four-hour ahead commitment step is included before the dispatch step and the impact of retiring generators to reduce the degree to which the system is overbuilt. We find that the largest effect of these assumptions is at the unit level on starts and ramps, particularly for the temporal resolution, and saw a smaller impact at the aggregate level on system costs and emissions. For each fossil fuel generator type we measured the average capacity started, average run-time per start, and average number of ramps. Linear programming results saw up to a 20% difference in number of starts and average run time of traditional generators, and up to a 4% difference in the number of ramps, when compared to mixed-integer programming. Utilizing hourly dispatch instead of sub-hourly dispatch saw no difference in coal or gas CC units for either start metric, while gas CT units had a 5% increase in the number of starts and 2% increase in the average on-time per start. The number of ramps decreased up to 44%. The smallest effect seen was on the CO2 emissions and total production cost, with a 0.8% and 0

  8. Introducing renewable energy and industrial restructuring to reduce GHG emission: Application of a dynamic simulation model

    International Nuclear Information System (INIS)

    Song, Junnian; Yang, Wei; Higano, Yoshiro; Wang, Xian’en

    2015-01-01

    Highlights: • Renewable energy development is expanded and introduced into socioeconomic activities. • A dynamic optimization simulation model is developed based on input–output approach. • Regional economic, energy and environmental impacts are assessed dynamically. • Industrial and energy structure is adjusted optimally for GHG emission reduction. - Abstract: Specifying the renewable energy development as new energy industries to be newly introduced into current socioeconomic activities, this study develops a dynamic simulation model with input–output approach to make comprehensive assessment of the impacts on economic development, energy consumption and GHG emission under distinct levels of GHG emission constraints involving targeted GHG emission reduction policies (ERPs) and industrial restructuring. The model is applied to Jilin City to conduct 16 terms of dynamic simulation work with GRP as objective function subject to mass, value and energy balances aided by the extended input–output table with renewable energy industries introduced. Simulation results indicate that achievement of GHG emission reduction target is contributed by renewable energy industries, ERPs and industrial restructuring collectively, which reshape the terminal energy consumption structure with a larger proportion of renewable energy. Wind power, hydropower and biomass combustion power industries account for more in the power generation structure implying better industrial prospects. Mining, chemical, petroleum processing, non-metal, metal and thermal power industries are major targets for industrial restructuring. This method is crucial for understanding the role of renewable energy development in GHG mitigation efforts and other energy-related planning settings, allowing to explore the optimal level for relationships among all socioeconomic activities and facilitate to simultaneous pursuit of economic development, energy utilization and environmental preservation

  9. Modeling and analysis of renewable energy obligations and technology bandings in the UK electricity market

    International Nuclear Information System (INIS)

    Gürkan, Gül; Langestraat, Romeo

    2014-01-01

    In the UK electricity market, generators are obliged to produce part of their electricity with renewable energy resources in accordance with the Renewable Obligation Order. Since 2009 technology banding has been added, meaning that different technologies are rewarded with a different number of certificates. We analyze these two different renewable obligation policies in a mathematical representation of an electricity market with random availabilities of renewable generation outputs and random electricity demand. We also present another, alternative, banding policy. We provide revenue adequate pricing schemes for the three obligation policies. We carry out a simulation study via sampling. A key finding is that the UK banding policy cannot guarantee that the original obligation target is met, hence potentially resulting in more pollution. Our alternative provides a way to make sure that the target is met while supporting less established technologies, but it comes with a significantly higher consumer price. Furthermore, as an undesirable side effect, we observe that a cost reduction in a technology with a high banding (namely offshore wind) leads to more CO 2 emissions under the UK banding policy and to higher consumer prices under the alternative banding policy. - Highlights: • We model and analyze three renewable obligation policies in a mathematical framework. • We provide revenue adequate pricing schemes for the three policies. • We carry out a simulation study via sampling. • The UK policy cannot guarantee that the original obligation target is met. • Cost reductions can lead to more pollution or higher prices under banding policies

  10. Agent-based model of intermittent renewables : Simulating emerging changes in energy markets in transition

    NARCIS (Netherlands)

    Chappin, E.J.L.; Viebahn, P.; Richstein, J.C.; Lechtenböhmer, S.; Nebel, A.

    2012-01-01

    The energy transition is taking shape in the German and, to a lesser extent also its neighbouring electricity markets. We have proposed adaptations to an existing model to represent the increasing shares of intermittent renewables, that may alter the structure of the market and the viability of

  11. Polling models with renewal arrivals: a new method to derive heavy-traffic asymptotics

    NARCIS (Netherlands)

    van der Mei, R.D.; Winands, E.M.M.

    2008-01-01

    We consider asymmetric cyclic polling systems with an arbitrary number of queues, general service-time distributions, zero switch-over times, gated service at each queue, and with general renewal arrival processes at each of the queues. For this classical model, we propose a new method to derive

  12. Optimal investment paths for future renewable based energy systems - Using the optimisation model Balmorel

    DEFF Research Database (Denmark)

    Karlsson, Kenneth Bernard; Meibom, Peter

    2008-01-01

    This paper investigates a possible long term investment path for the Nordic energy system focussing on renewable energy in the supply sector and on hydrogen as the main fuel for transportation, covering up to 70% of all transport in 2050. The optimisation model Balmorel [Ravn H, et al. Balmorel...... that with an oil price at 100 $/barrel, a CO2 price at40 €/ton and the assumed penetration of hydrogen in the transport sector, it is economically optimal to cover more than 95% of the primary energy consumption for electricity and district heat by renewables in 2050. When the transport sector is converted...... as assumed 65% of the transportation relies on renewable energy....

  13. A novel integrated renewable energy system modelling approach, allowing fast FPGA controller prototyping

    DEFF Research Database (Denmark)

    Teodorescu, Remus; Ruiz, Alberto Parera; Cirstea, Marcian

    2008-01-01

    The paper describes a new holistic approach to the modeling of integrated renewable energy systems. The method is using the DK5 modeling/design environment from Celoxica and is based on the new Handel-C programming language. The goal of the work carried out was to achieve a combined model...... containing a Xilinx Spartan II FPGA and was successfully experimentally tested. This approach enables the design and fast hardware implementation of efficient controllers for Distributed Energy Resource (DER) hybrid systems....

  14. CFD Modeling in Development of Renewable Energy Applications

    OpenAIRE

    Maher A.R. Sadiq Al-Baghdadi

    2013-01-01

    Chapter 1: A Multi-fluid Model to Simulate Heat and Mass Transfer in a PEM Fuel Cell. Torsten Berning, Madeleine Odgaard, Søren K. Kær Chapter 2: CFD Modeling of a Planar Solid Oxide Fuel Cell (SOFC) for Clean Power Generation. Meng Ni Chapter 3: Hydrodynamics and Hydropower in the New Paradigm for a Sustainable Engineering. Helena M. Ramos, Petra A. López-Jiménez Chapter 4: Opportunities for CFD in Ejector Solar Cooling. M. Dennis Chapter 5: Three Dimensional Modelling of Flow Field Around a...

  15. Values of Land and Renewable Resources in a Three-Sector Economic Growth Model

    Directory of Open Access Journals (Sweden)

    Zhang Wei-Bin

    2015-04-01

    Full Text Available This paper studies dynamic interdependence of capital, land and resource values in a three sector growth model with endogenous wealth and renewable resources. The model is based on the neoclassical growth theory, Ricardian theory and growth theory with renewable resources. The household’s decision is modeled with an alternative approach proposed by Zhang two decades ago. The economic system consists of the households, industrial, agricultural, and resource sectors. The model describes a dynamic interdependence between wealth accumulation, resource change, and division of labor under perfect competition. We simulate the model to demonstrate the existence of a unique stable equilibrium point and plot the motion of the dynamic system. The study conducts comparative dynamic analysis with regard to changes in the propensity to consume resources, the propensity to consume housing, the propensity to consume agricultural goods, the propensity to consume industrial goods, the propensity to save, the population, and the output elasticity of capital of the resource sector.

  16. Growth curves and sustained commissioning modelling of renewable energy: Investigating resource constraints for wind energy

    International Nuclear Information System (INIS)

    Davidsson, Simon; Grandell, Leena; Wachtmeister, Henrik; Höök, Mikael

    2014-01-01

    Several recent studies have proposed fast transitions to energy systems based on renewable energy technology. Many of them dismiss potential physical constraints and issues with natural resource supply, and do not consider the growth rates of the individual technologies needed or how the energy systems are to be sustained over longer time frames. A case study is presented modelling potential growth rates of the wind energy required to reach installed capacities proposed in other studies, taking into account the expected service life of wind turbines. A sustained commissioning model is proposed as a theoretical foundation for analysing reasonable growth patterns for technologies that can be sustained in the future. The annual installation and related resource requirements to reach proposed wind capacity are quantified and it is concluded that these factors should be considered when assessing the feasibility, and even the sustainability, of fast energy transitions. Even a sustained commissioning scenario would require significant resource flows, for the transition as well as for sustaining the system, indefinitely. Recent studies that claim there are no potential natural resource barriers or other physical constraints to fast transitions to renewable energy appear inadequate in ruling out these concerns. - Highlights: • Growth rates and service life is important when evaluating energy transitions. • A sustained commissioning model is suggested for analysing renewable energy. • Natural resource requirements for renewable energy are connected to growth rates. • Arguments by recent studies ruling out physical constraints appear inadequate

  17. Nanosecond laser ablated copper superhydrophobic surface with tunable ultrahigh adhesion and its renewability with low temperature annealing

    Science.gov (United States)

    He, An; Liu, Wenwen; Xue, Wei; Yang, Huan; Cao, Yu

    2018-03-01

    Recently, metallic superhydrophobic surfaces with ultrahigh adhesion have got plentiful attention on account of their significance in scientific researches and industrial applications like droplet transport, drug delivery and novel microfluidic devices. However, the long lead time and transience hindered its in-depth development and industrial application. In this work, nanosecond laser ablation was carried out to construct grid of micro-grooves on copper surface, whereafter, by applying fast ethanol assisted low-temperature annealing, we obtained surface with superhydrophobicity and ultrahigh adhesion within hours. And the ultrahigh adhesion force was found tunable by varying the groove spacing. Using ultrasonic cleaning as the simulation of natural wear and tear in service, the renewability of superhydrophobicity was also investigated, and the result shows that the contact angle can rehabilitate promptly by the processing of ethanol assisted low-temperature annealing, which gives a promising fast and cheap circuitous strategy to realize the long wish durable metallic superhydrophobic surfaces in practical applications.

  18. Going beyond best technology and lowest price: on renewable energy investors’ preference for service-driven business models

    International Nuclear Information System (INIS)

    Loock, Moritz

    2012-01-01

    Renewable energy is becoming increasingly important for economies in many countries. But still in an emerging industry, renewable energy requires supportive energy policy helping firms to develop and protect competitive advantages in global competition. As a guideline for designing such policy, we consult well-informed stakeholders within the renewable energy industry: investors. Their preferences serve as explorative indicator for assessing which business models might succeed in competition. To contribute to only limited research on renewable energy investors’ preferences, we ask, which business models investment managers for renewable energy prefer to invest in. We report from an explorative study of 380 choices of renewable energy investment managers. Based on the stated preferences, we modelled three generic business models to calculate the share of investors’ preferences. We find exiting evidence: a “customer intimacy” business model that proposes best services is much more preferred by investors than business models that propose lowest price or best technology. Policy-makers can use those insights for designing policy that supports service-driven business models for renewable energy with a scope on customer needs rather than technology or price. Additionally, we state important implications for renewable energy entrepreneurs, managers and research.

  19. Dispatchable Renewable Energy Model for Microgrid Power System

    Energy Technology Data Exchange (ETDEWEB)

    Chiou, Fred; Gentle, Jake P.; McJunkin, Timothy R.

    2017-04-01

    Over the years, many research projects have been performed and focused on finding out the effective ways to balance the power demands and supply on the utility grid. The causes of the imbalance could be the increasing demands from the end users, the loss of power generation (generators down), faults on the transmission lines, power tripped due to overload, and weather conditions, etc. An efficient Load Frequency Control (LFC) can assure the desired electricity quality provided to the residential, commercial and industrial end users. A simulation model is built in this project to investigate the contribution of the modeling of dispatchable energy such as solar energy, wind power, hydro power and energy storage to the balance of the microgrid power system. An analysis of simplified feedback control system with proportional, integral, and derivative (PID) controller was performed. The purpose of this research is to investigate a simulation model that achieves certain degree of the resilient control for the microgrid.

  20. FACTORS AFFECTING TEACHING THE CONCEPT of RENEWABLE ENERGY in TECHNOLOGY ASSISTED ENVIRONMENTS AND DESIGNING PROCESSES in THE DISTANCE EDUCATION MODEL

    Directory of Open Access Journals (Sweden)

    A. Seda YUCEL

    2007-01-01

    Full Text Available The energy policies of today focus mainly on sustainable energy systems and renewable energy resources. Chemistry is closely related to energy recycling, energy types, renewable energy, and nature-energy interaction; therefore, it is now an obligation to enrich chemistry classes with renewable energy concepts and related awareness. Before creating renewable energy awareness, the factors thought to affect such awareness should be determined. Knowing these factors would facilitate finding out what to take into account in creating renewable energy awareness. In this study, certain factors thought to affect the development of renewable energy awareness were investigated. The awareness was created through a technology-assisted renewable energy module and assessed using a renewable energy assessment tool. The effects of the students’ self-directed learning readiness with Guglielmino (1977, inner-individual orientation, and anxiety orientation on the awareness were examined. These three factors were found to have significant effects on renewable energy, which was developed through technology utilization. In addition, based on the finding that delivering the subject of renewable energy in technology assisted environments is more effective, the criteria that should be taken into consideration in transforming this subject into a design model that is more suitable for distance education were identified.

  1. REVIEW: Zebrafish: A Renewed Model System For Functional Genomics

    Science.gov (United States)

    Wen, Xiao-Yan

    2008-01-01

    In the post genome era, a major goal in molecular biology is to determine the function of the many thousands of genes present in the vertebrate genome. The zebrafish (Danio rerio) provides an almost ideal genetic model to identify the biological roles of these novel genes, in part because their embryos are transparent and develop rapidly. The zebrafish has many advantages over mouse for genome-wide mutagenesis studies, allowing for easier, cheaper and faster functional characterization of novel genes in the vertebrate genome. Many molecular research tools such as chemical mutagenesis, transgenesis, gene trapping, gene knockdown, TILLING, gene targeting, RNAi and chemical genetic screen are now available in zebrafish. Combining all the forward, reverse, and chemical genetic tools, it is expected that zebrafish will make invaluable contribution to vertebrate functional genomics in functional annotation of the genes, modeling human diseases and drug discoveries.

  2. Surface EXAFS - A mathematical model

    International Nuclear Information System (INIS)

    Bateman, J.E.

    2002-01-01

    Extended X-ray absorption fine structure (EXAFS) studies are a powerful technique for studying the chemical environment of specific atoms in a molecular or solid matrix. The study of the surface layers of 'thick' materials introduces special problems due to the different escape depths of the various primary and secondary emission products which follow X-ray absorption. The processes are governed by the properties of the emitted fluorescent photons or electrons and of the material. Their interactions can easily destroy the linear relation between the detected signal and the absorption cross-section. Also affected are the probe depth within the surface and the background superimposed on the detected emission signal. A general mathematical model of the escape processes is developed which permits the optimisation of the detection modality (X-rays or electrons) and the experimental variables to suit the composition of any given surface under study

  3. Business models for renewable energy in the built environment. Updated version

    Energy Technology Data Exchange (ETDEWEB)

    Wuertenberger, L.; Menkveld, M.; Vethman, P.; Van Tilburg, X. [ECN Policy Studies, Amsterdam (Netherlands); Bleyl, J.W. [Energetic Solutions, Graz (Austria)

    2012-04-15

    The project RE-BIZZ aims to provide insight to policy makers and market actors in the way new and innovative business models (and/or policy measures) can stimulate the deployment of renewable energy technologies (RET) and energy efficiency (EE) measures in the built environment. The project is initiated and funded by the IEA Implementing Agreement for Renewable Energy Technology Deployment (IEA-RETD). It analysed ten business models in three categories (amongst others different types of Energy Service Companies (ESCOs), Developing properties certified with a 'green' building label, Building owners profiting from rent increases after EE measures, Property Assessed Clean Energy (PACE) financing, On-bill financing, and Leasing of RET equipment) including their organisational and financial structure, the existing market and policy context, and an analysis of Strengths, Weaknesses, Opportunities and Threats (SWOT). The study concludes with recommendations for policy makers and other market actors.

  4. Metering systems and demand-side management models applied to hybrid renewable energy systems in micro-grid configuration

    International Nuclear Information System (INIS)

    Blasques, L.C.M.; Pinho, J.T.

    2012-01-01

    This paper proposes a demand-side management model integrated to a metering system for hybrid renewable energy systems in micro-grid configuration. The proposal is based on the management problems verified in most of this kind of renewable hybrid systems installed in Brazil. The main idea is the implementation of a pre-paid metering system with some control functions that directly act on the consumer demand, restricting the consumption proportionally to the monthly availability of renewable energy. The result is a better distribution of the electricity consumption by month and by consumer, preventing that only one user, with larger purchasing power, consumes all the renewable energy available at some time period. The proportionality between the consumption and the renewable energy's availability has the objective to prevent a lack of energy stored and a high use of the diesel generator-set on months of low renewable potential. This paper also aims to contribute to the Brazilian regulation of renewable energy systems supplying micro-grids. - Highlights: ► Review of the Brazilian electricity regulation for small-scale isolated systems. ► Renewable systems are the most feasible option in several isolated communities. ► One proposal is to guarantee government subsidies for renewable energy systems. ► Smart electronic meters to create electricity restrictions for the consumers.

  5. Regensim – Matlab toolbox for renewable energy sources modelling and simulation

    Directory of Open Access Journals (Sweden)

    Cristian Dragoş Dumitru

    2011-12-01

    Full Text Available This paper deals with the implementation and development of a Matlab Simulink library named RegenSim designed for modeling, simulations and analysis of real hybrid solarwind-hydro systems connected to local grids. Blocks like wind generators, hydro generators, solar photovoltaic modules and accumulators are implemented. The main objective is the study of the hybrid power system behavior, which allows employing renewable and variable in time energy sources while providing a continuous supply.

  6. Modeling surface imperfections in thin films and nanostructured surfaces

    DEFF Research Database (Denmark)

    Hansen, Poul-Erik; Madsen, J. S.; Jensen, S. A.

    2017-01-01

    Accurate scatterometry and ellipsometry characterization of non-perfect thin films and nanostructured surfaces are challenging. Imperfections like surface roughness make the associated modelling and inverse problem solution difficult due to the lack of knowledge about the imperfection...

  7. RESRO: A spatio-temporal model to optimise regional energy systems emphasising renewable energies

    Directory of Open Access Journals (Sweden)

    Gadocha S.

    2012-10-01

    Full Text Available RESRO (Reference Energy System Regional Optimization optimises the simultaneous fulfilment of the heat and power demand in regional energy systems. It is a mixed-integer program realised in the modelling language GAMS. The model handles information on geographically disaggregated data describing heat demand and renewable energy potentials (e.g. biomass, solar energy, ambient heat. Power demand is handled spatially aggregated in an hourly time resolution within 8 type days. The major idea is to use a high-spatial, low-temporal heat resolution and a low-spatial, hightemporal power resolution with both demand levels linked with each other. Due to high transport losses the possibilities for heat transport over long distances are unsatisfying. Thus, the spatial, raster-based approach is used to identify and utilise renewable energy resources for heat generation close to the customers as well as to optimize district heating grids and related energy flows fed by heating plants or combined heat and power (CHP plants fuelled by renewables. By combining the heat and electricity sector within the model, it is possible to evaluate relationships between these energy fields such as the use of CHP or heat pump technologies and also to examine relationships between technologies such as solar thermal and photovoltaic facilities, which are in competition for available, suitable roof or ground areas.

  8. Lunar surface vehicle model competition

    Science.gov (United States)

    1990-01-01

    During Fall and Winter quarters, Georgia Tech's School of Mechanical Engineering students designed machines and devices related to Lunar Base construction tasks. These include joint projects with Textile Engineering students. Topics studied included lunar environment simulator via drop tower technology, lunar rated fasteners, lunar habitat shelter, design of a lunar surface trenching machine, lunar support system, lunar worksite illumination (daytime), lunar regolith bagging system, sunlight diffusing tent for lunar worksite, service apparatus for lunar launch vehicles, lunar communication/power cables and teleoperated deployment machine, lunar regolith bag collection and emplacement device, soil stabilization mat for lunar launch/landing site, lunar rated fastening systems for robotic implementation, lunar surface cable/conduit and automated deployment system, lunar regolith bagging system, and lunar rated fasteners and fastening systems. A special topics team of five Spring quarter students designed and constructed a remotely controlled crane implement for the SKITTER model.

  9. Water renewal in Montevideo's bay: a two compartments model for tritium kinetics

    International Nuclear Information System (INIS)

    Suarez-Antola, Roberto

    2013-01-01

    During field work about dynamics and renewal of water in Montevideo's Bay, 100 Ci of tritiated water were evenly distributed in the north-east region of the bay, by a continuous injection of a solution, during 5 hours, from a 200 litres tank, using a peristaltic pump. The whole bay was divided in 20 concentration cells, taking into account available bathymetric charts and corrections from field data obtained in situ. Tritium concentrations (activities per unit volume) and other relevant parameters (temperature, electrical conductivity, etc.) were measured in vertical profiles during three weeks, in the mid-point of each cell, first twice a day and the on a daily basis. Remnant total tritium activity was estimated from cells volumes and midpoint cells activity concentrations. Consistency checks were done. A one compartment model was used to estimate a global renewal time of circa 29 hours. However, the details of the measured tritium kinetics, a careful consideration of bathymetric data, water movements in a tidal environment (measured with drogues, fluorescent tracers and current meters), as well as the results of computer fluid dynamics modelling (in depth averaged) suggests that the bay can be meaningfully divided in two main compartments: a North-East and a South-West compartment. The purpose of this paper is threefold: (1) to describe the construction of a two compartments model for water renewal in Montevideo's Bay, (2) to apply experimental data of tritium kinetics to estimate the parameters of the model, and (3) to discuss the validity of the model and its practical applicability. The meaning of the renewal time of each compartment and its relation with the measured tritium kinetics in each cell is discussed. The perturbations in water circulation and renewal produced by civil works already done or the perturbations that could be expected due to civil works to be done, in relation with Montevideo's harbour, is discussed. The tracer model, jointly with other

  10. Optimization modeling of U.S. renewable electricity deployment using local input variables

    Science.gov (United States)

    Bernstein, Adam

    For the past five years, state Renewable Portfolio Standard (RPS) laws have been a primary driver of renewable electricity (RE) deployments in the United States. However, four key trends currently developing: (i) lower natural gas prices, (ii) slower growth in electricity demand, (iii) challenges of system balancing intermittent RE within the U.S. transmission regions, and (iv) fewer economical sites for RE development, may limit the efficacy of RPS laws over the remainder of the current RPS statutes' lifetime. An outsized proportion of U.S. RE build occurs in a small number of favorable locations, increasing the effects of these variables on marginal RE capacity additions. A state-by-state analysis is necessary to study the U.S. electric sector and to generate technology specific generation forecasts. We used LP optimization modeling similar to the National Renewable Energy Laboratory (NREL) Renewable Energy Development System (ReEDS) to forecast RE deployment across the 8 U.S. states with the largest electricity load, and found state-level RE projections to Year 2031 significantly lower than thoseimplied in the Energy Information Administration (EIA) 2013 Annual Energy Outlook forecast. Additionally, the majority of states do not achieve their RPS targets in our forecast. Combined with the tendency of prior research and RE forecasts to focus on larger national and global scale models, we posit that further bottom-up state and local analysis is needed for more accurate policy assessment, forecasting, and ongoing revision of variables as parameter values evolve through time. Current optimization software eliminates much of the need for algorithm coding and programming, allowing for rapid model construction and updating across many customized state and local RE parameters. Further, our results can be tested against the empirical outcomes that will be observed over the coming years, and the forecast deviation from the actuals can be attributed to discrete parameter

  11. A multiple perspective modeling and simulation approach for renewable energy policy evaluation

    Science.gov (United States)

    Alyamani, Talal M.

    Environmental issues and reliance on fossil fuel sources, including coal, oil, and natural gas, are the two most common energy issues that are currently faced by the United States (U.S.). Incorporation of renewable energy sources, a non-economical option in electricity generation compared to conventional sources that burn fossil fuels, single handedly promises a viable solution for both of these issues. Several energy policies have concordantly been suggested to reduce the financial burden of adopting renewable energy technologies and make such technologies competitive with conventional sources throughout the U.S. This study presents a modeling and analysis approach for comprehensive evaluation of renewable energy policies with respect to their benefits to various related stakeholders--customers, utilities, governmental and environmental agencies--where the debilitating impacts, advantages, and disadvantages of such policies can be assessed and quantified at the state level. In this work, a novel simulation framework is presented to help policymakers promptly assess and evaluate policies from different perspectives of its stakeholders. The proposed framework is composed of four modules: 1) a database that collates the economic, operational, and environmental data; 2) elucidation of policy, which devises the policy for the simulation model; 3) a preliminary analysis, which makes predictions for consumption, supply, and prices; and 4) a simulation model. After the validity of the proposed framework is demonstrated, a series of planned Florida and Texas renewable energy policies are implemented into the presented framework as case studies. Two solar and one energy efficiency programs are selected as part of the Florida case study. A utility rebate and federal tax credit programs are selected as part of the Texas case study. The results obtained from the simulation and conclusions drawn on the assessment of current energy policies are presented with respect to the

  12. Building Energy Modeling and Control Methods for Optimization and Renewables Integration

    Science.gov (United States)

    Burger, Eric M.

    This dissertation presents techniques for the numerical modeling and control of building systems, with an emphasis on thermostatically controlled loads. The primary objective of this work is to address technical challenges related to the management of energy use in commercial and residential buildings. This work is motivated by the need to enhance the performance of building systems and by the potential for aggregated loads to perform load following and regulation ancillary services, thereby enabling the further adoption of intermittent renewable energy generation technologies. To increase the generalizability of the techniques, an emphasis is placed on recursive and adaptive methods which minimize the need for customization to specific buildings and applications. The techniques presented in this dissertation can be divided into two general categories: modeling and control. Modeling techniques encompass the processing of data streams from sensors and the training of numerical models. These models enable us to predict the energy use of a building and of sub-systems, such as a heating, ventilation, and air conditioning (HVAC) unit. Specifically, we first present an ensemble learning method for the short-term forecasting of total electricity demand in buildings. As the deployment of intermittent renewable energy resources continues to rise, the generation of accurate building-level electricity demand forecasts will be valuable to both grid operators and building energy management systems. Second, we present a recursive parameter estimation technique for identifying a thermostatically controlled load (TCL) model that is non-linear in the parameters. For TCLs to perform demand response services in real-time markets, online methods for parameter estimation are needed. Third, we develop a piecewise linear thermal model of a residential building and train the model using data collected from a custom-built thermostat. This model is capable of approximating unmodeled

  13. A real options evaluation model for the diffusion prospects of new renewable power generation technologies

    International Nuclear Information System (INIS)

    Kumbaroglu, Guerkan; Demirel, Mustafa; Madlener, Reinhard

    2008-01-01

    This study presents a policy planning model that integrates learning curve information on renewable power generation technologies into a dynamic programming formulation featuring real options analysis. The model recursively evaluates a set of investment alternatives on a year-by-year basis, thereby taking into account that the flexibility to delay an irreversible investment expenditure can profoundly affect the diffusion prospects of renewable power generation technologies. Price uncertainty is introduced through stochastic processes for the average wholesale price of electricity and for input fuel prices. Demand for electricity is assumed to be increasingly price-sensitive, as the electricity market deregulation proceeds, reflecting new options of consumers to react to electricity price changes (such as time-of-use pricing, unbundled electricity services, and choice of supplier). The empirical analysis is based on data for the Turkish electricity supply industry. Apart from general implications for policy-making, it provides some interesting insights about the impact of uncertainty and technical change on the diffusion of various emerging renewable energy technologies. (author)

  14. Renewable Generation (Wind/Solar and Load Modeling through Modified Fuzzy Prediction Interval

    Directory of Open Access Journals (Sweden)

    Syed Furqan Rafique

    2018-01-01

    Full Text Available The accuracy of energy management system for renewable microgrid, either grid-connected or isolated, is heavily dependent on the forecasting precision such as wind, solar, and load. In this paper, an improved fuzzy prediction horizon forecasting method is developed to address the issue of intermittence and uncertainty problem related to renewable generation and load forecast. In the first phase, a Takagi-Sugeno type fuzzy system is trained with many evolutionary optimization algorithms and established coverage grade indicator to check the accuracy of interval forecast. Secondly, a wind, solar, and load forecaster is developed for renewable microgrid test bed which is located in Beijing, China. One day and one step ahead results for the proposed forecaster are expressed with lowest RMSE and training time. In order to check the efficiency of the proposed method, a comparison is carried out with the existing models. The fuzzy interval-based model for the microgrid test bed will help to formulate the energy management problem with more accuracy and robustness.

  15. Scheduling Model for Renewable Energy Sources Integration in an Insular Power System

    Directory of Open Access Journals (Sweden)

    Gerardo J. Osório

    2018-01-01

    Full Text Available Insular power systems represent an asset and an excellent starting point for the development and analysis of innovative tools and technologies. The integration of renewable energy resources that has taken place in several islands in the south of Europe, particularly in Portugal, has brought more uncertainty to production management. In this work, an innovative scheduling model is proposed, which considers the integration of wind and solar resources in an insular power system in Portugal, with a strong conventional generation basis. This study aims to show the benefits of increasing the integration of renewable energy resources in this insular power system, and the objectives are related to minimizing the time for which conventional generation is in operation, maximizing profits, reducing production costs, and consequently, reducing greenhouse gas emissions.

  16. Integrated Agent-Based and Production Cost Modeling Framework for Renewable Energy Studies: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Giulia

    2015-10-07

    The agent-based framework for renewable energy studies (ARES) is an integrated approach that adds an agent-based model of industry actors to PLEXOS and combines the strengths of the two to overcome their individual shortcomings. It can examine existing and novel wholesale electricity markets under high penetrations of renewables. ARES is demonstrated by studying how increasing levels of wind will impact the operations and the exercise of market power of generation companies that exploit an economic withholding strategy. The analysis is carried out on a test system that represents the Electric Reliability Council of Texas energy-only market in the year 2020. The results more realistically reproduce the operations of an energy market under different and increasing penetrations of wind, and ARES can be extended to address pressing issues in current and future wholesale electricity markets.

  17. A hybrid model for the optimum integration of renewable technologies in power generation systems

    International Nuclear Information System (INIS)

    Poullikkas, Andreas; Kourtis, George; Hadjipaschalis, Ioannis

    2011-01-01

    The main purpose of this work is to assess the unavoidable increase in the cost of electricity of a generation system by the integration of the necessary renewable energy sources for power generation (RES-E) technologies in order for the European Union Member States to achieve their national RES energy target. The optimization model developed uses a genetic algorithm (GA) technique for the calculation of both the additional cost of electricity due to the penetration of RES-E technologies as well as the required RES-E levy in the electricity bills in order to fund this RES-E penetration. Also, the procedure enables the estimation of the optimum feed-in-tariff to be offered to future RES-E systems. Also, the overall cost increase in the electricity sector for the promotion of RES-E technologies, for the period 2010-2020, is analyzed taking into account factors, such as, the fuel avoidance cost, the carbon dioxide emissions avoidance cost, the conventional power system increased operation cost, etc. The overall results indicate that in the case of RES-E investments with internal rate of return (IRR) of 10% the cost of integration is higher, compared to RES-E investments with no profit, (i.e., IRR at 0%) by 0.3-0.5 Euro c/kWh (in real prices), depending on the RES-E penetration level. - Research Highlights: →Development of a hybrid optimization model for the integration of renewable technologies in power generation systems. →Estimation of the optimum feed-in-tariffs to be offered to future renewable systems. →Determination of the overall cost increase in the electricity sector for the promotion of renewable technologies. →Analyses taking into account fuel avoidance cost, the carbon dioxide emissions avoidance cost, the conventional power system increased operation cost, etc.

  18. Spatial demographic models to inform conservation planning of golden eagles in renewable energy landscapes

    Science.gov (United States)

    Wiens, J. David; Schumaker, Nathan H.; Inman, Richard D.; Esque, Todd C.; Longshore, Kathleen M.; Nussear, Kenneth E

    2017-01-01

    Spatial demographic models can help guide monitoring and management activities targeting at-risk species, even in cases where baseline data are lacking. Here, we provide an example of how site-specific changes in land use and anthropogenic stressors can be incorporated into a spatial demographic model to investigate effects on population dynamics of Golden Eagles (Aquila chrysaetos). Our study focused on a population of Golden Eagles exposed to risks associated with rapid increases in renewable energy development in southern California, U.S.A. We developed a spatially explicit, individual-based simulation model that integrated empirical data on demography of Golden Eagles with spatial data on the arrangement of nesting habitats, prey resources, and planned renewable energy development sites. Our model permitted simulated eagles of different stage-classes to disperse, establish home ranges, acquire prey resources, prospect for breeding sites, and reproduce. The distribution of nesting habitats, prey resources, and threats within each individual's home range influenced movement, reproduction, and survival. We used our model to explore potential effects of alternative disturbance scenarios, and proposed conservation strategies, on the future distribution and abundance of Golden Eagles in the study region. Results from our simulations suggest that probable increases in mortality associated with renewable energy infrastructure (e.g., collisions with wind turbines and vehicles, electrocution on power poles) could have negative consequences for population trajectories, but that site-specific conservation actions could reduce the magnitude of negative effects. Our study demonstrates the use of a flexible and expandable modeling framework to incorporate spatially dependent processes when determining relative effects of proposed management options to Golden Eagles and their habitats.

  19. Measuring evapotranspiration: comparison of in situ micrometeorological methods including eddy covariance, scintillometer, Bowen ratio, and surface renewal method

    Science.gov (United States)

    Poznikova, G.; Fischer, M.; Orsag, M.; Trnka, M.

    2016-12-01

    Quantifying evapotranspiration (ET) is a challenging task as different methods can induce large discrepancies. Comparisons of various techniques are not rare, however it is demanding to maintain several in situ measurements for longer time. In our study, we aimed to compare four micrometeorological methods measuring ET at relatively large homogeneous area. The study took place on a winter wheat field in Polkovice, the Czech Republic (49°23'42.8"N 17°14'47.3"E) from Jul 1st 2015 until Sep 15th 2015. In the centre of 26-ha experimental field we deployed the eddy covariance (EC) system, the Bowen ratio energy balance (BREB) system, thermocouples for surface renewal technique, and the surface layer scintillometer with 106 m path length. Additionally, we installed the large aperture scintillometer with 617 m path length across the field. Our results showed good agreement of compared methods during the wetter periods of the measurements with slight overestimation of the scintillometry. The BREB method agreed the best with EC. Both scintillometers gave very consistent results throughout the whole measurement period. The EC tended to underestimate other methods. One of potential reasons is energy balance disclosure which reached 27.4 % for the measured period. The surface renewal method showed good potential however, need to be further tested in our conditions. Our experimental locality is one of several we are running as a part of ground based measurement network for ET estimation. Gained results helped us to enhance and optimise our network to ensure effective and reliable data acquisition for future validation of airborne images (satellite based drought monitoring).

  20. Status Report on Modelling and Simulation Capabilities for Nuclear-Renewable Hybrid Energy Systems

    Energy Technology Data Exchange (ETDEWEB)

    Rabiti, C. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Epiney, A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Talbot, P. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Kim, J. S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Bragg-Sitton, S. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Alfonsi, A. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Yigitoglu, A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Greenwood, S. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Cetiner, S. M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ganda, F. [Argonne National Lab. (ANL), Argonne, IL (United States); Maronati, G. [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-09-01

    This report summarizes the current status of the modeling and simulation capabilities developed for the economic assessment of Nuclear-Renewable Hybrid Energy Systems (N-R HES). The increasing penetration of variable renewables is altering the profile of the net demand, with which the other generators on the grid have to cope. N-R HES analyses are being conducted to determine the potential feasibility of mitigating the resultant volatility in the net electricity demand by adding industrial processes that utilize either thermal or electrical energy as stabilizing loads. This coordination of energy generators and users is proposed to mitigate the increase in electricity cost and cost volatility through the production of a saleable commodity. Overall, the financial performance of a system that is comprised of peaking units (i.e. gas turbine), baseload supply (i.e. nuclear power plant), and an industrial process (e.g. hydrogen plant) should be optimized under the constraint of satisfying an electricity demand profile with a certain level of variable renewable (wind) penetration. The optimization should entail both the sizing of the components/subsystems that comprise the system and the optimal dispatch strategy (output at any given moment in time from the different subsystems). Some of the capabilities here described have been reported separately in [1, 2, 3]. The purpose of this report is to provide an update on the improvement and extension of those capabilities and to illustrate their integrated application in the economic assessment of N-R HES.

  1. Modeling of an Integrated Renewable Energy System (IRES) with hydrogen storage

    Science.gov (United States)

    Shenoy, Navin Kodange

    2010-12-01

    Scope and Method of Study. The purpose of the study was to consider the integration of hydrogen storage technology as means of energy storage with renewable sources of energy. Hydrogen storage technology consists of an alkaline electrolyzer, gas storage tank and a fuel cell. The Integrated Renewable Energy System (IRES) under consideration includes wind energy, solar energy from photovoltaics, solar thermal energy and biomass energy in the form of biogas. Energy needs are categorized depending on the type and quality of the energy requirements. After meeting all the energy needs, any excess energy available from wind and PVs is converted into hydrogen using an electrolyzer for later use in a fuel cell. Similarly, when renewable energy generation is not able to supply the actual load demand, the stored hydrogen is utilized through fuel cell to fulfill load demand. Analysis of how IRES operates in order to satisfy different types of energy needs is discussed. Findings and Conclusions. All simulations are performed using MATLAB software. Hydrogen storage technology consisting of an electrolyzer, gas storage tank and a fuel cell is incorporated in the IRES design process for a hypothetical remote community. Results show that whenever renewable energy generated is greater than the electrical demand, excess energy is stored in the form of hydrogen and in case of energy shortfall, the stored hydrogen is utilized through the fuel cell to supply to excess power demand. The overall operation of IRES is enhanced as a result of energy storage in the form of hydrogen. Hydrogen has immense potential to be the energy carrier of the future because of its clean character and the model of hydrogen storage discussed here can form an integral part of IRES for remote area applications.

  2. Modeling and simulation of CO methanation process for renewable electricity storage

    International Nuclear Information System (INIS)

    Er-rbib, Hanaâ; Bouallou, Chakib

    2014-01-01

    In this paper, a new approach of converting renewable electricity into methane via syngas (a mixture of CO and H 2 ) and CO methanation is presented. Surplus of electricity is used to electrolyze H 2 O and CO 2 to H 2 and CO by using a SOEC (Solid Oxide Electrolysis Cell). Syngas produced is then converted into methane. When high consumption peaks appear, methane is used to produce electricity. The main conversion step in this process is CO methanation. A modeling of catalytic fixed bed methanation reactor and a design of methanation unit composed of multistage adiabatic reactors are carried out using Aspen plus™ software. The model was validated by comparing the simulated results of gas composition (CH 4 , CO, CO 2 and H 2 ) with industrial data. In addition, the effects of recycle ratio on adiabatic reactor stages, outlet temperature, and H 2 and CO conversions are carefully investigated. It is found that for storing 10 MW of renewable electricity, methanation unit is composed of three adiabatic reactors with recycle loop and intermediate cooling at 553 K and 1.5 MPa. The methanation unit generates 3778.6 kg/h of steam at 523.2 K and 1 MPa (13.67 MW). - Highlights: • A catalytic fixed bed reactor of CO methanation was modeled. • The maximum relative error of the methanation reactor model is 12%. • For 10 MW storage of renewable electricity, three adiabatic reactors are required. • The recycle ratio affects the reactor outlet temperature and CO conversion

  3. GIS-Based Planning and Modeling for Renewable Energy: Challenges and Future Research Avenues

    Directory of Open Access Journals (Sweden)

    Bernd Resch

    2014-05-01

    Full Text Available In the face of the broad political call for an “energy turnaround”, we are currently witnessing three essential trends with regard to energy infrastructure planning, energy generation and storage: from planned production towards fluctuating production on the basis of renewable energy sources, from centralized generation towards decentralized generation and from expensive energy carriers towards cost-free energy carriers. These changes necessitate considerable modifications of the energy infrastructure. Even though most of these modifications are inherently motivated by geospatial questions and challenges, the integration of energy system models and Geographic Information Systems (GIS is still in its infancy. This paper analyzes the shortcomings of previous approaches in using GIS in renewable energy-related projects, extracts distinct challenges from these previous efforts and, finally, defines a set of core future research avenues for GIS-based energy infrastructure planning with a focus on the use of renewable energy. These future research avenues comprise the availability base data and their “geospatial awareness”, the development of a generic and unified data model, the usage of volunteered geographic information (VGI and crowdsourced data in analysis processes, the integration of 3D building models and 3D data analysis, the incorporation of network topologies into GIS, the harmonization of the heterogeneous views on aggregation issues in the fields of energy and GIS, fine-grained energy demand estimation from freely-available data sources, decentralized storage facility planning, the investigation of GIS-based public participation mechanisms, the transition from purely structural to operational planning, data privacy aspects and, finally, the development of a new dynamic power market design.

  4. A Distributed Model Predictive Control approach for the integration of flexible loads, storage and renewables

    DEFF Research Database (Denmark)

    Ferrarini, Luca; Mantovani, Giancarlo; Costanzo, Giuseppe Tommaso

    2014-01-01

    This paper presents an innovative solution based on distributed model predictive controllers to integrate the control and management of energy consumption, energy storage, PV and wind generation at customer side. The overall goal is to enable an advanced prosumer to autoproduce part of the energy...... he needs with renewable sources and, at the same time, to optimally exploit the thermal and electrical storages, to trade off its comfort requirements with different pricing schemes (including real-time pricing), and apply optimal control techniques rather than sub-optimal heuristics....

  5. Integrating Land Conservation and Renewable Energy Goals in California: Assessing Land Use and Economic Cost Impacts Using the Optimal Renewable Energy Build-Out (ORB) Model.

    Science.gov (United States)

    Wu, G. C.; Schlag, N. H.; Cameron, D. R.; Brand, E.; Crane, L.; Williams, J.; Price, S.; Hernandez, R. R.; Torn, M. S.

    2015-12-01

    There is a lack of understanding of the environmental impacts and economic costs of potential renewable energy (RE) siting decisions that achieve ambitious RE targets. Such analyses are needed to inform policy recommendations that minimize potential conflicts between conservation and RE development. We use the state of California's rapid development of utility-scale RE as a case study to examine how possible land use constraints impact the total electricity land area, areas with conservation value, water use, and electricity cost of ambitious RE portfolios. We developed the Optimal Renewable energy Build-out (ORB) model, and used it in conjunction with the Renewable Portfolio Standard (RPS) Calculator, a RE procurement and transmission planning tool used by utilities within California, to generate environmentally constrained renewable energy potential and assess the cost and siting-associated impacts of wind, solar photovoltaic, concentrating solar power (CSP), and geothermal technologies. We find that imposing environmental constraints on RE development achieves lower conservation impacts and results in development of more fragmented land areas. With increased RE and environmental exclusions, generation becomes more widely distributed across the state, which results in more development on herbaceous agricultural vegetation, grasslands, and developed & urban land cover types. We find land use efficiencies of RE technologies are relatively inelastic to changes in environmental constraints, suggesting that cost-effective substitutions that reduce environmental impact and achieve RE goals is possible under most scenarios and exclusion categories. At very high RE penetration that is limited to in-state development, cost effectiveness decreases substantially under the highest level of environmental constraint due to the over-reliance on solar technologies. This additional cost is removed once the in-state constraint is lifted, suggesting that minimizing both negative

  6. Modeling and Simulation of Renewable Hybrid Power System using Matlab Simulink Environment

    Directory of Open Access Journals (Sweden)

    Cristian Dragoş Dumitru

    2010-12-01

    Full Text Available The paper presents the modeling of a solar-wind-hydroelectric hybrid system in Matlab/Simulink environment. The application is useful for analysis and simulation of a real hybrid solar-wind-hydroelectric system connected to a public grid. Application is built on modular architecture to facilitate easy study of each component module influence. Blocks like wind model, solar model, hydroelectric model, energy conversion and load are implemented and the results of simulation are also presented. As an example, one of the most important studies is the behavior of hybrid system which allows employing renewable and variable in time energy sources while providing a continuous supply. Application represents a useful tool in research activity and also in teaching

  7. Renewable Distributed Generation Models in Three-Phase Load Flow Analysis for Smart Grid

    Directory of Open Access Journals (Sweden)

    K. M. Nor

    2013-11-01

    Full Text Available The paper presents renewable distributed generation  (RDG models as three-phase resource in load flow computation and analyzes their effect when they are connected in composite networks. The RDG models that have been considered comprise of photovoltaic (PV and wind turbine generation (WTG. The voltage-controlled node and complex power injection node are used in the models. These improvement models are suitable for smart grid power system analysis. The combination of IEEE transmission and distribution data used to test and analyze the algorithm in solving balanced/unbalanced active systems. The combination of IEEE transmission data and IEEE test feeder are used to test the the algorithm for balanced and unbalanced multi-phase distribution system problem. The simulation results show that by increased number and size of RDG units have improved voltage profile and reduced system losses.

  8. Enhancement of the REMix energy system model : global renewable energy potentials, optimized power plant siting and scenario validation

    OpenAIRE

    Stetter, Daniel

    2014-01-01

    As electricity generation based on volatile renewable resources is subject to fluctuations, data with high temporal and spatial resolution on their availability is indispensable for integrating large shares of renewable capacities into energy infrastructures. The scope of the present doctoral thesis is to enhance the existing energy modelling environment REMix in terms of (i.) extending the geographic coverage of the potential assessment tool REMix-EnDaT from a European to a global scal...

  9. Dynamic modeling of hybrid renewable energy systems for off-grid applications

    Science.gov (United States)

    Hasemeyer, Mark David

    The volatile prices of fossil fuels and their contribution to global warming have caused many people to turn to renewable energy systems. Many developing communities are forced to use these systems as they are too far from electrical distribution. As a result, numerous software models have been developed to simulate hybrid renewable energy systems. However almost, if not all, implementations are static in design. A static design limits the ability of the model to account for changes over time. Dynamic modeling can be used to fill the gaps where other modeling techniques fall short. This modeling practice allows the user to account for the effects of technological and economic factors over time. These factors can include changes in energy demand, energy production, and income level. Dynamic modeling can be particularly useful for developing communities who are off-grid and developing at rapid rates. In this study, a dynamic model was used to evaluate a real world system. A non-governmental organization interested in improving their current infrastructure was selected. Five different scenarios were analyzed and compared in order to discover which factors the model is most sensitive to. In four of the scenarios, a new energy system was purchased in order to account for the opening of a restaurant that would be used as a source of local income generation. These scenarios were then compared to a base case in which a new system was not purchased, and the restaurant was not opened. Finally, the results were used to determine which variables had the greatest impact on the various outputs of the simulation.

  10. Modelling renewable supply chain for electricity generation with forest, fossil, and wood-waste fuels

    International Nuclear Information System (INIS)

    Palander, Teijo

    2011-01-01

    In this paper, a multiple objective model to large-scale and long-term industrial energy supply chain scheduling problems is considered. The problems include the allocation of a number of fossil, peat, and wood-waste fuel procurement chains to an energy plant during different periods. This decision environment is further complicated by sequence-dependent procurement chains for forest fuels. A dynamic linear programming model can be efficiently used for modelling energy flows in fuel procurement planning. However, due to the complex nature of the problem, the resulting model cannot be directly used to solve the combined heat and electricity production problem in a manner that is relevant to the energy industry. Therefore, this approach was used with a multiple objective programming model to better describe the combinatorial complexity of the scheduling task. The properties of this methodology are discussed and four examples of how the model works based on real-world data and optional peat fuel tax, feed-in tariff of electricity and energy efficiency constraints are presented. The energy industry as a whole is subject to policy decisions regarding renewable energy production and energy efficiency regulation. These decisions should be made on the basis of comprehensive techno-economic analysis using local energy supply chain models. -- Highlights: → The energy policy decisions are made using comprehensive techno-economic analysis. → Peat tax, feed-in tariff and energy efficiency increases renewable energy production. → The potential of peat procurement deviates from the current assumptions of managers. → The dynamic MOLP model could easily be adapted to a changing decision environment.

  11. Surface-complexation models for sorption onto heterogeneous surfaces

    International Nuclear Information System (INIS)

    Harvey, K.B.

    1997-10-01

    This report provides a description of the discrete-logK spectrum model, together with a description of its derivation, and of its place in the larger context of surface-complexation modelling. The tools necessary to apply the discrete-logK spectrum model are discussed, and background information appropriate to this discussion is supplied as appendices. (author)

  12. Seeing about soil — management lessons from a simple model for renewable resources

    Science.gov (United States)

    Lichtenegger, Klaus; Schappacher, Wilhelm

    2014-02-01

    Employing an effective cellular automata model, we investigate and analyze the build-up and erosion of soil. Depending on the strategy employed for handling agricultural production, in many cases we find a critical dependence on the prescribed production target, with a sharp transition between stable production and complete breakdown of the system. Strategies which are particularly well-suited for mimicking real-world management approaches can produce almost cyclic behavior, which can also either lead to sustainable production or to breakdown. While designed to describe the dynamics of soil evolution, this model is quite general and may also be useful as a model for other renewable resources and may even be employed in other disciplines like psychology.

  13. Qualitative modeling identifies IL-11 as a novel regulator in maintaining self-renewal in human pluripotent stem cells

    Directory of Open Access Journals (Sweden)

    Hedi ePeterson

    2013-10-01

    Full Text Available Pluripotency in human embryonic stem cells (hESCs and induced pluripotent stem cells (iPSCs is regulated by three transcription factors - OCT3/4, SOX2 and NANOG. To fully exploit the therapeutic potential of these cells it is essential to have a good mechanistic understanding of the maintenance of self-renewal and pluripotency. In this study, we demonstrate a powerful systems biology approach in which we first expand literature-based network encompassing the core regulators of pluripotency by assessing the behaviour of genes targeted by perturbation experiments. We focused our attention on highly regulated genes encoding cell surface and secreted proteins as these can be more easily manipulated by the use of inhibitors or recombinant proteins. Qualitative modeling based on combining boolean networks and in silico perturbation experiments were employed to identify novel pluripotency-regulating genes. We validated Interleukin-11 (IL-11 and demonstrate that this cytokine is a novel pluripotency-associated factor capable of supporting self-renewal in the absence of exogenously added bFGF in culture. To date, the various protocols for hESCs maintenance require supplementation with bFGF to activate the Activin/Nodal branch of the TGFβ signaling pathway. Additional evidence supporting our findings is that IL-11 belongs to the same protein family as LIF, which is known to be necessary for maintaining pluripotency in mouse but not in human ESCs. These cytokines operate through the same gp130 receptor which interacts with Janus kinases. Our finding might explain why mESCs are in a more naïve cell state compared to hESCs and how to convert primed hESCs back to the naïve state. Taken together, our integrative modeling approach has identified novel genes as putative candidates to be incorporated into the expansion of the current gene regulatory network responsible for inducing and maintaining pluripotency.

  14. Economic modelling of price support mechanisms for renewable energy: Case study on Ireland

    International Nuclear Information System (INIS)

    Huber, Claus; Ryan, Lisa; O Gallachoir, Brian; Resch, Gustav; Polaski, Katrina; Bazilian, Morgan

    2007-01-01

    The Irish Government is considering its future targets, policy and programmes for renewable energy for the period beyond 2005. This follows a review in 2003 of policy options that identified a number of different measures to stimulate increased deployment of renewable energy generation capacity. This paper expands this review with an economic analysis of renewable energy price support mechanisms in the Irish electricity generation sector. The focus is on three primary price support mechanisms quota obligations, feed in tariffs and competitive tender schemes. The Green-X computer model is utilised to characterise the RES-E potential and costs in Ireland up until, and including, 2020. The results from this dynamic software tool are used to compare the different support mechanisms in terms of total costs to society and the average premium costs relative to the market price for electricity. The results indicate that in achieving a 20% RES-E proportion of gross electricity consumption by 2020, a tender scheme provides the least costs to society over the period 2006-2020 but only in case there is limited or no strategic bidding. Considering, however, strategic bidding, a feed-in tariff can be the more efficient solution. Between the other two support mechanisms, the total costs to society are highest for feed-in-tariffs (FIT) until 2013, at which point the costs for the quota system begin to rise rapidly and overtake FIT in 2014-2020. The paper also provides a sensitivity analysis of the support mechanism calculations by varying default parameters such as the interim (2010) target, the assumed investment risk levels and the amount of biomass co-firing. This analysis shows that a 2010 target of 15% rather than 13.2% generates lower costs for society over the whole period 2006-2020, but higher costs for the RES-E strategy over the period 2006-2010

  15. Surface Flux Modeling for Air Quality Applications

    Directory of Open Access Journals (Sweden)

    Limei Ran

    2011-08-01

    Full Text Available For many gasses and aerosols, dry deposition is an important sink of atmospheric mass. Dry deposition fluxes are also important sources of pollutants to terrestrial and aquatic ecosystems. The surface fluxes of some gases, such as ammonia, mercury, and certain volatile organic compounds, can be upward into the air as well as downward to the surface and therefore should be modeled as bi-directional fluxes. Model parameterizations of dry deposition in air quality models have been represented by simple electrical resistance analogs for almost 30 years. Uncertainties in surface flux modeling in global to mesoscale models are being slowly reduced as more field measurements provide constraints on parameterizations. However, at the same time, more chemical species are being added to surface flux models as air quality models are expanded to include more complex chemistry and are being applied to a wider array of environmental issues. Since surface flux measurements of many of these chemicals are still lacking, resistances are usually parameterized using simple scaling by water or lipid solubility and reactivity. Advances in recent years have included bi-directional flux algorithms that require a shift from pre-computation of deposition velocities to fully integrated surface flux calculations within air quality models. Improved modeling of the stomatal component of chemical surface fluxes has resulted from improved evapotranspiration modeling in land surface models and closer integration between meteorology and air quality models. Satellite-derived land use characterization and vegetation products and indices are improving model representation of spatial and temporal variations in surface flux processes. This review describes the current state of chemical dry deposition modeling, recent progress in bi-directional flux modeling, synergistic model development research with field measurements, and coupling with meteorological land surface models.

  16. Renewable Energy Cost Modeling: A Toolkit for Establishing Cost-Based Incentives in the United States; March 2010 -- March 2011

    Energy Technology Data Exchange (ETDEWEB)

    Gifford, J. S.; Grace, R. C.; Rickerson, W. H.

    2011-05-01

    This report is intended to serve as a resource for policymakers who wish to learn more about establishing cost-based incentives. The report will identify key renewable energy cost modeling options, highlight the policy implications of choosing one approach over the other, and present recommendations on the optimal characteristics of a model to calculate rates for cost-based incentives, feed-in tariffs (FITs), or similar policies. These recommendations will be utilized in designing the Cost of Renewable Energy Spreadsheet Tool (CREST). Three CREST models will be publicly available and capable of analyzing the cost of energy associated with solar, wind, and geothermal electricity generators. The CREST models will be developed for use by state policymakers, regulators, utilities, developers, and other stakeholders to assist them in current and future rate-setting processes for both FIT and other renewable energy incentive payment structures and policy analyses.

  17. Minimal Model Theory for Log Surfaces

    OpenAIRE

    Fujino, Osamu

    2012-01-01

    We discuss the log minimal model theory for log surfaces. We show that the log minimal model program, the finite generation of log canonical rings, and the log abundance theorem for log surfaces hold true under assumptions weaker than the usual framework of the log minimal model theory.

  18. Solar-based rural electrification policy design: The Renewable Energy Service Company (RESCO) model in Fiji

    Energy Technology Data Exchange (ETDEWEB)

    Dornan, M. [Resource Management in Asia-Pacific Program, The Crawford School of Economics and Government, The Australian National University, Acton ACT 2601 (Australia)

    2011-02-15

    Solar photovoltaic technologies have for some time been promoted as a cost effective means of rural electrification in developing countries. However, institutional structures resulting in poor maintenance have adversely affected the sustainability of past solar projects. In Fiji, the Renewable Energy Service Company (RESCO) program is the latest attempt to promote solar-based rural electrification in a fee-for-service model, aiming to remove the high upfront capital costs associated with solar technologies and using a public-private sector partnership for maintenance. This paper assesses the program using survey and interview data. Major flaws are identified, relating to incorrect treatment of principal-agent problems, information asymmetries, motivational problems, and resourcing of government agencies. General lessons for fee-for-service solar home system models emerge, including that incentives for stakeholders must take centre stage in designing and administering such programs, and that active government support and ownership are required to make programs sustainable. (author)

  19. Energy efficiency and renewable energy modeling with ETSAP TIAM - challenges, opportunities, and solutions

    DEFF Research Database (Denmark)

    Gregg, Jay Sterling; Balyk, Olexandr; Pérez, Cristian Hernán Cabrera

    The objectives of the Sustainable Energy for All (SE4ALL), a United Nations (UN) global initiative, are to achieve, by 2030: 1) universal access to modern energy services; 2) a doubling of the global rate of improvement in energy efficiency; and 3) a doubling of the share of renewable energy...... in the global energy mix (United Nations, 2011; SE4ALL, 2013a). The purpose of this study is to determine to what extent the energy efficiency objective supports the other two objectives, and to what extent the SE4ALL objectives support the climate target of limiting the global mean temperature increase to 2° C...... over pre-industrial times. To accomplish this, pathways are constructed for each objective, which then form the basis for a scenario analysis using the Energy Technology System Analysis Program TIMES Integrated Assessment Model (ETSAP-TIAM). This presentation focuses on the modeling challenges...

  20. On the continuing relevance of Mandelbrot's non-ergodic fractional renewal models of 1963 to 1967

    Science.gov (United States)

    Watkins, Nicholas W.

    2017-12-01

    The problem of "1/f" noise has been with us for about a century. Because it is so often framed in Fourier spectral language, the most famous solutions have tended to be the stationary long range dependent (LRD) models such as Mandelbrot's fractional Gaussian noise. In view of the increasing importance to physics of non-ergodic fractional renewal models, and their links to the CTRW, I present preliminary results of my research into the history of Mandelbrot's very little known work in that area from 1963 to 1967. I speculate about how the lack of awareness of this work in the physics and statistics communities may have affected the development of complexity science, and I discuss the differences between the Hurst effect, "1/f" noise and LRD, concepts which are often treated as equivalent. Contribution to the "Topical Issue: Continuous Time Random Walk Still Trendy: Fifty-year History, Current State and Outlook", edited by Ryszard Kutner and Jaume Masoliver.

  1. An Intelligent Ensemble Neural Network Model for Wind Speed Prediction in Renewable Energy Systems.

    Science.gov (United States)

    Ranganayaki, V; Deepa, S N

    2016-01-01

    Various criteria are proposed to select the number of hidden neurons in artificial neural network (ANN) models and based on the criterion evolved an intelligent ensemble neural network model is proposed to predict wind speed in renewable energy applications. The intelligent ensemble neural model based wind speed forecasting is designed by averaging the forecasted values from multiple neural network models which includes multilayer perceptron (MLP), multilayer adaptive linear neuron (Madaline), back propagation neural network (BPN), and probabilistic neural network (PNN) so as to obtain better accuracy in wind speed prediction with minimum error. The random selection of hidden neurons numbers in artificial neural network results in overfitting or underfitting problem. This paper aims to avoid the occurrence of overfitting and underfitting problems. The selection of number of hidden neurons is done in this paper employing 102 criteria; these evolved criteria are verified by the computed various error values. The proposed criteria for fixing hidden neurons are validated employing the convergence theorem. The proposed intelligent ensemble neural model is applied for wind speed prediction application considering the real time wind data collected from the nearby locations. The obtained simulation results substantiate that the proposed ensemble model reduces the error value to minimum and enhances the accuracy. The computed results prove the effectiveness of the proposed ensemble neural network (ENN) model with respect to the considered error factors in comparison with that of the earlier models available in the literature.

  2. Marketing of renewable energies. Foundations, business models, case studies; Marketing Erneuerbarer Energien. Grundlagen, Geschaeftsmodelle, Fallbeispiele

    Energy Technology Data Exchange (ETDEWEB)

    Herbes, Carsten [HfWU Nuertingen-Geislingen, Nuertingen (Germany); Friege, Christian (ed.)

    2015-07-01

    How to market green electricity or biomethane? What is the right price for renewable energy and how do you design the optimal use of social media? What impact have the EEG or electromobility to the Green Power Marketing? Does direct marketing works or is online marketing the guarantee of success? Answers to these and many other basic questions provides the band with contributions from leading scientists and renowned practitioners. For the first time they describe in a structured form the basics of marketing of renewable energies, provide an introduction to the legal and market-based features and present new business models. The book is based on the latest research results, treats all questions of marketing issues important for practitioners, provides case studies and specific recommendations. [German] Wie vermarktet man Oekostrom oder Biomethan? Was ist der richtige Preis fuer Erneuerbare Energien und wie gestaltet man den optimalen Einsatz von Social Media? Welche Auswirkungen haben das EEG oder die Elektromobilitaet auf das Gruenstrom-Marketing? Funktioniert Direktvertrieb oder ist Online-Marketing der Erfolgsgarant? Antworten auf diese und viele weitere grundlegende Fragen liefert dieser Band mit Beitraegen fuehrender Wissenschaftler und renommierter Praktiker. Erstmals beschreiben sie hier in strukturierter Form die Grundlagen der Vermarktung von Erneuerbaren Energien, fuehren in die gesetzlichen und marktlichen Besonderheiten ein und stellen neue Geschaeftsmodelle vor. Das Buch fusst auf aktuellen Forschungsergebnissen, behandelt saemtliche fuer Praktiker wichtige Fragen der Vermarktung, liefert Fallbeispiele und konkrete Empfehlungen.

  3. An approach to modeling and optimization of integrated renewable energy system (ires)

    Science.gov (United States)

    Maheshwari, Zeel

    The purpose of this study was to cost optimize electrical part of IRES (Integrated Renewable Energy Systems) using HOMER and maximize the utilization of resources using MATLAB programming. IRES is an effective and a viable strategy that can be employed to harness renewable energy resources to energize remote rural areas of developing countries. The resource- need matching, which is the basis for IRES makes it possible to provide energy in an efficient and cost effective manner. Modeling and optimization of IRES for a selected study area makes IRES more advantageous when compared to hybrid concepts. A remote rural area with a population of 700 in 120 households and 450 cattle is considered as an example for cost analysis and optimization. Mathematical models for key components of IRES such as biogas generator, hydropower generator, wind turbine, PV system and battery banks are developed. A discussion of the size of water reservoir required is also presented. Modeling of IRES on the basis of need to resource and resource to need matching is pursued to help in optimum use of resources for the needs. Fixed resources such as biogas and water are used in prioritized order whereas movable resources such as wind and solar can be used simultaneously for different priorities. IRES is cost optimized for electricity demand using HOMER software that is developed by the NREL (National Renewable Energy Laboratory). HOMER optimizes configuration for electrical demand only and does not consider other demands such as biogas for cooking and water for domestic and irrigation purposes. Hence an optimization program based on the need-resource modeling of IRES is performed in MATLAB. Optimization of the utilization of resources for several needs is performed. Results obtained from MATLAB clearly show that the available resources can fulfill the demand of the rural areas. Introduction of IRES in rural communities has many socio-economic implications. It brings about improvement in living

  4. The Effect of Wind Forcing on Modeling Coastal Circulation at a Marine Renewable Test Site

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2017-12-01

    Full Text Available The hydrodynamic circulation in estuaries is primarily driven by tides, river inflows and surface winds. While tidal and river data can be quite easily obtained for input to hydrodynamic models, sourcing accurate surface wind data is problematic. Inaccurate wind data can lead to inaccuracies in the surface currents computed by three-dimensional hydrodynamic models. In this research, a high-resolution wind model was coupled with a three-dimensional hydrodynamic model of Galway Bay, a semi-enclosed estuary on the west coast of Ireland, to investigate the effect of wind forcing on model accuracy. Two wind-forcing conditions were investigated: (1 using wind data measured onshore on the NUI Galway campus (NUIG and (2 using offshore wind data provided by a high resolution wind model (HR. A scenario with no wind forcing (NW was also assessed. The onshore wind data varied with time but the speed and direction were applied across the full model domain. The modeled offshore wind fields varied with both time and space. The effect of wind forcing on modeled hydrodynamics was assessed via comparison of modeled surface currents with surface current measurements obtained from a High-Frequency (HF radar Coastal Ocean Dynamics Applications Radar (CODAR observation system. Results indicated that winds were most significant in simulating the north-south surface velocity component. The model using high resolution temporally- and spatially-varying wind data achieved better agreement with the CODAR surface currents than the model using the onshore wind measurements and the model without any wind forcing.

  5. Dynamical modeling of surface tension

    International Nuclear Information System (INIS)

    Brackbill, J.U.; Kothe, D.B.

    1996-01-01

    In a recent review it is said that free-surface flows ''represent some of the difficult remaining challenges in computational fluid dynamics''. There has been progress with the development of new approaches to treating interfaces, such as the level-set method and the improvement of older methods such as the VOF method. A common theme of many of the new developments has been the regularization of discontinuities at the interface. One example of this approach is the continuum surface force (CSF) formulation for surface tension, which replaces the surface stress given by Laplace's equation by an equivalent volume force. Here, we describe how CSF might be made more useful. Specifically, we consider a derivation of the CSF equations from a minimization of surface energy as outlined by Jacqmin. This reformulation suggests that if one eliminates the computation of curvature in terms of a unit normal vector, parasitic currents may be eliminated For this reformulation to work, it is necessary that transition region thickness be controlled. Various means for this, in addition to the one discussed by Jacqmin are discussed

  6. A logistic regression approach to model the willingness of consumers to adopt renewable energy sources

    Science.gov (United States)

    Ulkhaq, M. M.; Widodo, A. K.; Yulianto, M. F. A.; Widhiyaningrum; Mustikasari, A.; Akshinta, P. Y.

    2018-03-01

    The implementation of renewable energy in this globalization era is inevitable since the non-renewable energy leads to climate change and global warming; hence, it does harm the environment and human life. However, in the developing countries, such as Indonesia, the implementation of the renewable energy sources does face technical and social problems. For the latter, renewable energy sources implementation is only effective if the public is aware of its benefits. This research tried to identify the determinants that influence consumers’ intention in adopting renewable energy sources. In addition, this research also tried to predict the consumers who are willing to apply the renewable energy sources in their houses using a logistic regression approach. A case study was conducted in Semarang, Indonesia. The result showed that only eight variables (from fifteen) that are significant statistically, i.e., educational background, employment status, income per month, average electricity cost per month, certainty about the efficiency of renewable energy project, relatives’ influence to adopt the renewable energy sources, energy tax deduction, and the condition of the price of the non-renewable energy sources. The finding of this study could be used as a basis for the government to set up a policy towards an implementation of the renewable energy sources.

  7. Assessment of renewable energy potential. Calculation model “AREP-LP”

    International Nuclear Information System (INIS)

    Penchev, Alexander

    2011-01-01

    Introduction Bulgaria is a country rich in renewable energy sources. There are all types of RES including: solar, geothermal, biomass, wind energy and hydropower. Per capita it ranks among the top in Europe. Bulgaria's target for 2020 is 16% of final consumption of electricity should be from renewable energy. To achieve this goal, the first and most important task is assessing the potential of renewable energy and its geographical distribution. Creating a database of renewable energy is essential for implementation of investment projects in this area. Key words: Renewable Energy (RES), Renewable Technologies (RET), Theoretical Potential, Technical Potential, Municipalities, Regions, Energy Planning(EP), Emission Reduction (EmR), Market Assessment (MA), Data base(DB)

  8. Dynamic Factor Models for the Volatility Surface

    DEFF Research Database (Denmark)

    van der Wel, Michel; Ozturk, Sait R.; Dijk, Dick van

    The implied volatility surface is the collection of volatilities implied by option contracts for different strike prices and time-to-maturity. We study factor models to capture the dynamics of this three-dimensional implied volatility surface. Three model types are considered to examine desirable...

  9. Modeling decision making as a support tool for policy making on renewable energy development

    International Nuclear Information System (INIS)

    Cannemi, Marco; García-Melón, Mónica; Aragonés-Beltrán, Pablo; Gómez-Navarro, Tomás

    2014-01-01

    This paper presents the findings of a study on decision making models for the analysis of capital-risk investors’ preferences on biomass power plants projects. The aim of the work is to improve the support tools for policy makers in the field of renewable energy development. Analytic Network Process (ANP) helps to better understand capital-risk investors preferences towards different kinds of biomass fueled power plants. The results of the research allow public administration to better foresee the investors’ reaction to the incentive system, or to modify the incentive system to better drive investors’ decisions. Changing the incentive system is seen as major risk by investors. Therefore, public administration must design better and longer-term incentive systems, forecasting market reactions. For that, two scenarios have been designed, one showing a typical decision making process and another proposing an improved decision making scenario. A case study conducted in Italy has revealed that ANP allows understanding how capital-risk investors interpret the situation and make decisions when investing on biomass power plants; the differences between the interests of public administrations’s and promoters’, how decision making could be influenced by adding new decision criteria, and which case would be ranked best according to the decision models. - Highlights: • We applied ANP to the investors’ preferences on biomass power plants projects. • The aim is to improve the advising tools for renewable energy policy making. • A case study has been carried out with the help of two experts. • We designed two scenarios: decision making as it is and how could it be improved. • Results prove ANP is a fruitful tool enhancing participation and transparency

  10. Modeling the optimal energy mix in 2030 : Impact of the integration of renewable energy sources

    OpenAIRE

    Arthur, Camu

    2016-01-01

    The European Council has recently set objectives in the matter of energy and climate policies and thus the interest in renewable energies is more than ever at stake. However, the introduction of renewable energies in an energy mix is also accelerated and altered by political targets. The two most widespread renewable technologies, photovoltaic and wind farms, have specific characteristics - decentralized, intermittency, uncertain production forecast up until a few hours ahead - that oblige to...

  11. Temporal and Spatial Explicit Modelling of Renewable Energy Systems : Modelling variable renewable energy systems to address climate change mitigation and universal electricity access

    NARCIS (Netherlands)

    Zeyringer, Marianne

    2017-01-01

    Two major global challenges climate change mitigation and universal electricity access, can be addressed by large scale deployment of renewable energy sources (Alstone et al., 2015). Around 60% of greenhouse gas emissions originate from energy generation and 90% of CO2 emissions are caused by fossil

  12. Impacts of subsidized renewable electricity generation on spot market prices in Germany: evidence from a Garch model with panel data

    International Nuclear Information System (INIS)

    Pham, Thao; Lemoine, Killian

    2015-01-01

    Electricity generated by renewable energy sources creates a downward pressure on wholesale prices through - the so-called 'merit order effect'. This effect tends to lower average power prices and average market revenue that renewables producers should have received, making integration costs of renewables very high at large penetration rate. It is therefore crucial to determine the amplitude of this merit order effect particularly in the context of increasing burden of renewable support policies borne by final consumers. Using hourly data for the period 2009-2012 in German electricity wholesale market for GARCH model under panel data framework, we find that wind and solar power generation injected into German electricity network during this period induces a decrease of electricity spot prices and a slight increase of their volatility. The model-based results suggest that the merit-order effect created by renewable production ranges from 3.86 to 8.34 euro/MWh which implies to the annual volume of consumers' surplus from 1.89 to 3.92 billion euros. However this surplus has not been re-distributed equally among different types of electricity consumers. (authors)

  13. Two-Tier Reactive Power and Voltage Control Strategy Based on ARMA Renewable Power Forecasting Models

    Directory of Open Access Journals (Sweden)

    Jinling Lu

    2017-10-01

    Full Text Available To address the static voltage stability issue and suppress the voltage fluctuation caused by the increasing integration of wind farms and solar photovoltaic (PV power plants, a two-tier reactive power and voltage control strategy based on ARMA power forecasting models for wind and solar plants is proposed in this paper. Firstly, ARMA models are established to forecast the output of wind farms and solar PV plants. Secondly, the discrete equipment is pre-regulated based on the single-step prediction information from ARMA forecasting models according to the optimization result. Thirdly, a multi-objective optimization model is presented and solved by particle swarm optimization (PSO according to the measured data and the proposed static voltage stability index. Finally, the IEEE14 bus system including a wind farm and solar PV plant is utilized to test the effectiveness of the proposed strategy. The results show that the proposed strategy can suppress voltage fluctuation and improve the static voltage stability under the condition of high penetration of renewables including wind and solar power.

  14. Comparing Multiple Evapotranspiration-calculating Methods, Including Eddy Covariance and Surface Renewal, Using Empirical Measurements from Alfalfa Fields in the Sacramento-San Joaquin River Delta

    Science.gov (United States)

    Clay, J.; Kent, E. R.; Leinfelder-Miles, M.; Lambert, J. J.; Little, C.; Paw U, K. T.; Snyder, R. L.

    2016-12-01

    Eddy covariance and surface renewal measurements were used to estimate evapotranspiration (ET) over a variety of crop fields in the Sacramento-San Joaquin River Delta during the 2016 growing season. However, comparing and evaluating multiple measurement systems and methods for determining ET was focused upon at a single alfalfa site. The eddy covariance systems included two systems for direct measurement of latent heat flux: one using a separate sonic anemometer and an open path infrared gas analyzer and another using a combined system (Campbell Scientific IRGASON). For these methods, eddy covariance was used with measurements from the Campbell Scientific CSAT3, the LI-COR 7500a, the Campbell Scientific IRGASON, and an additional R.M. Young sonic anemometer. In addition to those direct measures, the surface renewal approach included several energy balance residual methods in which net radiation, ground heat flux, and sensible heat flux (H) were measured. H was measured using several systems and different methods, including using multiple fast-response thermocouple measurements and using the temperatures measured by the sonic anemometers. The energy available for ET was then calculated as the residual of the surface energy balance equation. Differences in ET values were analyzed between the eddy covariance and surface renewal methods, using the IRGASON-derived values of ET as the standard for accuracy.

  15. Single-layer model for surface roughness.

    Science.gov (United States)

    Carniglia, C K; Jensen, D G

    2002-06-01

    Random roughness of an optical surface reduces its specular reflectance and transmittance by the scattering of light. The reduction in reflectance can be modeled by a homogeneous layer on the surface if the refractive index of the layer is intermediate to the indices of the media on either side of the surface. Such a layer predicts an increase in the transmittance of the surface and therefore does not provide a valid model for the effects of scatter on the transmittance. Adding a small amount of absorption to the layer provides a model that predicts a reduction in both reflectance and transmittance. The absorbing layer model agrees with the predictions of a scalar scattering theory for a layer with a thickness that is twice the rms roughness of the surface. The extinction coefficient k for the layer is proportional to the thickness of the layer.

  16. Measuring public acceptance on renewable energy (RE) development in Malaysia using ordered probit model

    Science.gov (United States)

    Zainudin, W. N. R. A.; Ishak, W. W. M.

    2017-09-01

    In 2009, government of Malaysia has announced a National Renewable Energy Policy and Action Plan as part of their commitment to accelerate the growth in renewable energies (RE). However, an adoption of RE as a main source of energy is still at an early stage due to lack of public awareness and acceptance on RE. Up to date, there are insufficient studies done on the reasons behind this lack of awareness and acceptance. Therefore, this paper is interested to investigate the public acceptance towards development of RE by measuring their willingness to pay slightly more for energy generated from RE sources, denote as willingness level and whether the importance for the electricity to be supplied at absolute lowest possible cost regardless of source and environmental impact, denote as importance level and other socio-economic factors could improve their willingness level. Both qualitative and quantitative research methods are used to achieve the research objectives. A total of 164 respondents from local universities in Malaysia participated in a survey to collect this relevant information. Using Ordered Probit model, the study shows that among the relevant socio-economic factors, age seems to be an important factor to influence the willingness level of the respondents. This paper concludes that younger generation are more willing to pay slightly more for energy generated from RE sources as compared to older generation. One of the possible reason may due to better information access by the younger generation on the RE issues and its positive implication to the world. Finding from this paper is useful to help policy maker in designing RE advocacy programs that would be able to secure public participation. These efforts are important to ensure future success of the RE policy.

  17. Bag model with diffuse surface

    International Nuclear Information System (INIS)

    Phatak, S.C.

    1986-01-01

    The constraint of a sharp bag boundary in the bag model is relaxed in the present work. This has been achieved by replacing the square-well potential of the bag model by a smooth scalar potential and introducing a term similar to the bag pressure term. The constraint of the conservation of the energy-momentum tensor is used to obtain an expression for the added bag pressure term. The model is then used to determine the static properties of the nucleon. The calculation shows that the rms charge radius and the nucleon magnetic moment are larger than the corresponding bag model values. Also, the axial vector coupling constant and the πNN coupling constant are in better agreement with the experimental values

  18. Response Surface Modeling Using Multivariate Orthogonal Functions

    Science.gov (United States)

    Morelli, Eugene A.; DeLoach, Richard

    2001-01-01

    A nonlinear modeling technique was used to characterize response surfaces for non-dimensional longitudinal aerodynamic force and moment coefficients, based on wind tunnel data from a commercial jet transport model. Data were collected using two experimental procedures - one based on modem design of experiments (MDOE), and one using a classical one factor at a time (OFAT) approach. The nonlinear modeling technique used multivariate orthogonal functions generated from the independent variable data as modeling functions in a least squares context to characterize the response surfaces. Model terms were selected automatically using a prediction error metric. Prediction error bounds computed from the modeling data alone were found to be- a good measure of actual prediction error for prediction points within the inference space. Root-mean-square model fit error and prediction error were less than 4 percent of the mean response value in all cases. Efficacy and prediction performance of the response surface models identified from both MDOE and OFAT experiments were investigated.

  19. Electricity Capacity Expansion Modeling, Analysis, and Visualization: A Summary of High-Renewable Modeling Experiences (Chinese Translation)

    Energy Technology Data Exchange (ETDEWEB)

    Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-10-01

    This is the Chinese translation of NREL/TP-6A20-64831. Mathematical and computational models are widely used for the analysis and design of both physical and financial systems. Modeling the electric grid is of particular importance to China for three reasons. First, power-sector assets are expensive and long-lived, and they are critical to any country's development. China's electric load, transmission, and other energy-related infrastructure are expected to continue to grow rapidly; therefore it is crucial to understand and help plan for the future in which those assets will operate. Second, China has dramatically increased its deployment of renewable energy (RE), and is likely to continue further accelerating such deployment over the coming decades. Careful planning and assessment of the various aspects (technical, economic, social, and political) of integrating a large amount of renewables on the grid is required. Third, companies need the tools to develop a strategy for their own involvement in the power market China is now developing, and to enable a possible transition to an efficient and high RE future.

  20. Electricity Capacity Expansion Modeling, Analysis, and Visualization. A Summary of High-Renewable Modeling Experience for China

    Energy Technology Data Exchange (ETDEWEB)

    Blair, Nate [National Renewable Energy Lab. (NREL), Golden, CO (United States); Zhou, Ella [National Renewable Energy Lab. (NREL), Golden, CO (United States); Getman, Dan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, Douglas J. [Joint Inst. for Strategic Energy Analysis, Golden, CO (United States)

    2015-10-01

    Mathematical and computational models are widely used for the analysis and design of both physical and financial systems. Modeling the electric grid is of particular importance to China for three reasons. First, power-sector assets are expensive and long-lived, and they are critical to any country's development. China's electric load, transmission, and other energy-related infrastructure are expected to continue to grow rapidly; therefore it is crucial to understand and help plan for the future in which those assets will operate (NDRC ERI 2015). Second, China has dramatically increased its deployment of renewable energy (RE), and is likely to continue further accelerating such deployment over the coming decades. Careful planning and assessment of the various aspects (technical, economic, social, and political) of integrating a large amount of renewables on the grid is required. Third, companies need the tools to develop a strategy for their own involvement in the power market China is now developing, and to enable a possible transition to an efficient and high RE future.

  1. Enhancement of the NEEDS-TIMES Model: Data for Spain on Biomass Resources and Renewable Electricity

    International Nuclear Information System (INIS)

    Labriet, M.; Cabal, H.; Lechon, Y.

    2008-01-01

    The objective of this report is to describe the data related to both electricity generation (focus on distributed generation and Renewable Energy Source) as well as biomass resources and transformation in Spain. It will contribute to the analysis of the renewable energy potential at the European level (RES2020 project). (Author)

  2. Enhancement of the NEEDS-TIMES Model: Data for Spain on Biomass Resources and Renewable Electricity

    Energy Technology Data Exchange (ETDEWEB)

    Labriet, M.; Cabal, H.; Lechon, Y.

    2008-07-01

    The objective of this report is to describe the data related to both electricity generation (focus on distributed generation and Renewable Energy Source) as well as biomass resources and transformation in Spain. It will contribute to the analysis of the renewable energy potential at the European level (RES2020 project). (Author)

  3. Modeling and analysis of renewable energy obligations and technology bandings in the UK electricity market

    NARCIS (Netherlands)

    Gurkan, G.; Langestraat, R.

    In the UK electricity market, generators are obliged to produce part of their electricity with renewable energy resources in accordance with the Renewable Obligation Order. Since 2009 technology banding has been added, meaning that different technologies are rewarded with a different number of

  4. Quantifying Co-benefits of Renewable Energy through Integrated Electricity and Air Quality Modeling

    Science.gov (United States)

    Abel, D.

    2016-12-01

    This work focuses on the coordination of electricity sector changes with air quality and health improvement strategies through the integration of electricity and air quality models. Two energy models are used to calculate emission perturbations associated with changes in generation technology (20% generation from solar photovoltaics) and demand (future electricity use under a warmer climate). Impacts from increased solar PV penetration are simulated with the electricity model GridView, in collaboration with the National Renewable Energy Laboratory (NREL). Generation results are used to scale power plant emissions from an inventory developed by the Lake Michigan Air Directors Consortium (LADCO). Perturbed emissions and are used to calculate secondary particulate matter with the Community Multiscale Air Quality (CMAQ) model. We find that electricity NOx and SO2 emissions decrease at a rate similar to the total fraction of electricity supplied by solar. Across the Eastern U.S. region, average PM2.5 is reduced 5% over the summer, with highest reduction in regions and on days of greater PM2.5. A similar approach evaluates the air quality impacts of elevated electricity demand under a warmer climate. Meteorology is selected from the North American Regional Climate Change Assessment Program (NARCCAP) and input to a building energy model, eQUEST, to assess electricity demand as a function of ambient temperature. The associated generation and emissions are calculated on a plant-by-plant basis by the MyPower power sector model. These emissions are referenced to the 2011 National Emissions Inventory to be modeled in CMAQ for the Eastern U.S. and extended to health impact evaluation with the Environmental Benefits Mapping and Analysis Program (BenMAP). All results focus on the air quality and health consequences of energy system changes, considering grid-level changes to meet climate and air quality goals.

  5. Unified System-Level Modeling of Intermittent Renewable Energy Sources and Energy Storage for Power System Operation

    DEFF Research Database (Denmark)

    Heussen, Kai; Koch, Stephan; Ulbig, Andreas

    2011-01-01

    The system-level consideration of inter- mittent renewable energy sources and small-scale en- ergy storage in power systems remains a challenge as either type is incompatible with traditional operation concepts. Non-controllability and energy-constraints are still considered contingent cases...... in market-based operation. The design of operation strategies for up to 100 % renewable energy systems requires an explicit consideration of non-dispatchable generation and stor- age capacities, as well as the evaluation of operational performance in terms of energy eciency, reliability, environmental...... in power system operation. After introducing the modeling ap- proach, a case study is presented for illustration....

  6. Modelling of landfill gas adsorption with bottom ash for utilization of renewable energy

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Chen

    2011-10-06

    Energy crisis, environment pollution and climate change are the serious challenges to people worldwide. In the 21st century, human being is trend to research new technology of renewable energy, so as to slow down global warming and develop society in an environmentally sustainable method. Landfill gas, produced by biodegradable municipal solid waste in landfill, is a renewable energy source. In this work, landfill gas utilization for energy generation is introduced. Landfill gas is able to produce hydrogen by steam reforming reactions. There is a steam reformer equipment in the fuel cells system. A sewage plant of Cologne in Germany has run the Phosphoric Acid Fuel Cells power station with biogas for more than 50,000 hours successfully. Landfill gas thus may be used as fuel for electricity generation via fuel cells system. For the purpose of explaining the possibility of landfill gas utilization via fuel cells, the thermodynamics of landfill gas steam reforming are discussed by simulations. In practice, the methane-riched gas can be obtained by landfill gas purification and upgrading. This work investigate a new method for upgrading-landfill gas adsorption with bottom ash experimentally. Bottom ash is a by-product of municipal solid waste incineration, some of its physical and chemical properties are analysed in this work. The landfill gas adsorption experimental data show bottom ash can be used as a potential adsorbent for landfill gas adsorption to remove CO{sub 2}. In addition, the alkalinity of bottom ash eluate can be reduced in these adsorption processes. Therefore, the interactions between landfill gas and bottom ash can be explained by series reactions accordingly. Furthermore, a conceptual model involving landfill gas adsorption with bottom ash is developed. In this thesis, the parameters of landfill gas adsorption equilibrium equations can be obtained by fitting experimental data. On the other hand, these functions can be deduced with theoretical approach

  7. An Improved MUSIC Model for Gibbsite Surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, Scott C.; Bickmore, Barry R.; Tadanier, Christopher J.; Rosso, Kevin M.

    2004-06-01

    Here we use gibbsite as a model system with which to test a recently published, bond-valence method for predicting intrinsic pKa values for surface functional groups on oxides. At issue is whether the method is adequate when valence parameters for the functional groups are derived from ab initio structure optimization of surfaces terminated by vacuum. If not, ab initio molecular dynamics (AIMD) simulations of solvated surfaces (which are much more computationally expensive) will have to be used. To do this, we had to evaluate extant gibbsite potentiometric titration data that where some estimate of edge and basal surface area was available. Applying BET and recently developed atomic force microscopy methods, we found that most of these data sets were flawed, in that their surface area estimates were probably wrong. Similarly, there may have been problems with many of the titration procedures. However, one data set was adequate on both counts, and we applied our method of surface pKa int prediction to fitting a MUSIC model to this data with considerable success—several features of the titration data were predicted well. However, the model fit was certainly not perfect, and we experienced some difficulties optimizing highly charged, vacuum-terminated surfaces. Therefore, we conclude that we probably need to do AIMD simulations of solvated surfaces to adequately predict intrinsic pKa values for surface functional groups.

  8. Modeling the power of renewable energy sources in the context of classical electricity system transformation

    Directory of Open Access Journals (Sweden)

    Rafał Kasperowicz

    2017-10-01

    Full Text Available Many regions, not only in the Europe, introduce plans for the modernization of energy systems so that in a few or several years most of the demand for electricity was being able to cover using renewable energy sources. The aim of this paper is to present the possibility of estimation of appropriate power supply based on the renewable energy sources in the context of the whole energy system in the annual balance, taking into account the technical and the economic optimization strategies. The article presents also the simplified structure of the 100% renewable energy system supported by energy storage systems and the production of synthetic fuels.

  9. Renewable energy

    DEFF Research Database (Denmark)

    Olsen, Birgitte Egelund

    2016-01-01

    Renewable energy projects are increasingly confronted by local opposition, which delays and sometimes even prevents their implementation. This reflects the frequent gap between support for the general idea of renewables as a strategy for reducing carbon emissions, and acceptance of renewable energy...

  10. Simultaneously Tailoring Surface Energies and Thermal Stabilities of Cellulose Nanocrystals Using Ion Exchange: Effects on Polymer Composite Properties for Transportation, Infrastructure, and Renewable Energy Applications.

    Science.gov (United States)

    Fox, Douglas M; Rodriguez, Rebeca S; Devilbiss, Mackenzie N; Woodcock, Jeremiah; Davis, Chelsea S; Sinko, Robert; Keten, Sinan; Gilman, Jeffrey W

    2016-10-12

    Cellulose nanocrystals (CNCs) have great potential as sustainable reinforcing materials for polymers, but there are a number of obstacles to commercialization that must first be overcome. High levels of water absorption, low thermal stabilities, poor miscibility with nonpolar polymers, and irreversible aggregation of the dried CNCs are among the greatest challenges to producing cellulose nanocrystal-polymer nanocomposites. A simple, scalable technique to modify sulfated cellulose nanocrystals (Na-CNCs) has been developed to address all of these issues. By using an ion exchange process to replace Na + with imidazolium or phosphonium cations, the surface energy is altered, the thermal stability is increased, and the miscibility of dried CNCs with a nonpolar polymer (epoxy and polystyrene) is enhanced. Characterization of the resulting ion exchanged CNCs (IE-CNCs) using potentiometry, inverse gas chromatography, dynamic vapor sorption, and laser scanning confocal microscopy reveals that the IE-CNCs have lower surface energies, adsorb less water, and have thermal stabilities of up to 100 °C higher than those of prepared protonated cellulose nanocrystals (H-CNCs) and 40 °C higher than that of neutralized Na-CNC. Methyl(triphenyl)phosphonium exchanged cellulose nanocrystals (MePh 3 P-CNC) adsorbed 30% less water than Na-CNC, retained less water during desorption, and were used to prepare well-dispersed epoxy composites without the aid of a solvent and well-dispersed polystyrene nanocomposites using a melt blending technique at 195 °C. Predictions of dispersion quality and glass transition temperatures from molecular modeling experiments match experimental observations. These fiber-reinforced polymers can be used as lightweight composites in transportation, infrastructure, and renewable energy applications.

  11. A Study of Synchronous Machine Model Implementations in Matlab/Simulink Simulations for New and Renewable Energy Systems

    DEFF Research Database (Denmark)

    Chen, Zhe; Blaabjerg, Frede; Iov, Florin

    2005-01-01

    A direct phase model of synchronous machines implemented in MA TLAB/SIMULINK is presented. The effects of the machine saturation have been included. Simulation studies are performed under various conditions. It has been demonstrated that the MATLAB/SIMULINK is an effective tool to study the complex...... synchronous machine and the implemented model could be used for studies of various applications of synchronous machines including in renewable and DG generation systems....

  12. Creation and evaluation of a database of renewable production time series and other data for energy system modelling

    International Nuclear Information System (INIS)

    Janker, Karl Albert

    2015-01-01

    This thesis describes a model which generates renewable power generation time series as input data for energy system models. The focus is on photovoltaic systems and wind turbines. The basis is a high resolution global raster data set of weather data for many years. This data is validated, corrected and preprocessed. The composition of the hourly generation data is done via simulation of the respective technology. The generated time series are aggregated for different regions and are validated against historical production time series.

  13. Assessing management models for off-grid renewable energy electrification projects using the Human Development approach: Case study in Peru

    OpenAIRE

    Lillo Rodrigo, Pau; Ferrer Martí, Laia; Boni Aristizábal, Alejandra; Fernández-Baldor, Álvaro

    2015-01-01

    Electrification systems based on renewable energy have proven suitable for providing electricity autonomously to rural communities, thus reducing poverty. When implementing these systems, a management model is usually designed to maximise technical and financial sustainability. Different evaluations of management models have been made that usually centre on products and final utilities. However, this excessively utilitarian vision of development restricts an analysis of the impact that these ...

  14. A new integral management model and evaluation method to enhance sustainability of renewable energy projects for energy and sanitation services

    OpenAIRE

    Lillo Rodrigo, Pau; Ferrer-Martí, Laia; Fernández-Baldor, Álvaro; Ramírez, Benito

    2015-01-01

    Autonomous systems based on the use of renewable energy (RE) have proven suitable for providing energy and sanitation services to isolated communities. However, most of these projects fail due to managerial weaknesses. Designing an appropriate management model is a key issue for sustainability and it is especially complex when includes different RE technologies. This paper is aimed at developing a novel management model for RE projects to provide energy and sanitation services with any kind o...

  15. Systems dynamics modelling to assess the sustainability of renewable energy technologies in developing countries

    CSIR Research Space (South Africa)

    Brent, AC

    2011-04-01

    Full Text Available supply, and the related cost implications, for water supply; concentrated solar thermal technology options are currently considered. In this paper a systems dynamics approach is used to assess the sustainability of these types of renewable energy...

  16. Foundations of elastoplasticity subloading surface model

    CERN Document Server

    Hashiguchi, Koichi

    2017-01-01

    This book is the standard text book of elastoplasticity in which the elastoplasticity theory is comprehensively described from the conventional theory for the monotonic loading to the unconventional theory for the cyclic loading behavior. Explanations of vector-tensor analysis and continuum mechanics are provided first as a foundation for elastoplasticity theory, covering various strain and stress measures and their rates with their objectivities. Elastoplasticity has been highly developed by the creation and formulation of the subloading surface model which is the unified fundamental law for irreversible mechanical phenomena in solids. The assumption that the interior of the yield surface is an elastic domain is excluded in order to describe the plastic strain rate due to the rate of stress inside the yield surface in this model aiming at the prediction of cyclic loading behavior, although the yield surface enclosing the elastic domain is assumed in all the elastoplastic models other than the subloading surf...

  17. Modeling of solution renewal with the Kindis code: example of R7T7 glass dissolution at 90 deg C

    International Nuclear Information System (INIS)

    Advocat, T.; Vernaz, E.; Crovisier, J.L.; Clement, A.; Gerard, F.

    1994-01-01

    The deep underground environment that would correspond to a geological repository is a system open to fluid flow. It is therefore necessary to investigate the effects of solution renewal on the long-term behavior of glass in contact with water. These effects can now be simulated using the new version of the geochemical KINDIS model (thermodynamic and kinetic model). We tested the model at 90 deg C with an SA/V ratio of 400 m -1 at twelve renewal rates of pure water ranging from 200 to 0 vol% per day. With renewal rates between 200 and 0.065 vol% per day, steady-state conditions were obtained in the reaction system: i.e. the glass corrosion rate remained constant as did the concentrations of the dissolved species in solution (although at different values depending on the renewal rate). The ionic strength never exceeded 1 (the validity limit for the DEBYE-HUCKEL law) and long term predictions of the dissolved glass mass, the solution composition and the potential secondary mineral sequence are possible. For simulated renewal rates of less than 0.065 vol% per day (27% per year), the ionic strength rose above 1 (as in a closed system) before steady-state conditions were reached, making it critical to calculate long-term rates; A constant and empirical long-term rate, derived from laboratory measurement, have to be extrapolated. These calculations were based on a first order equation to describe the glass dissolution kinetic. The results obtained with the KINDIS code show discrepancies with some major experimental kinetic data (the long term rate must decrease with the ''glass-water'' reaction progress, under silica saturation conditions). This clearly indicates that a more refine kinetic relation is needed for the glass matrix. (authors). 16 refs., 4 figs., 4 tabs

  18. Battery storage for supplementing renewable energy systems

    Energy Technology Data Exchange (ETDEWEB)

    None, None

    2009-01-18

    The battery storage for renewable energy systems section of the Renewable Energy Technology Characterizations describes structures and models to support the technical and economic status of emerging renewable energy options for electricity supply.

  19. Comparative Study on Assimilating Remote Sensing High Frequency Radar Surface Currents at an Atlantic Marine Renewable Energy Test Site

    Directory of Open Access Journals (Sweden)

    Lei Ren

    2017-12-01

    Full Text Available A variety of data assimilation approaches have been applied to enhance modelling capability and accuracy using observations from different sources. The algorithms have varying degrees of complexity of implementation, and they improve model results with varying degrees of success. Very little work has been carried out on comparing the implementation of different data assimilation algorithms using High Frequency radar (HFR data into models of complex inshore waters strongly influenced by both tides and wind dynamics, such as Galway Bay. This research entailed implementing four different data assimilation algorithms: Direct Insertion (DI, Optimal Interpolation (OI, Nudging and indirect data assimilation via correcting model forcing into a three-dimensional hydrodynamic model and carrying out detailed comparisons of model performances. This work will allow researchers to directly compare four of the most common data assimilation algorithms being used in operational coastal hydrodynamics. The suitability of practical data assimilation algorithms for hindcasting and forecasting in shallow coastal waters subjected to alternate wetting and drying using data collected from radars was assessed. Results indicated that a forecasting system of surface currents based on the three-dimensional model EFDC (Environmental Fluid Dynamics Code and the HFR data using a Nudging or DI algorithm was considered the most appropriate for Galway Bay. The largest averaged Data Assimilation Skill Score (DASS over the ≥6 h forecasting period from the best model NDA attained 26% and 31% for east–west and north–south surface velocity components respectively. Because of its ease of implementation and its accuracy, this data assimilation system can provide timely and useful information for various practical coastal hindcast and forecast operations.

  20. Surface Adsorption in Nonpolarizable Atomic Models.

    Science.gov (United States)

    Whitmer, Jonathan K; Joshi, Abhijeet A; Carlton, Rebecca J; Abbott, Nicholas L; de Pablo, Juan J

    2014-12-09

    Many ionic solutions exhibit species-dependent properties, including surface tension and the salting-out of proteins. These effects may be loosely quantified in terms of the Hofmeister series, first identified in the context of protein solubility. Here, our interest is to develop atomistic models capable of capturing Hofmeister effects rigorously. Importantly, we aim to capture this dependence in computationally cheap "hard" ionic models, which do not exhibit dynamic polarization. To do this, we have performed an investigation detailing the effects of the water model on these properties. Though incredibly important, the role of water models in simulation of ionic solutions and biological systems is essentially unexplored. We quantify this via the ion-dependent surface attraction of the halide series (Cl, Br, I) and, in so doing, determine the relative importance of various hypothesized contributions to ionic surface free energies. Importantly, we demonstrate surface adsorption can result in hard ionic models combined with a thermodynamically accurate representation of the water molecule (TIP4Q). The effect observed in simulations of iodide is commensurate with previous calculations of the surface potential of mean force in rigid molecular dynamics and polarizable density-functional models. Our calculations are direct simulation evidence of the subtle but sensitive role of water thermodynamics in atomistic simulations.

  1. Modeling and Inversion of Scattered Surface waves

    NARCIS (Netherlands)

    Riyanti, C.D.

    2005-01-01

    In this thesis, we present a modeling method based on a domain-type integral representation for waves propagating along the surface of the Earth which have been scattered in the vicinity of the source or the receivers. Using this model as starting point, we formulate an inversion scheme to estimate

  2. Hybrid modeling to support energy-climate policy: Effects of feed-in tariffs to promote renewable energy in Portugal

    International Nuclear Information System (INIS)

    Proença, Sara; St Aubyn, Miguel

    2013-01-01

    Feed-in tariffs have been the main policy instrument applied in Portugal for the promotion of electricity produced from renewable energy sources under the EU Directives on energy and climate regulation. In this paper, we provide an empirical impact assessment of the economic and environmental effects of Portugal's FITs policy to promote RES-E generation. Impact assessment of policy instruments plays a crucial role on decision-making process. For numerical simulations, we make use of a hybrid top-down/bottom-up general equilibrium modeling approach, which represents a reliable tool to analyze the complex interactions between economic, energy, and environmental issues related to energy policies. Numerical simulations confirm the empirical evidence that the FITs policy implemented by Portugal was both an effective and a cost-efficient way to increase the generation of electricity from renewable energy sources and thus to achieve the national RES-E target of 45% in 2010. Results show relatively modest macroeconomic impacts indicating potentially low economic adjustment costs. From an environmental perspective, the deployment of renewable energy source results in significant carbon emissions reductions. - Highlights: ► We provide an impact assessment of Portugal's FITs policy to promote RES-E generation. ► For numerical simulations, we make use of a hybrid top-down/bottom-up general equilibrium model. ► Portugal's FITs policy proved to be a cost-efficient way to increase generation of renewable electricity. ► Results show relatively modest macroeconomic effects indicating potentially low economic adjustment costs. ► The deployment of renewable energy sources results in significant carbon emission reductions

  3. Surface physics theoretical models and experimental methods

    CERN Document Server

    Mamonova, Marina V; Prudnikova, I A

    2016-01-01

    The demands of production, such as thin films in microelectronics, rely on consideration of factors influencing the interaction of dissimilar materials that make contact with their surfaces. Bond formation between surface layers of dissimilar condensed solids-termed adhesion-depends on the nature of the contacting bodies. Thus, it is necessary to determine the characteristics of adhesion interaction of different materials from both applied and fundamental perspectives of surface phenomena. Given the difficulty in obtaining reliable experimental values of the adhesion strength of coatings, the theoretical approach to determining adhesion characteristics becomes more important. Surface Physics: Theoretical Models and Experimental Methods presents straightforward and efficient approaches and methods developed by the authors that enable the calculation of surface and adhesion characteristics for a wide range of materials: metals, alloys, semiconductors, and complex compounds. The authors compare results from the ...

  4. Land-surface modelling in hydrological perspective

    DEFF Research Database (Denmark)

    Overgaard, Jesper; Rosbjerg, Dan; Butts, M.B.

    2006-01-01

    The purpose of this paper is to provide a review of the different types of energy-based land-surface models (LSMs) and discuss some of the new possibilities that will arise when energy-based LSMs are combined with distributed hydrological modelling. We choose to focus on energy-based approaches......, and the difficulties inherent in various evaluation procedures are presented. Finally, the dynamic coupling of hydrological and atmospheric models is explored, and the perspectives of such efforts are discussed....

  5. Estimation of grass reference evaporation and sensible heat flux using surface renewal and Monin-Obukhov similarity theory: A simple implementation of an iterative method

    Science.gov (United States)

    Savage, M. J.

    2017-04-01

    An iterative method was applied to daily crop reference evaporation ETo. The method correctly evaluated the slope of the saturation water vapour pressure vs temperature relationship between surface temperature and air temperature. Using daily meterological data spanning several decades from four selected locations in Australia, South Africa and USA, differences in ETo estimates were noted with and without the iteration method applied. The largest difference, which occurred under high water vapour pressure deficit conditions, ranged from 1.65 mm/day for Griffith, Australia to 0.51 mm/day for Pretoria, South Africa. The aerodynamic component of the ETo equation was more affected by not applying the spreadsheet iterative procedure compared to the radiative component. Other spreadsheet examples of the iterative method employed included obtaining the roots of a depressed cubic polynomial in the air temperature surface renewal (SR) ramp. This value was used for the measurement of sensible heat flux using surface renewal. An iterative method, together with Monin-Obukhov similarity theory (MOST) and surface-layer scintillometer (SLS) measurements in a mesic grassland, was also used to calculate the sensible heat flux. The simple iterative method is quick, accurate and convenient, easy to repeat following changes to equations or data, allows easy manipulation and allows convenient visual inspection of data and graphics. Sub-hourly measurements of sensible heat flux for the mesic grassland using SR and SLS MOST iterative methods compared favourably with Bowen ratio and eddy covariance measurements.

  6. Hybrid Systems of Distributed Generation with Renewable Sources: Modeling and Analysis of Their Operational Modes in Electric Power System

    Directory of Open Access Journals (Sweden)

    A. M. Gashimov

    2013-01-01

    Full Text Available The paper considers problems pertaining to modeling and simulation of operational hybrid system modes of the distributed generation comprising conventional sources – modular diesel generators, gas-turbine power units; and renewable sources – wind and solar power plants. Operational modes of the hybrid system have been investigated under conditions of electrical connection with electric power system and in case of its isolated operation. As a consequence

  7. Minimal model for spoof acoustoelastic surface states

    DEFF Research Database (Denmark)

    Christensen, Johan; Liang, Z.; Willatzen, Morten

    2014-01-01

    Similar to textured perfect electric conductors for electromagnetic waves sustaining artificial or spoof surface plasmons we present an equivalent phenomena for the case of sound. Aided by a minimal model that is able to capture the complex wave interaction of elastic cavity modes and airborne...... sound radiation in perfect rigid panels, we construct designer acoustoelastic surface waves that are entirely controlled by the geometrical environment. Comparisons to results obtained by full-wave simu- lations confirm the feasibility of the model and we demonstrate illustrative examples...

  8. CREST Cost of Renewable Energy Spreadsheet Tool: A Model for Developing Cost-based Incentives in the United States. User Manual Version 1

    Energy Technology Data Exchange (ETDEWEB)

    Gifford, Jason S. [Sustainable Energy Advantage, LLC, Framingham, MA (United States); Grace, Robert C. [Sustainable Energy Advantage, LLC, Framingham, MA (United States)

    2011-03-01

    This user manual helps model users understands how to use the CREST model to support renewable energy incentives, FITs, and other renewable energy rate-setting processes. It reviews the spreadsheet tool, including its layout and conventions, offering context on how and why it was created. It also provides instructions on how to populate the model with inputs that are appropriate for a specific jurisdiction’s policymaking objectives and context. And, it describes the results and outlines how these results may inform decisions about long-term renewable energy support programs.

  9. Social renewal

    OpenAIRE

    A.W. van der Pennen; V. Veldheer; E. ter Borg; M. Kunst; J. Boelhouwer; F.A. Knol

    1998-01-01

    Original title: Sociale vernieuwing. Social renewal began in Rotterdam in 1989, as a response to the presence of stubborn social disadvantage. The Idenburg Committee produced recommendations in that year suggesting how these social problems could best be tackled at local level. Central government adopted these ideas in 1990, since when social renewal policy has really taken off. Most municipalities have joined in, developing social renewal policy and creating an administrative apparatus for i...

  10. Renewable energy

    International Nuclear Information System (INIS)

    Yoon, Cheon Seok

    2009-09-01

    This book tells of renewable energy giving description of environment problem, market of renewable energy and vision and economics of renewable energy. It also deals with solar light like solar cell, materials performance, system and merit of solar cell, solar thermal power such as solar cooker and solar collector, wind energy, geothermal energy, ocean energy like tidal power and ocean thermal energy conversion, fuel cell and biomass.

  11. Optimal stochastic management of renewable MG (micro-grids) considering electro-thermal model of PV (photovoltaic)

    International Nuclear Information System (INIS)

    Najibi, Fatemeh; Niknam, Taher; Kavousi-Fard, Abdollah

    2016-01-01

    This paper aims to report the results of the research conducted to one thermal and electrical model for photovoltaic. Moreover, one probabilistic framework is introduced for considering all uncertainties in the optimal energy management of Micro-Grid problem. It should be noted that one typical Micro-Grid is being studied as a case, including different renewable energy sources, such as Photovoltaic, Micro Turbine, Wind Turbine, and one battery as a storage device for storing energy. The uncertainties of market price variation, photovoltaic and wind turbine output power change and load demand error are covered by the suggested probabilistic framework. The Micro-Grid problem is of nonlinear nature because of the stochastic behavior of the renewable energy sources such as Photovoltaic and Wind Turbine units, and hence there is need for a powerful tool to solve the problem. Therefore, in addition to the simulated thermal model and suggested probabilistic framework, a new algorithm is also introduced. The Backtracking Search Optimization Algorithm is described as a useful method to optimize the MG (micro-grids) problem. This algorithm has the benefit of escaping from the local optima while converging fast, too. The proposed algorithm is also tested on the typical Micro-Grid. - Highlights: • Proposing an electro-thermal model for PV. • Proposing a new stochastic formulation for optimal operation of renewable MGs. • Introduction of a new optimization method based on BSO to explore the problem search space.

  12. Modeling Thermal Comfort and Optimizing Local Renewal Strategies—A Case Study of Dazhimen Neighborhood in Wuhan City

    Directory of Open Access Journals (Sweden)

    Chong Peng

    2015-03-01

    Full Text Available Modeling thermal comfort provides quantitative evidence and parameters for effective and efficient urban planning, design, and building construction particularly in a dense and narrow inner city, which has become one of many concerns for sustainable urban development. This paper aims to develop geometric and mathematical models of wind and thermal comfort and use them to examine the impacts of six small-scale renewal strategies on the wind and thermal environment at pedestrian level in Dazhimen neighborhood, Wuhan, which is a typical case study of urban renewal project in a mega-city. The key parameters such as the solar radiation, natural convection, relative humidity, ambient crosswind have been incorporated into the mathematical models by using user-defined-function (UDF method. Detailed temperature and velocity distributions under different strategies have been compared for the optimization of local renewal strategies. It is concluded that five rules generated from the simulation results can provide guidance for building demolition and reconstruction in a neighborhood and there is no need of large-scale demolition. Particularly, combining the local demolition and city virescence can both improve the air ventilation and decrease the temperature level in the study area.

  13. Power flow modelling in electric networks with renewable energy sources in large areas

    International Nuclear Information System (INIS)

    Buhawa, Z. M.; Dvorsky, E.

    2012-01-01

    In many worlds regions there is a great potential for utilizing home grid connected renewable power generating systems, with capacities of MW thousands. The optimal utilization of these sources is connected with power flow possibilities trough the power network in which they have to be connected. There is necessary to respect the long distances among the electric power sources with great outputs and power consumption and non even distribution of the power sources as well. The article gives the solution possibilities for Libya region under utilization of wind renewable sources in north in shore regions. (Authors)

  14. Representation of variable renewable energy sources in TIMER, an aggregated energy system simulation model

    NARCIS (Netherlands)

    de Boer, Harmen Sytze (H S.).; van Vuuren, Detlef (D P.).

    2017-01-01

    The power system is expected to play an important role in climate change mitigation. Variable renewable energy (VRE) sources, such as wind and solar power, are currently showing rapid growth rates in power systems worldwide, and could also be important in future mitigation strategies. It is

  15. Modeling of Flexibility in Electricity Demand and Supply for Renewables Integration

    NARCIS (Netherlands)

    Verhoosel, J.P.C.; Rumph, F.J.; Konsman, M.

    2011-01-01

    The use of renewable energy sources is increasing due to national and international regulations. Such energy sources are less predictable than most of the classical energy production systems, like coal and nuclear power plants. This causes a challenge for balancing the electricity system. A

  16. Modeling the effects of the new Russian capacity mechanism on renewable energy investments

    International Nuclear Information System (INIS)

    Kozlova, Mariia; Collan, Mikael

    2016-01-01

    Russian renewable energy policy, introduced in May 2013, is a capacity mechanism-based approach to support wind, solar, and small hydro power development in Russia. This paper explores the effect of the new mechanism on the profitability of new renewable energy investments with a numerical example. The sensitivity of project profitability to selected factors is studied and the results are compared ceteris paribus to results from a generic feed-in premium case. Furthermore, the paper gives a complete and detailed presentation of the capacity price calculation procedure tied to the support mechanism. The results show that the new Russian renewable energy capacity mechanism offers a significant risk reduction to the investor in the form of dampening the sensitivity to external market factors. At the same time it shields the energy market system from excessive burden of renewable energy support. Even if the complexity of the method is a clear drawback to the detailed understanding of how the mechanism works, the design of the incentive policy could be an appealing alternative also for other emerging economies. - Highlights: •New Russian RE investment incentive mechanism is presented in detail. •Effect of the mechanism on RE investment profitability is numerically illustrated. •Sensitivity of project profitability to selected variables is studied. •Sensitivity results are compared to results under a generic feed-in premium. •The mechanism is shown to reduce market-related risks of RE investments.

  17. Global modelling of Cryptosporidium in surface water

    Science.gov (United States)

    Vermeulen, Lucie; Hofstra, Nynke

    2016-04-01

    Introduction Waterborne pathogens that cause diarrhoea, such as Cryptosporidium, pose a health risk all over the world. In many regions quantitative information on pathogens in surface water is unavailable. Our main objective is to model Cryptosporidium concentrations in surface waters worldwide. We present the GloWPa-Crypto model and use the model in a scenario analysis. A first exploration of global Cryptosporidium emissions to surface waters has been published by Hofstra et al. (2013). Further work has focused on modelling emissions of Cryptosporidium and Rotavirus to surface waters from human sources (Vermeulen et al 2015, Kiulia et al 2015). A global waterborne pathogen model can provide valuable insights by (1) providing quantitative information on pathogen levels in data-sparse regions, (2) identifying pathogen hotspots, (3) enabling future projections under global change scenarios and (4) supporting decision making. Material and Methods GloWPa-Crypto runs on a monthly time step and represents conditions for approximately the year 2010. The spatial resolution is a 0.5 x 0.5 degree latitude x longitude grid for the world. We use livestock maps (http://livestock.geo-wiki.org/) combined with literature estimates to calculate spatially explicit livestock Cryptosporidium emissions. For human Cryptosporidium emissions, we use UN population estimates, the WHO/UNICEF JMP sanitation country data and literature estimates of wastewater treatment. We combine our emissions model with a river routing model and data from the VIC hydrological model (http://vic.readthedocs.org/en/master/) to calculate concentrations in surface water. Cryptosporidium survival during transport depends on UV radiation and water temperature. We explore pathogen emissions and concentrations in 2050 with the new Shared Socio-economic Pathways (SSPs) 1 and 3. These scenarios describe plausible future trends in demographics, economic development and the degree of global integration. Results and

  18. Olkiluoto surface and near-surface hydrological modelling in 2010

    International Nuclear Information System (INIS)

    Karvonen, T.

    2011-08-01

    The modeling approaches carried out with the Olkiluoto surface hydrological model (SHYD) include palaeohydrological evolution of the Olkiluoto Island, examination of the boundary condition at the geosphere-biosphere interface zone, simulations related to infiltration experiment, prediction of the influence of ONKALO on hydraulic head in shallow and deep bedrock and optimisation of the shallow monitoring network. A so called short-term prediction system was developed for continuous updating of the estimated drawdowns caused by ONKALO. The palaeohydrological simulations were computed for a period starting from the time when the highest hills on Olkiluoto Island rose above sea level around 2 500 years ago. The input data needed in the model were produced by the UNTAMO-toolbox. The groundwater flow evolution is primarily driven by the postglacial land uplift and the uncertainty in the land uplift model is the biggest single factor that influences the accuracy of the results. The consistency of the boundary condition at the geosphere-biosphere interface zone (GBIZ) was studied during 2010. The comparison carried out during 2010 showed that pressure head profiles computed with the SHYD model and deep groundwater flow model FEFTRA are in good agreement with each other in the uppermost 100 m of the bedrock. This implies that flux profiles computed with the two approaches are close to each other and hydraulic heads computed at level z=0 m with the SHYD can be used as head boundary condition in the deep groundwater flow model FEFTRA. The surface hydrological model was used to analyse the results of the infiltration experiment. Increase in bedrock recharge inside WCA explains around 60-63 % from the amount of water pumped from OL-KR14 and 37-40 % of the water pumped from OL-KR14 flows towards pumping section via the hydrogeological zones. Pumping from OL-KR14 has only a minor effect on heads and fluxes in zones HZ19A and HZ19C compared to responses caused by leakages into

  19. Vision models for 3D surfaces

    Science.gov (United States)

    Mitra, Sunanda

    1992-11-01

    Different approaches to computational stereo to represent human stereo vision have been developed over the past two decades. The Marr-Poggio theory of human stereo vision is probably the most widely accepted model of the human stereo vision. However, recently developed motion stereo models which use a sequence of images taken by either a moving camera or a moving object provide an alternative method of achieving multi-resolution matching without the use of Laplacian of Gaussian operators. While using image sequences, the baseline between two camera positions for a image pair is changed for the subsequent image pair so as to achieve different resolution for each image pair. Having different baselines also avoids the inherent occlusion problem in stereo vision models. The advantage of using multi-resolution images acquired by camera positioned at different baselines over those acquired by LOG operators is that one does not have to encounter spurious edges often created by zero-crossings in the LOG operated images. Therefore in designing a computer vision system, a motion stereo model is more appropriate than a stereo vision model. However, in some applications where only a stereo pair of images are available, recovery of 3D surfaces of natural scenes are possible in a computationally efficient manner by using cepstrum matching and regularization techniques. Section 2 of this paper describes a motion stereo model using multi-scale cepstrum matching for the detection of disparity between image pairs in a sequence of images and subsequent recovery of 3D surfaces from depth-map obtained by a non convergent triangulation technique. Section 3 presents a 3D surface recovery technique from a stereo pair using cepstrum matching for disparity detection and cubic B-splines for surface smoothing. Section 4 contains the results of 3D surface recovery using both of the techniques mentioned above. Section 5 discusses the merit of 2D cepstrum matching and cubic B

  20. Nuclear surface vibrations in bag models

    International Nuclear Information System (INIS)

    Tomio, L.

    1984-01-01

    The main difficulties found in the hadron bag models are reviewed from the original version of the MIT bag model. Following, with the aim to answer two of the main difficulties in bag models, viz., the parity and the divergence illness, a dynamical model is presented. In the model, the confinement surface of the quarks (bag) is treated like a real physical object which interacts with the quarks and is exposed to vibrations. The model is applied to the nucleon, being observed that his spectrum, in the first excited levels, can be reproduced with resonable precision and obeying to the correct parity order. In the same way that in a similar work of Brown et al., it is observed to be instrumental the inclusion of the effect due to pions. (L.C.) [pt

  1. Liquid surface model for carbon nanotube energetics

    DEFF Research Database (Denmark)

    Solov'yov, Ilia; Mathew, Maneesh; Solov'yov, Andrey V.

    2008-01-01

    In the present paper we developed a model for calculating the energy of single-wall carbon nanotubes of arbitrary chirality. This model, which we call as the liquid surface model, predicts the energy of a nanotube with relative error less than 1% once its chirality and the total number of atoms a...... the calculated energies we determine the elastic properties of the single-wall carbon nanotubes (Young modulus, curvature constant) and perform a comparison with available experimental measurements and earlier theoretical predictions....

  2. License renewal

    International Nuclear Information System (INIS)

    Newberry, S.

    1993-01-01

    This article gives an overview of the process of license renewal for nuclear power plants. It explains what is meant by license renewal, the significance of license renewal, and goes over key elements involved in the process of license renewal. Those key elements are NRC requirements embodied in 10 CFR Part 54 (Reactor Safety) and 10 CFR Part 51 (Environmental Issues). In addition Industry Reports must be developed and reviewed. License renewal is essentially the process of applying for a 20 year extension to the original 40 year operating license granted for the plant. This is a very long term process, which involves a lot of preparation, and compliance with regulatory rules and guidelines. In general it is a process which is expected to begin when plants reach an operating lifetime of 20 years. It has provisions for allowing the public to become involved in the review process

  3. Renewable Energy

    DEFF Research Database (Denmark)

    Sørensen, Bent Erik

    Bent Sorensen’s Renewable Energy: Physics, Engineering, Environmental Impacts, Economics and Planning, Fifth Edition, continues the tradition by providing a thorough and current overview of the entire renewable energy sphere. Since its first edition, this standard reference source helped put...... renewable energy on the map of scientific agendas. Several renewable energy solutions no longer form just a marginal addition to energy supply, but have become major players, with the promise to become the backbone of an energy system suitable for life in the sustainability lane. This volume is a problem...... structured around three parts in order to assist readers in focusing on the issues that impact them the most for a given project or question. PART I covers the basic scientific principles behind all major renewable energy resources, such as solar, wind, and biomass. PART II provides in-depth information...

  4. Grain Surface Models and Data for Astrochemistry

    Science.gov (United States)

    Cuppen, H. M.; Walsh, C.; Lamberts, T.; Semenov, D.; Garrod, R. T.; Penteado, E. M.; Ioppolo, S.

    2017-10-01

    The cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of {˜}25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions.

  5. AMMA Land surface Model Intercomparison Project (ALMIP)

    Science.gov (United States)

    Boone, A. A.; Derosnay, P.

    2007-05-01

    Extreme climatic variability has afflicted West Africa over the last half century, which has resulted in significant socio-economic consequences for the people of this region. There is therefore a need to improve seasonal to inter-annual prediction of the West-African monsoon (WAM), however, difficulties modeling the WAM arise from both the paucity of observations at sufficient space-time resolutions, and due to the complex interactions between the biosphere, atmosphere and hydrosphere over this region. In particular, there is evidence that the land surface influences the variability of the WAM over a wide range of spatio-temporal scales. A critical aspect of this coupling is the feedback between the regional atmospheric circulation and the strong meridional surface flux gradients of mass and energy. One of the main goals of the African Monsoon Multi-disciplinary Analysis (AMMA) Project is to obtain a better understanding of the physical processes influencing the West-African Monsoon (WAM) on daily to inter-annual timescales. An improved comprehension of the relevant land surface processes is being addressed through the construction of a multi-scale atmospheric and land surface parameter forcing database using a variety of sources; numerical weather prediction forecast data, remote sensing products and local scale observations. The goal of this database is to drive land surface, vegetation and hydrological models over a range of spatial scales (local to regional) in order to gain better insights into the attendant processes. This goal is being met under the auspices of the AMMA Land surface Model Intercomparison Project (ALMIP). In the recently completed Phase 1 of this project, an ensemble of state-of-the-art land surface schemes have been run in "off-line" mode (i.e. decoupled from an atmospheric model) at a regional scale over western Africa for four annual cycles (2002-5). In this talk, intercomparison results will be presented. In addition, results from a

  6. INTEGRATION OF HETEROGENOUS DIGITAL SURFACE MODELS

    Directory of Open Access Journals (Sweden)

    R. Boesch

    2012-08-01

    Full Text Available The application of extended digital surface models often reveals, that despite an acceptable global accuracy for a given dataset, the local accuracy of the model can vary in a wide range. For high resolution applications which cover the spatial extent of a whole country, this can be a major drawback. Within the Swiss National Forest Inventory (NFI, two digital surface models are available, one derived from LiDAR point data and the other from aerial images. Automatic photogrammetric image matching with ADS80 aerial infrared images with 25cm and 50cm resolution is used to generate a surface model (ADS-DSM with 1m resolution covering whole switzerland (approx. 41000 km2. The spatially corresponding LiDAR dataset has a global point density of 0.5 points per m2 and is mainly used in applications as interpolated grid with 2m resolution (LiDAR-DSM. Although both surface models seem to offer a comparable accuracy from a global view, local analysis shows significant differences. Both datasets have been acquired over several years. Concerning LiDAR-DSM, different flight patterns and inconsistent quality control result in a significantly varying point density. The image acquisition of the ADS-DSM is also stretched over several years and the model generation is hampered by clouds, varying illumination and shadow effects. Nevertheless many classification and feature extraction applications requiring high resolution data depend on the local accuracy of the used surface model, therefore precise knowledge of the local data quality is essential. The commercial photogrammetric software NGATE (part of SOCET SET generates the image based surface model (ADS-DSM and delivers also a map with figures of merit (FOM of the matching process for each calculated height pixel. The FOM-map contains matching codes like high slope, excessive shift or low correlation. For the generation of the LiDAR-DSM only first- and last-pulse data was available. Therefore only the point

  7. Renewable Resources: a national catalog of model projects. Volume 1. Northeast Solar Energy Center Region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    This compilation of diverse conservation and renewable energy projects across the United States was prepared through the enthusiastic participation of solar and alternate energy groups from every state and region. Compiled and edited by the Center for Renewable Resources, these projects reflect many levels of innovation and technical expertise. In many cases, a critique analysis is presented of how projects performed and of the institutional conditions associated with their success or failure. Some 2000 projects are included in this compilation; most have worked, some have not. Information about all is presented to aid learning from these experiences. The four volumes in this set are arranged in state sections by geographic region, coinciding with the four Regional Solar Energy Centers. The table of contents is organized by project category so that maximum cross-referencing may be obtained. This volume includes information on the Northeast Solar Energy Center Region. (WHK).

  8. Renewable Resources: a national catalog of model projects. Volume 3. Southern Solar Energy Center Region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    This compilation of diverse conservation and renewable energy projects across the United States was prepared through the enthusiastic participation of solar and alternate energy groups from every state and region. Compiled and edited by the Center for Renewable Resources, these projects reflect many levels of innovation and technical expertise. In many cases, a critique analysis is presented of how projects performed and of the institutional conditions associated with their success or failure. Some 2000 projects are included in this compilation; most have worked, some have not. Information about all is presented to aid learning from these experiences. The four volumes in this set are arranged in state sections by geographic region, coinciding with the four Regional Solar Energy Centers. The table of contents is organized by project category so that maximum cross-referencing may be obtained. This volume includes information on the Southern Solar Energy Center Region. (WHK)

  9. Renewable Resources: a national catalog of model projects. Volume 4. Western Solar Utilization Network Region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    This compilation of diverse conservation and renewable energy projects across the United States was prepared through the enthusiastic participation of solar and alternate energy groups from every state and region. Compiled and edited by the Center for Renewable Resources, these projects reflect many levels of innovation and technical expertise. In many cases, a critique analysis is presented of how projects performed and of the institutional conditions associated with their success or failure. Some 2000 projects are included in this compilation; most have worked, some have not. Information about all is presented to aid learning from these experiences. The four volumes in this set are arranged in state sections by geographic region, coinciding with the four Regional Solar Energy Centers. The table of contents is organized by project category so that maximum cross-referencing may be obtained. This volume includes information on the Western Solar Utilization Network Region. (WHK)

  10. Modeling superhydrophobic surfaces comprised of random roughness

    Science.gov (United States)

    Samaha, M. A.; Tafreshi, H. Vahedi; Gad-El-Hak, M.

    2011-11-01

    We model the performance of superhydrophobic surfaces comprised of randomly distributed roughness that resembles natural surfaces, or those produced via random deposition of hydrophobic particles. Such a fabrication method is far less expensive than ordered-microstructured fabrication. The present numerical simulations are aimed at improving our understanding of the drag reduction effect and the stability of the air-water interface in terms of the microstructure parameters. For comparison and validation, we have also simulated the flow over superhydrophobic surfaces made up of aligned or staggered microposts for channel flows as well as streamwise or spanwise ridge configurations for pipe flows. The present results are compared with other theoretical and experimental studies. The numerical simulations indicate that the random distribution of surface roughness has a favorable effect on drag reduction, as long as the gas fraction is kept the same. The stability of the meniscus, however, is strongly influenced by the average spacing between the roughness peaks, which needs to be carefully examined before a surface can be recommended for fabrication. Financial support from DARPA, contract number W91CRB-10-1-0003, is acknowledged.

  11. Impact of variable renewable production on electricity prices in Germany: a Markov switching model

    International Nuclear Information System (INIS)

    Martin de Lagarde, Cyril; Lantz, Frederic

    2016-01-01

    This paper aims at assessing the impact of renewable energy sources (RES) production on electricity spot prices. To do so, we use a two-regime Markov Switching (MS) model, that enables to disentangle the so-called 'merit-order effect' due to wind and solar photovoltaic productions (used in relative share of the electricity demand), depending on the price being high or low. We find that there are effectively two distinct price regimes that are put to light thanks to an inverse hyperbolic sine transformation that allows to treat negative prices. We also show that these two regimes coincide quite well with two regimes for the electricity demand (load). Indeed, when demand is low, prices are low and the merit-order effect is lower than when prices are high, which is consistent with the fact that the inverse supply curve is convex (i.e. has increasing slope). To illustrate this, we computed the mean marginal effects of RES production and load. On average, an increase of 1 GW of wind will decrease the price in regime 1 (resp. 2) by 0.77 euro /MWh (resp. 1 euro /MWh). The influence of solar is slightly weaker, as an extra gigawatt lowers the price of 0.73 euro /MWh in period 1, and 0.96 euro /MWh in regime 2. On the contrary, if the demand increases by 1 GW in regime 1 (resp. 2), the price increases on average by 0.93 euro /MWh (resp. 1.18 euro /MWh). Although we made sure these marginal effects are significantly different from one another, they are much more variable than the estimated coefficients of the model. Also, note that these marginal effects are only valid inside each regime when there is no switching. The latter regime partly corresponds to the high load regime, at the exception of periods during which RES production is high. The impact on volatility could also be observed: the variance of the (transformed) price is higher during the high-price regime than in the low-price one. In addition to the switching of the coefficients, we allowed the

  12. Assessing renewables-to-electricity systems: a fuzzy expert system model

    Energy Technology Data Exchange (ETDEWEB)

    Kaminaris, S.D. [Department of Electrical and Computer Engineering, Electric Power Division, National Technical University of Athens, 9, Iroon Politechniou Str., GR 157 80 Zografou (Greece)]. E-mail: stakamin@hol.gr; Tsoutsos, T.D. [Department of Environmental Engineering, Technical University of Crete, Kounoupidiana Campus, 19009 Chania (Greece) and Centre for Renewable Energy Sources, 19th km Marathon Avenue, GR-19009 Pikermi (Greece)]. E-mail: tsoutsos@mred.tuc.gr; Agoris, D. [University of Patras, Electrical and Computer Engineering Department, High Voltage Laboratory, GR 26500 Rio (Greece); Machias, A.V. [Department of Electrical and Computer Engineering, Electric Power Division, National Technical University of Athens, 9, Iroon Politechniou Str., GR 157 80 Zografou (Greece)

    2006-08-15

    The assessment of Renewables-to-Electricity Systems is a complex, time-consuming task and requires skilled, experienced engineers. This paper describes the on-going research effort that takes place in the development of a new Intelligent Approach, an efficient decision making tool in this problem based on the employment of the Expert Systems and Fuzzy Logic techniques. As far as expert knowledge representation is concerned, the proposed approach is based on Expert System techniques (rule-based methodology). Moreover, trying to assess a Renewables-to-Electricity project or several alternative ones, the analysis has to face, in general, a series of uncertainties. To handle effectively these uncertainties, a new methodology is proposed (by use of Fuzzy Sets Theory and Fuzzy Logic Techniques). The proposed Fuzzy Project Priority Index for each Renewables-to-Electricity System is very useful especially in decision-makers. In order to demonstrate the proposed intelligent fuzzy analysis-based approach a simple case study is provided, supposing that a legal entity is to assess and finally select/propose an electricity production system, which uses RES (wind energy OR solar energy to photovoltaic OR small hydro). As fuzzy variables are concerned the Life Cycle Analysis (versus equipment production, plant preparation, operation and decommissioning) and the Development Cost (versus firm capabilities, spillover effects and potential downside damage)

  13. Assessing renewables-to-electricity systems: a fuzzy expert system model

    International Nuclear Information System (INIS)

    Kaminaris, S.D.; Tsoutsos, T.D.; Agoris, D.; Machias, A.V.

    2006-01-01

    The assessment of Renewables-to-Electricity Systems is a complex, time-consuming task and requires skilled, experienced engineers. This paper describes the on-going research effort that takes place in the development of a new Intelligent Approach, an efficient decision making tool in this problem based on the employment of the Expert Systems and Fuzzy Logic techniques. As far as expert knowledge representation is concerned, the proposed approach is based on Expert System techniques (rule-based methodology). Moreover, trying to assess a Renewables-to-Electricity project or several alternative ones, the analysis has to face, in general, a series of uncertainties. To handle effectively these uncertainties, a new methodology is proposed (by use of Fuzzy Sets Theory and Fuzzy Logic Techniques). The proposed Fuzzy Project Priority Index for each Renewables-to-Electricity System is very useful especially in decision-makers. In order to demonstrate the proposed intelligent fuzzy analysis-based approach a simple case study is provided, supposing that a legal entity is to assess and finally select/propose an electricity production system, which uses RES (wind energy OR solar energy to photovoltaic OR small hydro). As fuzzy variables are concerned the Life Cycle Analysis (versus equipment production, plant preparation, operation and decommissioning) and the Development Cost (versus firm capabilities, spillover effects and potential downside damage)

  14. Modeling of ESD events from polymeric surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Pfeifer, Kent Bryant

    2014-03-01

    Transient electrostatic discharge (ESD) events are studied to assemble a predictive model of discharge from polymer surfaces. An analog circuit simulation is produced and its response is compared to various literature sources to explore its capabilities and limitations. Results suggest that polymer ESD events can be predicted to within an order of magnitude. These results compare well to empirical findings from other sources having similar reproducibility.

  15. Parameter optimization for surface flux transport models

    Science.gov (United States)

    Whitbread, T.; Yeates, A. R.; Muñoz-Jaramillo, A.; Petrie, G. J. D.

    2017-11-01

    Accurate prediction of solar activity calls for precise calibration of solar cycle models. Consequently we aim to find optimal parameters for models which describe the physical processes on the solar surface, which in turn act as proxies for what occurs in the interior and provide source terms for coronal models. We use a genetic algorithm to optimize surface flux transport models using National Solar Observatory (NSO) magnetogram data for Solar Cycle 23. This is applied to both a 1D model that inserts new magnetic flux in the form of idealized bipolar magnetic regions, and also to a 2D model that assimilates specific shapes of real active regions. The genetic algorithm searches for parameter sets (meridional flow speed and profile, supergranular diffusivity, initial magnetic field, and radial decay time) that produce the best fit between observed and simulated butterfly diagrams, weighted by a latitude-dependent error structure which reflects uncertainty in observations. Due to the easily adaptable nature of the 2D model, the optimization process is repeated for Cycles 21, 22, and 24 in order to analyse cycle-to-cycle variation of the optimal solution. We find that the ranges and optimal solutions for the various regimes are in reasonable agreement with results from the literature, both theoretical and observational. The optimal meridional flow profiles for each regime are almost entirely within observational bounds determined by magnetic feature tracking, with the 2D model being able to accommodate the mean observed profile more successfully. Differences between models appear to be important in deciding values for the diffusive and decay terms. In like fashion, differences in the behaviours of different solar cycles lead to contrasts in parameters defining the meridional flow and initial field strength.

  16. The daily hour forecasting of the electrical energy production from renewable energy sources – a required condition for the operation of the new energy market model

    International Nuclear Information System (INIS)

    Kalpachka, Gergana; Kalpachki, Georgi

    2011-01-01

    The report presented the new energy market model in Bulgaria and the main attention is directed to a daily hour forecasting of the electrical energy production from renewable energy sources. The need of development of a methodology and the development of the most precise methods for predicting is reviewed and some of the used methods at the moment are presented. An analysis of the problems related to the daily hour forecasting is done using data from the producers of electrical energy from renewable energy sources in the territory of western Bulgaria. Keywords: Renewable energy sources, daily hour forecasting, electrical energy

  17. Assessing the Plurality of Actors and Policy Interactions: Agent-Based Modelling of Renewable Energy Market Integration

    Directory of Open Access Journals (Sweden)

    Marc Deissenroth

    2017-01-01

    Full Text Available The ongoing deployment of renewable energy sources (RES calls for an enhanced integration of RES into energy markets, accompanied by a new set of regulations. In Germany, for instance, the feed-in tariff legislation for renewables has been successively replaced by first optional and then obligatory marketing of RES on competitive wholesale markets. This paper introduces an agent-based model that allows studying the impact of changing energy policy instruments on the economic performance of RES operators and marketers. The model structure, its components, and linkages are presented in detail; an additional case study demonstrates the capability of our sociotechnical model. We find that changes in the political framework cannot be mapped directly to RES operators as behaviour of intermediary market actors has to be considered as well. Characteristics and strategies of intermediaries are thus an important factor for successful RES marketing and further deployment. It is shown that the model is able to assess the emergence and stability of market niches.

  18. Renewable energy.

    Science.gov (United States)

    Destouni, Georgia; Frank, Harry

    2010-01-01

    The Energy Committee of the Royal Swedish Academy of Sciences has in a series of projects gathered information and knowledge on renewable energy from various sources, both within and outside the academic world. In this article, we synthesize and summarize some of the main points on renewable energy from the various Energy Committee projects and the Committee's Energy 2050 symposium, regarding energy from water and wind, bioenergy, and solar energy. We further summarize the Energy Committee's scenario estimates of future renewable energy contributions to the global energy system, and other presentations given at the Energy 2050 symposium. In general, international coordination and investment in energy research and development is crucial to enable future reliance on renewable energy sources with minimal fossil fuel use.

  19. Renewables in the Midwest

    International Nuclear Information System (INIS)

    Wager, J.S.

    1994-01-01

    Over the past three years, the Union of Concerned Scientists (UCS) has evaluated the potential for using renewable energy for electricity in the Midwest, and has been carrying out a multifaceted effort to expand the use of renewables in the region. The UCS study presents a strategy for developing renewable-electric technologies and resources in 12 midwestern states. UCS analysts used a geographic information system (GIS) to create data-bases of renewable resources, land uses, vegetation cover, terrain elevation and locations of utility transmission lines, and to analyze and present information on a .6 mi x .6 mi (1 km x 1 km) grid scale. In addition, UCS developed a model to calculate the net employment impact of renewable versus conventional electricity technologies on a state-by-state basis. In evaluating the costs and benefits of renewable energy sources, UCS analysts explored a cost assessment that accounted for the impact of pollution from fossil fuels on energy resource cost. Researchers also considered the risks associated with fuel-price volatility, environmental regulation, construction lead times and other uncertainties. Finally, UCS researchers suggested steps to remove the institutional, regulatory and legislative barriers that inhibit renewable energy development, and proposed policies to expand the use of the region's renewable resources. The UCS analysis showed that wind is currently the least expensive renewable resource. UCS also found numerous opportunities to expand biomass-electric generation in the near term, such as converting small coal-fired power plants to wood fuel, making greater use of logging residues and co-firing a small percentage of biomass with fossil fuel at large power plants

  20. A new model for commercially sustainable renewable energy-based rural electrification in Indonesia

    Energy Technology Data Exchange (ETDEWEB)

    Walt, Robb [Integrated Power Corporation-Indonesia, (United states)

    1995-12-31

    Rapidly increasing demands and requirements for access to electricity throughout the remote areas of Indonesia coupled with annual subsidies in excess of $500 million of dollars for rural electrification have forced the Government of Indonesia to search for alternatives to the conventional utility model for rural electrification. In 1992-1993 a study was conducted in collaboration with the Government of Indonesia`s Agency Application and Assessment of Technology (BPPT) and the national power utility, PLN to support the search for sustainable solutions for electrification of remote communities. This study produced a New commercial model for electrification of off-grid rural communities in Indonesia with utility quality electricity services. This new model is characterized by the use of new technologies for power generation, distribution, and sales of electricity. Key to the success of the new model are renewable energy-based hybrid power plants and the use of flexible, on-demand electricity dispensing meters. Estimated fees for electricity service are based on the current amounts now being paid by rural households for kerosene, candles and battery services at different income levels. The study showed that most rural households are willing and able to pay additional amounts for reliable, utility grade electricity for valuable services, such as better lighting, TV entertainment and for productive (economic) uses during daytime hours. A financial assessment was conducted for investments in hybrid power systems for off-grid communities with revenues generated on the basis of market fees, and collected through new technology for electricity purchase and prepayment on a commodity basis. The assessment demonstrates that this approach would provide superior electricity services on a full-time basis, with little or no subsidy required during the three- to five-year commercialization phase, and with profitability as an achievable goal in the full commercial phase. [Espanol

  1. An over painted oriental arts: Evaluation of the development of the Chinese renewable energy market using the wind power market as a model

    International Nuclear Information System (INIS)

    Yu, James; Ji, Fuxing; Zhang, Ling; Chen, Yushou

    2009-01-01

    China is now the largest CO 2 polluter in the world. However, the renewable energy policies in China are controversial and one can easily draw the wrong conclusions that Chinese renewable energy development has taken off from a surface assessment of the policies. By investigating and summarizing the first-hand experiences of participation in the Chinese renewable market (mainly wind farm development) in the past five years, this paper provides another dimension of policy analysis and independent review of the current issues facing the market. An investigation of policy changes and consequences clearly demonstrates the transformation of the Chinese renewable market. The domestic manufacturing quality and unprofessional design of wind farms made most developers' financial returns unrealistic in the wind market. Despite the difficulties and inconsistency in the system, China is tackling environmental issues seriously and heading in the right direction. With centrally controlled management, the Chinese strategies do not have to be justified financially. It is envisioned by the authors that re-organizing over 70 existing Chinese wind turbine manufacturers is unavoidable. Establishment of an internal renewable market, such as Renewable Obligation Certificate (ROC) system in the UK whose effectiveness is another subject of debate, would be an effective means by which the Chinese government in their post-2012 strategy could make the wind market more financially viable. (author)

  2. Modelling renewable energy resource and the electricity network (East Midlands region)

    Energy Technology Data Exchange (ETDEWEB)

    Newton, P.A.; Ma, T.

    2002-07-01

    The UK Government's targets for renewable generation and combined heat and power (CHP) are expected to result in a significant growth in embedded generation. This report describes the results of a study of the capability of the electricity distribution network in the East Midlands to accept embedded generation. Detailed network studies were performed for two sample networks: one representing an urban network (Leicester) and one representing a rural network (Boston). The 132 kV networks of the grid groups covering these areas were also studied. This included an examination of the connection points from major 132 kV busbars at grid supply points down to 11 kV primary substations. Power system studies were performed to identify the constraints and capabilities of the existing network, These studies included load flow to examine voltage profile and overloading, fault level analysis and transient studies to examine generator and network stability following faults on the network and voltage step change due to generator tripping. Space network capacity for the region was identified and used to assess the ability to accommodate regional targets for renewables and CHP. The study also examined constraining factors and potential solutions, including four improvement scenarios.

  3. Modelling and simulation of current fed dc to dc converter for PHEV applications using renewable source

    Science.gov (United States)

    Milind Metha, Manish; Tutki, Sanjay; Rajan, Aju; Elangovan, D.; Arunkumar, G.

    2017-11-01

    With the current rate of depletion of the fossil fuel the need to switch on to the renewable energy sources is the need of the hour. Thus the need for new and efficient converters arises so as to replace the existing less efficient diesel and petroleum IC engines with renewable energy sources. The PHEVs, which have been launched in the market, and Upcoming PHEVs have converters around 380V to 400V generated with a power range between 2KW to 2.8KW. The fundamental target of this paper is to plan a productive converter keeping in mind cost and size restriction. In this paper, a two-stage dc-dc converter is proposed. The proposed converter is utilized to venture up a voltage from 24V (photovoltaic source) to a yield voltage of 400V to take care of a power demand of 2.4kW for a plug-in hybrid electric vehicle (PHEV) application considering the real time scenario of PHEV. This paper talks about in detail why the current fed converter is utilized alongside a voltage doubler thus minimizing the transformer turns thereby reducing the overall size of the final product. Simulation results along with calculation for the duty cycle of the firing sequence for different value of transformer turns are presented for a prototype unit.

  4. Enhancement of the REMix energy system model. Global renewable energy potentials, optimized power plant siting and scenario validation

    International Nuclear Information System (INIS)

    Stetter, Daniel

    2014-01-01

    As electricity generation based on volatile renewable resources is subject to fluctuations, data with high temporal and spatial resolution on their availability is indispensable for integrating large shares of renewable capacities into energy infrastructures. The scope of the present doctoral thesis is to enhance the existing energy modelling environment REMix in terms of (i.) extending the geographic coverage of the potential assessment tool REMix-EnDaT from a European to a global scale, (ii.) adding a new plant siting optimization module REMix-PlaSMo, capable of assessing siting effects of renewable power plants on the portfolio output and (iii.) adding a new alternating current power transmission model between 30 European countries and CSP electricity imports from power plants located in North Africa and the Middle East via high voltage direct current links into the module REMix-OptiMo. With respect to the global potential assessment tool, a thorough investigation is carried out creating an hourly global inventory of the theoretical potentials of the major renewable resources solar irradiance, wind speed and river discharge at a spatial resolution of 0.45°x0.45°. A detailed global land use analysis determines eligible sites for the installation of renewable power plants. Detailed power plant models for PV, CSP, wind and hydro power allow for the assessment of power output, cost per kWh and respective full load hours taking into account the theoretical potentials, technological as well as economic data. The so-obtined tool REMix-EnDaT can be used as follows: First, as an assessment tool for arbitrary geographic locations, countries or world regions, deriving either site-specific or aggregated installable capacities, cost as well as full load hour potentials. Second, as a tool providing input data such as installable capacities and hourly renewable electricity generation for further assessments using the modules REMix-PlasMo and OptiMo. The plant siting tool

  5. AN AGENT-BASED SIMULATION MODEL FOR THE ANALYSIS OF MARKET INTEGRATION OF RENEWABLE ENERGY FOR THE GERMAN ELECTRICITY MARKET

    OpenAIRE

    Reeg, Matthias; Nienhaus, Kristina; Deissenroth, Marc; Wassermann, Sandra; Hauser, Wolfgang; Klann, Uwe; Kast, Thomas

    2014-01-01

    To further ensure a successful integration of renewable energies, technical, financial and organizational aspects of the electricity system have to be redesigned. A main challenge lies in the alignment of generation and demand of energy due to the fluctuating character of renewables. Several possibilities are being discussed to align this imbalance. One possibility is the market integration of renewables by linking the generation of renewable electricity to the price signals of the energy exc...

  6. Factors Affecting Teaching the Concept of Renewable Energy In Technology Assisted Environments and Designing Processes In The Distance Education Model

    OpenAIRE

    YUCEL, A. Seda

    2007-01-01

    The energy policies of today focus mainly on sustainable energy systems and renewable energy resources. Chemistry is closely related to energy recycling, energy types, renewable energy, and nature-energy interaction; therefore, it is now an obligation to enrich chemistry classes with renewable energy concepts and related awareness. Before creating renewable energy awareness, the factors thought to affect such awareness should be determined. Knowing these factors would facilitate finding out w...

  7. Factors Affecting Teaching the Concept of Renewable Energy In Technology Assisted Environments and Designing Processes In The Distance Education Model

    OpenAIRE

    YUCEL, A. Seda

    2015-01-01

    The energy policies of today focus mainly on sustainable energy systems and renewable energy resources. Chemistry is closely related to energy recycling, energy types, renewable energy, and nature-energy interaction; therefore, it is now an obligation to enrich chemistry classes with renewable energy concepts and related awareness. Before creating renewable energy awareness, the factors thought to affect such awareness should be determined. Knowing these factors would facilitate finding out w...

  8. Modelling the future development of renewable energy technologies in the European electricity sector using agent-based simulation

    Energy Technology Data Exchange (ETDEWEB)

    Held, Anne Mirjam [Fraunhofer Institute for Systems and Innovation Research ISI, Karlsruhe (Germany)

    2011-07-01

    Increasing the share of renewable energy sources (RES) in final energy consumption forms an important part of the EU's energy and climate strategy due to the potential contribution of RES to climate protection and security of supply and to the economic competitiveness of the energy system. Several factors substantially influence the future prospects for the use of renewable energy technologies (RET); these include the combination of regionally heterogeneous resource availability and electricity generation costs, referred to as cost-resource curves. Most of the existing RET are not yet economically competitive with conventional conversion technologies. To try and make renewable energy technologies (RET) economically viable for investors, various policy support schemes, such as feed-in tariffs or quota obligations, have been applied for over a decade. This raises the questions how the use of RES will develop in the future under different policy regimes and what the involved economic implications are. A quantitative modelling tool is developed in this thesis to assess the potential long-term contribution of RET in the European power sector. Since the future market development of RET is judged to depend in particular on individual investors' decisions, an agent-based simulation (ABS) approach is chosen. ABS is an approach which analyses global complexities based on interactions on the microlevel. This thesis pursues a novel approach to assessing RET diffusion processes and policies from an agent-based perspective based on spatially explicit cost-resource curves. The cost-resource curves derived in this analysis are adapted to the requirements of a multi-agent model. Owing to the detailed techno-economic characterisation of RET and the potential to depict various policy options, the developed simulation model could help to design policies suited to the relevant agents in the renewable energy sector, or point out existing investment opportunities for interested

  9. Surface response model for quasielastic scattering

    International Nuclear Information System (INIS)

    Esbensen, H.

    1987-01-01

    The description of nucleon-nucleus inelastic scattering in terms of single-scattering has been very successful at intermediate energies. Nuclear structure is the most dominant feature at low excitations and forward scattering, and the Distorted Wave Impulse Approximation (DWIA) has been the most useful technique to extract structure information. The conventional DWIA has also been applied to quasielastic scattering. However, this method is very time-consuming at large scattering angles, since many different excitations of different multipolarities contribute to the inelastic cross section. It has therefore been useful to develop an approximate treatment that contains the main physics of quasielastic scattering. In the following the author will try to establish the connection between the DWIA and the much simpler Surface Response Model. The author will give a short description of the Random Phase Approximation that is used to calculate the nuclear response, and illustrate the spin-isospin dependence of the nucleon-nucleon t-matrix interaction, which is used to generate the excitations of the target nucleus. Finally, some of the applications of the surface response model to (p,p'), (p,n) and ( 3 H,t) reactions are reviewed. 19 refs., 5 figs

  10. Bioadhesion to model thermally responsive surfaces

    Science.gov (United States)

    Andrzejewski, Brett Paul

    This dissertation focuses on the characterization of two surfaces: mixed self-assembled monolayers (SAMs) of hexa(ethylene glycol) and alkyl thiolates (mixed SAM) and poly(N-isopropylacrylamide) (PNIPAAm). The synthesis of hexa(ethylene gylcol) alkyl thiol (C11EG 6OH) is presented along with the mass spectrometry and nuclear magnetic resonance results. The gold substrates were imaged prior to SAM formation with atomic force micrscopy (AFM). Average surface roughness of the gold substrate was 0.44 nm, 0.67 nm, 1.65 nm for 15, 25 and 60 nm gold thickness, respectively. The height of the mixed SAM was measured by ellipsometry and varied from 13 to 28°A depending on surface mole fraction of C11EG6OH. The surface mole fraction of C11EG6OH for the mixed SAM was determined by X-ray photoelectron spectroscopy (XPS) with optimal thermal responsive behavior in the range of 0.4 to 0.6. The mixed SAM surface was confirmed to be thermally responsive by contact angle goniometry, 35° at 28°C and ˜55° at 40°C. In addition, the mixed SAM surfaces were confirmed to be thermally responsive for various aqueous mediums by tensiometry. Factors such as oxygen, age, and surface mole fraction and how they affect the thermal responsive of the mixed SAM are discussed. Lastly, rat fibroblasts were grown on the mixed SAM and imaged by phase contrast microscopy to show inhibition of attachment at temperatures below the molecular transition. Qualitative and quantitative measurements of the fibroblast adhesion data are provided that support the hypothesis of the mixed SAM exhibits a dominantly non-fouling molecular conformation at 25°C whereas it exhibits a dominantly fouling molecular conformation at 40°C. The adhesion of six model proteins: bovine serum albumin, collagen, pyruvate kinase, cholera toxin subunit B, ribonuclease, and lysozyme to the model thermally responsive mixed SAM were examined using AFM. All six proteins possessed adhesion to the pure component alkyl thiol, in

  11. Renewable energy

    DEFF Research Database (Denmark)

    Olsen, Birgitte Egelund

    2016-01-01

    Renewable energy projects are increasingly confronted by local opposition, which delays and sometimes even prevents their implementation. This reflects the frequent gap between support for the general idea of renewables as a strategy for reducing carbon emissions, and acceptance of renewable energy...... installations in the local landscape. A number of countries have introduced financial incentives to promote community acceptance. The tool box of incentives is still limited but in recent years it has been expanded to address local concerns. Certain general characteristics can be identified, suggesting...... that there are at least three distinct categories of incentives: individual compensation, community benefits and ownership measures. Local opposition must be approached with caution, as financial incentives to promote local acceptance can be seen as buying consent or even ‘bribery’, stirring up further opposition....

  12. MERGING DIGITAL SURFACE MODELS IMPLEMENTING BAYESIAN APPROACHES

    Directory of Open Access Journals (Sweden)

    H. Sadeq

    2016-06-01

    Full Text Available In this research different DSMs from different sources have been merged. The merging is based on a probabilistic model using a Bayesian Approach. The implemented data have been sourced from very high resolution satellite imagery sensors (e.g. WorldView-1 and Pleiades. It is deemed preferable to use a Bayesian Approach when the data obtained from the sensors are limited and it is difficult to obtain many measurements or it would be very costly, thus the problem of the lack of data can be solved by introducing a priori estimations of data. To infer the prior data, it is assumed that the roofs of the buildings are specified as smooth, and for that purpose local entropy has been implemented. In addition to the a priori estimations, GNSS RTK measurements have been collected in the field which are used as check points to assess the quality of the DSMs and to validate the merging result. The model has been applied in the West-End of Glasgow containing different kinds of buildings, such as flat roofed and hipped roofed buildings. Both quantitative and qualitative methods have been employed to validate the merged DSM. The validation results have shown that the model was successfully able to improve the quality of the DSMs and improving some characteristics such as the roof surfaces, which consequently led to better representations. In addition to that, the developed model has been compared with the well established Maximum Likelihood model and showed similar quantitative statistical results and better qualitative results. Although the proposed model has been applied on DSMs that were derived from satellite imagery, it can be applied to any other sourced DSMs.

  13. Model project to promote cultivation and utilization of renewable resources. Modellvorhaben zur Foerderung des Anbaus und der Verwertung nachwachsender Rohstoffe

    Energy Technology Data Exchange (ETDEWEB)

    1991-09-01

    This revised report on the model projects presents individual projects and measures complementary to each other, documenting, in their totality, an advanced state of development. Moreover it shows the following: that the basic challenge of a model project, especially in the field of the energetic use of biomass, can be met by marrying agriculture to power utilities. So, projects are under way where cultivation of China reed and its utilization in power-and-heat cogeneration plants will, in the future, complement each other. Further questions that are not represented in the research programme of Lower Saxonia are dealt with at the federal level, so that the field of renewable resurces may currently be considered as comprehensively covered. (orig./EF).

  14. The Optimization Model for Interregional Power System Planning considering Carbon Emissions Trading and Renewable Energy Quota Mechanism

    Directory of Open Access Journals (Sweden)

    Liwei Ju

    2016-01-01

    Full Text Available In China, the rapid construction of ultra-high-voltage (UHV transmission lines promotes interregional resource optimizing configuration and interregional power system planning. This paper analyzes external environment of interregional power system planning from geographical, technical, and policy environments. Then, the paper takes the minimum system investment cost as the optimization objective and constructs the optimization model of interregional power system planning considering carbon emissions trading (CET and renewable energy quota mechanism (REQ. Finally, this paper sets base scenario, carbon emissions trading scenario, renewable energy quota mechanism scenario, and comprehensive scenario for case simulation. The results show that interregional power system planning could connect power grids in different regions, enlarge wind power consumption space, and relieve the inconformity problem between power resource and load demand. CET and REQ can increase the installed proportion of clean energy and reduce carbon dioxide emissions, but the cost of transmission lines construction and system reserve will increase correspondingly. The optimization effect of REQ on power system planning is better than CET. When they are both introduced, the power structure will reach the best, carbon dioxide emissions will achieve the minimum, and comprehensive benefits will become more balanced.

  15. Social renewal

    NARCIS (Netherlands)

    A.W. van der Pennen; V. Veldheer; E. ter Borg; M. Kunst; J. Boelhouwer; F.A. Knol

    1998-01-01

    Original title: Sociale vernieuwing. Social renewal began in Rotterdam in 1989, as a response to the presence of stubborn social disadvantage. The Idenburg Committee produced recommendations in that year suggesting how these social problems could best be tackled at local level. Central

  16. Renewable Energy

    NARCIS (Netherlands)

    Turkenburg, W.C.; Arent, D.; Bertani, R.; Faaij, A.P.C.; Hand, M.; Krewitt, W.; Larson, E.D.; Lund, J.; Mehos, M.; Merrigan, T.; Mitchell, C.; Moreira, J.R.; Sinke, W.C.; Sonntag-O'Brien, V.; Thresher, B.; Sark, W.G.J.H.M. van; Usher, E.

    2012-01-01

    This chapter presents an in-depth examination of major renewable energy technologies, including their installed capacity and energy supply in 2009 , the current state of market and technology development, their economic and financial feasibility in 2009 and in the near future, as well as major

  17. Optimal model of congestion management in deregulated environment of power sector with promotion of renewable energy sources

    International Nuclear Information System (INIS)

    Sood, Yog Raj; Singh, Randhir

    2010-01-01

    In the competitive electricity market it becomes very much important to give special consideration for development of renewable energy sources (RESs) due to environmental and other social problems related with conventional generations. So this paper presents an optimal model of congestion management with special emphasis for promotion of RES in competitive electricity market. This paper presents a generalized optimal model of congestion management for deregulated power sector that dispatches the pool in combination with privately negotiated bilateral and multilateral contracts while maximizing social benefit. This model determines the locational marginal pricing (LMP) based on marginal cost theory. It also determines the size of non-firm transactions as well as pool demand and generations. Both firms as well as non-firm transactions are considered in this model. The proposed model has been applied to IEEE-30 bus test system with addition of some RES for analysis of the proposed model. The RES supplies its power to load either through the firm transaction or through power pool. The power from RES is not subjected to any curtailment in proposed model of congestion management. (author)

  18. Renewable Diesel from Algal Lipids: An Integrated Baseline for Cost, Emissions, and Resource Potential from a Harmonized Model

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.; Fishman, D.; Frank, E. D.; Wigmosta, M. S.; Aden, A.; Coleman, A. M.; Pienkos, P. T.; Skaggs, R. J.; Venteris, E. R.; Wang, M. Q.

    2012-06-01

    The U.S. Department of Energy's Biomass Program has begun an initiative to obtain consistent quantitative metrics for algal biofuel production to establish an 'integrated baseline' by harmonizing and combining the Program's national resource assessment (RA), techno-economic analysis (TEA), and life-cycle analysis (LCA) models. The baseline attempts to represent a plausible near-term production scenario with freshwater microalgae growth, extraction of lipids, and conversion via hydroprocessing to produce a renewable diesel (RD) blendstock. Differences in the prior TEA and LCA models were reconciled (harmonized) and the RA model was used to prioritize and select the most favorable consortium of sites that supports production of 5 billion gallons per year of RD. Aligning the TEA and LCA models produced slightly higher costs and emissions compared to the pre-harmonized results. However, after then applying the productivities predicted by the RA model (13 g/m2/d on annual average vs. 25 g/m2/d in the original models), the integrated baseline resulted in markedly higher costs and emissions. The relationship between performance (cost and emissions) and either productivity or lipid fraction was found to be non-linear, and important implications on the TEA and LCA results were observed after introducing seasonal variability from the RA model. Increasing productivity and lipid fraction alone was insufficient to achieve cost and emission targets; however, combined with lower energy, less expensive alternative technology scenarios, emissions and costs were substantially reduced.

  19. A surface hydrology model for regional vector borne disease models

    Science.gov (United States)

    Tompkins, Adrian; Asare, Ernest; Bomblies, Arne; Amekudzi, Leonard

    2016-04-01

    Small, sun-lit temporary pools that form during the rainy season are important breeding sites for many key mosquito vectors responsible for the transmission of malaria and other diseases. The representation of this surface hydrology in mathematical disease models is challenging, due to their small-scale, dependence on the terrain and the difficulty of setting soil parameters. Here we introduce a model that represents the temporal evolution of the aggregate statistics of breeding sites in a single pond fractional coverage parameter. The model is based on a simple, geometrical assumption concerning the terrain, and accounts for the processes of surface runoff, pond overflow, infiltration and evaporation. Soil moisture, soil properties and large-scale terrain slope are accounted for using a calibration parameter that sets the equivalent catchment fraction. The model is calibrated and then evaluated using in situ pond measurements in Ghana and ultra-high (10m) resolution explicit simulations for a village in Niger. Despite the model's simplicity, it is shown to reproduce the variability and mean of the pond aggregate water coverage well for both locations and validation techniques. Example malaria simulations for Uganda will be shown using this new scheme with a generic calibration setting, evaluated using district malaria case data. Possible methods for implementing regional calibration will be briefly discussed.

  20. Energy system modelling – interactions and synergies in a highly renewable Pan-European power system

    Directory of Open Access Journals (Sweden)

    Weitemeyer Stefan

    2014-01-01

    Full Text Available It is very likely that the European power supply system will be transformed in the next decades to a low carbon system based almost entirely on Renewable Energy Sources (RES. However, due to the natural fluctuations of the most powerful RES (wind and solar energy, it is also very likely that a significant amount of balancing and controllable backup power capacities will be required to ensure a stable grid operation. This implies high additional investments and operating costs. Therefore this work provides an overview of potential options and possibly more cost-effective alternatives to the installation of costly storage capacities, namely grid expansion, demand side management, an optimised mix between different RES as well as the use of overcapacities. Furthermore, the paper provides an approximation of the maximum RES penetration of the German electricity system in the absence of significant storage capacities. Our calculations show that from a numerical perspective on average approximately half of the load can be met by RES if flexible conventional power stations would provide the remaining electricity demand. However, in a 100% RES scenario a significant amount of storage capacities as well as limited overcapacities are required to ensure a reliable electricity supply.

  1. Spatiotemporal Modeling for Assessing Complementarity of Renewable Energy Sources in Distributed Energy Systems

    Science.gov (United States)

    Ramirez Camargo, L.; Zink, R.; Dorner, W.

    2015-07-01

    Spatial assessments of the potential of renewable energy sources (RES) have become a valuable information basis for policy and decision-making. These studies, however, do not explicitly consider the variability in time of RES such as solar energy or wind. Until now, the focus is usually given to economic profitability based on yearly balances, which do not allow a comprehensive examination of RES-technologies complementarity. Incrementing temporal resolution of energy output estimation will permit to plan the aggregation of a diverse pool of RES plants i.e., to conceive a system as a virtual power plant (VPP). This paper presents a spatiotemporal analysis methodology to estimate RES potential of municipalities. The methodology relies on a combination of open source geographic information systems (GIS) processing tools and the in-memory array processing environment of Python and NumPy. Beyond the typical identification of suitable locations to build power plants, it is possible to define which of them are the best for a balanced local energy supply. A case study of a municipality, using spatial data with one square meter resolution and one hour temporal resolution, shows strong complementarity of photovoltaic and wind power. Furthermore, it is shown that a detailed deployment strategy of potential suitable locations for RES, calculated with modest computational requirements, can support municipalities to develop VPPs and improve security of supply.

  2. SPATIOTEMPORAL MODELING FOR ASSESSING COMPLEMENTARITY OF RENEWABLE ENERGY SOURCES IN DISTRIBUTED ENERGY SYSTEMS

    Directory of Open Access Journals (Sweden)

    L. Ramirez Camargo

    2015-07-01

    Full Text Available Spatial assessments of the potential of renewable energy sources (RES have become a valuable information basis for policy and decision-making. These studies, however, do not explicitly consider the variability in time of RES such as solar energy or wind. Until now, the focus is usually given to economic profitability based on yearly balances, which do not allow a comprehensive examination of RES-technologies complementarity. Incrementing temporal resolution of energy output estimation will permit to plan the aggregation of a diverse pool of RES plants i.e., to conceive a system as a virtual power plant (VPP. This paper presents a spatiotemporal analysis methodology to estimate RES potential of municipalities. The methodology relies on a combination of open source geographic information systems (GIS processing tools and the in-memory array processing environment of Python and NumPy. Beyond the typical identification of suitable locations to build power plants, it is possible to define which of them are the best for a balanced local energy supply. A case study of a municipality, using spatial data with one square meter resolution and one hour temporal resolution, shows strong complementarity of photovoltaic and wind power. Furthermore, it is shown that a detailed deployment strategy of potential suitable locations for RES, calculated with modest computational requirements, can support municipalities to develop VPPs and improve security of supply.

  3. A Linear Regression Model for Global Solar Radiation on Horizontal Surfaces at Warri, Nigeria

    Directory of Open Access Journals (Sweden)

    Michael S. Okundamiya

    2013-10-01

    Full Text Available The growing anxiety on the negative effects of fossil fuels on the environment and the global emission reduction targets call for a more extensive use of renewable energy alternatives. Efficient solar energy utilization is an essential solution to the high atmospheric pollution caused by fossil fuel combustion. Global solar radiation (GSR data, which are useful for the design and evaluation of solar energy conversion system, are not measured at the forty-five meteorological stations in Nigeria. The dearth of the measured solar radiation data calls for accurate estimation. This study proposed a temperature-based linear regression, for predicting the monthly average daily GSR on horizontal surfaces, at Warri (latitude 5.020N and longitude 7.880E an oil city located in the south-south geopolitical zone, in Nigeria. The proposed model is analyzed based on five statistical indicators (coefficient of correlation, coefficient of determination, mean bias error, root mean square error, and t-statistic, and compared with the existing sunshine-based model for the same study. The results indicate that the proposed temperature-based linear regression model could replace the existing sunshine-based model for generating global solar radiation data. Keywords: air temperature; empirical model; global solar radiation; regression analysis; renewable energy; Warri

  4. Describing high-dimensional dynamics with low-dimensional piecewise affine models: applications to renewable energy.

    Science.gov (United States)

    Hirata, Yoshito; Aihara, Kazuyuki

    2012-06-01

    We introduce a low-dimensional description for a high-dimensional system, which is a piecewise affine model whose state space is divided by permutations. We show that the proposed model tends to predict wind speeds and photovoltaic outputs for the time scales from seconds to 100 s better than by global affine models. In addition, computations using the piecewise affine model are much faster than those of usual nonlinear models such as radial basis function models.

  5. A Kolmogorov-Brutsaert Structure Function Model for Evaporation from a Rough Surface into a Turbulent Atmosphere

    Science.gov (United States)

    Katul, Gabriel; Liu, Heping

    2017-04-01

    In his 1881 acceptance letter of the Rumford Medal, Gibbs declared that "One of the principal objects of theoretical research is to find the point of view from which the subject appears in the greatest simplicity". Guided by this quotation, the subject of evaporation into the atmosphere from rough surfaces by turbulence offered in a 1965 study by Brutsaert is re-examined. Brutsaert proposed a model that predicted mean evaporation rate E from rough surfaces to scale with the 3/4 power-law of the friction velocity (u∗) and the square-root of molecular diffusivity (Dm) for water vapor. This result was supported by a large corpus of experiments and spawned a number of studies on inter-facial transfer of scalars, evaporation from porous media at single and multiple pore scales, bulk evaporation from bare soil surfaces, as well as isotopic fractionation in hydrological applications. It also correctly foreshadowed the much discussed 1/4 'universal' scaling of liquid transfer coefficients of sparingly soluble gases in air-sea exchange studies. In arriving at these results, a number of assumptions were made regarding the surface renewal rate describing the contact durations between eddies and the evaporating surface, the diffusional mass process from the surface into eddies, and the cascade of turbulent kinetic energy sustaining the eddy renewal process itself. The anzats explored here is that E ˜√Dm-u∗3/4 is a direct outcome of the Kolmogorov scaling for inertial subrange eddies modified to include viscous-cutoff thereby by-passing the need for a surface renewal assumption. It is demonstrated that Brutsaert's model for E may be more general than its original derivation assumed. Extensions to canopy surfaces as well as other scalars with different molecular Schmidt numbers are also featured.

  6. A State-Based Approach to Building a Liquid National Market for Renewable Energy Certificates: The REC-EX Model

    International Nuclear Information System (INIS)

    Berendt, Christopher B.

    2006-01-01

    RECs are the currency driving the growth of renewable energy markets and the sale of RECs from renewable energy generation projects could promise a predictable return. But the existing REC markets in the U.S. sorely lack the liquidity needed to make good on that promise. The author proposes a Renewable Energy Certificate Exchange program rooted in the construction of a national trading platform for RECs in tandem with the execution of a new agreement among the states with REC-based renewable portfolio standards. (author)

  7. New renewables - a business challenge

    International Nuclear Information System (INIS)

    Jochum, G.

    2004-01-01

    This article takes a look at the increased use of renewable forms of energy and, in particular, the so-called 'new renewables' that are the subject of discussion in Europe and Switzerland. The wide divergence between the political and economical viewpoints concerning renewables is examined and the question is posed on how political desires and economical sense can be brought closer together. Questions concerning the public acceptance of various forms of energy are looked at and the expectations placed on renewable forms of energy are commented on. Criteria for models of promotion are listed including CO 2 emissions, technology and cost efficiency, marketing aspects and flexibility. Also, aspects concerning plausibility, fairness and responsibility are looked at. A model named 'Swiss Renewables Model' is proposed and its efficiency, functionality and financing are discussed

  8. RIPPLE: A new model for incompressible flows with free surfaces

    Science.gov (United States)

    Kothe, D. B.; Mjolsness, R. C.

    1991-09-01

    A new free surface flow model, RIPPLE, is summarized. RIPPLE obtains finite difference solutions for incompressible flow problems having strong surface tension forces at free surfaces of arbitrarily complex topology. The key innovation is the Continuum Surface Force (CSF) model which represents surface tension as a (strongly) localized volume force. Other features include a high-order momentum advection model, a volume-of-fluid free surface treatment, and an efficient two-step projection solution method. RIPPLE'S unique capabilities are illustrated with two example problems: low-gravity jet-induced tank flow, and the collision and coalescence of two cylindrical rods.

  9. RIPPLE - A new model for incompressible flows with free surfaces

    Science.gov (United States)

    Kothe, D. B.; Mjolsness, R. C.

    1991-09-01

    A new free surface flow model, RIPPLE, is summarized. RIPPLE obtains finite difference solutions for incompressible flow problems having strong surface tension forces at free surfaces of arbitrarily complex topology. The key innovation is the continuum surface force model which represents surface tension as a (strongly) localized volume force. Other features include a higher-order momentum advection model, a volume-of-fluid free surface treatment, and an efficient two-step projection solution method. RIPPLE's unique capabilities are illustrated with two example problems: low-gravity jet-induced tank flow, and the collision and coalescence of two cylindrical rods.

  10. Modeling and Simulation of Renewable Hybrid Power System using Matlab Simulink Environment

    OpenAIRE

    Cristian Dragoş Dumitru; Adrian Gligor

    2010-01-01

    The paper presents the modeling of a solar-wind-hydroelectric hybrid system in Matlab/Simulink environment. The application is useful for analysis and simulation of a real hybrid solar-wind-hydroelectric system connected to a public grid. Application is built on modular architecture to facilitate easy study of each component module influence. Blocks like wind model, solar model, hydroelectric model, energy conversion and load are implemented and the results of simulation are also presented. A...

  11. Comment on 'Modelling of surface energies of elemental crystals'

    International Nuclear Information System (INIS)

    Li Jinping; Luo Xiaoguang; Hu Ping; Dong Shanliang

    2009-01-01

    Jiang et al (2004 J. Phys.: Condens. Matter 16 521) present a model based on the traditional broken-bond model for predicting surface energies of elemental crystals. It is found that bias errors can be produced in calculating the coordination numbers of surface atoms, especially in the prediction of high-Miller-index surface energies. (comment)

  12. An Improved Interval Fuzzy Modeling Method: Applications to the Estimation of Photovoltaic/Wind/Battery Power in Renewable Energy Systems

    Directory of Open Access Journals (Sweden)

    Nguyen Gia Minh Thao

    2018-02-01

    Full Text Available This paper proposes an improved interval fuzzy modeling (imIFML technique based on modified linear programming and actual boundary points of data. The imIFML technique comprises four design stages. The first stage is based on conventional interval fuzzy modeling (coIFML with first-order model and linear programming. The second stage defines reference lower and upper bounds of data using MATLAB. The third stage initially adjusts scaling parameters in the modified linear programming. The last stage automatically fine-tunes parameters in the modified linear programming to realize the best possible model. Lower and upper bounds approximated by the imIFML technique are closely fitted to the reference lower and upper bounds, respectively. The proposed imIFML is thus significantly less conservative in cases of large variation in data, while robustness is inherited from the coIFML. Design flowcharts, equations, and sample MATLAB code are presented for reference in future experiments. Performance and efficacy of the introduced imIFML are evaluated to estimate solar photovoltaic, wind and battery power in a demonstrative renewable energy system under large data changes. The effectiveness of the proposed imIFML technique is also compared with the coIFML technique.

  13. Developing a green lending model for renewable energy project (case study electricity from biogas fuel at Palm Oil Industry)

    Science.gov (United States)

    Sukirman, Y. A.

    2018-03-01

    In the last two decades, development initiatives solely aimed to generate economic growth has been placed under scrutiny, particularly amidst the rampant discussion on the quality decline of the environment, growing social divide and climate change along with its implications thereof. Considerations of the negative impacts brought about by the economic development process prompted the move to adopt the sustainable financing model that gives precedence to economic, environmental and social aspects. We introduced Green Lending Model for Renewable Energy Project (Case Study Electricity From Biogas at Palm Oil Industry) based on sustainability financing, which is used as variable to implementing financial institutions’ lending policies. There are two major trends in the literature relating to sustainability and the banking industry: external and internal practices. The external practices strand analyzes the relevance of sustainability to the bank’s communication with shareholders and other stakeholders, and how investors use it as a measure to help achieve optimal portfolio allocation. The internal practices literature, more relevant to the present work, studies how sustainability criteria are integrated into risk management models and lending practices. Its first implementation is in the Palm Oil industry at South Sumatera. The results explained that sustainability is not related to profit either from a short- or long-term perspective. The Sustainable Green Lending Model is related to the Equator Principles and its application is driven to project financing. It also related with short- and long-term risks and opportunities, instead of short-term sustainability impacts.

  14. Estimation and asymptotic theory for transition probabilities in markov renewal multi-state models

    NARCIS (Netherlands)

    Spitoni, Cristian|info:eu-repo/dai/nl/304625957; Verduijn, Marion; Putter, Hein

    2014-01-01

    In this paper we discuss estimation of transition probabilities for semi-Markov multi-state models. Non-parametric and semi-parametric estimators of the transition probabilities for a large class of models (forward going models) are proposed. Large sample theory is derived using the functional delta

  15. Surface CUrrents from a Diagnostic model (SCUD): Pacific

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The SCUD data product is an estimate of upper-ocean velocities computed from a diagnostic model (Surface CUrrents from a Diagnostic model). This model makes daily...

  16. Surface and near-surface hydrological model of Olkiluoto island

    International Nuclear Information System (INIS)

    Karvonen, T.

    2008-04-01

    The aim of the study was to develop a 3D-model that calculates the overall water balance components of Olkiluoto Island in the present-day condition utilizing the existing extensive data sets available. The model links the unsaturated and saturated soil water in the overburden and groundwater in bedrock to a continuous pressure system. The parameterization of land use and vegetation was done in such a way that the model can later on be used for description of the past evolution of the overburden hydrology at the site and overburden's hydrological evolution in the future. Measured groundwater level in overburden tubes, pressure heads in shallow bedrock holes, snow depth, soil temperature, frost depth and discharge measurements were used in assessing the performance of the models in the calibration period (01.05.2001- 31.12.2005). Computed groundwater level variation can be characterized by variables ΔH MEAS and ΔH COMP , which are the difference between maximum and minimum measured and computed groundwater level value during the calibration period. Average ΔH MEAS for all tubes located in fine-textured till soil was 1.99 m and the corresponding computed value ΔH COMP was 1.83 m. Average ΔH MEAS for all tubes located in sandy till soil was 2.12 m and the corresponding computed value ΔH COMP was 1.93 m. The computed results indicate that in future studies it is necessary to divide the two most important soil types into several subclasses. In the present study the uncertainty and sensitivity analysis was carried out through a parameter uncertainty framework known as GLUE. According to the uncertainty analysis the average yearly runoff was around 175 mm a -1 and 50 % confidence limits were 155 and 195 mm a -1 . Measured average yearly runoff during the calibration period was 190 mm a -1 . Average yearly evapotranspiration estimate was 310 mm a -1 and the 50 % confidence limits were 290 and 330 mm a -1 . Average value for recharge through the bedrock system was 1

  17. Potential Teaching Model for Applying Novel Approaches of Renewed Estonian National Curriculum into Visual Art Classes in Primary School

    Science.gov (United States)

    Vahter, Edna

    2015-01-01

    In 2010, the renewed national curriculum was legislated in Estonia. Major changes include a new list of cross-curricular topics, increased importance of integration and specification of the components of the art learning process. In this situation, the question arises--how to fully implement the challenges of the renewed curriculum in primary…

  18. Multiwalled Carbon Nanotube Deposition on Model Environmental Surfaces

    Science.gov (United States)

    Deposition of multiwalled carbon nanotubes (MWNTs) on model environmental surfaces was investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D). Deposition behaviors of MWNTs on positively and negatively charged surfaces were in good agreement with Der...

  19. Modeling sea-surface temperature and its variability

    Science.gov (United States)

    Sarachik, E. S.

    1985-01-01

    A brief review is presented of the temporal scales of sea surface temperature variability. Progress in modeling sea surface temperature, and remaining obstacles to the understanding of the variability is discussed.

  20. A non-autonomous optimal control model of renewable energy production under the aspect of fluctuating supply and learning by doing.

    Science.gov (United States)

    Moser, Elke; Grass, Dieter; Tragler, Gernot

    Given the constantly raising world-wide energy demand and the accompanying increase in greenhouse gas emissions that pushes the progression of climate change, the possibly most important task in future is to find a carbon-low energy supply that finds the right balance between sustainability and energy security. For renewable energy generation, however, especially the second aspect turns out to be difficult as the supply of renewable sources underlies strong volatility. Further on, investment costs for new technologies are so high that competitiveness with conventional energy forms is hard to achieve. To address this issue, we analyze in this paper a non-autonomous optimal control model considering the optimal composition of a portfolio that consists of fossil and renewable energy and which is used to cover the energy demand of a small country. While fossil energy is assumed to be constantly available, the supply of the renewable resource fluctuates seasonally. We further on include learning effects for the renewable energy technology, which will underline the importance of considering the whole life span of such a technology for long-term energy planning decisions.

  1. Renewable energy: Renewing the environment

    Energy Technology Data Exchange (ETDEWEB)

    Noun, R.J. [National Renewable Energy Lab., Golden, CO (United States)

    1996-12-31

    During the past 20 years, the United States has enacted some of the world`s most comprehensive legislation to protect and preserve its environmental heritage. These regulations have spawned a $115-billion-per-year industry for {open_quotes}green{close_quotes} products and services, with more than 35,000 companies providing jobs for American workers. On the other hand, environmental regulations have placed heavy cost burdens on many U.S. businesses as they struggle to remain competitive in both domestic and foreign markets. How, then, can one reconcile the growing need for environmental protection with the desire for a stronger, healthier economy? Even as Congress debates the value of existing environmental legislation, new threats are appearing on the horizon. For example, extensive storm damage from Hurricane Andrew and other natural disasters has prompted members of the $650-billion insurance industry to begin studying the effects that global warming may have on future property damage claims. More and more people are realizing that the most efficient and economical way to control pollution is to avoid creating it in the first place. And that`s where renewable energy comes in. Technologies based on nonpolluting renewable energy sources such as sunlight and wind can help preserve our environmental heritage without a tangled web of regulations to burden industry. Renewable energy technologies can also help the United States become a world leader in a potential $400-billion-a-year global market for environmentally friendly products.

  2. Utilisation of real-scale renewable energy test facility for validation of generic wind turbine and wind power plant controller models

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Gevorgian, Vahan; Wallen, Robb

    2016-01-01

    This article presents an example of application of a modern test facility conceived for experiments regarding the integration of renewable energy in the power system. The capabilities of the test facility are used to validate dynamic simulation models of wind power plants and their controllers...

  3. Analysis, Design, Modeling, and Control of an Interleaved-Boost Full-Bridge Three-Port Converter for Hybrid Renewable Energy Systems

    DEFF Research Database (Denmark)

    Mira Albert, Maria del Carmen; Zhang, Zhe; Knott, Arnold

    2017-01-01

    This paper presents the design, modeling, and control of an isolated dc-dc three-port converter (TPC) based on an interleaved-boost full-bridge converter with pulsewidth modulation (PWM) and phase-shift control for hybrid renewable energy systems. In the proposed topology, the switches are driven...

  4. Sustainable use of renewable resources in a stylized social-ecological network model under heterogeneous resource distribution

    Science.gov (United States)

    Barfuss, Wolfram; Donges, Jonathan F.; Wiedermann, Marc; Lucht, Wolfgang

    2017-04-01

    Human societies depend on the resources ecosystems provide. Particularly since the last century, human activities have transformed the relationship between nature and society at a global scale. We study this coevolutionary relationship by utilizing a stylized model of private resource use and social learning on an adaptive network. The latter process is based on two social key dynamics beyond economic paradigms: boundedly rational imitation of resource use strategies and homophily in the formation of social network ties. The private and logistically growing resources are harvested with either a sustainable (small) or non-sustainable (large) effort. We show that these social processes can have a profound influence on the environmental state, such as determining whether the private renewable resources collapse from overuse or not. Additionally, we demonstrate that heterogeneously distributed regional resource capacities shift the critical social parameters where this resource extraction system collapses. We make these points to argue that, in more advanced coevolutionary models of the planetary social-ecological system, such socio-cultural phenomena as well as regional resource heterogeneities should receive attention in addition to the processes represented in established Earth system and integrated assessment models.

  5. Surfaces foliated by planar geodesics: a model forcurved wood design

    DEFF Research Database (Denmark)

    Brander, David; Gravesen, Jens

    2017-01-01

    Surfaces foliated by planar geodesics are a natural model for surfaces made from wood strips. We outline how to construct all solutions, and produce non-trivial examples, such as a wood-strip Klein bottle......Surfaces foliated by planar geodesics are a natural model for surfaces made from wood strips. We outline how to construct all solutions, and produce non-trivial examples, such as a wood-strip Klein bottle...

  6. Modelling and simulation of surface water waves

    NARCIS (Netherlands)

    van Groesen, Embrecht W.C.; Westhuis, J.H.

    2002-01-01

    The evolution of waves on the surface of a layer of fluid is governed by non-linear effects from surface deformations and dispersive effects from the interaction with the interior fluid motion. Several simulation tools are described in this paper and compared with real life experiments in large

  7. Sustainable energy for the future. Modelling transitions to renewable and clean energy in rapidly developing countries.

    NARCIS (Netherlands)

    Urban, Frauke

    2009-01-01

    The main objective of this thesis is first to adapt energy models for the use in developing countries and second to model sustainable energy transitions and their effects in rapidly developing countries like China and India. The focus of this thesis is three-fold: a) to elaborate the differences

  8. Precise large deviations of aggregate claims in a size-dependent renewal risk model with stopping time claim-number process

    Directory of Open Access Journals (Sweden)

    Shuo Zhang

    2017-04-01

    Full Text Available Abstract In this paper, we consider a size-dependent renewal risk model with stopping time claim-number process. In this model, we do not make any assumption on the dependence structure of claim sizes and inter-arrival times. We study large deviations of the aggregate amount of claims. For the subexponential heavy-tailed case, we obtain a precise large-deviation formula; our method substantially relies on a martingale for the structure of our models.

  9. A comparison of nuclear and renewable power plants with an AHP model: The case of Turkey

    International Nuclear Information System (INIS)

    Kara, Y.; Koene, C.

    2009-01-01

    Various selection criteria can be taken into account in determination of fuel mix by giving different priorities. In this paper, we present a multiple criteria decision-making model to evaluate five types of power plants -namely solar, wind, geothermal, biomass and nuclear power plants- for electricity generation in Turkey by means of Analytical Hierarchy Process (AHP). The proposed model implemented two alternative scenarios; each gives different relative importance to the control criteria (production costs, external costs, national and international acceptance) in the model. Under all alternative scenarios of our model, the highest value alternative is nuclear power plants. The share of nuclear energy is in the range of 36% - 32% in our model results although nuclear energy is not available yet. The calculated percentage of wind and solar power plants are 24% and 29% for Scenario 1 and 17% and 16% for Scenario 2 respectively.

  10. A Review of Models for Dose Assessment Employed by SKB in the Renewed Safety Assessment for SFR 1

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, George [Imperial College of Science Technology and Medicine (United Kingdom)

    2002-09-01

    This document provides a critical review, on behalf of SSI, of the models employed by the Swedish Nuclear Fuel and Waste Management Co (SKB) for dose assessment in the renewed safety assessment for the final repository for radioactive operational waste (SFR 1) in Forsmark, Sweden. The main objective of the review is to examine the models used by SKB for radiological dose assessment in a series of evolving biotopes in the vicinity of the Forsmark repository within a time frame beginning in 3000 AD and extending beyond 7500 AD. Five biosphere models (for coasts, lakes, agriculture, mires and wells) are described in Report TR-01-04. The principal consideration of the review is to determine whether these models are fit for the purpose of dose evaluation over the time frames involved and in the evolving sequence of biotopes specified. As well as providing general observations and comments on the modelling approach taken, six specific questions are addressed, as follows. Are the assumptions underlying the models justifiable? Are all reasonably foreseeable environmental processes considered? Has parameter uncertainty been sufficiently and reasonably addressed? Have sufficient models been used to address all reasonably foreseeable biotopes? Are the transitions between biotopes modelled adequately (specifically, are initial conditions for developing biotopes adequately specified by calculations for subsiding biotopes)? Have all critical radionuclides been identified? It is concluded that, in general, the assumptions underlying most of the models are justifiable. The exceptions are a) the rather simplistic approach taken in the Coastal Model and b) the lack of consideration of wild foods and age-dependence when calculating exposures of humans to radionuclides via dietary pathways. Most foreseeable processes appear to have been accounted for within the constraints of the models used, although it is recommended that attention be paid to future climate states when considering

  11. Modelling of energetic molecule-surface interactions

    International Nuclear Information System (INIS)

    Kerford, M.

    2000-09-01

    This thesis contains the results of molecular dynamics simulations of molecule-surface interactions, looking particularly at fullerene molecules and carbon surfaces. Energetic impacts of fullerene molecules on graphite create defect craters. The relationship between the parameters of the impacting molecule and the parameters of the crater axe examined and found to be a function of the energy and velocity of the impacting molecule. Less energetic fullerene molecules can be scattered from a graphite surface and the partitioning of energy after a scattering event is investigated. It is found that a large fraction of the kinetic energy retained after impact is translational energy, with a small fraction of rotational energy and a number of vibrational modes. At impact energies where the surface is not broken and at normal incidence, surface waves axe seen to occur. These waves axe used to develop a method of desorbing molecules from a graphite surface without damage to either the surface or the molecules being desorbed. A number of fullerene molecules are investigated and ways to increase the desorption yield are examined. It is found that this is a successful technique for desorbing large numbers of intact molecules from graphite. This technique could be used for desorbing intact molecules into a gas phase for mass spectrometric analysis. (author)

  12. Model castings with composite surface layer - application

    Directory of Open Access Journals (Sweden)

    J. Szajnar

    2008-10-01

    Full Text Available The paper presents a method of usable properties of surface layers improvement of cast carbon steel 200–450, by put directly in foundingprocess a composite surface layer on the basis of Fe-Cr-C alloy. Technology of composite surface layer guarantee mainly increase inhardness and aberasive wear resistance of cast steel castings on machine elements. This technology can be competition for generallyapplied welding technology (surfacing by welding and thermal spraying. In range of studies was made cast steel test castings withcomposite surface layer, which usability for industrial applications was estimated by criterion of hardness and aberasive wear resistance of type metal-mineral and quality of joint cast steel – (Fe-Cr-C. Based on conducted studies a thesis, that composite surface layer arise from liquid state, was formulated. Moreover, possible is control of composite layer thickness and its hardness by suitable selection of parameters i.e. thickness of insert, pouring temperature and solidification modulus of casting. Possibility of technology application of composite surface layer in manufacture of cast steel slide bush for combined cutter loader is presented.

  13. Coupled Modeling of Hydrodynamics and Sound in Coastal Ocean for Renewable Ocean Energy Development

    Energy Technology Data Exchange (ETDEWEB)

    Long, Wen; Jung, Ki Won; Yang, Zhaoqing; Copping, Andrea; Deng, Z. Daniel

    2016-03-01

    An underwater sound model was developed to simulate sound propagation from marine and hydrokinetic energy (MHK) devices or offshore wind (OSW) energy platforms. Finite difference methods were developed to solve the 3D Helmholtz equation for sound propagation in the coastal environment. A 3D sparse matrix solver with complex coefficients was formed for solving the resulting acoustic pressure field. The Complex Shifted Laplacian Preconditioner (CSLP) method was applied to solve the matrix system iteratively with MPI parallelization using a high performance cluster. The sound model was then coupled with the Finite Volume Community Ocean Model (FVCOM) for simulating sound propagation generated by human activities, such as construction of OSW turbines or tidal stream turbine operations, in a range-dependent setting. As a proof of concept, initial validation of the solver is presented for two coastal wedge problems. This sound model can be useful for evaluating impacts on marine mammals due to deployment of MHK devices and OSW energy platforms.

  14. A surface diffuse scattering model for the mobility of electrons in surface charge coupled devices

    International Nuclear Information System (INIS)

    Ionescu, M.

    1977-01-01

    An analytical model for the mobility of electrons in surface charge coupled devices is studied on the basis of the results previously obtained, considering a surface diffuse scattering; the importance of the results obtained for a better understanding of the influence of the fringing field in surface charge coupled devices is discussed. (author)

  15. Virtual Inertia Control-Based Model Predictive Control for Microgrid Frequency Stabilization Considering High Renewable Energy Integration

    Directory of Open Access Journals (Sweden)

    Thongchart Kerdphol

    2017-05-01

    Full Text Available Renewable energy sources (RESs, such as wind and solar generations, equip inverters to connect to the microgrids. These inverters do not have any rotating mass, thus lowering the overall system inertia. This low system inertia issue could affect the microgrid stability and resiliency in the situation of uncertainties. Today’s microgrids will become unstable if the capacity of RESs become larger and larger, leading to the weakening of microgrid stability and resilience. This paper addresses a new concept of a microgrid control incorporating a virtual inertia system based on the model predictive control (MPC to emulate virtual inertia into the microgrid control loop, thus stabilizing microgrid frequency during high penetration of RESs. The additional controller of virtual inertia is applied to the microgrid, employing MPC with virtual inertia response. System modeling and simulations are carried out using MATLAB/Simulink® software. The simulation results confirm the superior robustness and frequency stabilization effect of the proposed MPC-based virtual inertia control in comparison to the fuzzy logic system and conventional virtual inertia control in a system with high integration of RESs. The proposed MPC-based virtual inertia control is able to improve the robustness and frequency stabilization of the microgrid effectively.

  16. The renewable alternative

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses renewable energy sources as an alternative to a fossil fuel based economy. The topics discussed in the chapter include the historic aspects and current status of use of renewable energy, status of the renewable energy industry, market barriers to renewable energy, research and development and commercialization of renewable energy, the environmental and social costs associated with renewable energy, valuing future costs and benefits of energy use, and the potential market of renewable energy

  17. JEDI: Jobs and Economic Development Impact Model; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-08-01

    The Jobs and Economic Development Impact (JEDI) models are user-friendly tools that estimate the economic impacts of constructing and operating power generation and biofuel plants at the local (usually state) level. First developed by NREL’s researchers to model wind energy jobs and impacts, JEDI has been expanded to also estimate the economic impacts of biofuels, coal, conventional hydro, concentrating solar power, geothermal, marine and hydrokinetic power, natural gas, photovoltaics, and transmission lines. This fact sheet focuses on JEDI for wind energy projects.

  18. The PDS Model as a Vehicle for Simultaneous Renewal in Mathematics Education

    Science.gov (United States)

    Martinie, Sherri L.; Rumsey, Chepina; Allen, David S.

    2014-01-01

    For a quarter century, Kansas State University's College of Education has supported a Professional Development School (PDS) model involving professional collaboration with selected public school systems across Kansas. In that time, this relationship has proved to be an instrumental vehicle for educational change. The state of Kansas' adoption and…

  19. Biomass Scenario Model: BETO Analysis Platform Peer Review; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Bush, B.

    2015-03-23

    The Biomass Scenario Model (BSM) is a unique, carefully validated, state-of-the-art fourth-generation model of the domestic bioenergy supply chain which explicitly focuses on policy issues and their potential side effects. It integrates resource availability, behavior, policy, and physical, technological, and economic constraints. The BSM uses system-dynamics simulation to model dynamic interactions across the supply chain; it tracks the deployment of biofuels given technological development and the reaction of the investment community to those technologies in the context of land availability, the competing oil market, consumer demand for biofuels, and government policies over time. It places a strong emphasis on the behavior and decision-making of various economic agents. The model treats the major infrastructure-compatible fuels. Scenario analysis based on the BSM shows that the biofuels industry tends not to rapidly thrive without significant external actions in the early years of its evolution. An initial focus for jumpstarting the industry typically has strongest results in the BSM in areas where effects of intervention have been identified to be multiplicative. In general, we find that policies which are coordinated across the whole supply chain have significant impact in fostering the growth of the biofuels industry and that the production of tens of billions of gallons of biofuels may occur under sufficiently favorable conditions.

  20. Strategic Cognition in Transition? Individual Mental Model Renewal in the Energy Sector

    NARCIS (Netherlands)

    Gooyert, V. de; Rouwette, E.A.J.A.; Kranenburg, H.L. van; Freeman, R.E.; Breen, H.J. van

    2013-01-01

    A turbulent environment requires organizations to adjust their strategy to changing circumstances. Accordingly, the managers responsible for strategic change need to make timely adjustments to their mental models. This study contributes to the managerial cognition literature by showing a process of

  1. Spatial demographic models to inform conservation planning of golden eagles in renewable energy landscapes.

    Science.gov (United States)

    Spatial demographic models can help guide monitoring and management activities targeting at-risk species, even in cases where baseline data are lacking. Here, we provide an example of how site-specific changes in land-use and other anthropogenic stressors can be incorporated int...

  2. Simple model of surface roughness for binary collision sputtering simulations

    International Nuclear Information System (INIS)

    Lindsey, Sloan J.; Hobler, Gerhard; Maciążek, Dawid; Postawa, Zbigniew

    2017-01-01

    Highlights: • A simple model of surface roughness is proposed. • Its key feature is a linearly varying target density at the surface. • The model can be used in 1D/2D/3D Monte Carlo binary collision simulations. • The model fits well experimental glancing incidence sputtering yield data. - Abstract: It has been shown that surface roughness can strongly influence the sputtering yield – especially at glancing incidence angles where the inclusion of surface roughness leads to an increase in sputtering yields. In this work, we propose a simple one-parameter model (the “density gradient model”) which imitates surface roughness effects. In the model, the target’s atomic density is assumed to vary linearly between the actual material density and zero. The layer width is the sole model parameter. The model has been implemented in the binary collision simulator IMSIL and has been evaluated against various geometric surface models for 5 keV Ga ions impinging an amorphous Si target. To aid the construction of a realistic rough surface topography, we have performed MD simulations of sequential 5 keV Ga impacts on an initially crystalline Si target. We show that our new model effectively reproduces the sputtering yield, with only minor variations in the energy and angular distributions of sputtered particles. The success of the density gradient model is attributed to a reduction of the reflection coefficient – leading to increased sputtering yields, similar in effect to surface roughness.

  3. Mathematical modeling of rainwater runoff over catchment surface ...

    African Journals Online (AJOL)

    Mathematical modeling of rainwater runoff over catchment surface and mass transfer of contaminant incoming to water stream from soil. ... rainwater runoff along the surface catchment taking account the transport of pollution which permeates into the water flow from a porous media of soil at the certain areas of this surface.

  4. Modeling laser-induced periodic surface structures: an electromagnetic approach

    NARCIS (Netherlands)

    Skolski, J.Z.P.

    2014-01-01

    This thesis presents and discusses laser-induced periodic surface structures (LIPSSs), as well as a model explaining their formation. LIPSSs are regular wavy surface structures with dimensions usually in the submicrometer range, which can develop on the surface of many materials exposed to laser

  5. TWO-COMPONENT GALACTIC BULGE PROBED WITH RENEWED GALACTIC CHEMICAL EVOLUTION MODEL

    International Nuclear Information System (INIS)

    Tsujimoto, Takuji; Bekki, Kenji

    2012-01-01

    Results of recent observations of the Galactic bulge demand that we discard a simple picture of its formation, suggesting the presence of two stellar populations represented by two peaks of stellar metallicity distribution (MDF) in the bulge. To assess this issue, we construct Galactic chemical evolution models that have been updated in two respects: first, the delay time distribution of Type Ia supernovae (SNe Ia) recently revealed by extensive SN Ia surveys is incorporated into the models. Second, the nucleosynthesis clock, the s-processing in asymptotic giant branch stars, is carefully considered in this study. This novel model first shows that the Galaxy feature tagged by the key elements, Mg, Fe, and Ba, for the bulge as well as thin and thick disks is compatible with a short-delay SN Ia. We present a successful modeling of a two-component bulge including the MDF and the evolutions of [Mg/Fe] and [Ba/Mg], and reveal its origin as follows. A metal-poor component (([Fe/H]) ∼ –0.5) is formed with a relatively short timescale of ∼1 Gyr. These properties are identical to the thick disk's characteristics in the solar vicinity. Subsequently from its remaining gas mixed with a gas flow from the disk outside the bulge, a metal-rich component (([Fe/H]) ∼ +0.3) is formed with a longer timescale (∼4 Gyr) together with a top-heavy initial mass function that might be identified with the thin disk component within the bulge.

  6. Using modeling, satellite images and existing global datasets for rapid preliminary assessments of renewable energy resources: The case of Mali

    DEFF Research Database (Denmark)

    Nygaard, Ivan; Rasmussen, K.; Badger, Jake

    2010-01-01

    in the irrigated areas of the Niger inland delta that might be interesting from a renewable energy resource perspective. Finally, the paper discusses the role that renewable energy resources might play in the energy systems of Mali, given the spatio-temporal distribution of renewable energy resources. It is argued...... that at the current price of about 70 US$/barrel for fossil fuels, renewable energy resources are becoming economically as well as environmentally attractive options.......This paper presents a novel approach to the preliminary, low-cost, national-scale mapping of wind energy, solar energy and certain categories of bio-energy resources in developing countries, using Mali as an example. The methods applied make extensive use of satellite remote sensing...

  7. Current trends of surface science and catalysis

    CERN Document Server

    Park, Jeong Young

    2014-01-01

    Including detail on applying surface science in renewable energy conversion, this book covers the latest results on model catalysts including single crystals, bridging "materials and pressure gaps", and hot electron flows in heterogeneous catalysis.

  8. Stochastic renewal process models for estimation of damage cost over the life-cycle of a structure

    OpenAIRE

    Pandey, Mahesh D.; van der Weide, J.A.M.

    2017-01-01

    In the life-cycle cost analysis of a structure, the total cost of damage caused by external hazards like earthquakes, wind storms and flood is an important but highly uncertain component. In the literature, the expected damage cost is typically analyzed under the assumption of either the homogeneous Poisson process or the renewal process in an infinite time horizon (i.e., asymptotic solution). The paper reformulates the damage cost estimation problem as a compound renewal process and derives ...

  9. Multi-physics Modeling for Improving Li-Ion Battery Safety; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    Pesaran, A.; Kim, G.; Santhanagopalan, S.; Yang, C.

    2015-04-21

    Battery performance, cost, and safety must be further improved for larger market share of HEVs/PEVs and penetration into the grid. Significant investment is being made to develop new materials, fine tune existing ones, improve cell and pack designs, and enhance manufacturing processes to increase performance, reduce cost, and make batteries safer. Modeling, simulation, and design tools can play an important role by providing insight on how to address issues, reducing the number of build-test-break prototypes, and accelerating the development cycle of generating products.

  10. Methanol Oxidation on Model Elemental and Bimetallic Transition Metal Surfaces

    DEFF Research Database (Denmark)

    Tritsaris, G. A.; Rossmeisl, J.

    2012-01-01

    Direct methanol fuel cells are a key enabling technology for clean energy conversion. Using density functional theory calculations, we study the methanol oxidation reaction on model electrodes. We discuss trends in reactivity for a set of monometallic and bimetallic transition metal surfaces, flat...... sites on the surface and to screen for novel bimetallic surfaces of enhanced activity. We suggest platinum copper surfaces as promising anode catalysts for direct methanol fuel cells....

  11. Sediment Transport Model for a Surface Irrigation System

    OpenAIRE

    Mailapalli, Damodhara R.; Raghuwanshi, Narendra S.; Singh, Rajendra

    2013-01-01

    Controlling irrigation-induced soil erosion is one of the important issues of irrigation management and surface water impairment. Irrigation models are useful in managing the irrigation and the associated ill effects on agricultural environment. In this paper, a physically based surface irrigation model was developed to predict sediment transport in irrigated furrows by integrating an irrigation hydraulic model with a quasi-steady state sediment transport model to predict sediment load in fur...

  12. Towards a Revised Monte Carlo Neutral Particle Surface Interaction Model

    International Nuclear Information System (INIS)

    Stotler, D.P.

    2005-01-01

    The components of the neutral- and plasma-surface interaction model used in the Monte Carlo neutral transport code DEGAS 2 are reviewed. The idealized surfaces and processes handled by that model are inadequate for accurately simulating neutral transport behavior in present day and future fusion devices. We identify some of the physical processes missing from the model, such as mixed materials and implanted hydrogen, and make some suggestions for improving the model

  13. A model of the ideal molecular surface

    Science.gov (United States)

    Henson, Bryan; Smilowitz, Laura

    2014-03-01

    We utilize two manifestations of the phenomena of the quasiliquid phase on the surface of molecular crystals to formulate a universal thermodynamic theory describing the thickness of the layer as a function of the liquid phase activity. We use direct measurements of the liquid thickness as a function of temperature and measurements of the acceleration of thermal decomposition as a function of temperature approaching the melting point to illustrate the mechanism. We show that given the existence of a liquid phase below the melting point the ideal liquid activity is necessarily a fixed function of the free energies of sublimation and vaporization. We use this activity to create a reduced formula for the liquid thickness generally applicable to the molecular surface. We provide a prediction of the mechanism and kinetics of quasiliquid formation and show that the phase exists as a metastable kinetic steady state. We show that to first order the principle controlling feature of the system is the configurational entropy of the liquid/solid interface, rather than the specifics of the surface potential energy. This is analogous to other bulk colligative phenomena such as ideal gas and solution theories, and is thus an ideal, universal formulation of inherent, thermodynamically driven, surface disorder.

  14. Surface aerodynamic temperature modeling over rainfed cotton

    Science.gov (United States)

    Evapotranspiration (ET) or latent heat flux (LE) can be spatially estimated as an energy balance (EB) residual for land surfaces using remote sensing inputs. The EB equation requires the estimation of net radiation (Rn), soil heat flux (G), and sensible heat flux (H). Rn and G can be estimated with ...

  15. Probabilistic prosumer node modeling for estimating planning parameters in distribution networks with renewable energy sources

    DEFF Research Database (Denmark)

    Millar, Robert John; Ekstrom, Jussi; Lehtonen, Matti

    With the increase in distributed generation, the demand-only nature of many secondary substation nodes in medium voltage networks is becoming a mix of temporally varying consumption and generation with significant stochastic components. Traditional planning, however, has often assumed that the ma......With the increase in distributed generation, the demand-only nature of many secondary substation nodes in medium voltage networks is becoming a mix of temporally varying consumption and generation with significant stochastic components. Traditional planning, however, has often assumed...... that the maximum demands of all connected substations are fully coincident, and in cases where there is local generation, the conditions of maximum consumption and minimum generation, and maximum generation and minimum consumption are checked, again assuming unity coincidence. Statistical modelling is used...... in this paper to produce network solutions that optimize investment, running and interruption costs, assessed from a societal perspective. The decoupled utilization of expected consumption profiles and stochastic generation models enables a more detailed estimation of the driving parameters using the Monte...

  16. Model for the Evolving Bed Surface around an Offshore Monopile

    DEFF Research Database (Denmark)

    Hartvig, Peres Akrawi

    2012-01-01

    This paper presents a model for the bed surface around an offshore monopile. The model has been designed from measured laboratory bed surfaces and is shown to reproduce these satisfactorily for both scouring and backfilling. The local rate of the bed elevation is assumed to satisfy a certain gene...

  17. Modeling the Soul Surface Seal from a Filtration Perspective

    OpenAIRE

    N.M. Somaratne; K.R.J. Smettem

    1998-01-01

    A physically based model of soil surface scaling is proposed. The governing equations are formulated on the principle of conservation of mass assuming Darcy's law applies to suspension flowing through the soil surface. The model incorporates the physics of surface sealing by mechanisms that capture suspended particles moving with infiltrating water. As a result of particle retention in the soil system, the intrinsic porosity is reduced and hulk density is increased, resulting in changes to so...

  18. Estimates of surface methane emissions over Europe using observed surface concentrations and the FLEXPART trajectory model

    Science.gov (United States)

    Weaver, C. J.; Kiemle, C.; Kawa, S. R.; Aalto, T.; Necki, J.; Steinbacher, M.; Arduini, J.; Apadula, F.; Berkhout, H.; Hatakka, J.; O'Doherty, S.

    2013-12-01

    We use surface methane observations from nine European ground stations, and the FLEXPART Lagrangian transport model to obtain surface methane emissions for 2010. Our inversion shows the strongest emissions from the Netherlands and the coal mines in Upper Silesia Poland. This is qualitatively consistent with the EDGAR surface flux inventory. We also report significant surface fluxes from wetlands in southern Finland during July and August and reduced wetland fluxes later in the year. Our simulated methane surface concentration captures at least half of the daily variability in the observations, suggesting that the transport model is correctly simulating the regional transport pathways over Europe. We also use our trajectory model to determine whether future space-based remote sensing instruments (MERLIN) will be able to detect both natural and anthropogenic changes in the surface flux strengths.

  19. How do dynamic capabilities transform external technologies into firms’ renewed technological resources? – A mediation model

    DEFF Research Database (Denmark)

    Li-Ying, Jason; Wang, Yuandi; Ning, Lutao

    2016-01-01

    How externally acquired resources may become valuable, rare, hard-to-imitate, and non-substitute resource bundles through the development of dynamic capabilities? This study proposes and tests a mediation model of how firms’ internal technological diversification and R&D, as two distinctive...... microfoundations of dynamic technological capabilities, mediate the relationship between external technology breadth and firms’ technological innovation performance, based on the resource-based view and dynamic capability view. Using a sample of listed Chinese licensee firms, we find that firms must broadly...... explore external technologies to ignite the dynamism in internal technological diversity and in-house R&D, which play their crucial roles differently to transform and reconfigure firms’ technological resources....

  20. A cost optimization model for 100% renewable residential energy supply systems

    DEFF Research Database (Denmark)

    Milan, Christian; Bojesen, Carsten; Nielsen, Mads Pagh

    2012-01-01

    The concept of net zero energy buildings (Net ZEB) has received increased attention throughout the last years. A well adapted and optimized design of the energy supply system is crucial for the performance of these buildings. To achieve this, a holistic approach is needed which accounts for the i......The concept of net zero energy buildings (Net ZEB) has received increased attention throughout the last years. A well adapted and optimized design of the energy supply system is crucial for the performance of these buildings. To achieve this, a holistic approach is needed which accounts......'s involving on-site production of heat and electricity in combination with electricity exchanged with the public grid. The model is based on linear programming and determines the optimal capacities for each relevant supply technology in terms of the overall system costs. It has been successfully applied...

  1. An inventory control project in a major Danish company using compound renewal demand models

    DEFF Research Database (Denmark)

    Larsen, Christian; Seiding, Claus Hoe; Teller, Christian

    2008-01-01

    -conditioning systems. The warehouse logistics operation is highly automated. However, the procedures for estimating demands and the policies for the inventory control system that were in use at the beginning of the project did not fully match the sophisticated technological standard of the physical system. During...... procedures for determining suitable inventory control variables based on the fitted demand distributions and a service-level requirement stated in terms of an order fill rate. Finally, we validated the results of our models against the procedures that had been in use in the company. It was concluded......We describe the development of a framework to compute the optimal inventory policy for a large spare parts distribution centre operation in the refrigeration and air conditioning (RA) division of the Danfoss Group in Denmark. The RA division distributes spare parts worldwide for cooling and air...

  2. Modeling wind adjustment factor and midflame wind speed for Rothermel's surface fire spread model

    Science.gov (United States)

    Patricia L. Andrews

    2012-01-01

    Rothermel's surface fire spread model was developed to use a value for the wind speed that affects surface fire, called midflame wind speed. Models have been developed to adjust 20-ft wind speed to midflame wind speed for sheltered and unsheltered surface fuel. In this report, Wind Adjustment Factor (WAF) model equations are given, and the BehavePlus fire modeling...

  3. Olkiluoto surface hydrological modelling: Update 2012 including salt transport modelling

    International Nuclear Information System (INIS)

    Karvonen, T.

    2013-11-01

    Posiva Oy is responsible for implementing a final disposal program for spent nuclear fuel of its owners Teollisuuden Voima Oyj and Fortum Power and Heat Oy. The spent nuclear fuel is planned to be disposed at a depth of about 400-450 meters in the crystalline bedrock at the Olkiluoto site. Leakages located at or close to spent fuel repository may give rise to the upconing of deep highly saline groundwater and this is a concern with regard to the performance of the tunnel backfill material after the closure of the tunnels. Therefore a salt transport sub-model was added to the Olkiluoto surface hydrological model (SHYD). The other improvements include update of the particle tracking algorithm and possibility to estimate the influence of open drillholes in a case where overpressure in inflatable packers decreases causing a hydraulic short-circuit between hydrogeological zones HZ19 and HZ20 along the drillhole. Four new hydrogeological zones HZ056, HZ146, BFZ100 and HZ039 were added to the model. In addition, zones HZ20A and HZ20B intersect with each other in the new structure model, which influences salinity upconing caused by leakages in shafts. The aim of the modelling of long-term influence of ONKALO, shafts and repository tunnels provide computational results that can be used to suggest limits for allowed leakages. The model input data included all the existing leakages into ONKALO (35-38 l/min) and shafts in the present day conditions. The influence of shafts was computed using eight different values for total shaft leakage: 5, 11, 20, 30, 40, 50, 60 and 70 l/min. The selection of the leakage criteria for shafts was influenced by the fact that upconing of saline water increases TDS-values close to the repository areas although HZ20B does not intersect any deposition tunnels. The total limit for all leakages was suggested to be 120 l/min. The limit for HZ20 zones was proposed to be 40 l/min: about 5 l/min the present day leakages to access tunnel, 25 l/min from

  4. Predictive model for ice formation on superhydrophobic surfaces.

    Science.gov (United States)

    Bahadur, Vaibhav; Mishchenko, Lidiya; Hatton, Benjamin; Taylor, J Ashley; Aizenberg, Joanna; Krupenkin, Tom

    2011-12-06

    The prevention and control of ice accumulation has important applications in aviation, building construction, and energy conversion devices. One area of active research concerns the use of superhydrophobic surfaces for preventing ice formation. The present work develops a physics-based modeling framework to predict ice formation on cooled superhydrophobic surfaces resulting from the impact of supercooled water droplets. This modeling approach analyzes the multiple phenomena influencing ice formation on superhydrophobic surfaces through the development of submodels describing droplet impact dynamics, heat transfer, and heterogeneous ice nucleation. These models are then integrated together to achieve a comprehensive understanding of ice formation upon impact of liquid droplets at freezing conditions. The accuracy of this model is validated by its successful prediction of the experimental findings that demonstrate that superhydrophobic surfaces can fully prevent the freezing of impacting water droplets down to surface temperatures of as low as -20 to -25 °C. The model can be used to study the influence of surface morphology, surface chemistry, and fluid and thermal properties on dynamic ice formation and identify parameters critical to achieving icephobic surfaces. The framework of the present work is the first detailed modeling tool developed for the design and analysis of surfaces for various ice prevention/reduction strategies. © 2011 American Chemical Society

  5. Surface potential modeling and reconstruction in Kelvin probe force microscopy.

    Science.gov (United States)

    Xu, Jie; Wu, Yangqing; Li, Wei; Xu, Jun

    2017-09-08

    Kelvin probe force microscopy (KPFM) measurement has been extensively applied in metallic, semiconductor and organic electronic or photovoltaic devices, to characterize the local contact potential difference or surface potential of the samples at the nanoscale. Here, a comprehensive modeling of surface potential in KPFM is established, from the well-known single capacitance model to a precise electrodynamic model, considering the long range property of the electrostatic force in KPFM. The limitations and relations of different models are also discussed. Besides, the feedback condition of the KPFM system is reconsidered and modified, showing that the influence of the cantilever has been overestimated by about 20% in previous reports. Afterwards, the surface potential of charged Si-nanocrystals is reconstructed based on the electrodynamic model, and the calculated surface charge density is very consistent with the macroscopic capacitance-voltage (C-V) measurement. A deep understanding and correct reconstruction of surface potential is crucial to the quantitative analysis of KPFM results.

  6. Numerical modeling of the effects of a free surface on the operating characteristics of Marine Hydrokinetic Turbines

    Science.gov (United States)

    Adamski, Samantha; Aliseda, Alberto

    2012-11-01

    Marine Hydrokinetic (MHK) turbines are a growing area of research in the renewable energy field because tidal currents are a highly predictable clean energy source. The presence of a free surface may influence the flow around the turbine and in the wake, critically affecting turbine performance and environmental effects through modification of wake physical variables. The characteristic Froude number that control these processes is still a matter of controversy, with the channel depth and turbine's depth, blade tip depth and diameter as potential candidates for a length scale used in literature. We use the Volume of Fluid model to track the free surface dynamics in a RANS simulation with a BEMT model of the turbine to understand the physics of the wake-free surface interactions. Pressure and flow rate boundary conditions for channel's inlet, outlet and air side have been tested in an effort to determine the optimum set of simulation conditions for MHK turbines in rivers or estuaries. Stability and accuracy in terms of power extraction and kinetic and potential energy budgets are considered. The goal of this research is to determine, quantitatively in non dimensional parameter space, the limit between negligible and significant free surface effects on MHK turbine analysis. Supported by DOE through the National Northwest Marine Renewable Energy Center.

  7. Modeling Photovoltaic Module-Level Power Electronics in the System Advisor Model; NREL (National Renewable Energy Laboratory)

    Energy Technology Data Exchange (ETDEWEB)

    None

    2015-07-01

    Module-level power electronics, such as DC power optimizers, microinverters, and those found in AC modules, are increasing in popularity in smaller-scale photovoltaic (PV) systems as their prices continue to decline. Therefore, it is important to provide PV modelers with guidelines about how to model these distributed power electronics appropriately in PV modeling software. This paper extends the work completed at NREL that provided recommendations to model the performance of distributed power electronics in NREL’s popular PVWatts calculator [1], to provide similar guidelines for modeling these technologies in NREL's more complex System Advisor Model (SAM). Module-level power electronics - such as DC power optimizers, microinverters, and those found in AC modules-- are increasing in popularity in smaller-scale photovoltaic (PV) systems as their prices continue to decline. Therefore, it is important to provide PV modelers with guidelines about how to model these distributed power electronics appropriately in PV modeling software.

  8. A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

    Science.gov (United States)

    Błaszczuk, Artur; Krzywański, Jarosław

    2017-03-01

    The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB) has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K) and 111-240 W/(m2K), for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

  9. A comparison of fuzzy logic and cluster renewal approaches for heat transfer modeling in a 1296 t/h CFB boiler with low level of flue gas recirculation

    Directory of Open Access Journals (Sweden)

    Błaszczuk Artur

    2017-03-01

    Full Text Available The interrelation between fuzzy logic and cluster renewal approaches for heat transfer modeling in a circulating fluidized bed (CFB has been established based on a local furnace data. The furnace data have been measured in a 1296 t/h CFB boiler with low level of flue gas recirculation. In the present study, the bed temperature and suspension density were treated as experimental variables along the furnace height. The measured bed temperature and suspension density were varied in the range of 1131-1156 K and 1.93-6.32 kg/m3, respectively. Using the heat transfer coefficient for commercial CFB combustor, two empirical heat transfer correlation were developed in terms of important operating parameters including bed temperature and also suspension density. The fuzzy logic results were found to be in good agreement with the corresponding experimental heat transfer data obtained based on cluster renewal approach. The predicted bed-to-wall heat transfer coefficient covered a range of 109-241 W/(m2K and 111-240 W/(m2K, for fuzzy logic and cluster renewal approach respectively. The divergence in calculated heat flux recovery along the furnace height between fuzzy logic and cluster renewal approach did not exceeded ±2%.

  10. Modeling noncontact atomic force microscopy resolution on corrugated surfaces

    Directory of Open Access Journals (Sweden)

    Kristen M. Burson

    2012-03-01

    Full Text Available Key developments in NC-AFM have generally involved atomically flat crystalline surfaces. However, many surfaces of technological interest are not atomically flat. We discuss the experimental difficulties in obtaining high-resolution images of rough surfaces, with amorphous SiO2 as a specific case. We develop a quasi-1-D minimal model for noncontact atomic force microscopy, based on van der Waals interactions between a spherical tip and the surface, explicitly accounting for the corrugated substrate (modeled as a sinusoid. The model results show an attenuation of the topographic contours by ~30% for tip distances within 5 Å of the surface. Results also indicate a deviation from the Hamaker force law for a sphere interacting with a flat surface.

  11. Conformally parametrized surfaces associated with CPN-1 sigma models

    International Nuclear Information System (INIS)

    Grundland, A M; Hereman, W A; Yurdusen, I-dot

    2008-01-01

    Two-dimensional parametrized surfaces immersed in the su(N) algebra are investigated. The focus is on surfaces parametrized by solutions of the equations for the CP N-1 sigma model. The Lie-point symmetries of the CP N-1 model are computed for arbitrary N. The Weierstrass formula for immersion is determined and an explicit formula for a moving frame on a surface is constructed. This allows us to determine the structural equations and geometrical properties of surfaces in R N 2 -1 . The fundamental forms, Gaussian and mean curvatures, Willmore functional and topological charge of surfaces are given explicitly in terms of any holomorphic solution of the CP 2 model. The approach is illustrated through several examples, including surfaces immersed in low-dimensional su(N) algebras

  12. Theoretical model of fast electron emission from surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Reinhold, C.; Burgdoerfer, J. [Univ. of Tennessee, Knoxville, TN (United States)]|[Oak Ridge National Laboratory, TN (United States)

    1993-05-01

    Electron emission in glancing-angle ion-surface collisions has become a focus of ion-surface interactions. Electron spectra can provide detailed information on the above surface neutralization dynamics of multiply charged ions, the electronic structure of the surface (surface density of states), and the long-ranged image interactions near the surface. Recent experiments have found that the convoy peak, well known from ion-atom and ion-solid collisions, is dramatically altered. The peak is broadened and shifted in energy which has been attributed to dynamical image interactions. We present a microscopic model for the emission of fast electrons in glancing-angle surface collisions. A classical trajectory Monte Carlo approach is utilized to calculate the evolution of electrons in the presence of their self image, the projectile Coulomb field and the image potential induced by the projectile. The excitation of collective surface modes is also incorporated.

  13. Renewing governance.

    Science.gov (United States)

    Loos, Gregory P

    2003-01-01

    Globalization's profound influence on social and political institutions need not be negative. Critics of globalization have often referred to the "Impossible Trinity" because decision-making must 1. respect national sovereignty, 2. develop and implement firm regulation, and 3. allow capital markets to be as free as possible. To many, such goals are mutually exclusive because history conditions us to view policy-making and governance in traditional molds. Thus, transnational governance merely appears impossible because current forms of governance were not designed to provide it. The world needs new tools for governing, and its citizens must seize the opportunity to help develop them. The rise of a global society requires a greater level of generality and inclusion than is found in most policy bodies today. Politicians need to re-examine key assumptions about government. States must develop ways to discharge their regulatory responsibilities across borders and collaborate with neighboring jurisdictions, multilateral bodies, and business. Concepts such as multilateralism and tripartism show great promise. Governments must engage civil society in the spirit of shared responsibility and democratic decision-making. Such changes will result in a renewal of the state's purpose and better use of international resources and expertise in governance.

  14. Explanatory models for ecological response surfaces

    International Nuclear Information System (INIS)

    Jager, H.I.; Overton, W.S.

    1991-01-01

    Understanding the spatial organization of ecological systems is a fundamental part of ecosystem study. While discovering the causal relationships of this organization is an important goal, our purpose of spatial description on a regional scale is best met by use of explanatory variables that are somewhat removed from the mechanistic causal level. Regional level understanding is best obtained from explanatory variables that reflect spatial gradients at the regional scale and from categorical variables that describe the discrete constituents of (statistical) populations, such as lakes. In this paper, we use a regression model to predict lake acid neutralizing capacity (ANC) based on environmental predictor variables over a large region. These predictions are used to produce model-based population estimates. Two key features of our modeling approach are that is honors the spatial context and the design of the sample data. The spatial context of the data are brought into the analysis of model residuals through the interpretation of residual maps and semivariograms. The sampling design is taken into account by including stratification variables from the design in the model. This ensures that the model applies to a real population of lakes (the target population), rather than whatever hypothetical population the sample is a random sample of

  15. Spatiotemporal Co-variability of Surface Climate for Renewable Energy across the Contiguous United States: Role of the North Atlantic Subtropical High

    Science.gov (United States)

    Doering, K.; Steinschneider, S.

    2017-12-01

    The variability of renewable energy supply and drivers of demand across space and time largely determines the energy balance within power systems with a high penetration of renewable technologies. This study examines the joint spatiotemporal variability of summertime climate linked to renewable energy production (precipitation, wind speeds, insolation) and energy demand (temperature) across the contiguous United States (CONUS) between 1948 and 2015. Canonical correlation analysis is used to identify the major modes of joint variability between summer wind speeds and precipitation and related patterns of insolation and temperature. Canonical variates are then related to circulation anomalies to identify common drivers of the joint modes of climate variability. Results show that the first two modes of joint variability between summer wind speeds and precipitation exhibit pan-US dipole patterns with centers of action located in the eastern and central CONUS. Temperature and insolation also exhibit related US-wide dipoles. The relationship between canonical variates and lower-tropospheric geopotential height indicates that these modes are related to variability in the North Atlantic subtropical high (NASH). This insight can inform optimal strategies for siting renewables in an interconnected electric grid, and has implications for the impacts of climate variability and change on renewable energy systems.

  16. The economic impact of renewable energy

    International Nuclear Information System (INIS)

    1998-02-01

    This report summarises the findings of a project investigating the economic impact of renewable energy. The background to the study is traced, and potential sources of public finance for renewable projects, sensitivity analysis of the employment estimates , estimates of demand met by renewable energy technologies, the expenditures involved in investment in renewable energy; and sectoral linkages are examined. Wealth creation through investment in renewable energy, and the economic and employment impacts are explored. Plant retirement and replacement analysis, and input-output models are considered in appendices

  17. Digital terrain modeling and industrial surface metrology: Converging realms

    Science.gov (United States)

    Pike, R.J.

    2001-01-01

    Digital terrain modeling has a micro-and nanoscale counterpart in surface metrology, the numerical characterization of industrial surfaces. Instrumentation in semiconductor manufacturing and other high-technology fields can now contour surface irregularities down to the atomic scale. Surface metrology has been revolutionized by its ability to manipulate square-grid height matrices that are analogous to the digital elevation models (DEMs) used in physical geography. Because the shaping of industrial surfaces is a spatial process, the same concepts of analytical cartography that represent ground-surface form in geography evolved independently in metrology: The surface topography of manufactured components, exemplified here by automobile-engine cylinders, is routinely modeled by variogram analysis, relief shading, and most other techniques of parameterization and visualization familiar to geography. This article introduces industrial surface-metrology, examines the field in the context of terrain modeling and geomorphology and notes their similarities and differences, and raises theoretical issues to be addressed in progressing toward a unified practice of surface morphometry.

  18. Land Surface Microwave Emissivity Dynamics: Observations, Analysis and Modeling

    Science.gov (United States)

    Tian, Yudong; Peters-Lidard, Christa D.; Harrison, Kenneth W.; Kumar, Sujay; Ringerud, Sarah

    2014-01-01

    Land surface microwave emissivity affects remote sensing of both the atmosphere and the land surface. The dynamical behavior of microwave emissivity over a very diverse sample of land surface types is studied. With seven years of satellite measurements from AMSR-E, we identified various dynamical regimes of the land surface emission. In addition, we used two radiative transfer models (RTMs), the Community Radiative Transfer Model (CRTM) and the Community Microwave Emission Modeling Platform (CMEM), to simulate land surface emissivity dynamics. With both CRTM and CMEM coupled to NASA's Land Information System, global-scale land surface microwave emissivities were simulated for five years, and evaluated against AMSR-E observations. It is found that both models have successes and failures over various types of land surfaces. Among them, the desert shows the most consistent underestimates (by approx. 70-80%), due to limitations of the physical models used, and requires a revision in both systems. Other snow-free surface types exhibit various degrees of success and it is expected that parameter tuning can improve their performances.

  19. Modeling a power-to-renewable methane system for an assessment of power grid balancing options in the Baltic States’ region

    International Nuclear Information System (INIS)

    Zoss, Toms; Dace, Elina; Blumberga, Dagnija

    2016-01-01

    Highlights: • A mathematical modeling framework developed for assessing power-to-methane systems. • An integrated system of wind power, electrolysis, biogas and methanation assessed. • Power system is more stable with methanizing biogas with H 2 from excess wind power. • Accumulation of H 2 limits production of renewable methane. • Large potential for wind power development in the Baltic States. - Abstract: The explicit tendency to increase the power generation from stochastic renewable resources forces to look for technological solutions of energy management and storage. In the recent years, the concept of power-to-gas, where the excess energy is converted into hydrogen and/or further methanized into renewable methane, is gaining high popularity among researchers. In this study, we assess the power-to-renewable methane system as the potential technology for power grid balancing. For the assessment, a mathematical model has been developed that assists in understanding of whether a power-to-renewable methane system can be developed in a region with specific installed and planned capacities of wind energy and biogas plants. Considering the varying amount of excess power available for H 2 production and the varying biogas quality, the aim of the model is to simulate the system to determine, if wind power generation meets the needs of biogas plants for storing the excess energy in the form of methane via the methanation process. For the case study, the Baltic States (Estonia, Latvia, and Lithuania) have been selected, as the region is characterized by high dependence on fossil energy sources and electricity import. The results show that with the wind power produced in the region it would be possible to increase the average CH 4 content in the methanized biogas by up to 48.4%. Yet, even with a positive H 2 net production rate, not in all cases the maximum possible quality of the renewable methane would be achieved, as at moments the necessary amount of H 2 for

  20. CREST Cost of Renewable Energy Spreadsheet Tool: A Model for Developing Cost-Based Incentives in the United States; User Manual Version 4, August 2009 - March 2011 (Updated July 2013)

    Energy Technology Data Exchange (ETDEWEB)

    Gifford, J. S.; Grace, R. C.

    2013-07-01

    The objective of this document is to help model users understand how to use the CREST model to support renewable energy incentives, FITs, and other renewable energy rate-setting processes. This user manual will walk the reader through the spreadsheet tool, including its layout and conventions, offering context on how and why it was created. This user manual will also provide instructions on how to populate the model with inputs that are appropriate for a specific jurisdiction's policymaking objectives and context. Finally, the user manual will describe the results and outline how these results may inform decisions about long-term renewable energy support programs.

  1. Will domestic consumers take up the renewable heat incentive? An analysis of the barriers to heat pump adoption using agent-based modelling

    International Nuclear Information System (INIS)

    Snape, J.R.; Boait, P.J.; Rylatt, R.M.

    2015-01-01

    The UK Government introduced the tariff-based domestic Renewable Heat Incentive (RHI) in April 2014 to encourage installation of renewable heat technologies as a key component of its carbon reduction policy. Of these, heat pumps are considered to be the most promising for widespread adoption and as such are the subject of this paper. Pilot studies prior to introduction of the policy identified non-financial barriers to uptake, such as the “hassle factor” involved, and initial figures indeed indicate that uptake is lower than expected. We analyse these non-financial barriers using an agent-based model and conclude that there is a tipping point beyond which adoption is likely to fall very sharply. We suggest that the RHI’s complex and stringent compliance requirements for home inspections and heat emitter performance may well have driven adoption past this point and that further intervention may be required if the key aims of the RHI are to be achieved. -- Highlights: •We examine the uptake of the UK Renewable Heat Incentive (RHI). •We use Agent-based modelling to simulate uptake in a heterogeneous population. •Simulation modelling suggests that uptake is sensitive to non-financial barriers. •Non-financial barriers were introduced after RHI policy impact assessment. •New barriers combined with sensitivity could explain observed lower than expected uptake

  2. Business model renewal and ambidexterity: Structural alteration and strategy formation process during transition to a Cloud business model

    NARCIS (Netherlands)

    S. Khanagha (Saeed); H.W. Volberda (Henk); I. Oshri (Ilan)

    2014-01-01

    textabstractThis paper presents the findings of a longitudinal study of a large corporation's transition to a new business model in the face of a major transformation in the ICT industry brought about by Cloud computing. We build theory on the process of business model innovation through a

  3. Simple model of surface roughness for binary collision sputtering simulations

    Science.gov (United States)

    Lindsey, Sloan J.; Hobler, Gerhard; Maciążek, Dawid; Postawa, Zbigniew

    2017-02-01

    It has been shown that surface roughness can strongly influence the sputtering yield - especially at glancing incidence angles where the inclusion of surface roughness leads to an increase in sputtering yields. In this work, we propose a simple one-parameter model (the "density gradient model") which imitates surface roughness effects. In the model, the target's atomic density is assumed to vary linearly between the actual material density and zero. The layer width is the sole model parameter. The model has been implemented in the binary collision simulator IMSIL and has been evaluated against various geometric surface models for 5 keV Ga ions impinging an amorphous Si target. To aid the construction of a realistic rough surface topography, we have performed MD simulations of sequential 5 keV Ga impacts on an initially crystalline Si target. We show that our new model effectively reproduces the sputtering yield, with only minor variations in the energy and angular distributions of sputtered particles. The success of the density gradient model is attributed to a reduction of the reflection coefficient - leading to increased sputtering yields, similar in effect to surface roughness.

  4. Renewable Energy Symposium

    International Nuclear Information System (INIS)

    2016-01-01

    Representatives of state universities, public institutions and Costa Rican private sector, and American experts have exposed projects or experiences about the use and generation of renewable energy in different fields. The thematics presented have been about: development of smart grids and design of electrical energy production systems that allow money saving and reducing emissions to the environment; studies on the use of non-traditional plants and agricultural waste; sustainable energy model in the process of coffee production; experiments from biomass for the fabrication of biodiesel, biogas production and storage; and the use of non-conventional energy. Researches were presented at the Renewable Energy Symposium, organized by the Centro de Investigacion en Estructuras Microscopicas and support of the Vicerrectoria de Investigacion, both from the Universidad de Costa Rica [es

  5. RENEWABLE ENERGY IN TOURISM

    Directory of Open Access Journals (Sweden)

    MĂDĂLINA MIHĂILĂ

    2012-06-01

    Full Text Available Recent reports published by the International Energy Agency and U.S. Department of Energy, regarding the global energy outlook for the first three decades of the XXI century, warns of global trends on energy demand, increasing dependence on energy imports, coal use and volume emissions of greenhouse gases, torism industry being one of the biggest energy consumption industry. Uncertainties on different models of regional development and access of the world to traditional energy resources require a change of orientation towards long-term scenarios for assessing energy domain, increasing the share of energy from renewable resources beeing one of the solutions. Intourism the renewable energy is a solution for a positive impact on enviroment , reduced operational costs and even won an extra-profit.

  6. MODELING THE INTERACTION OF AGROCHEMICALS WITH ENVIRONMENTAL SURFACES: PESTICIDES ON RUTILE AND ORGANO-RUTILE SURFACES

    Science.gov (United States)

    Non-bonded interactions between model pesticides and organo-mineral surfaces have been studied using molecular mechanical conformational calculations and molecular dynamics simulations. The minimum energy conformations and relative binding energies for the interaction of atrazine...

  7. Measuring and modeling surface sorption dynamics of organophosphate flame retardants on impervious surfaces

    Data.gov (United States)

    U.S. Environmental Protection Agency — The data presented in this data file is a product of a journal publication. The dataset contains measured and model predicted OPFRs gas-phase and surface-phase...

  8. A Two-Surface Viscoplastic Model for the Structural Steel

    Directory of Open Access Journals (Sweden)

    Dong-Keon Kim

    Full Text Available Abstract As extension of the previous two-surface model in plasticity, a two-surface model for viscoplasticity is presented herein. In order to validate and investigate the performance of the proposed model, several numerical simulations are undertaken especially for structural steel under monotonic and cyclic loading cases, where experimental results and numerical results from the rate dependent kinematic hardening model are also provided for the reference. For all the cases studied, the proposed model can appropriately account for the rate-effects in both maximum stress and hysteretic shapes.

  9. Models for the promotion of renewable energy sources. A legal comparing investigation of models for the promotion of renewable enegy sources by the example of Poland and Germany; Modelle zur Foerderung erneuerbarer Energietraeger. Eine rechtsvergleichende Untersuchung von Modellen zur Foerderung erneuerbarer Energietraeger am Beispiel Polens und Deutschlands

    Energy Technology Data Exchange (ETDEWEB)

    Michalowska, Dorota

    2008-04-08

    Energy sources such as coal, natural gas, petroleum, and nuclear fission have long been established on the marketplace and considered competitive. However, a comprehensive restructuring of energy generation is necessary, as conventional energy generation pollutes the environment. Therefore environmentally friendly energy sources, such as solar, wind or water power need to be promoted. However, regenerative energy sources are still not capable of competing with conventional energy. Marketability of renewable energy sources can only be achieved through government-sponsored promotion and regulation. Such measures include fixed price and fixed quantity models with green certificates. The support schemes for renewable energy sources are characterized by their wide-ranging adaptability. The various elements of a scheme must be adapted to a given country's set goals and specific circumstances. There is no universally applicable model. Based on given goals and opportunities, every domestic legislator faces the challenge of choosing the best scheme or developing a mixed model that combines various elements. The aim of this study is to provide a legal analysis of regulations concerning the support schemes for renewable energy sources within the framework of EU and international law. Furthermore, the study aimed at comparing support schemes implemented in Poland and Germany. In the EU, the electricity directive from 1996 and 2003, the directive on the promotion of electricity from renewable energy sources from 2003 and 2008, non-binding documents, such as the ''green and white book'', as well as the ''ALTENER'' program, successfully contributed to establishing the topic of renewable energies. Regarding international law, it is primarily the Kyoto protocol that has to be mentioned as a basis for the promotion of renewable energy sources. Poland introduced a fixed quantity model with green certificates. Separated reimbursements for

  10. Improved simulation of groundwater - surface water interaction in catchment models

    Science.gov (United States)

    teklesadik, aklilu; van Griensven, Ann; Anibas, Christian; Huysmans, Marijke

    2016-04-01

    Groundwater storage can have a significant contribution to stream flow, therefore a thorough understanding of the groundwater surface water interaction is of prime important when doing catchment modeling. The aim of this study is to improve the simulation of groundwater - surface water interaction in a catchment model of the upper Zenne River basin located in Belgium. To achieve this objective we used the "Groundwater-Surface water Flow" (GSFLOW) modeling software, which is an integration of the surface water modeling tool "Precipitation and Runoff Modeling system" (PRMS) and the groundwater modeling tool MODFLOW. For this case study, the PRMS model and MODFLOW model were built and calibrated independently. The PRMS upper Zenne River basin model is divided into 84 hydrological response units (HRUs) and is calibrated with flow data at the Tubize gauging station. The spatial discretization of the MODFLOW upper Zenne groundwater flow model consists of 100m grids. Natural groundwater divides and the Brussels-Charleroi canal are used as boundary conditions for the MODFLOW model. The model is calibrated using piezometric data. The GSFLOW results were evaluated against a SWAT model application and field observations of groundwater-surface water interactions along a cross section of the Zenne River and riparian zone. The field observations confirm that there is no exchange of groundwater beyond the Brussel-Charleroi canal and that the interaction at the river bed is relatively low. The results show that there is a significant difference in the groundwater simulations when using GSFLOW versus SWAT. This indicates that the groundwater component representation in the SWAT model could be improved and that a more realistic implementation of the interactions between groundwater and surface water is advisable. This could be achieved by integrating SWAT and MODFLOW.

  11. Modeling marine surface microplastic transport to assess optimal removal locations

    OpenAIRE

    Sherman, P; Van Sebille, E

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the ...

  12. Modeling the Acid-Base Properties of Montmorillonite Edge Surfaces.

    Science.gov (United States)

    Tournassat, Christophe; Davis, James A; Chiaberge, Christophe; Grangeon, Sylvain; Bourg, Ian C

    2016-12-20

    The surface reactivity of clay minerals remains challenging to characterize because of a duality of adsorption surfaces and mechanisms that does not exist in the case of simple oxide surfaces: edge surfaces of clay minerals have a variable proton surface charge arising from hydroxyl functional groups, whereas basal surfaces have a permanent negative charge arising from isomorphic substitutions. Hence, the relationship between surface charge and surface potential on edge surfaces cannot be described using the Gouy-Chapman relation, because of a spillover of negative electrostatic potential from the basal surface onto the edge surface. While surface complexation models can be modified to account for these features, a predictive fit of experimental data was not possible until recently, because of uncertainty regarding the densities and intrinsic pK a values of edge functional groups. Here, we reexamine this problem in light of new knowledge on intrinsic pK a values obtained over the past decade using ab initio molecular dynamics simulations, and we propose a new formalism to describe edge functional groups. Our simulation results yield reasonable predictions of the best available experimental acid-base titration data.

  13. Modeling and Simulating Airport Surface Operations with Gate Conflicts

    Science.gov (United States)

    Zelinski, Shannon; Windhorst, Robert

    2017-01-01

    The Surface Operations Simulator and Scheduler (SOSS) is a fast-time simulation platform used to develop and test future surface scheduling concepts such as NASAs Air Traffic Demonstration 2 of time-based surface metering at Charlotte Douglas International Airport (CLT). Challenges associated with CLT surface operations have driven much of SOSS development. Recently, SOSS functionality for modeling hardstand operations was developed to address gate conflicts, which occur when an arrival and departure wish to occupy the same gate at the same time. Because surface metering concepts such as ATD2 have the potential to increase gates conflicts as departure are held at their gates, it is important to study the interaction between surface metering and gate conflict management. Several approaches to managing gate conflicts with and without the use of hardstands were simulated and their effects on surface operations and scheduler performance compared.

  14. Hadamard model on the super Riemann surface

    Science.gov (United States)

    Shuji, Matsumoto; Shozo, Uehara; Yukinori, Yasui

    1988-12-01

    A supersymmetrically extended version of the Hadamard model is investigated. Classical solutions are given, which imply that the system is chaotic. Quantization is performed in the path integral method. The quantized energy sum rule is shown to be a superanalog of the Selberg trace formula. The Selberg super zeta function is introduced and energy spectra associated with bosonic (fermionic) states are given by order 1 zero-points (poles) of the zeta function.

  15. A Surface Water Model for the Orinoco river basin

    NARCIS (Netherlands)

    Schot, P.P.; Poot, A.; Vonk, G.; Peeters, W.H.M.

    2001-01-01

    This report describes the surface water model developed for the Orinoco river basin. In the next chapter hydrology and climate of the study area are presented. In the third chapter the general model concept is described. The fourth chapter describes the effects of various processes in the model

  16. Integrating Surface Modeling into the Engineering Design Graphics Curriculum

    Science.gov (United States)

    Hartman, Nathan W.

    2006-01-01

    It has been suggested there is a knowledge base that surrounds the use of 3D modeling within the engineering design process and correspondingly within engineering design graphics education. While solid modeling receives a great deal of attention and discussion relative to curriculum efforts, and rightly so, surface modeling is an equally viable 3D…

  17. Modeling of a nanoscale flexoelectric energy harvester with surface effects

    Science.gov (United States)

    Yan, Zhi

    2017-04-01

    This work presents the modeling of a beam energy harvester scavenging energy from ambient vibration based on the phenomenon of flexoelectricity. By considering surface elasticity, residual surface stress, surface piezoelectricity and bulk flexoelectricity, a modified Euler-Bernoulli beam model for the energy harvester is developed. After deriving the requisite energy expressions, the extended Hamilton's principle and the assumed-modes method are employed to obtain the discrete electromechanical Euler-Lagrange's equations. Then, the expressions of the steady-state electromechanical responses are given for harmonic base excitation. Numerical simulations are conducted to show the output voltage and the output power of the flexoelectric energy harvesters with different materials and sizes. Particular emphasis is given to the surface effects on the performance of the energy harvesters. It is found that the surface effects are sensitive to the beam geometries and the surface material constants, and the effect of residual surface stress is more significant than that of the surface elasticity and the surface piezoelectricity. The axial deformation of the beam is also considered in the model to account for the electromechanical coupling due to piezoelectricity, and results indicate that piezoelectricity will diminish the output electrical quantities for the case investigated. This work could lead to the development of flexoelectric energy harvesters that can make the micro- and nanoscale sensor systems autonomous.

  18. Empirical model for estimating the surface roughness of machined ...

    African Journals Online (AJOL)

    Michael Horsfall

    Regression Analysis to construct a prediction model for surface roughness such that once the process parameters (cutting speed, feed, depth of cut, Nose. Radius and Speed) are given, the surface roughness can be predicted. The work piece material was EN8 which was processed by carbide-inserted tool conducted on ...

  19. A tri-objective, dynamic weapon assignment model for surface ...

    African Journals Online (AJOL)

    2015-05-11

    May 11, 2015 ... of available surface-based weapon systems to engage aerial threats in an attempt to protect defended surface ...... time stages to include in the fixed mean calculation in (2) be fixed to the minimum length of a FW. ... to solve the model in 139 seconds on an Intel Core i7-4770 processor with 8GB of random.

  20. Mathematical and computer modeling of component surface shaping

    Science.gov (United States)

    Lyashkov, A.

    2016-04-01

    The process of shaping technical surfaces is an interaction of a tool (a shape element) and a component (a formable element or a workpiece) in their relative movements. It was established that the main objects of formation are: 1) a discriminant of a surfaces family, formed by the movement of the shape element relatively the workpiece; 2) an enveloping model of the real component surface obtained after machining, including transition curves and undercut lines; 3) The model of cut-off layers obtained in the process of shaping. When modeling shaping objects there are a lot of insufficiently solved or unsolved issues that make up a single scientific problem - a problem of qualitative shaping of the surface of the tool and then the component surface produced by this tool. The improvement of known metal-cutting tools, intensive development of systems of their computer-aided design requires further improvement of the methods of shaping the mating surfaces. In this regard, an important role is played by the study of the processes of shaping of technical surfaces with the use of the positive aspects of analytical and numerical mathematical methods and techniques associated with the use of mathematical and computer modeling. The author of the paper has posed and has solved the problem of development of mathematical, geometric and algorithmic support of computer-aided design of cutting tools based on computer simulation of the shaping process of surfaces.

  1. Land surface Verification Toolkit (LVT) - a generalized framework for land surface model evaluation

    Science.gov (United States)

    Kumar, S. V.; Peters-Lidard, C. D.; Santanello, J.; Harrison, K.; Liu, Y.; Shaw, M.

    2012-06-01

    Model evaluation and verification are key in improving the usage and applicability of simulation models for real-world applications. In this article, the development and capabilities of a formal system for land surface model evaluation called the Land surface Verification Toolkit (LVT) is described. LVT is designed to provide an integrated environment for systematic land model evaluation and facilitates a range of verification approaches and analysis capabilities. LVT operates across multiple temporal and spatial scales and employs a large suite of in-situ, remotely sensed and other model and reanalysis datasets in their native formats. In addition to the traditional accuracy-based measures, LVT also includes uncertainty and ensemble diagnostics, information theory measures, spatial similarity metrics and scale decomposition techniques that provide novel ways for performing diagnostic model evaluations. Though LVT was originally designed to support the land surface modeling and data assimilation framework known as the Land Information System (LIS), it supports hydrological data products from non-LIS environments as well. In addition, the analysis of diagnostics from various computational subsystems of LIS including data assimilation, optimization and uncertainty estimation are supported within LVT. Together, LIS and LVT provide a robust end-to-end environment for enabling the concepts of model data fusion for hydrological applications. The evolving capabilities of LVT framework are expected to facilitate rapid model evaluation efforts and aid the definition and refinement of formal evaluation procedures for the land surface modeling community.

  2. Including Finite Surface Span Effects in Empirical Jet-Surface Interaction Noise Models

    Science.gov (United States)

    Brown, Clifford A.

    2016-01-01

    The effect of finite span on the jet-surface interaction noise source and the jet mixing noise shielding and reflection effects is considered using recently acquired experimental data. First, the experimental setup and resulting data are presented with particular attention to the role of surface span on far-field noise. These effects are then included in existing empirical models that have previously assumed that all surfaces are semi-infinite. This extended abstract briefly describes the experimental setup and data leaving the empirical modeling aspects for the final paper.

  3. Microwave Remote Sensing Modeling of Ocean Surface Salinity and Winds Using an Empirical Sea Surface Spectrum

    Science.gov (United States)

    Yueh, Simon H.

    2004-01-01

    Active and passive microwave remote sensing techniques have been investigated for the remote sensing of ocean surface wind and salinity. We revised an ocean surface spectrum using the CMOD-5 geophysical model function (GMF) for the European Remote Sensing (ERS) C-band scatterometer and the Ku-band GMF for the NASA SeaWinds scatterometer. The predictions of microwave brightness temperatures from this model agree well with satellite, aircraft and tower-based microwave radiometer data. This suggests that the impact of surface roughness on microwave brightness temperatures and radar scattering coefficients of sea surfaces can be consistently characterized by a roughness spectrum, providing physical basis for using combined active and passive remote sensing techniques for ocean surface wind and salinity remote sensing.

  4. Microscopic Analysis and Modeling of Airport Surface Sequencing, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — Although a number of airportal surface models exist and have been successfully used for analysis of airportal operations, only recently has it become possible to...

  5. Surface Ship Shock Modeling and Simulation: Two-Dimensional Analysis

    Directory of Open Access Journals (Sweden)

    Young S. Shin

    1998-01-01

    Full Text Available The modeling and simulation of the response of a surface ship system to underwater explosion requires an understanding of many different subject areas. These include the process of underwater explosion events, shock wave propagation, explosion gas bubble behavior and bubble-pulse loading, bulk and local cavitation, free surface effect, fluid-structure interaction, and structural dynamics. This paper investigates the effects of fluid-structure interaction and cavitation on the response of a surface ship using USA-NASTRAN-CFA code. First, the one-dimensional Bleich-Sandler model is used to validate the approach, and second, the underwater shock response of a two-dimensional mid-section model of a surface ship is predicted with a surrounding fluid model using a constitutive equation of a bilinear fluid which does not allow transmission of negative pressures.

  6. Source Term Model for Fine Particle Resuspension from Indoor Surfaces

    National Research Council Canada - National Science Library

    Kim, Yoojeong; Gidwani, Ashok; Sippola, Mark; Sohn, Chang W

    2008-01-01

    This Phase I effort developed a source term model for particle resuspension from indoor surfaces to be used as a source term boundary condition for CFD simulation of particle transport and dispersion in a building...

  7. Modeling of liquid flow in surface discontinuities

    Science.gov (United States)

    Lobanova, I. S.; Meshcheryakov, V. A.; Kalinichenko, A. N.

    2018-01-01

    Polymer composite and metallic materials have found wide application in various industries such as aviation, rocket, car manufacturing, ship manufacturing, etc. Many design elements need permanent quality control. Ensuring high quality and reliability of products is impossible without effective nondestructive testing methods. One of these methods is penetrant testing using penetrating substances based on liquid penetration into defect cavities. In this paper, we propose a model of liquid flow to determine the rates of filling the defect cavities with various materials and, based on this, to choose optimal control modes.

  8. A model of the ground surface temperature for micrometeorological analysis

    Science.gov (United States)

    Leaf, Julian S.; Erell, Evyatar

    2017-07-01

    Micrometeorological models at various scales require ground surface temperature, which may not always be measured in sufficient spatial or temporal detail. There is thus a need for a model that can calculate the surface temperature using only widely available weather data, thermal properties of the ground, and surface properties. The vegetated/permeable surface energy balance (VP-SEB) model introduced here requires no a priori knowledge of soil temperature or moisture at any depth. It combines a two-layer characterization of the soil column following the heat conservation law with a sinusoidal function to estimate deep soil temperature, and a simplified procedure for calculating moisture content. A physically based solution is used for each of the energy balance components allowing VP-SEB to be highly portable. VP-SEB was tested using field data measuring bare loess desert soil in dry weather and following rain events. Modeled hourly surface temperature correlated well with the measured data (r 2 = 0.95 for a whole year), with a root-mean-square error of 2.77 K. The model was used to generate input for a pedestrian thermal comfort study using the Index of Thermal Stress (ITS). The simulation shows that the thermal stress on a pedestrian standing in the sun on a fully paved surface, which may be over 500 W on a warm summer day, may be as much as 100 W lower on a grass surface exposed to the same meteorological conditions.

  9. Biological Surface Adsorption Index of Nanomaterials: Modelling Surface Interactions of Nanomaterials with Biomolecules.

    Science.gov (United States)

    Chen, Ran; Riviere, Jim E

    2017-01-01

    Quantitative analysis of the interactions between nanomaterials and their surrounding environment is crucial for safety evaluation in the application of nanotechnology as well as its development and standardization. In this chapter, we demonstrate the importance of the adsorption of surrounding molecules onto the surface of nanomaterials by forming biocorona and thus impact the bio-identity and fate of those materials. We illustrate the key factors including various physical forces in determining the interaction happening at bio-nano interfaces. We further discuss the mathematical endeavors in explaining and predicting the adsorption phenomena, and propose a new statistics-based surface adsorption model, the Biological Surface Adsorption Index (BSAI), to quantitatively analyze the interaction profile of surface adsorption of a large group of small organic molecules onto nanomaterials with varying surface physicochemical properties, first employing five descriptors representing the surface energy profile of the nanomaterials, then further incorporating traditional semi-empirical adsorption models to address concentration effects of solutes. These Advancements in surface adsorption modelling showed a promising development in the application of quantitative predictive models in biological applications, nanomedicine, and environmental safety assessment of nanomaterials.

  10. Impacts of large-scale Intermittent Renewable Energy Sources on electricity systems, and how these can be modeled

    NARCIS (Netherlands)

    Brouwer, Anne Sjoerd; Van Den Broek, Machteld; Seebregts, Ad; Faaij, André

    The electricity sector in OECD countries is on the brink of a large shift towards low-carbon electricity generation. Power systems after 2030 may consist largely of two low-carbon generator types: Intermittent Renewable Energy Sources (IRES) such as wind and solar PV and thermal generators such as

  11. Companion modeling for integrated renewable resource management: a new collaborative approach to create common values for sustainable development

    NARCIS (Netherlands)

    Ruankaew, N.; Page, Le C.; Dumrongrojwattana, P.; Barnaud, C.; Gajaseni, N.; Paassen, van A.; Trebuil, G.

    2010-01-01

    The sustainable management of renewable resources is often complicated by the diversity and dynamic nature of the ecological and socio-economic systems involved. As the dynamics and interactions of these systems are highly complex and frequently unpredictable, there is a need to opt for

  12. Wetting kinetics of oil mixtures on fluorinated model cellulose surfaces.

    Science.gov (United States)

    Aulin, Christian; Shchukarev, Andrei; Lindqvist, Josefina; Malmström, Eva; Wågberg, Lars; Lindström, Tom

    2008-01-15

    The wetting of two different model cellulose surfaces has been studied; a regenerated cellulose (RG) surface prepared by spin-coating, and a novel multilayer film of poly(ethyleneimine) and a carboxymethylated microfibrillated cellulose (MFC). The cellulose films were characterized in detail using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). AFM indicates smooth and continuous films on a nanometer scale and the RMS roughness of the RG cellulose and MFC surfaces was determined to be 3 and 6 nm, respectively. The cellulose films were modified by coating with various amounts of an anionic fluorosurfactant, perfluorooctadecanoic acid, or covalently modified with pentadecafluorooctanyl chloride. The fluorinated cellulose films were used to follow the spreading mechanisms of three different oil mixtures. The viscosity and surface tension of the oils were found to be essential parameters governing the spreading kinetics on these surfaces. XPS and dispersive surface energy measurements were made on the cellulose films coated with perfluorooctadecanoic acid. A strong correlation was found between the surface concentration of fluorine, the dispersive surface energy and the contact angle of castor oil on the surface. A dispersive surface energy less than 18 mN/m was required in order for the cellulose surface to be non-wetting (theta e>90 degrees ) by castor oil.

  13. Fusion fuel and renewables

    International Nuclear Information System (INIS)

    Entler, Slavomir

    2015-01-01

    It is shown that fusion fuel meets all aspects applied when defining renewables. A table of definitions of renewables is presented. The sections of the paper are as follows: An industrial renewable source; Nuclear fusion; Current situation in research; Definitions of renewable sources; Energy concept of nuclear fusion; Fusion fuel; Natural energy flow; Environmental impacts; Fusion fuel assessment; Sustainable power; and Energy mix from renewables. (P.A.)

  14. Alternative methods to model frictional contact surfaces using NASTRAN

    Science.gov (United States)

    Hoang, Joseph

    1992-01-01

    Elongated (slotted) holes have been used extensively for the integration of equipment into Spacelab racks. In the past, this type of interface has been modeled assuming that there is not slippage between contact surfaces, or that there is no load transfer in the direction of the slot. Since the contact surfaces are bolted together, the contact friction provides a load path determined by the normal applied force (bolt preload) and the coefficient of friction. Three alternate methods that utilize spring elements, externally applied couples, and stress dependent elements are examined to model the contacted surfaces. Results of these methods are compared with results obtained from methods that use GAP elements and rigid elements.

  15. A discrete surface growth model for two components

    International Nuclear Information System (INIS)

    El-Nashar, H.F.; Cerdeira, H.A.

    2000-04-01

    We present a ballistic deposition model for the surface growth of a binary species A and C. Numerical simulations of the growth kinetics show a deviation from the Kardar-Parisi-Zhang universality class, model valid for only one kind of deposited particles. The study also shows that when the deposition of particles with less active bonds occurs more frequently the voids under the surface become relevant. However, the increase in overhang/voids processes under the moving interface does not strengthen greatly the local surface gradient. (author)

  16. Lectures on Modification, Characterization and Modeling of Surfaces. Vol. I

    International Nuclear Information System (INIS)

    1997-01-01

    The field of surfaces and thin films is now so broad that has applications in protective coatings, electronic devices, displays, sensors, optical equipment, bio-compatible coatings for surgical implants, odontological and cardiovascular use, and numerous other technologies that depend on the deposition processes. Even though there exist well established methods for both, production and characterization of high-quality surfaces, the interest in finding alternative methods more reliable and less expensive is one of the challenges of present technologies. In this special issue the attention is focused on some areas concerning surface modification, characterization and modeling of surfaces. The volume contains reviews and articles on plasma processing, nitriding, nitrocarburising, diamond-like films, laser and ion-beam surface modification,texture in films and coatings, nuclear techniques in surface analysis, electron spectroscopies, ion scattering spectroscopy, secondary ion mass spectroscopy, STM and AFM applications to surface science, nano structure preparation magnetic and electric properties, surface modeling, calculation of electric and magnetic properties, statistical thermodynamics of surfaces

  17. Integrated Surface/subsurface flow modeling in PFLOTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Painter, Scott L [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-10-01

    Understanding soil water, groundwater, and shallow surface water dynamics as an integrated hydrological system is critical for understanding the Earth’s critical zone, the thin outer layer at our planet’s surface where vegetation, soil, rock, and gases interact to regulate the environment. Computational tools that take this view of soil moisture and shallow surface flows as a single integrated system are typically referred to as integrated surface/subsurface hydrology models. We extend the open-source, highly parallel, subsurface flow and reactive transport simulator PFLOTRAN to accommodate surface flows. In contrast to most previous implementations, we do not represent a distinct surface system. Instead, the vertical gradient in hydraulic head at the land surface is neglected, which allows the surface flow system to be eliminated and incorporated directly into the subsurface system. This tight coupling approach leads to a robust capability and also greatly simplifies implementation in existing subsurface simulators such as PFLOTRAN. Successful comparisons to independent numerical solutions build confidence in the approximation and implementation. Example simulations of the Walker Branch and East Fork Poplar Creek watersheds near Oak Ridge, Tennessee demonstrate the robustness of the approach in geometrically complex applications. The lack of a robust integrated surface/subsurface hydrology capability had been a barrier to PFLOTRAN’s use in critical zone studies. This work addresses that capability gap, thus enabling PFLOTRAN as a community platform for building integrated models of the critical zone.

  18. A spatial and temporal continuous surface-subsurface hydrologic model

    Science.gov (United States)

    Xiao, Qing-Fu; Ustin, Susan L.; Wallender, Wesley W.

    1996-12-01

    A hydrologic model integrating surface-subsurface processes was developed based on spatial and temporal continuity theory. The raster-based mass balance hydrologic model consists of several submodels which determine spatial and temporal patterns in precipitation, surface flow, infiltration, subsurface flow, and the linkages between these submodels. Model parameters and variables are derived directly or indirectly from satellite remote sensing data, topographic maps, soil maps, literature, and weather station data and are stored in a Geographic Information System (GIS) database used for visualization. Surface resolution of cells in the model is 20 m by 20 m (pixel resolution of the Systeme Probatoire d'Observation de la Terre (SPOT) satellite image) over a 2511 km2 study area around the Crazy Mountains, Alaska, a watershed on the Arctic Circle draining into the Yukon River. The outputs from this model illustrate the interaction of physical and biologic factors on the partitioning of hydrologic components in a complex landscape.

  19. A theoretical study of rotatable renewable energy system for stratospheric airship

    International Nuclear Information System (INIS)

    Lv, Mingyun; Li, Jun; Zhu, Weiyu; Du, Huafei; Meng, Junhui; Sun, Kangwen

    2017-01-01

    Highlights: • A new rotatable renewable energy system is designed for stratospheric airship. • A theoretical model of optimal rotation angle and required area are studied. • The effects of latitude and date on output energy per day are investigated. • The advantages of the rotatable renewable energy system are studied. - Abstract: Renewable energy system is very critical for solving the energy problem of a long endurance stratospheric airship. Output performance of the traditional solar array fixed on the upper surface of the airship remains to be improved to reduce the area and weight of renewable energy system. Inspired by the solar tracking system and kirigami, a rotatable renewable energy system (mainly including solar array) is designed to improve the current status of the energy system. The advantages of the rotatable solar array are studied using a MATLAB computer program based on the theoretical model established in this paper. The improvements in output energy and required area of the solar array were compared between the traditional airship and improved one. Studies had shown that the rotatable renewable energy system made the total weight of energy system decreased by 1000 kg when the maximum design speed of the airship was greater than 22 m/s. The results demonstrate that the rotatable renewable energy system for the airship can be a good way to improve the output performance of solar array, and the conceptual design and theoretical model suggest a pathway towards solving the energy problem of a stratospheric airship.

  20. Modeling Apple Surface Temperature Dynamics Based on Weather Data

    Directory of Open Access Journals (Sweden)

    Lei Li

    2014-10-01

    Full Text Available The exposure of fruit surfaces to direct sunlight during the summer months can result in sunburn damage. Losses due to sunburn damage are a major economic problem when marketing fresh apples. The objective of this study was to develop and validate a model for simulating fruit surface temperature (FST dynamics based on energy balance and measured weather data. A series of weather data (air temperature, humidity, solar radiation, and wind speed was recorded for seven hours between 11:00–18:00 for two months at fifteen minute intervals. To validate the model, the FSTs of “Fuji” apples were monitored using an infrared camera in a natural orchard environment. The FST dynamics were measured using a series of thermal images. For the apples that were completely exposed to the sun, the RMSE of the model for estimating FST was less than 2.0 °C. A sensitivity analysis of the emissivity of the apple surface and the conductance of the fruit surface to water vapour showed that accurate estimations of the apple surface emissivity were important for the model. The validation results showed that the model was capable of accurately describing the thermal performances of apples under different solar radiation intensities. Thus, this model could be used to more accurately estimate the FST relative to estimates that only consider the air temperature. In addition, this model provides useful information for sunburn protection management.

  1. Adhesion of perfume-filled microcapsules to model fabric surfaces.

    Science.gov (United States)

    He, Yanping; Bowen, James; Andrews, James W; Liu, Min; Smets, Johan; Zhang, Zhibing

    2014-01-01

    The retention and adhesion of melamine formaldehyde (MF) microcapsules on a model fabric surface in aqueous solution were investigated using a customised flow chamber technique and atomic force microscopy (AFM). A cellulose film was employed as a model fabric surface. Modification of the cellulose with chitosan was found to increase the retention and adhesion of microcapsules on the model fabric surface. The AFM force-displacement data reveal that bridging forces resulting from the extension of cellulose chains dominate the adhesion between the microcapsule and the unmodified cellulose film, whereas electrostatic attraction helps the microcapsules adhere to the chitosan-modified cellulose film. The correlation between results obtained using these two complementary techniques suggests that the flow chamber device can be potentially used for rapid screening of the effect of chemical modification on the adhesion of microparticles to surfaces, reducing the time required to achieve an optimal formulation.

  2. A physically based model of global freshwater surface temperature

    Science.gov (United States)

    van Beek, Ludovicus P. H.; Eikelboom, Tessa; van Vliet, Michelle T. H.; Bierkens, Marc F. P.

    2012-09-01

    Temperature determines a range of physical properties of water and exerts a strong control on surface water biogeochemistry. Thus, in freshwater ecosystems the thermal regime directly affects the geographical distribution of aquatic species through their growth and metabolism and indirectly through their tolerance to parasites and diseases. Models used to predict surface water temperature range between physically based deterministic models and statistical approaches. Here we present the initial results of a physically based deterministic model of global freshwater surface temperature. The model adds a surface water energy balance to river discharge modeled by the global hydrological model PCR-GLOBWB. In addition to advection of energy from direct precipitation, runoff, and lateral exchange along the drainage network, energy is exchanged between the water body and the atmosphere by shortwave and longwave radiation and sensible and latent heat fluxes. Also included are ice formation and its effect on heat storage and river hydraulics. We use the coupled surface water and energy balance model to simulate global freshwater surface temperature at daily time steps with a spatial resolution of 0.5° on a regular grid for the period 1976-2000. We opt to parameterize the model with globally available data and apply it without calibration in order to preserve its physical basis with the outlook of evaluating the effects of atmospheric warming on freshwater surface temperature. We validate our simulation results with daily temperature data from rivers and lakes (U.S. Geological Survey (USGS), limited to the USA) and compare mean monthly temperatures with those recorded in the Global Environment Monitoring System (GEMS) data set. Results show that the model is able to capture the mean monthly surface temperature for the majority of the GEMS stations, while the interannual variability as derived from the USGS and NOAA data was captured reasonably well. Results are poorest for

  3. Optimized sizing model for renewable energy systems in rural areas; Modelo de dimensionamento otimizado para sistemas energeticos renovaveis em ambiente rurais

    Energy Technology Data Exchange (ETDEWEB)

    Nogueira, Carlos E.C. [UNIOESTE, Cascavel, PR (Brazil). Centro de Ciencias Exatas e Tecnologicas]. E-mail: cecn@correios.net.br; Zuern, Hans H. [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Engenharia Eletrica

    2005-05-15

    The purpose of this research was to develop a methodology for sizing integrated renewable energy systems, useful for rural areas, using simulation and optimization tools developed in MATLAB 6.0. The sizing model produces a system with minimum cost and high reliability level, based on the concept of loss of power supply probability (LPSP) for consecutive hours. An optimization model is presented and three different sizing scenarios are calculated and compared, showing flexibility in the elaboration of different project conceptions. The obtained results show a complete sizing of the energy conversion devices and a long-term cost evaluation. (author)

  4. Utilisation of real-scale renewable energy test facility for validation of generic wind turbine and wind power plant controller models

    Energy Technology Data Exchange (ETDEWEB)

    Zeni, Lorenzo; Hesselbæk, Bo; Bech, John; Sørensen, Poul Ejnar; Gevorgian, Vahan; Wallen, Robb

    2016-09-01

    This article presents an example of application of a modern test facility conceived for experiments regarding the integration of renewable energy in the power system. The capabilities of the test facility are used to validate dynamic simulation models of wind power plants and their controllers. The models are based on standard and generic blocks. The successful validation of events related to the control of active power (control phenomena in <10 Hz range, including frequency control and power oscillation damping) is described, demonstrating the capabilities of the test facility and drawing the track for future work and improvements.

  5. Standard fire behavior fuel models: a comprehensive set for use with Rothermel's surface fire spread model

    Science.gov (United States)

    Joe H. Scott; Robert E. Burgan

    2005-01-01

    This report describes a new set of standard fire behavior fuel models for use with Rothermel's surface fire spread model and the relationship of the new set to the original set of 13 fire behavior fuel models. To assist with transition to using the new fuel models, a fuel model selection guide, fuel model crosswalk, and set of fuel model photos are provided.

  6. Waste-to-wheel analysis of anaerobic-digestion-based renewable natural gas pathways with the GREET model.

    Energy Technology Data Exchange (ETDEWEB)

    Han, J.; Mintz, M.; Wang, M. (Energy Systems)

    2011-12-14

    In 2009, manure management accounted for 2,356 Gg or 107 billion standard cubic ft of methane (CH{sub 4}) emissions in the United States, equivalent to 0.5% of U.S. natural gas (NG) consumption. Owing to the high global warming potential of methane, capturing and utilizing this methane source could reduce greenhouse gas (GHG) emissions. The extent of that reduction depends on several factors - most notably, how much of this manure-based methane can be captured, how much GHG is produced in the course of converting it to vehicular fuel, and how much GHG was produced by the fossil fuel it might displace. A life-cycle analysis was conducted to quantify these factors and, in so doing, assess the impact of converting methane from animal manure into renewable NG (RNG) and utilizing the gas in vehicles. Several manure-based RNG pathways were characterized in the GREET (Greenhouse gases, Regulated Emissions, and Energy use in Transportation) model, and their fuel-cycle energy use and GHG emissions were compared to petroleum-based pathways as well as to conventional fossil NG pathways. Results show that despite increased total energy use, both fossil fuel use and GHG emissions decline for most RNG pathways as compared with fossil NG and petroleum. However, GHG emissions for RNG pathways are highly dependent on the specifics of the reference case, as well as on the process energy emissions and methane conversion factors assumed for the RNG pathways. The most critical factors are the share of flared controllable CH{sub 4} and the quantity of CH{sub 4} lost during NG extraction in the reference case, the magnitude of N{sub 2}O lost in the anaerobic digestion (AD) process and in AD residue, and the amount of carbon sequestered in AD residue. In many cases, data for these parameters are limited and uncertain. Therefore, more research is needed to gain a better understanding of the range and magnitude of environmental benefits from converting animal manure to RNG via AD.

  7. Surface-source modeling and estimation using biomagnetic measurements.

    Science.gov (United States)

    Yetik, Imam Samil; Nehorai, Arye; Muravchik, Carlos H; Haueisen, Jens; Eiselt, Michael

    2006-10-01

    We propose a number of electric source models that are spatially distributed on an unknown surface for biomagnetism. These can be useful to model, e.g., patches of electrical activity on the cortex. We use a realistic head (or another organ) model and discuss the special case of a spherical head model with radial sensors resulting in more efficient computations of the estimates for magnetoencephalography. We derive forward solutions, maximum likelihood (ML) estimates, and Cramér-Rao bound (CRB) expressions for the unknown source parameters. A model selection method is applied to decide on the most appropriate model. We also present numerical examples to compare the performances and computational costs of the different models and illustrate when it is possible to distinguish between surface and focal sources or line sources. Finally, we apply our methods to real biomagnetic data of phantom human torso and demonstrate the applicability of them.

  8. Estimation of shape model parameters for 3D surfaces

    DEFF Research Database (Denmark)

    Erbou, Søren Gylling Hemmingsen; Darkner, Sune; Fripp, Jurgen

    2008-01-01

    is applied to a database of 3D surfaces from a section of the porcine pelvic bone extracted from 33 CT scans. A leave-one-out validation shows that the parameters of the first 3 modes of the shape model can be predicted with a mean difference within [-0.01,0.02] from the true mean, with a standard deviation......Statistical shape models are widely used as a compact way of representing shape variation. Fitting a shape model to unseen data enables characterizing the data in terms of the model parameters. In this paper a Gauss-Newton optimization scheme is proposed to estimate shape model parameters of 3D...... surfaces using distance maps, which enables the estimation of model parameters without the requirement of point correspondence. For applications with acquisition limitations such as speed and cost, this formulation enables the fitting of a statistical shape model to arbitrarily sampled data. The method...

  9. The Blake-Zisserman model for digital surface models segmentation

    Directory of Open Access Journals (Sweden)

    M. Zanetti

    2013-10-01

    Full Text Available The Blake-Zisserman functional is a second-order variational model for data segmentation. The model is build up of several terms, the nature and the interaction of them allow to obtain a smooth approximation of the data that preserves the constant-gradient areas morphology, which are explicitly detected by partitioning the data with the graph of two special functions: the edge-detector function, which detects discontinuities of the datum, and the edge/crease-detector function, which also detects discontinuities of the gradient. First, the main features of the model are presented to justify the sense of the application of the model to DSMs. It is stressed the fact that the model can yield an almost piecewise-linear approximation of the data. This result is certainly of some interest for the specific application of the model to urban DSMs. Then, an example of its application is presented and the results are discussed to highlight how the features of the model affect the model outputs. The smooth approximation of the data produced by the model is thought to be a better candidate for further processing. In this sense, the application of the Blake-Zisserman model can be seen as a useful preprocessing step in the chain of DSMs processing. Eventually, some perspectives are presented to show some promising applications and developments of the Blake-Zisserman model.

  10. Modeling and analysis for surface roughness and material removal ...

    African Journals Online (AJOL)

    user

    terms of cutting parameters is also developed using regression modeling. The results indicate that the developed model is suitable for prediction of surface roughness and material removal rate in machining of unidirectional glass fiber reinforced plastics (UD-GFRP) composites. The predicted values and measured values ...

  11. Modeling Alaska boreal forests with a controlled trend surface approach

    Science.gov (United States)

    Mo Zhou; Jingjing Liang

    2012-01-01

    An approach of Controlled Trend Surface was proposed to simultaneously take into consideration large-scale spatial trends and nonspatial effects. A geospatial model of the Alaska boreal forest was developed from 446 permanent sample plots, which addressed large-scale spatial trends in recruitment, diameter growth, and mortality. The model was tested on two sets of...

  12. Modelling surface run-off and trends analysis over India

    Indian Academy of Sciences (India)

    responsible for run-off generation plays a major role in run-off modelling at region scales. Remote sensing, GIS and advancement of the computer technology based evaluation of land surface prop- erties at spatial and temporal scales are very useful input data for hydrological models. Using remote sensing data is not only ...

  13. Modeling and analysis for surface roughness and material removal ...

    African Journals Online (AJOL)

    International Journal of Engineering, Science and Technology ... A multiple objective utility model has been studied to optimize both the dependent parameters. ... Keywords: UD-GFRP composites, ANOVA, multi response optimization, utility concept, regression modeling, surface roughness, material removal rate, ...

  14. Modified Critical State Two-Surface Plasticity Model for Sands

    DEFF Research Database (Denmark)

    Sørensen, Kris Wessel; Nielsen, Søren Kjær; Shajarati, Amir

    This article describes the outline of a numerical integration scheme for a critical state two-surface plasticity model for sands. The model is slightly modified by LeBlanc (2008) compared to the original formulation presented by Manzari and Dafalias (1997) and has the ability to correctly model...... the stress-strain response of sands. The model is versatile and can be used to simulate drained and undrained conditions, due to the fact that the model can efficiently calculate change in void ratio as well as pore pressure. The objective of the constitutive model is to investigate if the numerical...

  15. Renewable Resources: a national catalog of model projects. Volume 2. Mid-American Solar Energy Complex Region

    Energy Technology Data Exchange (ETDEWEB)

    None

    1980-07-01

    This compilation of diverse conservation and renewable energy projects across the United States was prepared through the enthusiastic participation of solar and alternate energy groups from every state and region. Compiled and edited by the Center for Renewable Resources, these projects reflect many levels of innovation and technical expertise. In many cases, a critique analysis is presented of how projects performed and of the institutional conditions associated with their success or failure. Some 2000 projects are included in this compilation; most have worked, some have not. Information about all is presented to aid learning from these experiences. The four volumes in this set are arranged in state sections by geographic region, coinciding with the four Regional Solar Energy Centers. The table of contents is organized by project category so that maximum cross-referencing may be obtained. This volume includes information on the Mid-American Solar Energy Complex Region. (WHK)

  16. A 2-D model for friction of complex anisotropic surfaces

    Science.gov (United States)

    Costagliola, Gianluca; Bosia, Federico; Pugno, Nicola M.

    2018-03-01

    The friction force observed at macroscale is the result of interactions at various lower length scales that are difficult to model in a combined manner. For this reason, simplified approaches are required, depending on the specific aspect to be investigated. In particular, the dimensionality of the system is often reduced, especially in models designed to provide a qualitative description of frictional properties of elastic materials, e.g. the spring-block model. In this paper, we implement for the first time a two dimensional extension of the spring-block model, applying it to structured surfaces and investigating by means of numerical simulations the frictional behaviour of a surface in the presence of features like cavities, pillars or complex anisotropic structures. We show how friction can be effectively tuned by appropriate design of such surface features.

  17. Levels of Organisation in agent-based modelling for renewable resources management. Agricultural water management collective rules enforcement in the French Drome River Valley Case Study

    International Nuclear Information System (INIS)

    Abrami, G.

    2004-11-01

    Levels of Organisation in agent-based modelling for renewable resources management. Agricultural water management collective rules enforcement in the French Dr me River Valley Case Study. In the context of Agent-Based Modelling for participative renewable resources management, this thesis is concerned with representing multiple tangled levels of organisation of a system. The Agent-Group-Role (AGR) formalism is borrowed from computer science research. It has been conceptually specified to handle levels of organisation, and behaviours within levels of organisation. A design methodology dedicated to AGR modelling has been developed, together with an implementation of the formalism over a multi-agent platform. AGR models of agricultural water management in the French Dr me River Valley have been built and tested. This experiment demonstrates the AGR formalism ability to (1) clarify usually implicit hypothesis on action modes, scales or viewpoints (2) facilitate the definition of scenarios with various collective rules, and various rules in enforcement behaviours (3) generate bricks for generic irrigated catchment models. (author)

  18. Scale-adaptive surface modeling of vascular structures

    Directory of Open Access Journals (Sweden)

    Ma Xin

    2010-11-01

    Full Text Available Abstract Background The effective geometric modeling of vascular structures is crucial for diagnosis, therapy planning and medical education. These applications require good balance with respect to surface smoothness, surface accuracy, triangle quality and surface size. Methods Our method first extracts the vascular boundary voxels from the segmentation result, and utilizes these voxels to build a three-dimensional (3D point cloud whose normal vectors are estimated via covariance analysis. Then a 3D implicit indicator function is computed from the oriented 3D point cloud by solving a Poisson equation. Finally the vessel surface is generated by a proposed adaptive polygonization algorithm for explicit 3D visualization. Results Experiments carried out on several typical vascular structures demonstrate that the presented method yields both a smooth morphologically correct and a topologically preserved two-manifold surface, which is scale-adaptive to the local curvature of the surface. Furthermore, the presented method produces fewer and better-shaped triangles with satisfactory surface quality and accuracy. Conclusions Compared to other state-of-the-art approaches, our method reaches good balance in terms of smoothness, accuracy, triangle quality and surface size. The vessel surfaces produced by our method are suitable for applications such as computational fluid dynamics simulations and real-time virtual interventional surgery.

  19. Surface Winds and Dust Biases in Climate Models

    Science.gov (United States)

    Evan, A. T.

    2018-01-01

    An analysis of North African dust from models participating in the Fifth Climate Models Intercomparison Project (CMIP5) suggested that, when forced by observed sea surface temperatures, these models were unable to reproduce any aspects of the observed year-to-year variability in dust from North Africa. Consequently, there would be little reason to have confidence in the models' projections of changes in dust over the 21st century. However, no subsequent study has elucidated the root causes of the disagreement between CMIP5 and observed dust. Here I develop an idealized model of dust emission and then use this model to show that, over North Africa, such biases in CMIP5 models are due to errors in the surface wind fields and not due to the representation of dust emission processes. These results also suggest that because the surface wind field over North Africa is highly spatially autocorrelated, intermodel differences in the spatial structure of dust emission have little effect on the relative change in year-to-year dust emission over the continent. I use these results to show that similar biases in North African dust from the NASA Modern Era Retrospective analysis for Research and Applications (MERRA) version 2 surface wind field biases but that these wind biases were not present in the first version of MERRA.

  20. Renewable energy annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary.

  1. Renewable target in sight

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    Australia's renewable energy industry is expecting several billion dollars of investment over the next 10 years following passage in December last year of the Renewable Energy Electricity) Act 2000 through Federal Parliament. The Act requires an additional 9500GWh of Australia's electricity production to be sourced from renewables by the year 2010. It also establishes a market for the 'green' component of the energy separate from the electricity itself, through a Renewable Energy Certificate (REC), whereby an accredited generator of renewable energy is able to issue one REC for each megawatt-hour of renewable energy generated

  2. Renewable energy annual 1996

    International Nuclear Information System (INIS)

    1997-03-01

    This report presents summary data on renewable energy consumption, the status of each of the primary renewable technologies, a profile of each of the associated industries, an analysis of topical issues related to renewable energy, and information on renewable energy projects worldwide. It is the second in a series of annual reports on renewable energy. The renewable energy resources included in the report are biomass (wood and ethanol); municipal solid waste, including waste-to-energy and landfill gas; geothermal; wind; and solar energy, including solar thermal and photovoltaic. The report also includes various appendices and a glossary

  3. Modelling cell motility and chemotaxis with evolving surface finite elements.

    Science.gov (United States)

    Elliott, Charles M; Stinner, Björn; Venkataraman, Chandrasekhar

    2012-11-07

    We present a mathematical and a computational framework for the modelling of cell motility. The cell membrane is represented by an evolving surface, with the movement of the cell determined by the interaction of various forces that act normal to the surface. We consider external forces such as those that may arise owing to inhomogeneities in the medium and a pressure that constrains the enclosed volume, as well as internal forces that arise from the reaction of the cells' surface to stretching and bending. We also consider a protrusive force associated with a reaction-diffusion system (RDS) posed on the cell membrane, with cell polarization modelled by this surface RDS. The computational method is based on an evolving surface finite-element method. The general method can account for the large deformations that arise in cell motility and allows the simulation of cell migration in three dimensions. We illustrate applications of the proposed modelling framework and numerical method by reporting on numerical simulations of a model for eukaryotic chemotaxis and a model for the persistent movement of keratocytes in two and three space dimensions. Movies of the simulated cells can be obtained from http://homepages.warwick.ac.uk/∼maskae/CV_Warwick/Chemotaxis.html.

  4. Surface Structures of Model Metal Catalysts in Reactant Gases.

    Science.gov (United States)

    Tao, Franklin Feng; Ralston, Walter T; Liu, Huimin; Somorjai, Gabor A

    2018-01-18

    Atomic scale knowledge of the surface structure of a metal catalyst is essential for fundamentally understanding the catalytic reactions performed on it. A correlation between the true atomic surface structure of a metal catalyst under reaction conditions and the corresponding catalytic performance is the key in pursuing mechanistic insight at a molecular level. Here the surface structures of model, metal catalysts in both ultrahigh vacuum (UHV) and gaseous environments of CO at a wide range of pressures are discussed. The complexity of observed surface structures in CO is illustrated, driving the necessity for visualization of the catalytic metals under realistic reaction conditions. Technical barriers for visualization of metal surfaces in situ at high temperature and high pressure are discussed.

  5. Assessment of Response Surface Models using Independent Confirmation Point Analysis

    Science.gov (United States)

    DeLoach, Richard

    2010-01-01

    This paper highlights various advantages that confirmation-point residuals have over conventional model design-point residuals in assessing the adequacy of a response surface model fitted by regression techniques to a sample of experimental data. Particular advantages are highlighted for the case of design matrices that may be ill-conditioned for a given sample of data. The impact of both aleatory and epistemological uncertainty in response model adequacy assessments is considered.

  6. Modelling of frost formation and growth on microstuctured surface

    Science.gov (United States)

    Muntaha, Md. Ali; Haider, Md. Mushfique; Rahman, Md. Ashiqur

    2016-07-01

    Frost formation on heat exchangers is an undesirable phenomenon often encountered in different applications where the cold surface with a temperature below freezing point of water is exposed to humid air. The formation of frost on the heat transfer surface results in an increase in pressure drop and reduction in heat transfer, resulting in a reduction of the system efficiency. Many factors, including the temperature and moisture content of air, cold plate temperature, surface wettability etc., are known to affect frost formation and growth. In our present study, a model for frost growth on rectangular, periodic microgroove surfaces for a range of microgroove dimension (ten to hundreds of micron) is presented. The mathematical model is developed analytically by solving the governing heat and mass transfer equations with appropriate boundary conditions using the EES (Engineering Equation Solver) software. For temperature, a convective boundary condition at frost-air interface and a fixed cold plate surface temperature is used. Instead of considering the saturation or super-saturation models, density gradient at the surface is obtained by considering experimentally-found specified heat flux. The effect of surface wettability is incorporated by considering the distribution of condensed water droplets at the early stage of frost formation. Thickness, density and thermal conductivity of frost layer on the micro-grooved surfaces are found to vary with the dimension of the grooves. The variation of density and thickness of the frost layer on these micro-grooved surfaces under natural convection is numerally determined for a range of plate temperature and air temperature conditions and is compared with experimental results found in the open literature.

  7. Development of a module for taking remuneration under the Renewable Energy Law into account in a model for calculating the economic efficiency of smart electricity grids

    International Nuclear Information System (INIS)

    Ludwig, Maximilian Uwe; Toprani, Vipul; Witte, Frank

    2014-01-01

    The enactment of the Law Giving Priority to Renewable Energies (EEG) in 2000 laid the cornerstone for the transformation of the German electricity supply. Since then the proportion of renewable energy in electricity production has grown dramatically, confronting the German network infrastructure, which was initially designed for a centralised supply system, with new problems and challenges. In order to achieve optimal coordination between volatile energy infeeds, electricity storage plants and consumers it is necessary to bring all components involved together in a smart grid. A small-scale grid of this description is currently being operated and investigated on the EUREF Campus in Berlin Schoeneberg. The task of achieving optimal allocation of energy flows and getting the micro smart grid to run accordingly, i.e. at a profit, poses new challenges to all involved. To be able to determine the economic efficiency of smart grids a calculation model was developed which simulates the operation of production and storage plants and takes the behaviour of real consumers into account. The model rates the profitability of investments made in terms of their capital value. In its current version the model still disregards the legal regulations for the remuneration of electricity produced from a mix of renewable resources. These cannot be considered as physically separate in a smart grid. In the present study a module based on EEG provisions was developed which calculates remuneration rates as a function of production and demand at a given moment. This is one of several factors which influence the economic efficiency of smart grids. The study undertakes to identify these factors and describe their influence on the profitability of the total investment.

  8. Modeling Power Plant Cooling Water Requirements: A Regional Analysis of the Energy-Water Nexus Considering Renewable Sources within the Power Generation Mix

    Science.gov (United States)

    Peck, Jaron Joshua

    Water is used in power generation for cooling processes in thermoelectric power. plants and currently withdraws more water than any other sector in the U.S. Reducing water. use from power generation will help to alleviate water stress in at risk areas, where droughts. have the potential to strain water resources. The amount of water used for power varies. depending on many climatic aspects as well as plant operation factors. This work presents. a model that quantifies the water use for power generation for two regions representing. different generation fuel portfolios, California and Utah. The analysis of the California Independent System Operator introduces the methods. of water energy modeling by creating an overall water use factor in volume of water per. unit of energy produced based on the fuel generation mix of the area. The idea of water. monitoring based on energy used by a building or region is explored based on live fuel mix. data. This is for the purposes of increasing public awareness of the water associated with. personal energy use and helping to promote greater energy efficiency. The Utah case study explores the effects more renewable, and less water-intensive, forms of energy will have on the overall water use from power generation for the state. Using a similar model to that of the California case study, total water savings are quantified. based on power reduction scenarios involving increased use of renewable energy. The. plausibility of implementing more renewable energy into Utah’s power grid is also. discussed. Data resolution, as well as dispatch methods, economics, and solar variability, introduces some uncertainty into the analysis.

  9. Surface photovoltage measurements and finite element modeling of SAW devices.

    Energy Technology Data Exchange (ETDEWEB)

    Donnelly, Christine

    2012-03-01

    Over the course of a Summer 2011 internship with the MEMS department of Sandia National Laboratories, work was completed on two major projects. The first and main project of the summer involved taking surface photovoltage measurements for silicon samples, and using these measurements to determine surface recombination velocities and minority carrier diffusion lengths of the materials. The SPV method was used to fill gaps in the knowledge of material parameters that had not been determined successfully by other characterization methods. The second project involved creating a 2D finite element model of a surface acoustic wave device. A basic form of the model with the expected impedance response curve was completed, and the model is ready to be further developed for analysis of MEMS photonic resonator devices.

  10. DNSC08 mean sea surface and mean dynamic topography models

    DEFF Research Database (Denmark)

    Andersen, Ole Baltazar; Knudsen, Per

    2009-01-01

    -2004. It is the first global MSS without a polar gap including all of the Arctic Ocean by including laser altimetry from the ICESat mission. The mean dynamic topography (MDT) is the quantity that bridges the geoid and the mean sea surface constraining large-scale ocean circulation. Here we present a new high...... models. This way a consistent modeling of the interannual sea level variability is carried out before different MSS and MDT models are compared. Altimetric derived physical MSS can be converted into an "inverse barometer corrected MSS'' by correcting the altimeter range for the inverse barometer effect......The Danish National Space Center data set DNSC08 mean sea surface (MSS) is a new enhanced mapping of the mean sea surface height of the worlds oceans, derived from a combination of 12 years of satellite altimetry from a total of eight different satellites covering the period 1993...

  11. TECHNICAL VISION SYSTEM FOR THE ROBOTIC MODEL OF SURFACE VESSEL

    Directory of Open Access Journals (Sweden)

    V. S. Gromov

    2016-07-01

    Full Text Available The paper presents results of work on creation of technical vision systems within the training complex for the verification of control systems by the model of surface vessel. The developed system allows determination of the coordinates and orientation angle of the object of control by means of an external video camera on one bench mark and without the need to install additional equipment on the object of control itself. Testing of the method was carried out on the robotic complex with the model of a surface vessel with a length of 430 mm; coordinates of the control object were determined with the accuracy of 2 mm. This method can be applied as a subsystem of receiving coordinates for systems of automatic control of surface vessels when testing on the scale models.

  12. Surface complexation modeling of americium sorption onto volcanic tuff.

    Science.gov (United States)

    Ding, M; Kelkar, S; Meijer, A

    2014-10-01

    Results of a surface complexation model (SCM) for americium sorption on volcanic rocks (devitrified and zeolitic tuff) are presented. The model was developed using PHREEQC and based on laboratory data for americium sorption on quartz. Available data for sorption of americium on quartz as a function of pH in dilute groundwater can be modeled with two surface reactions involving an americium sulfate and an americium carbonate complex. It was assumed in applying the model to volcanic rocks from Yucca Mountain, that the surface properties of volcanic rocks can be represented by a quartz surface. Using groundwaters compositionally representative of Yucca Mountain, americium sorption distribution coefficient (Kd, L/Kg) values were calculated as function of pH. These Kd values are close to the experimentally determined Kd values for americium sorption on volcanic rocks, decreasing with increasing pH in the pH range from 7 to 9. The surface complexation constants, derived in this study, allow prediction of sorption of americium in a natural complex system, taking into account the inherent uncertainty associated with geochemical conditions that occur along transport pathways. Published by Elsevier Ltd.

  13. Sediment Transport Model for a Surface Irrigation System

    Directory of Open Access Journals (Sweden)

    Damodhara R. Mailapalli

    2013-01-01

    Full Text Available Controlling irrigation-induced soil erosion is one of the important issues of irrigation management and surface water impairment. Irrigation models are useful in managing the irrigation and the associated ill effects on agricultural environment. In this paper, a physically based surface irrigation model was developed to predict sediment transport in irrigated furrows by integrating an irrigation hydraulic model with a quasi-steady state sediment transport model to predict sediment load in furrow irrigation. The irrigation hydraulic model simulates flow in a furrow irrigation system using the analytically solved zero-inertial overland flow equations and 1D-Green-Ampt, 2D-Fok, and Kostiakov-Lewis infiltration equations. Performance of the sediment transport model was evaluated for bare and cropped furrow fields. The results indicated that the sediment transport model can predict the initial sediment rate adequately, but the simulated sediment rate was less accurate for the later part of the irrigation event. Sensitivity analysis of the parameters of the sediment module showed that the soil erodibility coefficient was the most influential parameter for determining sediment load in furrow irrigation. The developed modeling tool can be used as a water management tool for mitigating sediment loss from the surface irrigated fields.

  14. Renewable Fuel Standard Program

    Science.gov (United States)

    Information about regulations, developed by EPA, in collaboration with refiners, renewable fuel producers, and many other stakeholders, that ensure that transportation fuel sold in the United States contains a minimum volume of renewable fuel.

  15. Renewable Energy Certificates (RECs)

    Science.gov (United States)

    Renewable Energy Certificates (RECs), are tradable, non-tangible energy commodities in the United States that represent proof that 1 megawatt-hour (MWh) of electricity was generated from an eligible renewable energy resource.

  16. Online driver's license renewal.

    Science.gov (United States)

    2015-09-01

    The Kentucky Department of Vehicle Regulation is exploring the possibility of developing and implementing online : drivers license renewal. The objective of this project was to: 1) evaluate online drivers license and REAL ID renewal : programs ...

  17. Improvement of a land surface model for accurate prediction of surface energy and water balances

    International Nuclear Information System (INIS)

    Katata, Genki

    2009-02-01

    In order to predict energy and water balances between the biosphere and atmosphere accurately, sophisticated schemes to calculate evaporation and adsorption processes in the soil and cloud (fog) water deposition on vegetation were implemented in the one-dimensional atmosphere-soil-vegetation model including CO 2 exchange process (SOLVEG2). Performance tests in arid areas showed that the above schemes have a significant effect on surface energy and water balances. The framework of the above schemes incorporated in the SOLVEG2 and instruction for running the model are documented. With further modifications of the model to implement the carbon exchanges between the vegetation and soil, deposition processes of materials on the land surface, vegetation stress-growth-dynamics etc., the model is suited to evaluate an effect of environmental loads to ecosystems by atmospheric pollutants and radioactive substances under climate changes such as global warming and drought. (author)

  18. Do Lateral Flows Matter for the Hyperresolution Land Surface Modeling?

    Science.gov (United States)

    Ji, Peng; Yuan, Xing; Liang, Xin-Zhong

    2017-11-01

    Hyperresolution land surface modeling provides an unprecedented opportunity to simulate locally relevant water and energy cycle, but lateral surface and/or subsurface flows that are essential at fine scale are often neglected by most one-dimensional land surface models (LSMs). To analyze effects of lateral flows across scales, a Conjunctive Surface-Subsurface Process model, which considers soil moisture-surface flow interaction and quasi-three-dimensional subsurface flow, is implemented over a mountainous HyperHydro test bed in southwestern USA at different resolutions. Validation over more than 70 International Soil Moisture Network stations shows that there are significant improvements in soil moisture simulations from 30 km to 4 km as finer soil property and precipitation data are used, with correlation increased by 5%-16% and error decreased by 5%. Lateral surface flow has a significant influence on surface soil moisture and ground evaporation even at coarse resolution. Effect of lateral subsurface flow on soil moisture is nontrivial at 1 km or finer resolution especially over wet areas. At 100 m resolution, topography-induced lateral subsurface flow causes drier peaks and wetter valleys, decreases latent heat by 8% at peaks, while increases it by 12% at valleys. Furthermore, influences of lateral subsurface flow on ground evaporation and vegetation transpiration are more significant during dry season due to a stronger coupling between soil moisture and evapotranspiration. Therefore, it is worthy to incorporate lateral flow processes in hyperresolution LSMs to better represent water and energy heterogeneity even with limited hyperresolution meteorological and surface data.

  19. Surface science studies of model fuel cell electrocatalysts

    Science.gov (United States)

    Marković, N. M.; Ross, P. N.

    2002-04-01

    The purpose of this review is to discuss progress in the understanding of electrocatalytic reactions through the study of model systems with surface spectroscopies. Pure metal single crystals and well-characterized bulk alloys have been used quite successfully as models for real (commercial) electrocatalysts. Given the sheer volume of all work in electrocatalysis that is on fuel cell reactions, we will focus on electrocatalysts for fuel cells. Since Pt is the model fuel cell electrocatalyst, we will focus entirely on studies of pure Pt and Pt bimetallic alloys. The electrode reactions discussed include hydrogen oxidation/evolution, oxygen reduction, and the electrooxidation of carbon monoxide, formic acid, and methanol. Surface spectroscopies emphasized are FTIR, STM/AFM and surface X-ray scattering (SXS). The discussion focuses on the relation between the energetics of adsorption of intermediates and the reaction pathway and kinetics, and how the energetics and kinetics relate to the extrinsic properties of the model system, e.g. surface structure and/or composition. Finally, we conclude by discussing the limitations that are reached by using pure metal single crystals and well-characterized bulk alloys as models for real catalysts, and suggest some directions for developing more realistic systems.

  20. Surface growth of two kinds of particles deposition models

    International Nuclear Information System (INIS)

    Wei Wang; Cerdeira, H.A.

    1993-10-01

    The surface kinetics with diffusion of two kinds of particles (A and C) deposition models, randomlike and ballisticlike depositing on a (1 + 1)-dimensional substrate, has been studied in this paper. The scaling behaviour of the surface width for these two models is obtained for various deposition probability P of particle C (the probability of particle A, being 1 - P). We found that both models have a scaling behaviour: the surface width growth only depends on the time, W ∼ t α(p) for the early stage and W ∼ t β(P) for the intermediate time, as well as W ∼ L z for the later time with different exponents α(P) and β(P) and z for two models. In addition, there is a phase transition when the saturation surface widths are scaled to the deposition probability P for both models W(t = ∞) ∼ P γ : before and after the transition the scaling exponent γ is different. This transition is interpreted as that there are different morphologic structures when the depositing probability for one kind of particle, particle C, is larger than a critical value P c . (author). 16 refs, 5 figs, 2 tabs

  1. A land surface scheme for atmospheric and hydrologic models: SEWAB (Surface Energy and Water Balance)

    Energy Technology Data Exchange (ETDEWEB)

    Mengelkamp, H.T.; Warrach, K.; Raschke, E. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Atmosphaerenphysik

    1997-12-31

    A soil-vegetation-atmosphere-transfer scheme is presented here which solves the coupled system of the Surface Energy and Water Balance (SEWAB) equations considering partly vegetated surfaces. It is based on the one-layer concept for vegetation. In the soil the diffusion equations for heat and moisture are solved on a multi-layer grid. SEWAB has been developed to serve as a land-surface scheme for atmospheric circulation models. Being forced with atmospheric data from either simulations or measurements it calculates surface and subsurface runoff that can serve as input to hydrologic models. The model has been validated with field data from the FIFE experiment and has participated in the PILPS project for intercomparison of land-surface parameterization schemes. From these experiments we feel that SEWAB reasonably well partitions the radiation and precipitation into sensible and latent heat fluxes as well as into runoff and soil moisture Storage. (orig.) [Deutsch] Ein Landoberflaechenschema wird vorgestellt, das den Transport von Waerme und Wasser zwischen dem Erdboden, der Vegetation und der Atmosphaere unter Beruecksichtigung von teilweise bewachsenem Boden beschreibt. Im Erdboden werden die Diffusionsgleichungen fuer Waerme und Feuchte auf einem Gitter mit mehreren Schichten geloest. Das Schema SEWAB (Surface Energy and Water Balance) beschreibt die Landoberflaechenprozesse in atmosphaerischen Modellen und berechnet den Oberflaechenabfluss und den Basisabfluss, die als Eingabedaten fuer hydrologische Modelle genutzt werden koennen. Das Modell wurde mit Daten des FIFE-Experiments kalibriert und hat an Vergleichsexperimenten fuer Landoberflaechen-Schemata im Rahmen des PILPS-Projektes teilgenommen. Dabei hat sich gezeigt, dass die Aufteilung der einfallenden Strahlung und des Niederschlages in den sensiblen und latenten Waermefluss und auch in Abfluss und Speicherung der Bodenfeuchte in SEWAB den beobachteten Daten recht gut entspricht. (orig.)

  2. Renewable Energy Marketplace

    Science.gov (United States)

    Ghadimian, Vachik

    The renewable energy sector is evolving, and today, renewable energy has become a viable alternative for many facilities. Because this sector is in its infancy stage, lack of experience has resulted in failing solar projects. This project involves the design and implementation of a functioning web application that streamlines and automates the planning, risk assessment and financing of a solar development project. The three key stakeholders, the host facility, solar installer and financier are seamlessly integrated into a single marketplace. By designing a project development workflow, projects are vetted early on and terminated if deemed infeasible, saving time and resources. By risk assessing the project using the proposed scoring model, one can inherit more confident investors. The project scoring model also serves as a debt rating system, where investors can measure the risk/rewards. The platform will also serve as a communication medium between the three stakeholders. Besides storing documents like engineering drawings, permits, etc., the platform auto-generates all necessary transactional documents, legal documents and agreements among the three stakeholders.

  3. Exposing earth surface process model simulations to a large audience

    Science.gov (United States)

    Overeem, I.; Kettner, A. J.; Borkowski, L.; Russell, E. L.; Peddicord, H.

    2015-12-01

    The Community Surface Dynamics Modeling System (CSDMS) represents a diverse group of >1300 scientists who develop and apply numerical models to better understand the Earth's surface. CSDMS has a mandate to make the public more aware of model capabilities and therefore started sharing state-of-the-art surface process modeling results with large audiences. One platform to reach audiences outside the science community is through museum displays on 'Science on a Sphere' (SOS). Developed by NOAA, SOS is a giant globe, linked with computers and multiple projectors and can display data and animations on a sphere. CSDMS has developed and contributed model simulation datasets for the SOS system since 2014, including hydrological processes, coastal processes, and human interactions with the environment. Model simulations of a hydrological and sediment transport model (WBM-SED) illustrate global river discharge patterns. WAVEWATCH III simulations have been specifically processed to show the impacts of hurricanes on ocean waves, with focus on hurricane Katrina and super storm Sandy. A large world dataset of dams built over the last two centuries gives an impression of the profound influence of humans on water management. Given the exposure of SOS, CSDMS aims to contribute at least 2 model datasets a year, and will soon provide displays of global river sediment fluxes and changes of the sea ice free season along the Arctic coast. Over 100 facilities worldwide show these numerical model displays to an estimated 33 million people every year. Datasets storyboards, and teacher follow-up materials associated with the simulations, are developed to address common core science K-12 standards. CSDMS dataset documentation aims to make people aware of the fact that they look at numerical model results, that underlying models have inherent assumptions and simplifications, and that limitations are known. CSDMS contributions aim to familiarize large audiences with the use of numerical

  4. Validating modeled turbulent heat fluxes across large freshwater surfaces

    Science.gov (United States)

    Lofgren, B. M.; Fujisaki-Manome, A.; Gronewold, A.; Anderson, E. J.; Fitzpatrick, L.; Blanken, P.; Spence, C.; Lenters, J. D.; Xiao, C.; Charusambot, U.

    2017-12-01

    Turbulent fluxes of latent and sensible heat are important physical processes that influence the energy and water budgets of the Great Lakes. Validation and improvement of bulk flux algorithms to simulate these turbulent heat fluxes are critical for accurate prediction of hydrodynamics, water levels, weather, and climate over the region. Here we consider five heat flux algorithms from several model systems; the Finite-Volume Community Ocean Model, the Weather Research and Forecasting model, and the Large Lake Thermodynamics Model, which are used in research and operational environments and concentrate on different aspects of the Great Lakes' physical system, but interface at the lake surface. The heat flux algorithms were isolated from each model and driven by meteorological data from over-lake stations in the Great Lakes Evaporation Network. The simulation results were compared with eddy covariance flux measurements at the same stations. All models show the capacity to the seasonal cycle of the turbulent heat fluxes. Overall, the Coupled Ocean Atmosphere Response Experiment algorithm in FVCOM has the best agreement with eddy covariance measurements. Simulations with the other four algorithms are overall improved by updating the parameterization of roughness length scales of temperature and humidity. Agreement between modelled and observed fluxes notably varied with geographical locations of the stations. For example, at the Long Point station in Lake Erie, observed fluxes are likely influenced by the upwind land surface while the simulations do not take account of the land surface influence, and therefore the agreement is worse in general.

  5. Resilient Renewable Energy Microgrids

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Katherine H [National Renewable Energy Laboratory (NREL), Golden, CO (United States); DiOrio, Nicholas A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Butt, Robert S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Richards, Allison [Unaffiliated

    2017-11-14

    This presentation for the Cable-Tec Expo 2017 offers information about how renewable microgrids can be used to increase resiliency. It includes information about why renewable energy battery diesel hybrids microgrids should be considered for backup power, how to estimate economic savings of microgrids, quantifying the resiliency gain of microgrids, and where renewable microgrids will be successful.

  6. Land-Surface-Atmosphere Coupling in Observations and Models

    Directory of Open Access Journals (Sweden)

    Alan K Betts

    2009-07-01

    Full Text Available The diurnal cycle and the daily mean at the land-surface result from the coupling of many physical processes. The framework of this review is largely conceptual; looking for relationships and information in the coupling of processes in models and observations. Starting from the surface energy balance, the role of the surface and cloud albedos in the shortwave and longwave fluxes is discussed. A long-wave radiative scaling of the diurnal temperature range and the night-time boundary layer is summarized. Several aspects of the local surface energy partition are presented: the role of soilwater availability and clouds; vector methods for understanding mixed layer evolution, and the coupling between surface and boundary layer that determines the lifting condensation level. Moving to larger scales, evaporation-precipitation feedback in models is discussed; and the coupling of column water vapor, clouds and precipitation to vertical motion and moisture convergence over the Amazon. The final topic is a comparison of the ratio of surface shortwave cloud forcing to the diabatic precipitation forcing of the atmosphere in ERA-40 with observations.

  7. Characterization, modeling and simulation of fused deposition modeling fabricated part surfaces

    Science.gov (United States)

    Taufik, Mohammad; Jain, Prashant K.

    2017-12-01

    Surface roughness is generally used for characterization, modeling and simulation of fused deposition modeling (FDM) fabricated part surfaces. But the average surface roughness is not able to provide the insight of surface characteristics with sharp peaks and deep valleys. It deals in the average sense for all types of surfaces, including FDM fabricated surfaces with distinct surface profile features. The present research work shows that kurtosis and skewness can be used for characterization, modeling and simulation of FDM surfaces because these roughness parameters have the ability to characterize a surface with sharp peaks and deep valleys. It can be critical in certain application areas in tribology and biomedicine, where the surface profile plays an important role. Thus, in this study along with surface roughness, skewness and kurtosis are considered to show a novel strategy to provide new transferable knowledge about FDM fabricated part surfaces. The results suggest that the surface roughness, skewness and kurtosis are significantly different at 0° and in the range (0°, 30°], [30°, 90°] of build orientation.

  8. Performance of fire behavior fuel models developed for the Rothermel Surface Fire Spread Model

    Science.gov (United States)

    Robert Ziel; W. Matt Jolly

    2009-01-01

    In 2005, 40 new fire behavior fuel models were published for use with the Rothermel Surface Fire Spread Model. These new models are intended to augment the original 13 developed in 1972 and 1976. As a compiled set of quantitative fuel descriptions that serve as input to the Rothermel model, the selected fire behavior fuel model has always been critical to the resulting...

  9. Stochastic Modeling and Deterministic Limit of Catalytic Surface Processes

    DEFF Research Database (Denmark)

    Starke, Jens; Reichert, Christian; Eiswirth, Markus

    2007-01-01

    Three levels of modeling, microscopic, mesoscopic and macroscopic are discussed for the CO oxidation on low-index platinum single crystal surfaces. The introduced models on the microscopic and mesoscopic level are stochastic while the model on the macroscopic level is deterministic. It can......, such that in contrast to the microscopic model the spatial resolution is reduced. The derivation of deterministic limit equations is in correspondence with the successful description of experiments under low-pressure conditions by deterministic reaction-diffusion equations while for intermediate pressures phenomena...

  10. Mathematical model of the metal mould surface temperature optimization

    International Nuclear Information System (INIS)

    Mlynek, Jaroslav; Knobloch, Roman; Srb, Radek

    2015-01-01

    The article is focused on the problem of generating a uniform temperature field on the inner surface of shell metal moulds. Such moulds are used e.g. in the automotive industry for artificial leather production. To produce artificial leather with uniform surface structure and colour shade the temperature on the inner surface of the mould has to be as homogeneous as possible. The heating of the mould is realized by infrared heaters located above the outer mould surface. The conceived mathematical model allows us to optimize the locations of infrared heaters over the mould, so that approximately uniform heat radiation intensity is generated. A version of differential evolution algorithm programmed in Matlab development environment was created by the authors for the optimization process. For temperate calculations software system ANSYS was used. A practical example of optimization of heaters locations and calculation of the temperature of the mould is included at the end of the article

  11. Mathematical modeling for surface hardness in investment casting applications

    International Nuclear Information System (INIS)

    Singh, Rupinder

    2012-01-01

    Investment casting (IC) has many potential engineering applications. Not much work hitherto has been reported for modeling the surface hardness (SH) in IC of industrial components. In the present study, outcome of Taguchi based macro model has been used for developing a mathematical model for SH; using Buckingham's π theorem. Three input parameters namely volume/surface area (V/A) ratio of cast components, slurry layer's combination (LC) and molten metal pouring temperature were selected to give output in form of SH. This study will provide main effects of these variables on SH and will shed light on the SH mechanism in IC. The comparison with experimental results will also serve as further validation of model

  12. Modeling the Soul Surface Seal from a Filtration Perspective

    Directory of Open Access Journals (Sweden)

    N.M. Somaratne

    1998-01-01

    Full Text Available A physically based model of soil surface scaling is proposed. The governing equations are formulated on the principle of conservation of mass assuming Darcy's law applies to suspension flowing through the soil surface. The model incorporates the physics of surface sealing by mechanisms that capture suspended particles moving with infiltrating water. As a result of particle retention in the soil system, the intrinsic porosity is reduced and hulk density is increased, resulting in changes to soil hydraulic properties such as moisture retention and hydraulic conductivity. Empirical functions are developed to describe the changes of these properties as the seal develops. With this approach, the seal can be mathematically described by well defined initial and boundary conditions and transient seal properties can be simulated in a physically realistic manner.

  13. Scattering of surface waves modelled by the integral equation method

    Science.gov (United States)

    Lu, Laiyu; Maupin, Valerie; Zeng, Rongsheng; Ding, Zhifeng

    2008-09-01

    The integral equation method is used to model the propagation of surface waves in 3-D structures. The wavefield is represented by the Fredholm integral equation, and the scattered surface waves are calculated by solving the integral equation numerically. The integration of the Green's function elements is given analytically by treating the singularity of the Hankel function at R = 0, based on the proper expression of the Green's function and the addition theorem of the Hankel function. No far-field and Born approximation is made. We investigate the scattering of surface waves propagating in layered reference models imbedding a heterogeneity with different density, as well as Lamé constant contrasts, both in frequency and time domains, for incident plane waves and point sources.

  14. Wetting and free surface flow modeling for potting and encapsulation.

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, Carlton, F.; Brooks, Michael J. (Los Alamos National Laboratory, Los Alamos, NM); Graham, Alan Lyman (Los Alamos National Laboratory, Los Alamos, NM); Noble, David F. (David Frederick) (.; )); Notz, Patrick K.; Hopkins, Matthew Morgan; Castaneda, Jaime N.; Mahoney, Leo James (Kansas City Plant, Kansas City, MO); Baer, Thomas A.; Berchtold, Kathryn (Los Alamos National Laboratory, Los Alamos, NM); Adolf, Douglas Brian; Wilkes, Edward Dean; Rao, Rekha Ranjana; Givler, Richard C.; Sun, Amy Cha-Tien; Cote, Raymond O.; Mondy, Lisa Ann; Grillet, Anne Mary; Kraynik, Andrew Michael

    2007-06-01

    As part of an effort to reduce costs and improve quality control in encapsulation and potting processes the Technology Initiative Project ''Defect Free Manufacturing and Assembly'' has completed a computational modeling study of flows representative of those seen in these processes. Flow solutions are obtained using a coupled, finite-element-based, numerical method based on the GOMA/ARIA suite of Sandia flow solvers. The evolution of the free surface is solved with an advanced level set algorithm. This approach incorporates novel methods for representing surface tension and wetting forces that affect the evolution of the free surface. In addition, two commercially available codes, ProCAST and MOLDFLOW, are also used on geometries representing encapsulation processes at the Kansas City Plant. Visual observations of the flow in several geometries are recorded in the laboratory and compared to the models. Wetting properties for the materials in these experiments are measured using a unique flowthrough goniometer.

  15. Computational model of surface ablation from tokamak disruptions

    International Nuclear Information System (INIS)

    Ehst, D.; Hassanein, A.

    1993-10-01

    Energy transfer to material surfaces is dominated by photon radiation through low temperature plasma vapors if tokamak disruptions are due to low kinetic energy particles ( < 100 eV). Simple models of radiation transport are derived and incorporated into a fast-running computer routine to model this process. The results of simulations are in fair agreement with plasma gun erosion tests on several metal targets

  16. Optimized Model Surfaces for Advanced Atomic Force Microscopy Studies of Surface Nanobubbles.

    Science.gov (United States)

    Song, Bo; Zhou, Yi; Schönherr, Holger

    2016-11-01

    The formation of self-assembled monolayers (SAMs) of binary mixtures of 16-mercaptohexadecanoic acid (MHDA) and 1-octadecanethiol (ODT) on ultraflat template-stripped gold (TSG) surfaces was systematically investigated to clarify the assembly behavior, composition, and degree of possible phase segregation in light of atomic force microscopy (AFM) studies of surface nanobubbles on these substrates. The data for SAMs on TSG were compared to those obtained by adsorption on rough evaporated gold, as reported in a previous study. Quartz crystal microbalance and surface plasmon resonance data acquired in situ on TSG indicate that similar to SAM formation on conventional evaporated gold substrates ODT and MHDA form monolayers and bilayers, respectively. The second layer on MHDA, whose formation is attributed to hydrogen bonding, can be easily removed by adequate rinsing with water. The favorable agreement of the grazing incidence reflection Fourier transform infrared (GIR FTIR) spectroscopy and contact angle data analyzed with the Israelachvili-Gee model suggests that the binary SAMs do not segregate laterally. This conclusion is fully validated by high-resolution friction force AFM observations down to a length scale of 8-10 nm, which is much smaller than the typical observed surface nanobubble radii. Finally, correspondingly functionalized TSG substrates are shown to be valuable supports for studying surface nanobubbles by AFM in water and for addressing the relation between surface functionality and nanobubble formation and properties.

  17. Models for prediction of global solar radiation on horizontal surface ...

    African Journals Online (AJOL)

    The estimation of global solar radiation continues to play a fundamental role in solar engineering systems and applications. This paper compares various models for estimating the average monthly global solar radiation on horizontal surface for Akure, Nigeria, using solar radiation and sunshine duration data covering years ...

  18. Surface-complexation modelling for describing adsorption of ...

    African Journals Online (AJOL)

    2013-06-08

    Jun 8, 2013 ... Adsorption of dissolved phosphate onto synthetic hydrous ferric oxide (HFO) was measured in the laboratory as a function of pH, ionic strength, and phosphate relative concentration. Experimental data were used to constrain optimal values of surface complexation reactions using a geochemical modeling ...

  19. Modeling marine surface microplastic transport to assess optimal removal locations

    NARCIS (Netherlands)

    Sherman, Peter; Van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics

  20. Remote sensing estimates of impervious surfaces for pluvial flood modelling

    DEFF Research Database (Denmark)

    Kaspersen, Per Skougaard; Drews, Martin

    This paper investigates the accuracy of medium resolution (MR) satellite imagery in estimating impervious surfaces for European cities at the detail required for pluvial flood modelling. Using remote sensing techniques enables precise and systematic quantification of the influence of the past 30...

  1. Infrared Analysis Of Enzymes Adsorbed Onto Model Surfaces

    Science.gov (United States)

    Story, Gloria M.; Rauch, Deborah S.; Brode, Philip F.; Marcott, Curtis A.

    1989-12-01

    The adsorption of the enzymes, subtilisin BPN' and lysozyme, onto model surfaces was examined using attenuated total reflectance (ATR) infrared (IR) spectroscopy. Using a cylindrical internal reflection (CIRcle) cell with a Germanium (Ge) internal reflection element (IRE), model hydrophilic surfaces were made by plasma cleaning the IRE and model hydrophobic surfaces were made by precoating the IRE with a thin film of polystyrene. Gas chromatography (GC)-IR data collection software was used to monitor adsorption kinetics during the first five minutes after injection of the enzyme into the CIRcle cell. It was found that for both lysozyme and BPN', most of the enzyme that was going to adsorb onto the model surface did so within ten seconds after injection. Nearly an order-of-magnitude more BPN' adsorbed on the hydrophobic Ge surface than the hydrophilic one, while lysozyme adsorbed somewhat more strongly to the hydrophilic Ge surface. Overnight, the lysozyme layer continued to increase in thickness, while BPN' maintained its initial coverage. The appearance of carboxylate bands in some of the adsorbed BPN' spectra suggests the occurrence of peptide bond hydrolysis. A Au/Pd coating on the CIRcle cell o-rings had a significant effect on the adsorption of BPN'. (This coating was applied in an attempt to eliminate interfering Teflon absorption bands.) An apparent electrochemical reaction occurred, involving BPN', Ge, Au/Pd, and the salt solution used to stabilize BPN'. The result of this reaction was enhanced adsorption of the enzyme around the coated o-rings, etching of the Ge IRE at the o-ring site, and some autolysis of the enzyme. No such reaction was observed with lysozyme.

  2. Soliton surfaces associated with sigma models: differential and algebraic aspects

    International Nuclear Information System (INIS)

    Goldstein, P P; Grundland, A M; Post, S

    2012-01-01

    In this paper, we consider both differential and algebraic properties of surfaces associated with sigma models. It is shown that surfaces defined by the generalized Weierstrass formula for immersion for solutions of the CP N-1 sigma model with finite action, defined in the Riemann sphere, are themselves solutions of the Euler–Lagrange equations for sigma models. On the other hand, we show that the Euler–Lagrange equations for surfaces immersed in the Lie algebra su(N), with conformal coordinates, that are extremals of the area functional, subject to a fixed polynomial identity, are exactly the Euler–Lagrange equations for sigma models. In addition to these differential constraints, the algebraic constraints, in the form of eigenvalues of the immersion functions, are systematically treated. The spectrum of the immersion functions, for different dimensions of the model, as well as its symmetry properties and its transformation under the action of the ladder operators are discussed. Another approach to the dynamics is given, i.e. description in terms of the unitary matrix which diagonalizes both the immersion functions and the projectors constituting the model. (paper)

  3. Mapping of renewable energies

    International Nuclear Information System (INIS)

    Boulanger, V.

    2013-01-01

    Germany is the champion of green energy in Europe: the contribution of renewable energies to electricity generation reached about 20% in 2011. This article describes the situation of renewable energies in Germany in 2011 with the help of 2 maps, the first one gives the installed electrical generation capacity for each region and for each renewable energy source (wind power, hydro-electricity, biomass, photovoltaic energy and biogas) and the second one details the total number of jobs (direct and indirect) for each renewable energy source and for each region. In 2011 about 372000 people worked in the renewable energy sector in Germany. (A.C.)

  4. Adjustable Model of Renewable Energy Projects for Sustainable Development: A Case Study of the Nišava District in Serbia

    Directory of Open Access Journals (Sweden)

    Violeta Dimić

    2018-03-01

    Full Text Available This paper explores and ranks the key performance indicators of multi-criteria decision-making in the process of selecting renewable energy sources (RES. Different categories of factors (e.g., political, legal, technological, economic and financial, sociocultural, and physical are crucial for the analysis of such projects. In this paper, we apply the fuzzy analytic hierarchy process (fuzzy AHP method—a mathematical method—in order to analyze the main criteria for such projects, which include the environment, the organizational management structure, project participants, and participants’ relationship with the performance indicators. In order of ranking, the indicators are the following: time, costs, quality, monitoring the project’s sustainability, user feedback, and users’ health and safety. The aim of this paper is to point out the necessity of creating an adjustable model for renewable energy projects in order to proceed with the sustainable development of the southeast part of Serbia. This model should lead the creation process for such a project, with the aim of increasing its energy efficiency.

  5. Stochastic multi-objective model for optimal energy exchange optimization of networked microgrids with presence of renewable generation under risk-based strategies.

    Science.gov (United States)

    Gazijahani, Farhad Samadi; Ravadanegh, Sajad Najafi; Salehi, Javad

    2018-02-01

    The inherent volatility and unpredictable nature of renewable generations and load demand pose considerable challenges for energy exchange optimization of microgrids (MG). To address these challenges, this paper proposes a new risk-based multi-objective energy exchange optimization for networked MGs from economic and reliability standpoints under load consumption and renewable power generation uncertainties. In so doing, three various risk-based strategies are distinguished by using conditional value at risk (CVaR) approach. The proposed model is specified as a two-distinct objective function. The first function minimizes the operation and maintenance costs, cost of power transaction between upstream network and MGs as well as power loss cost, whereas the second function minimizes the energy not supplied (ENS) value. Furthermore, the stochastic scenario-based approach is incorporated into the approach in order to handle the uncertainty. Also, Kantorovich distance scenario reduction method has been implemented to reduce the computational burden. Finally, non-dominated sorting genetic algorithm (NSGAII) is applied to minimize the objective functions simultaneously and the best solution is extracted by fuzzy satisfying method with respect to risk-based strategies. To indicate the performance of the proposed model, it is performed on the modified IEEE 33-bus distribution system and the obtained results show that the presented approach can be considered as an efficient tool for optimal energy exchange optimization of MGs. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  6. Soil Structure - A Neglected Component of Land-Surface Models

    Science.gov (United States)

    Fatichi, S.; Or, D.; Walko, R. L.; Vereecken, H.; Kollet, S. J.; Young, M.; Ghezzehei, T. A.; Hengl, T.; Agam, N.; Avissar, R.

    2017-12-01

    Soil structure is largely absent in most standard sampling and measurements and in the subsequent parameterization of soil hydraulic properties deduced from soil maps and used in Earth System Models. The apparent omission propagates into the pedotransfer functions that deduce parameters of soil hydraulic properties primarily from soil textural information. Such simple parameterization is an essential ingredient in the practical application of any land surface model. Despite the critical role of soil structure (biopores formed by decaying roots, aggregates, etc.) in defining soil hydraulic functions, only a few studies have attempted to incorporate soil structure into models. They mostly looked at the effects on preferential flow and solute transport pathways at the soil profile scale; yet, the role of soil structure in mediating large-scale fluxes remains understudied. Here, we focus on rectifying this gap and demonstrating potential impacts on surface and subsurface fluxes and system wide eco-hydrologic responses. The study proposes a systematic way for correcting the soil water retention and hydraulic conductivity functions—accounting for soil-structure—with major implications for near saturated hydraulic conductivity. Modification to the basic soil hydraulic parameterization is assumed as a function of biological activity summarized by Gross Primary Production. A land-surface model with dynamic vegetation is used to carry out numerical simulations with and without the role of soil-structure for 20 locations characterized by different climates and biomes across the globe. Including soil structure affects considerably the partition between infiltration and runoff and consequently leakage at the base of the soil profile (recharge). In several locations characterized by wet climates, a few hundreds of mm per year of surface runoff become deep-recharge accounting for soil-structure. Changes in energy fluxes, total evapotranspiration and vegetation productivity

  7. Renewable energies - Situation and perspectives

    International Nuclear Information System (INIS)

    Acket, Claude; Vaillant, Jacques

    2011-01-01

    The world has to face increasing energy needs while it is today dependent of fossil fuels at 80%. Getting out of the fossil fuels dependence model requires an important effort to promote the energy saving and the carbon-free energies as well, and in particular the renewable energy sources. Taking all this information into account, the authors evaluate the global share that renewable energies could represent in the energy mix, in France and in the entire world. This share represents today only 10% of the energy consumed, but will it remain marginal or will it become important and eventually prominent? (J.S.)

  8. Source Surface Models and Their Impact on Solar Wind Research

    Science.gov (United States)

    Sokolov, I. V.; Roussev, I. I.; Gombosi, T. I.; Liu, Y.

    2005-05-01

    To perform realistic modeling of the important processes in the solar corona, such as coronal mass ejections, flares, as well as the acceleration of solar particles, one needs to incorporate into the physical models any complicated pattern of the coronal magnetic field. The coronal magnetic field topology is determined by the helmet streamers (with closed field lines), the coronal holes (with open field lines) as well as the fine, but crucially important, details of the small-scale active regions. The standard practice to recover the global 3-D structure of the solar magnetic field from observations is to use the source surface model, in which the field is assumed to be potential, i.e., current-free. This approach ignores any volumetric current there may be present in the corona, and also neglects the existence of the equatorial current sheet, which starts from a height of 3-5 Rs above the solar surface. The fully potential solar magnetic field would have only closed field lines, not allowing for the solar wind to exist. In our Solar Corona model, incorparated into the Space Weather Modelling Framework, the solar magnetic field is split into two constituitive parts: one potential part which is recovered from the magnetic field data (e.g., from WSO, MWO, or MDI data) using the source surface method; and, one other non-potential part. For the potential field, we keep only the spherical harmonics decreasing with distance from the Sun or, equivalently, we use a very large value of the source surface radius. For the non-potential field, we solve the time-dependent induction equation with zero boundary condition at the solar surface. The full set of conservation laws for the MHD system is solved numerically using the BATS-R-US code. To power the solar wind in our model, we use a phenomenological turbulence model described in an earlier paper. The resulting steady-state MHD solution includes the well-resolved current sheet and helmet streamers. The modeled structure of

  9. Renewable energy annual 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic.

  10. Renewable energy annual 1995

    International Nuclear Information System (INIS)

    1995-12-01

    The Renewable Energy Annual 1995 is the first in an expected series of annual reports the Energy Information Administration (EIA) intends to publish to provide a comprehensive assessment of renewable energy. This report presents the following information on the history, status, and prospects of renewable energy data: estimates of renewable resources; characterizations of renewable energy technologies; descriptions of industry infrastructures for individual technologies; evaluations of current market status; and assessments of near-term prospects for market growth. An international section is included, as well as two feature articles that discuss issues of importance for renewable energy as a whole. The report also contains a number of technical appendices and a glossary. The renewable energy sources included are biomass (wood), municipal solid waste, biomass-derived liquid fuels, geothermal, wind, and solar and photovoltaic

  11. An inexact bi-level simulation–optimization model for conjunctive regional renewable energy planning and air pollution control for electric power generation systems

    International Nuclear Information System (INIS)

    Chen, Yizhong; He, Li; Li, Jing; Cheng, Xi; Lu, Hongwei

    2016-01-01

    Highlights: • Detailed model developed for power generation and pollutants mitigation. • Dynamic integration of bi-level programming with uncertainty analyses. • Application of the novel bi-level model for EPS in Fengtai District. • Development of renewable energy under different probability levels. - Abstract: In this study, an IBSOM (inexact bi-level simulation–optimization model) is developed for conjunctive regional renewable energy planning and air pollution control for EPS (electric power systems) under uncertainty. The IBSOM integrates techniques of CFMTVW (combined forecasting model with time-varying weights), ILP (interval linear programming), MIP (mixed integer programming), CCP (chance-constrained programming), as well as BLP (bi-level programming) into a general framework. In the IBSOM, uncertainties expressed as interval and stochastic parameters within multi-period and multi-option contexts can be effectively tackled. In addition, a leader-follower decision strategy is incorporated into the optimization process where two non-competitive objectives are sequentially proposed, with the environmental sector dominating the upper-level objective (leader’s one) and the energy sector providing the lower-level objective (follower’s one). To solve the proposed model, an improved bi-level interactive solution algorithm based on satisfactory degree is introduced into the decision-making process for balancing to what extent the constraints are met and the objective reaches its optima. Then, the IBSOM is applied to a real-world case study of EPS in Fengtai District, Beijing, China. Interval solutions associated with renewable energy development, electricity generation, facility-expansion scheme, as well as pollutants mitigation can be obtained under different system-violation risk. Results indicate that a higher violation risk would lead to a decreased strictness of the constraints or an expanded decision space, which results in the decreased system

  12. Renewable Energy: Policy Considerations for Deploying Renewables

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    This information paper accompanies the IEA publication Deploying Renewables 2011: Best and Future Policy Practice (IEA, 2011a). It provides more detailed data and analysis on policies for Deploying Renewables, and is intended to complement the main publication. It provides an account of the strategic drivers underpinning renewable energy (RE) technology deployment (energy security, economic development and environment protection) and assesses RE technologies with respect to these drivers, including an estimate of GHG emissions reductions due to RE technologies. The paper also explores the different barriers to deploying renewables at a given stage of market maturity and discusses what tools policy makers can avail of to succeed in removing deployment barriers. An additional topical highlight explores the challenges associated with accelerating the diffusion of RE technologies in developing countries.

  13. VT Renewable Energy Sites - Renewable Energy Professionals

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The Renewable Energy Atlas of Vermont and this dataset were created to assist town energy committees, the Clean Energy Development Fund and other...

  14. Spatial aggregation of land surface characteristics : impact of resolution of remote sensing data on land surface modelling

    NARCIS (Netherlands)

    Pelgrum, H.

    2000-01-01

    Land surface models describe the exchange of heat, moisture and momentum between the land surface and the atmosphere. These models can be solved regionally using remote sensing measurements as input. Input variables which can be derived from remote sensing measurements are surface albedo,

  15. Multipoint contact modeling of nanoparticle manipulation on rough surface

    Energy Technology Data Exchange (ETDEWEB)

    Zakeri, M., E-mail: m.zakeri@tabrizu.ac.ir; Faraji, J.; Kharazmi, M. [University of Tabriz, School of Engineering Emerging Technologies (Iran, Islamic Republic of)

    2016-12-15

    In this paper, the atomic force microscopy (AFM)-based 2-D pushing of nano/microparticles investigated on rough substrate by assuming a multipoint contact model. First, a new contact model was extracted and presented based on the geometrical profiles of Rumpf, Rabinovich and George models and the contact mechanics theories of JKR and Schwartz, to model the adhesion forces and the deformations in the multipoint contact of rough surfaces. The geometry of a rough surface was defined by two main parameters of asperity height (size of roughness) and asperity wavelength (compactness of asperities distribution). Then, the dynamic behaviors of nano/microparticles with radiuses in range of 50–500 nm studied during their pushing on rough substrate with a hexagonal or square arrangement of asperities. Dynamic behavior of particles were simulated and compared by assuming multipoint and single-point contact schemes. The simulation results show that the assumption of multipoint contact has a considerable influence on determining the critical manipulation force. Additionally, the assumption of smooth surfaces or single-point contact leads to large error in the obtained results. According to the results of previous research, it anticipated that a particles with the radius less than about 550 nm start to slide on smooth substrate; but by using multipoint contact model, the predicted behavior changed, and particles with radii of smaller than 400 nm begin to slide on rough substrate for different height of asperities, at first.

  16. Evaluation of the WAMME model surface fluxes using results from the AMMA land-surface model intercomparison project

    Energy Technology Data Exchange (ETDEWEB)

    Boone, Aaron Anthony [GAME-CNRM, Meteo-France, Toulouse (France); Poccard-Leclercq, Isabelle [Universite de Nantes, LETG-Geolittomer, Nantes (France); Xue, Yongkang; Feng, Jinming [University of California at Los Angeles, Los Angeles, CA (United States); Rosnay, Patricia de [European Centre for Medium Range Weather Forecasting, Reading (United Kingdom)

    2010-07-15

    The West African monsoon (WAM) circulation and intensity have been shown to be influenced by the land surface in numerous numerical studies using regional scale and global scale atmospheric climate models (RCMs and GCMs, respectively) over the last several decades. The atmosphere-land surface interactions are modulated by the magnitude of the north-south gradient of the low level moist static energy, which is highly correlated with the steep latitudinal gradients of the vegetation characteristics and coverage, land use, and soil properties over this zone. The African Multidisciplinary Monsoon Analysis (AMMA) has organised comprehensive activities in data collection and modelling to further investigate the significance land-atmosphere feedbacks. Surface energy fluxes simulated by an ensemble of land surface models from AMMA Land-surface Model Intercomparison Project (ALMIP) have been used as a proxy for the best estimate of the ''real world'' values in order to evaluate GCM and RCM simulations under the auspices of the West African Monsoon Modelling Experiment (WAMME) project, since such large-scale observations do not exist. The ALMIP models have been forced in off-line mode using forcing based on a mixture of satellite, observational, and numerical weather prediction data. The ALMIP models were found to agree well over the region where land-atmosphere coupling is deemed to be most important (notably the Sahel), with a high signal to noise ratio (generally from 0.7 to 0.9) in the ensemble and a inter-model coefficient of variation between 5 and 15%. Most of the WAMME models simulated spatially averaged net radiation values over West Africa which were consistent with the ALMIP estimates, however, the partitioning of this energy between sensible and latent heat fluxes was significantly different: WAMME models tended to simulate larger (by nearly a factor of two) monthly latent heat fluxes than ALMIP. This results due to a positive precipitation

  17. Models of the solvent-accessible surface of biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Smith, R.E.

    1996-09-01

    Many biopolymers such as proteins, DNA, and RNA have been studied because they have important biomedical roles and may be good targets for therapeutic action in treating diseases. This report describes how plastic models of the solvent-accessible surface of biopolymers were made. Computer files containing sets of triangles were calculated, then used on a stereolithography machine to make the models. Small (2 in.) models were made to test whether the computer calculations were done correctly. Also, files of the type (.stl) required by any ISO 9001 rapid prototyping machine were written onto a CD-ROM for distribution to American companies.

  18. Numerical modelling of surface hydrology and near-surface hydrogeology at Forsmark. Site descriptive modelling SDM. Site Forsmark

    International Nuclear Information System (INIS)

    Bosson, Emma; Gustafsson, Lars-Goeran; Sassner, Mona

    2008-09-01

    SKB is currently performing site investigations at two potential sites for a final repository for spent nuclear fuel. This report presents results of water flow and solute transport modelling of the Forsmark site. The modelling reported in this document focused on the near-surface groundwater, i.e. groundwater in Quaternary deposits and shallow rock, and surface water systems, and was performed using the MIKE SHE tool. The most recent site data used in the modelling were delivered in the Forsmark 2.3 dataset, which had its 'data freeze' on March 31, 2007. The present modelling is performed in support of the final version of the Forsmark site description that is produced during the site investigation phase. In this work, the hydrological modelling system MIKE SHE has been used to describe near-surface groundwater flow and the contact between groundwater and surface water at the Forsmark site. The surface water system at Forsmark is described with the one-dimensional 'channel flow' modelling tool MIKE 11, which is fully and dynamically integrated with MIKE SHE. The MIKE SHE model was updated with data from the F2.3 data freeze. The main updates concerned the geological description of the saturated zone and the time series data on water levels and surface water discharges. The time series data used as input data and for calibration and validation was extended until the Forsmark 2.3 data freeze (March 31, 2007). The present work can be subdivided into the following four parts: 1. Update of the numerical flow model. 2. Sensitivity analysis and calibration of the model parameters. 3. Validation of the calibrated model, followed by evaluation and identification of discrepancies between measurements and model results. 4. Additional sensitivity analysis and calibration in order to resolve the problems identified in point three above. The main actions taken during the calibration can be summarised as follows: 1. The potential evapotranspiration was reduced in order to reach

  19. Modeling of laser damage initiated by surface contamination

    International Nuclear Information System (INIS)

    Feit, M.D.; Rubenchik, A.M.; Faux, D.R.; Riddle, R.A.; Shapiro, A.; Eder, D.C.; Penetrante, B.M.; Milam, D.; Genin, F.Y.; Kozlowski, M.R.

    1996-11-01

    The authors are engaged in a comprehensive effort to understand and model the initiation and growth of laser damage initiated by surface contaminants. This includes, for example, the initial absorption by the contaminant, heating and plasma generation, pressure and thermal loading of the transparent substrate, and subsequent shockwave propagation, 'splashing' of molten material and possible spallation, optical propagation and scattering, and treatment of material fracture. The integration use of large radiation hydrodynamics codes, optical propagation codes and material strength codes enables a comprehensive view of the damage process The following picture of surface contaminant initiated laser damage is emerging from our simulations

  20. Surface Complexation Modelling in Metal-Mineral-Bacteria Systems

    Science.gov (United States)

    Johnson, K. J.; Fein, J. B.

    2002-12-01

    The reactive surfaces of bacteria and minerals can determine the fate, transport, and bioavailability of aqueous heavy metal cations. Geochemical models are instrumental in accurately accounting for the partitioning of the metals between mineral surfaces and bacteria cell walls. Previous research has shown that surface complexation modelling (SCM) is accurate in two-component systems (metal:mineral and metal:bacteria); however, the ability of SCMs to account for metal distribution in mixed metal-mineral-bacteria systems has not been tested. In this study, we measure aqueous Cd distributions in water-bacteria-mineral systems, and compare these observations with predicted distributions based on a surface complexation modelling approach. We measured Cd adsorption in 2- and 3-component batch adsorption experiments. In the 2-component experiments, we measured the extent of adsorption of 10 ppm aqueous Cd onto either a bacterial or hydrous ferric oxide sorbent. The metal:bacteria experiments contained 1 g/L (wet wt.) of B. subtilis, and were conducted as a function of pH; the metal:mineral experiments were conducted as a function of both pH and HFO content. Two types of 3-component Cd adsorption experiments were also conducted in which both mineral powder and bacteria were present as sorbents: 1) one in which the HFO was physically but not chemically isolated from the system using sealed dialysis tubing, and 2) others where the HFO, Cd and B. subtilis were all in physical contact. The dialysis tubing approach enabled the direct determination of the concentration of Cd on each sorbing surface, after separation and acidification of each sorbent. The experiments indicate that both bacteria and mineral surfaces can dominate adsorption in the system, depending on pH and bacteria:mineral ratio. The stability constants, determined using the data from the 2-component systems, along with those for other surface and aqueous species in the systems, were used with FITEQL to

  1. ELECTRON AVALANCHE MODEL OF DIELECTRIC-VACUUM SURFACE BREAKDOWN

    Energy Technology Data Exchange (ETDEWEB)

    Lauer, E J

    2007-02-21

    The model assumes that an 'initiating event' results in positive ions on the surface near the anode and reverses the direction of the normal component of electric field so that electrons in vacuum are attracted to the dielectric locally. A sequence of surface electron avalanches progresses in steps from the anode to the cathode. For 200 kV across 1 cm, the spacing of avalanches is predicted to be about 13 microns. The time for avalanches to step from the anode to the cathode is predicted to be about a ns.

  2. Advances in land modeling of KIAPS based on the Noah Land Surface Model

    Science.gov (United States)

    Koo, Myung-Seo; Baek, Sunghye; Seol, Kyung-Hee; Cho, Kyoungmi

    2017-08-01

    As of 2013, the Noah Land Surface Model (LSM) version 2.7.1 was implemented in a new global model being developed at the Korea Institute of Atmospheric Prediction Systems (KIAPS). This land surface scheme is further refined in two aspects, by adding new physical processes and by updating surface input parameters. Thus, the treatment of glacier land, sea ice, and snow cover are addressed more realistically. Inconsistencies in the amount of absorbed solar flux at ground level by the land surface and radiative processes are rectified. In addition, new parameters are available by using 1-km land cover data, which had usually not been possible at a global scale. Land surface albedo/emissivity climatology is newly created using Moderate-Resolution Imaging Spectroradiometer (MODIS) satellitebased data and adjusted parameterization. These updates have been applied to the KIAPS-developed model and generally provide a positive impact on near-surface weather forecasting.

  3. Surface wind mixing in the Regional Ocean Modeling System (ROMS)

    Science.gov (United States)

    Robertson, Robin; Hartlipp, Paul

    2017-12-01

    Mixing at the ocean surface is key for atmosphere-ocean interactions and the distribution of heat, energy, and gases in the upper ocean. Winds are the primary force for surface mixing. To properly simulate upper ocean dynamics and the flux of these quantities within the upper ocean, models must reproduce mixing in the upper ocean. To evaluate the performance of the Regional Ocean Modeling System (ROMS) in replicating the surface mixing, the results of four different vertical mixing parameterizations were compared against observations, using the surface mixed layer depth, the temperature fields, and observed diffusivities for comparisons. The vertical mixing parameterizations investigated were Mellor- Yamada 2.5 level turbulent closure (MY), Large- McWilliams- Doney Kpp (LMD), Nakanishi- Niino (NN), and the generic length scale (GLS) schemes. This was done for one temperate site in deep water in the Eastern Pacific and three shallow water sites in the Baltic Sea. The model reproduced the surface mixed layer depth reasonably well for all sites; however, the temperature fields were reproduced well for the deep site, but not for the shallow Baltic Sea sites. In the Baltic Sea, the models overmixed the water column after a few days. Vertical temperature diffusivities were higher than those observed and did not show the temporal fluctuations present in the observations. The best performance was by NN and MY; however, MY became unstable in two of the shallow simulations with high winds. The performance of GLS nearly as good as NN and MY. LMD had the poorest performance as it generated temperature diffusivities that were too high and induced too much mixing. Further observational comparisons are needed to evaluate the effects of different stratification and wind conditions and the limitations on the vertical mixing parameterizations.

  4. Renewable energy in India: Status and potential

    Energy Technology Data Exchange (ETDEWEB)

    Pillai, Indu R.; Banerjee, Rangan [Department of Energy Science and Engineering, Indian Institute of Technology Bombay, Powai, Mumbai 400076 (India)

    2009-08-15

    A majority of the Indian population does not have access to convenient energy services (LPG, electricity). Though India has made significant progress in renewable energy, the share of modern renewables in the energy mix is marginal. This paper reviews the status and potential of different renewables (except biomass) in India. This paper documents the trends in the growth of renewables in India and establishes diffusion model as a basis for setting targets. The diffusion model is fitted tot the past trends for wind, small hydro and solar water heating and is used to establish future targets. The economic viability and green house gas (GHG) saving potential is estimated for each option. Several renewables have high growth rates, for example wind, Photovoltaic (PV) module manufacture and solar water heaters. New technologies like Tidal, OTEC, Solar thermal power plants and geothermal power plants are at the demonstration stage and future dissemination will depend on the experience of these projects. (author)

  5. Thermodynamic Modeling of Surface Tension of Aqueous Electrolyte Solution by Competitive Adsorption Model

    Directory of Open Access Journals (Sweden)

    Mohamad Javad Kamali

    2015-01-01

    Full Text Available Thermodynamic modeling of surface tension of different electrolyte systems in presence of gas phase is studied. Using the solid-liquid equilibrium, Langmuir gas-solid adsorption, and ENRTL activity coefficient model, the surface tension of electrolyte solutions is calculated. The new model has two adjustable parameters which could be determined by fitting the experimental surface tension of binary aqueous electrolyte solution in single temperature. Then the values of surface tension for other temperatures in binary and ternary system of aqueous electrolyte solution are predicted. The average absolute deviations for calculation of surface tension of binary and mixed electrolyte systems by new model are 1.98 and 1.70%, respectively.

  6. Modeling of dust emission for a crusted surface

    Science.gov (United States)

    Ghodsi Zadeh, Z.; Klose, M.; DuBois, D. W.

    2017-12-01

    Dust storms are frequent phenomena in the southwestern United Sates. Dust source areas in the region are often (partly) crusted. A critical prerequisite in dust aerosol modeling is an accurate representation of dust emission. While several dust emission schemes have been developed over the last decades, their applicability for crusted surfaces is not well tested. In this study, we use and test the applicability of the dust emission scheme of Shao (2004) (S04), which estimates dust emission based on the soil volume removed by saltation particle impacts, to model dust emission from a crusted surface in New Mexico, USA, for three dust events in spring 2016. Detailed field data are available for these events which are used as scheme input (surface crust and vegetation fraction, friction velocity, minimally- and fully-dispersed particle-size distributions) and for evaluation (saltation flux and dust emission flux). Results show that the saltation flux modeled with the scheme of White (1979) was overestimated by three orders of magnitude. This is expected as the supply of particles available for saltation is limited at the site. As our focus is on dust emission, a constant scaling factor was applied to match modeled and observed saltation fluxes. Parameters that describe the efficiency of saltator impacts to emit dust and the degree of dispersion during erosion need to be adapted in the S04 scheme to represent the soil surface setting at the study site. Our results show that changing those parameters has little effect on the modeled dust emission and dust emission is generally underestimated when PSDs of the top 1 cm soil layer are used as it is common. The reason for this is that the crust at the site is relatively thin and the soil overall sandy, which results in only a small difference between the two PSDs. If, however, the minimally- and fully-dispersed PSDs are replaced with the PSDs of, respectively, loose erodible material and crust, then the difference increases

  7. Linking least-cost energy system costs models with MCA: An assessment of the EU renewable energy targets and supporting policies

    Energy Technology Data Exchange (ETDEWEB)

    Oikonomou, V., E-mail: vlasis@jiqweb.or [Joint Implementation Network, Laan Corpus den Hoorn, 300, Groningen (Netherlands); Flamos, A., E-mail: aflamos@unipi.g [Department of Industrial Management and Technology, University of Piraeus, 80 Karaoli and Dimitriou str., 18534 Piraeus (Greece); Gargiulo, M., E-mail: Maurizio.gargiulo@e4sma.co [Energy Engineering Economic Environment Systems Modelling and Analysis S.r.L (34SMA), Turin (Italy); Giannakidis, G., E-mail: ggian@cres.g [Energy Systems Analysis Laboratory, Centre for Renewable Energy Sources and Savings, 19th Km Marathonos Ave. 19009 Pikermi, Attiki (Greece); Kanudia, A., E-mail: amit@kanors.co [Kanors, Vasundhra Enclave, Delhi (India); Spijker, E. [Joint Implementation Network, Laan Corpus den Hoorn, 300, Groningen (Netherlands); Grafakos, S., E-mail: s.grafakos@ihs.n [Dutch Research Institute For Transitions (Drift) and Institute for Housing and Urban Development Studies (IHS), Erasmus University Rotterdam, BurgemeesterOudlaan 50, P.O. Box 1935, 3000 BX, Rotterdam (Netherlands)

    2011-05-15

    There are several technoeconomic modeling approaches that provide quantitative results such as costs and the level of achievement of certain renewable energy (RE) policy targets. These approaches often do not consider other important factors for policy implementation (such as socio-political aspects and stakeholders' preferences). Recent multicriteria analysis (MCA) approaches attempt to integrate these multiple aspects in decision making process. In this respect, aim of this paper is to combine technoeconomic modeling and MCA approaches in a general analytical framework incorporating multiple aspects. Each method in an RE policy interaction problem can feed in the necessary policy information for the subsequent steps of an ex-ante and an ex-post assessment in a decision tree, starting from recognizing the need for implementing a new policy in parallel to the incumbent ones, assessing the actual policy costs and finally identifying the social acceptability of these RE policies.

  8. Assessing policy options for increasing the use of renewable energy for sustainable development: Modelling energy scenarios for Sichuan, China. A UN-ENERGY demonstration study

    International Nuclear Information System (INIS)

    2007-01-01

    UN-Energy was created in 2004 as the United Nations' principal interagency mechanism in the field of energy. Its creation responds to a request in the Johannesburg Plan of Implementation, adopted by the 2002 World Summit on Sustainable Development, for a new collaborative mechanism between UN agencies, programmes and institutions. UN-Energy has published several reports. The first was prepared for the September 2005 World Summit, 'The Energy Challenge for Achieving the Millennium Development Goals', showing the key role energy access plays for countries to achieve the MDGs. A second report was presented at the May 2006 session of the UN Commission on Sustainable Development (CSD-14), 'Energy in the United Nations: An Overview of UN-Energy Activities'. For the May 2007 CSD-15 UN-Energy brought forward 'Sustainable Bio-Energy: A Framework for Decision-Makers' to help inform dialogue in one critical area of future energy policy choice. Another critical energy policy issue is how renewable energy can be promoted as countries plan for sustainable development. UN-Energy therefore decided to look at how the tools for energy modelling could be evolved. In May 2006, for CSD-14, UN-Energy presented 'Assessing Policy Options for Increasing the Use of Renewable Energy for Sustainable Development: Modelling Energy Scenarios for Ghana'. The Ghana study was carried out by five UN organizations and the Energy Commission of Ghana. It was led by the International Atomic Energy Agency (IAEA) and included the Department of Economic and Social Affairs (DESA) in the UN Secretariat, the Food and Agriculture Organization (FAO), the UN Environment Programme (UNEP) and the UN Industrial Development Organization (UNIDO). UN-Energy now presents a similar study for Sichuan, China. Together these two reports are the first UN-Energy reports to present analytic results from interagency cooperation that, without UN-Energy, would not have happened. This report analyzes alternative provincial

  9. Employment Effects of Renewable Energy Expansion on a Regional Level—First Results of a Model-Based Approach for Germany

    Directory of Open Access Journals (Sweden)

    Ulrike Lehr

    2012-02-01

    Full Text Available National studies have shown that both gross and net effects of the expansion of energy from renewable sources on employment are positive for Germany. These modeling approaches also revealed that this holds true for both present and future perspectives under certain assumptions on the development of exports, fossil fuel prices and national politics. Yet how are employment effects distributed within Germany? What components contribute to growth impacts on a regional level? To answer these questions (new methods of regionalization were explored and developed for the example “wind energy onshore” for Germany’s federal states. The main goal was to develop a methodology which is applicable to all renewable energy technologies in future research. For the quantification and projection, it was necessary to distinguish between jobs generated by domestic investments and exports on the one hand, and jobs for operation and maintenance of existing plants on the other hand. Further, direct and indirect employment is analyzed. The results show, that gross employment is particularly high in the northwestern regions of Germany. However, especially the indirect effects are spread out over the whole country. Regions in the south not only profit from the delivery of specific components, but also from other industry and service inputs.

  10. Surface and Flow Field Measurements on the FAITH Hill Model

    Science.gov (United States)

    Bell, James H.; Heineck, James T.; Zilliac, Gregory; Mehta, Rabindra D.; Long, Kurtis R.

    2012-01-01

    A series of experimental tests, using both qualitative and quantitative techniques, were conducted to characterize both surface and off-surface flow characteristics of an axisymmetric, modified-cosine-shaped, wall-mounted hill named "FAITH" (Fundamental Aero Investigates The Hill). Two separate models were employed: a 6" high, 18" base diameter machined aluminum model that was used for wind tunnel tests and a smaller scale (2" high, 6" base diameter) sintered nylon version that was used in the water channel facility. Wind tunnel and water channel tests were conducted at mean test section speeds of 165 fps (Reynolds Number based on height = 500,000) and 0.1 fps (Reynolds Number of 1000), respectively. The ratio of model height to boundary later height was approximately 3 for both tests. Qualitative techniques that were employed to characterize the complex flow included surface oil flow visualization for the wind tunnel tests, and dye injection for the water channel tests. Quantitative techniques that were employed to characterize the flow included Cobra Probe to determine point-wise steady and unsteady 3D velocities, Particle Image Velocimetry (PIV) to determine 3D velocities and turbulence statistics along specified planes, Pressure Sensitive Paint (PSP) to determine mean surface pressures, and Fringe Imaging Skin Friction (FISF) to determine surface skin friction (magnitude and direction). This initial report summarizes the experimental set-up, techniques used, data acquired and describes some details of the dataset that is being constructed for use by other researchers, especially the CFD community. Subsequent reports will discuss the data and their interpretation in more detail

  11. Modeling marine surface microplastic transport to assess optimal removal locations

    International Nuclear Information System (INIS)

    Sherman, Peter; Van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy. The simulations show that the optimal removal locations are primarily located off the coast of China and in the Indonesian Archipelago for both scenarios. Our estimates show that 31% of the modeled microplastic mass can be removed by 2025 using 29 plastic collectors operating at a 45% capture efficiency from these locations, compared to only 17% when the 29 plastic collectors are moored in the North Pacific garbage patch, between Hawaii and California. The overlap of ocean surface microplastics and phytoplankton growth can be reduced by 46% at our proposed locations, while sinks in the North Pacific can only reduce the overlap by 14%. These results are an indication that oceanic plastic removal might be more effective in removing a greater microplastic mass and in reducing potential harm to marine life when closer to shore than inside the plastic accumulation zones in the centers of the gyres. (letter)

  12. Constraining Agricultural Irrigation Surface Energy Budget Feedbacks in Atmospheric Models

    Science.gov (United States)

    Aufforth, M. E.; Desai, A. R.; Suyker, A.

    2017-12-01

    The expansion and modernization of irrigation increased the relevance of knowing the effects it has on regional weather and climate feedbacks. We conducted a set of observationally-constrained simulations determining the result irrigation exhibits on the surface energy budget, the atmospheric boundary layer, and regional precipitation feedbacks. Eddy covariance flux tower observations were analyzed from two irrigated and one rain-fed corn/soybean rotation sites located near Mead, Nebraska. The evaluated time period covered the summer growing months of June, July, and August (JJA) during the years when corn grew at all three sites. As a product of higher continuous surface moisture availability, the irrigated crops had significantly higher amounts of energy partitioned towards latent heating than the non-irrigated site. The daily average peak of latent heating at the rain-fed site occurred before the irrigated sites and was approximately 45 W/m2 lower. Land surface models were evaluated on their ability to reproduce these effects, including those used in numerical weather prediction and those used in agricultural carbon cycle projection. Model structure, mechanisms, and parameters that best represent irrigation-surface energy impacts will be compared and discussed.

  13. Modeling marine surface microplastic transport to assess optimal removal locations

    Science.gov (United States)

    Sherman, Peter; van Sebille, Erik

    2016-01-01

    Marine plastic pollution is an ever-increasing problem that demands immediate mitigation and reduction plans. Here, a model based on satellite-tracked buoy observations and scaled to a large data set of observations on microplastic from surface trawls was used to simulate the transport of plastics floating on the ocean surface from 2015 to 2025, with the goal to assess the optimal marine microplastic removal locations for two scenarios: removing the most surface microplastic and reducing the impact on ecosystems, using plankton growth as a proxy. The simulations show that the optimal removal locations are primarily located off the coast of China and in the Indonesian Archipelago for both scenarios. Our estimates show that 31% of the modeled microplastic mass can be removed by 2025 using 29 plastic collectors operating at a 45% capture efficiency from these locations, compared to only 17% when the 29 plastic collectors are moored in the North Pacific garbage patch, between Hawaii and California. The overlap of ocean surface microplastics and phytoplankton growth can be reduced by 46% at our proposed locations, while sinks in the North Pacific can only reduce the overlap by 14%. These results are an indication that oceanic plastic removal might be more effective in removing a greater microplastic mass and in reducing potential harm to marine life when closer to shore than inside the plastic accumulation zones in the centers of the gyres.

  14. Interactive system for quick modeling of aircraft surfaces

    Science.gov (United States)

    Mudur, S. P.; Khandekar, Dilip R.

    1990-08-01

    The precise specification of surface geometry of an aircraft is one of the most important and major activities inits design. An initial design, defined by the fundamental requirements, is iteratively analysed and modified till a satisfactory configuration is obtained. Very often in the early stages the need to rapidly make modifications to the geometry for immediate analysis overrides the stringency of smoothness and correctness ofthe surfaces. This paper describes the design of an interactive system which enables the designer to quickly specify the surface geometry and to modify it easily and rapidly. In particular, the software engineering aspects are emphasized. The system uses B-splines for the representation of complex geometry. Surfaces of revolution, required to model certain parts ofthe aircraft, and other simple geometric primitives are also supported. Apart from the usual modeller facilities, features such as camber, twist and form constraints such as tangent or curvature control at a point, etc., are also provided. The system enables easy input and rapid editing of geomeiry through the use of a number of innovative concepts which aim at simplifying and speeding up the man-machine interaction. Multiple window display of entities, augmented by plots of curvature, cross sections etc. provide the visualization tool necessary to assist the designer in decision making.

  15. Can atom-surface potential measurements test atomic structure models?

    Science.gov (United States)

    Lonij, Vincent P A; Klauss, Catherine E; Holmgren, William F; Cronin, Alexander D

    2011-06-30

    van der Waals (vdW) atom-surface potentials can be excellent benchmarks for atomic structure calculations. This is especially true if measurements are made with two different types of atoms interacting with the same surface sample. Here we show theoretically how ratios of vdW potential strengths (e.g., C₃(K)/C₃(Na)) depend sensitively on the properties of each atom, yet these ratios are relatively insensitive to properties of the surface. We discuss how C₃ ratios depend on atomic core electrons by using a two-oscillator model to represent the contribution from atomic valence electrons and core electrons separately. We explain why certain pairs of atoms are preferable to study for future experimental tests of atomic structure calculations. A well chosen pair of atoms (e.g., K and Na) will have a C₃ ratio that is insensitive to the permittivity of the surface, whereas a poorly chosen pair (e.g., K and He) will have a ratio of C₃ values that depends more strongly on the permittivity of the surface.

  16. Commercializing Emerging Renewable Energy: A Case Study

    OpenAIRE

    Lehtovaara, Matti; Karvonen, Matti; Tuunanen, Jussi; Pyrhönen, Olli; Kässi, Tuomo

    2012-01-01

    A broad scientific consensus exists that the global climate is changing. The Earth’s surface temperature could rise significantly over the next few decades, leading to us witnessing an entirely new and unknown planet. Improved energy efficiency, decreasing use of fossil fuels and wide diffusion of various renewable energy sources are among the focal measures to limit global warming to a sustainable level. The objective of this study is to analyse how renewable energy, such as wind power and b...

  17. Nanoimprint Lithography on curved surfaces prepared by fused deposition modelling

    International Nuclear Information System (INIS)

    Köpplmayr, Thomas; Häusler, Lukas; Bergmair, Iris; Mühlberger, Michael

    2015-01-01

    Fused deposition modelling (FDM) is an additive manufacturing technology commonly used for modelling, prototyping and production applications. The achievable surface roughness is one of its most limiting aspects. It is however of great interest to create well-defined (nanosized) patterns on the surface for functional applications such as optical effects, electronics or bio-medical devices. We used UV-curable polymers of different viscosities and flexible stamps made of poly(dimethylsiloxane) (PDMS) to perform Nanoimprint Lithography (NIL) on FDM-printed curved parts. Substrates with different roughness and curvature were prepared using a commercially available 3D printer. The nanoimprint results were characterized by optical light microscopy, profilometry and atomic force microscopy (AFM). Our experiments show promising results in creating well-defined microstructures on the 3D-printed parts. (paper)

  18. Renewable acrylonitrile production.

    Science.gov (United States)

    Karp, Eric M; Eaton, Todd R; Sànchez I Nogué, Violeta; Vorotnikov, Vassili; Biddy, Mary J; Tan, Eric C D; Brandner, David G; Cywar, Robin M; Liu, Rongming; Manker, Lorenz P; Michener, William E; Gilhespy, Michelle; Skoufa, Zinovia; Watson, Michael J; Fruchey, O Stanley; Vardon, Derek R; Gill, Ryan T; Bratis, Adam D; Beckham, Gregg T

    2017-12-08

    Acrylonitrile (ACN) is a petroleum-derived compound used in resins, polymers, acrylics, and carbon fiber. We present a process for renewable ACN production using 3-hydroxypropionic acid (3-HP), which can be produced microbially from sugars. The process achieves ACN molar yields exceeding 90% from ethyl 3-hydroxypropanoate (ethyl 3-HP) via dehydration and nitrilation with ammonia over an inexpensive titanium dioxide solid acid catalyst. We further describe an integrated process modeled at scale that is based on this chemistry and achieves near-quantitative ACN yields (98 ± 2%) from ethyl acrylate. This endothermic approach eliminates runaway reaction hazards and achieves higher yields than the standard propylene ammoxidation process. Avoidance of hydrogen cyanide as a by-product also improves process safety and mitigates product handling requirements. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  19. Renewable Energy Systems

    DEFF Research Database (Denmark)

    Lund, Henrik; Mathiesen, Brian Vad; Connolly, David

    2014-01-01

    on the electricity sector, smart energy systems include the entire energy system in its approach to identifying suitable energy infrastructure designs and operation strategies. The typical smart grid sole focus on the electricity sector often leads to the conclusion that transmission lines, flexible electricity...... grids should be seen as part of overall smart energy systems and emphasizes the inclusion of flexible combined heat and power (CHP) production in the electricity balancing and grid stabilization. Furthermore, it highlights how to design and model future sustainable smart energy systems.......This paper presents the learning of a series of studies that analyse the problems and perspectives of converting the present energy system into a 100 % renewable energy system using a smart energy systems approach. As opposed to, for instance, the smart grid concept, which takes a sole focus...

  20. Renewable Acrylonitrile Production

    Energy Technology Data Exchange (ETDEWEB)

    Beckham, Gregg T [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Karp, Eric M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Eaton, Todd R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Sanchez i Nogue, Violeta [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vorotnikov, Vassili [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Biddy, Mary J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Tan, Eric C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brandner, David [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Manker, Lorenz [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Michener, William E [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Vardon, Derek R [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Bratis, Adam D [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Liu, Rongming [University of Colorado; Gill, Ryan T. [University of Colorado; Gilhespy, Michelle [Johnson Matthey Technology Centre; Skoufa, Zinovia [Johnson Matthey Technology Centre; Watson, Michael J. [Johnson Matthey Technology Centre; Fruchey, O. Stanley [MATRIC; Cywar, Robin M. [Formerly NREL

    2017-12-08

    Acrylonitrile (ACN) is a petroleum-derived compound used in resins, polymers, acrylics, and carbon fiber. We present a process for renewable ACN production using 3-hydroxypropionic acid (3-HP), which can be produced microbially from sugars. The process achieves ACN molar yields exceeding 90% from ethyl 3-hydroxypropanoate (ethyl 3-HP) via dehydration and nitrilation with ammonia over an inexpensive titanium dioxide solid acid catalyst. We further describe an integrated process modeled at scale that is based on this chemistry and achieves near-quantitative ACN yields (98 +/- 2%) from ethyl acrylate. This endothermic approach eliminates runaway reaction hazards and achieves higher yields than the standard propylene ammoxidation process. Avoidance of hydrogen cyanide as a by-product also improves process safety and mitigates product handling requirements.

  1. Renewable Energy Certificate Program

    Energy Technology Data Exchange (ETDEWEB)

    Gwendolyn S. Andersen

    2012-07-17

    This project was primarily to develop and implement a curriculum which will train undergraduate and graduate students at the University seeking a degree as well as training for enrollees in a special certification program to prepare individuals to be employed in a broad range of occupations in the field of renewable energy and energy conservation. Curriculum development was by teams of Saint Francis University Faculty in the Business Administration and Science Departments and industry experts. Students seeking undergraduate and graduate degrees are able to enroll in courses offered within these departments which will combine theory and hands-on training in the various elements of wind power development. For example, the business department curriculum areas include economic modeling, finance, contracting, etc. The science areas include meteorology, energy conversion and projection, species identification, habitat protection, field data collection and analysis, etc.

  2. Modeling Turbulence Generation in the Atmospheric Surface and Boundary Layers

    Science.gov (United States)

    2015-10-01

    ZT ). The initial acceleration of the rising buoyant air will be a = g∆T/TA. This is simply Archimedes ’ principle applied to the buoyant air. The... applications . 1 Various rules are employed to model C2n in the surface layer, but a key question is how to extend this estimation technique into the lower...in terms of wind turbulence the structure of the fluctuations produces a Reynolds stress tensor whose principle axes are not equal, meaning that at the

  3. Policies for Renewable Heat

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-07-01

    This paper builds on IEA publications, Deploying Renewables, Principles for Effective Policies and Deploying Renewables, Best and Future Policy Practice, that discuss the 'integrated policy approach,' whereby renewable energy technologies require different support policies at different stages of their maturity pathways. The paper discusses how the integrated policy approach applies to renewable heat. It attempts to provide guidance for policy-makers on renewable heat throughout the different phases of the policy lifecycle, allowing for the specific challenges of renewable heat and needs of the many stakeholders involved. Stimulating a market for heat involves challenges that are different and, often, more difficult to overcome than in the electricity and transport sectors.

  4. Using advanced surface complexation models for modelling soil chemistry under forests: Solling forest, Germany

    International Nuclear Information System (INIS)

    Bonten, Luc T.C.; Groenenberg, Jan E.; Meesenburg, Henning; Vries, Wim de

    2011-01-01

    Various dynamic soil chemistry models have been developed to gain insight into impacts of atmospheric deposition of sulphur, nitrogen and other elements on soil and soil solution chemistry. Sorption parameters for anions and cations are generally calibrated for each site, which hampers extrapolation in space and time. On the other hand, recently developed surface complexation models (SCMs) have been successful in predicting ion sorption for static systems using generic parameter sets. This study reports the inclusion of an assemblage of these SCMs in the dynamic soil chemistry model SMARTml and applies this model to a spruce forest site in Solling Germany. Parameters for SCMs were taken from generic datasets and not calibrated. Nevertheless, modelling results for major elements matched observations well. Further, trace metals were included in the model, also using the existing framework of SCMs. The model predicted sorption for most trace elements well. - Highlights: → Surface complexation models can be well applied in field studies. → Soil chemistry under a forest site is adequately modelled using generic parameters. → The model is easily extended with extra elements within the existing framework. → Surface complexation models can show the linkages between major soil chemistry and trace element behaviour. - Surface complexation models with generic parameters make calibration of sorption superfluous in dynamic modelling of deposition impacts on soil chemistry under nature areas.

  5. 76 FR 59186 - Renewal of Rail Energy Transportation Advisory Committee

    Science.gov (United States)

    2011-09-23

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. EP 670 (Sub-No. 3)] Renewal of Rail Energy Transportation Advisory Committee AGENCY: Surface Transportation Board. ACTION: Notice...) intends to renew the charter of the Rail Energy Transportation Advisory Committee (RETAC). ADDRESSES: A...

  6. 78 FR 58383 - Renewal of Rail Energy Transportation Advisory Committee

    Science.gov (United States)

    2013-09-23

    ... DEPARTMENT OF TRANSPORTATION Surface Transportation Board [Docket No. EP 670 (Sub-No. 3)] Renewal of Rail Energy Transportation Advisory Committee AGENCY: Surface Transportation Board, DOT. ACTION...) intends to renew the charter of the Rail Energy Transportation Advisory Committee (RETAC). ADDRESSES: A...

  7. Modeling a novel CCHP system including solar and wind renewable energy resources and sizing by a CC-MOPSO algorithm

    International Nuclear Information System (INIS)

    Soheyli, Saman; Shafiei Mayam, Mohamad Hossein; Mehrjoo, Mehri

    2016-01-01

    Highlights: • Considering renewable energy resources as the main prime movers in CCHP systems. • Simultaneous application of FEL and FTL by optimizing two probability functions. • Simultaneous optimization the equipment and penalty factors by CC-MOPSO algorithm. • Reducing fuel consumption and pollution up to 263 and 353 times, respectively. - Abstract: Due to problems, such as, heat losses of equipment, low energy efficiency, increasing pollution and the fossil fuels consumption, combined cooling, heating, and power (CCHP) systems have attracted lots of attention during the last decade. In this paper, for minimizing fossil fuel consumption and pollution, a novel CCHP system including photovoltaic (PV) modules, wind turbines, and solid oxide fuel cells (SOFC) as the prime movers is considered. Moreover, in order to minimize the excess electrical and heat energy production of the CCHP system and so reducing the need for the local power grid and any auxiliary heat production system, following electrical load (FEL) and following thermal load (FTL) operation strategies are considered, simultaneously. In order to determine the optimal number of each system component and also set the penalty factors in the used penalty function, a co-constrained multi objective particle swarm optimization (CC-MOPSO) algorithm is applied. Utilization of the renewable energy resources, the annual total cost (ATC) and the CCHP system area are considered as the objective functions. It also includes constraints such as, loss of power supply probability (LPSP), loss of heat supply probability (LHSP), state of battery charge (SOC), and the number of each CCHP component. A hypothetical hotel in Kermanshah, Iran is conducted to verify the feasibility of the proposed system. 10 wind turbines, 430 PV modules, 11 SOFCs, 106 batteries and 2 heat storage tanks (HST) are numerical results for the spring as the best season in terms of decreasing cost and fuel consumption. Comparing the results

  8. Corrected electrostatic model for dipoles adsorbed on a metal surface

    Energy Technology Data Exchange (ETDEWEB)

    Maschhoff, B.L.; Cowin, J.P. (Enviornmental and Molecular Science Laboratory, Pacific Northwest Laboratories Box 999 MS K2-14, Richland, Washington 99352 (United States))

    1994-11-01

    We present a dipole--dipole interaction model for polar molecules vertically adsorbed on a idealized metal surface in an approximate analytic form suitable for estimating the coverage dependence of the work function, binding energies, and thermal desorption activation energies. In contrast to previous treatments, we have included all contributions to the interaction energy within the dipole model, such as the internal polarization energy and the coverage dependence of the self-image interaction with the metal. We show that these can contribute significantly to the total interaction energy. We present formulae for both point and extended dipole cases.

  9. Kinetic computer modeling of microwave surface-wave plasma production

    International Nuclear Information System (INIS)

    Ganachev, Ivan P.

    2004-01-01

    Kinetic computer plasma modeling occupies an intermediate position between the time consuming rigorous particle dynamic simulation and the fast but rather rough cold- or warm-plasma fluid models. The present paper reviews the kinetic modeling of microwave surface-wave discharges with accent on recent kinetic self-consistent models, where the external input parameters are reduced to the necessary minimum (frequency and intensity of the applied microwave field and pressure and geometry of the discharge vessel). The presentation is limited to low pressures, so that Boltzmann equation is solved in non-local approximation and collisional electron heating is neglected. The numerical results reproduce correctly the bi-Maxwellian electron energy distribution functions observed experimentally. (author)

  10. Impact of embedded renewable on transmission and distribution network

    International Nuclear Information System (INIS)

    Pistora, M.; Maslo, K.

    2012-01-01

    This paper deals with impact of renewable energy sources on both interconnected transmission systems and distribution networks. It evaluates the role of phase-shifting transformers in controlling active power flows created by renewable as well as embedded renewable' role in is landing operation in distribution network. Model of photovoltaic power plant from MODES simulation software is described as well. (Authors)

  11. A framework for modeling connections between hydraulics, water surface roughness, and surface reflectance in open channel flows

    Science.gov (United States)

    Legleiter, Carl; Mobley, Curtis D.; Overstreet, Brandon

    2017-01-01

    This paper introduces a framework for examining connections between the flow field, the texture of the air-water interface, and the reflectance of the water surface and thus evaluating the potential to infer hydraulic information from remotely sensed observations of surface reflectance. We used a spatial correlation model describing water surface topography to illustrate the application of our framework. Nondimensional relations between model parameters and flow intensity were established based on a prior flume study. Expressing the model in the spatial frequency domain allowed us to use an efficient Fourier transform-based algorithm for simulating water surfaces. Realizations for both flume and field settings had water surface slope distributions positively correlated with velocity and water surface roughness. However, most surface facets were gently sloped and thus unlikely to yield strong specular reflections; the model exaggerated the extent of water surface features, leading to underestimation of facet slopes. A ray tracing algorithm indicated that reflectance was greatest when solar and view zenith angles were equal and the sensor scanned toward the Sun to capture specular reflections of the solar beam. Reflected energy was concentrated in a small portion of the sky, but rougher water surfaces reflected rays into a broader range of directions. Our framework facilitates flight planning to avoid surface-reflected radiance while mapping other river attributes, or to maximize this component to exploit relationships between hydraulics and surface reflectance. This initial analysis also highlighted the need for improved models of water surface topography in natural rivers.

  12. A framework for modeling connections between hydraulics, water surface roughness, and surface reflectance in open channel flows

    Science.gov (United States)

    Legleiter, Carl J.; Mobley, Curtis D.; Overstreet, Brandon T.

    2017-09-01

    This paper introduces a framework for examining connections between the flow field, the texture of the air-water interface, and the reflectance of the water surface and thus evaluating the potential to infer hydraulic information from remotely sensed observations of surface reflectance. We used a spatial correlation model describing water surface topography to illustrate the application of our framework. Nondimensional relations between model parameters and flow intensity were established based on a prior flume study. Expressing the model in the spatial frequency domain allowed us to use an efficient Fourier transform-based algorithm for simulating water surfaces. Realizations for both flume and field settings had water surface slope distributions positively correlated with velocity and water surface roughness. However, most surface facets were gently sloped and thus unlikely to yield strong specular reflections; the model exaggerated the extent of water surface features, leading to underestimation of facet slopes. A ray tracing algorithm indicated that reflectance was greatest when solar and view zenith angles were equal and the sensor scanned toward the Sun to capture specular reflections of the solar beam. Reflected energy was concentrated in a small portion of the sky, but rougher water surfaces reflected rays into a broader range of directions. Our framework facilitates flight planning to avoid surface-reflected radiance while mapping other river attributes, or to maximize this component to exploit relationships between hydraulics and surface reflectance. This initial analysis also highlighted the need for improved models of water surface topography in natural rivers.

  13. Heterogeneous nucleation of ice on model carbon surfaces

    Science.gov (United States)

    Molinero, V.; Lupi, L.; Hudait, A.

    2014-12-01

    Carbonaceous particles account for 10% of the particulate matter in the atmosphere. The experimental investigation of heterogeneous freezing of water droplets by carbonaceous particles reveals widespread ice freezing temperatures. The origin of the soot and its oxidation and aging modulate its ice nucleation ability, however, it is not known which structural and chemical characteristics of soot account for the variability in ice nucleation efficiency. We find that atomically flat carbon surfaces promote heterogeneous nucleation of ice, while molecularly rough surfaces with the same hydrophobicity do not. We investigate a large set of graphitic surfaces of various dimensions and radii of curvature consistent with those of soot in experiments, and find that variations in nanostructures alone could account for the spread in the freezing temperatures of ice on soot in experiments. A characterization of the nanostructure of soot is needed to predict its ice nucleation efficiency. Atmospheric oxidation and aging of soot modulates its ice nucleation ability. It has been suggested that an increase in the ice nucleation ability of aged soot results from an increase in the hydrophilicity of the surfaces upon oxidation. Oxidation, however, also impacts the nanostructure of soot, making it difficult to assess the separate effects of soot nanostructure and hydrophilicity in experiments. We investigate the effect of changes in hydrophilicity of model graphitic surfaces on the freezing temperature of ice. Our results indicate that the hydrophilicity of the surface is not in general a good predictor of ice nucleation ability. We find a correlation between the ability of a surface to promote nucleation of ice and the layering of liquid water at the surface. The results of this work suggest that ordering of liquid water in contact with the surface plays an important role in the heterogeneous ice nucleation mechanism. References: L. Lupi, A. Hudait and V. Molinero, J. Am. Chem. Soc

  14. Renewables. The clean advantage

    International Nuclear Information System (INIS)

    Klein, A.

    2006-01-01

    Europe's big utilities are increasingly seeing renewable energy as a viable alternative to conventional forms of power generation which at present have disadvantages in terms of cost and/or environment. Europe's biggest 20 utilities aim to double their renewables capacity in the next five years and nearly 20 billion US dollars have been earmarked for such projects. This report by Emerging Energy Research discusses the likely trends for the next five years. The various sources of renewable energy and how they might be developed are discussed. The companies leading exploitation of renewables and their market share are named

  15. Renewable energy action agenda

    International Nuclear Information System (INIS)

    Anon

    2000-01-01

    To assist the long-term development of the renewable energy industry, the Commonwealth Government, in partnership with industry, has developed the Renewable Energy Action Agenda. New Era -New Energy, launched in June 2000 by Minister for Industry, Science and Resources, Senator Nick Minchin, Minister for the Environment and Heritage, Senator Robert Hill, and Greg Bourne, Regional President of BP Amoco, sets an ambitious target for growth and identifies the strategies and actions necessary to achieve it. The objective of the Renewable Energy Action Agenda was to develop a policy framework underpinning growth in a commercially viable and internationally competitive Australian renewable energy industry

  16. Renewable energy resources

    CERN Document Server

    Twidell, John

    2015-01-01

    Renewable Energy Resources is a numerate and quantitative text covering the full range of renewable energy technologies and their implementation worldwide. Energy supplies from renewables (such as from biofuels, solar heat, photovoltaics, wind, hydro, wave, tidal, geothermal, and ocean-thermal) are essential components of every nation's energy strategy, not least because of concerns for the local and global environment, for energy security and for sustainability. Thus in the years between the first and this third edition, most renewable energy technologies have grown from fledgling impact to s

  17. The renewable chemicals industry

    DEFF Research Database (Denmark)

    Christensen, Claus H.; Rass-Hansen, J.; Marsden, Charlotte Clare

    2008-01-01

    The possibilities for establishing a renewable chemicals industry featuring renewable resources as the dominant feedstock rather than fossil resources are discussed in this Concept. Such use of biomass can potentially be interesting from both an economical and ecological perspective. Simple...... per kilogram of desired product to illustrate in which processes the use of renewable resources lead to the most substantial reduction of CO2 emissions. The steps towards a renewable chemicals industry will most likely involve intimate integration of biocatalytic and conventional catalytic processes...

  18. Models of rural disperse electrification by means of renewable energies in Latin America: an alternative proposal based on rural development

    International Nuclear Information System (INIS)

    Fuentes, M.; Fuentes, M.; Alvarez, M.

    2004-01-01

    This paper discusses the overdue change in the processes of rural electrification by means of renewable energies. The actors involve in these processes have failed to contemplate every dimension of this issue: Social, Institutional, Technological, Economical, Financial and Political. We will account for the reason why the concept of sustainability must be closely related to that of local socioeconomic development. Rural electrification must be a vector for social development. It is in this context that it cannot depend exclusively on the market and its actors, but it must be immersed within rural development planning. For this new paradigm to work properly, donor agencies -mainly- should understand the dynamics of socioeconomic development, contemplating the different local characteristics of small rural communities; they should provide genuine financial support within an adequate regulatory framework and active participation should be encouraged, both of the local community and of local enterprises. The sustainability of these initiatives is determined not only by the consideration of the dimensions above but also by the creation of labour possibilities or lack thereof. (authors)

  19. Coupled Surface and Groundwater Hydrological Modeling in a Changing Climate.

    Science.gov (United States)

    Sridhar, Venkataramana; Billah, Mirza M; Hildreth, John W

    2017-11-09

    Many current watershed modeling efforts now incorporate surface water and groundwater for managing water resources since the exchanges between groundwater and surface water need a special focus considering the changing climate. The influence of groundwater dynamics on water and energy balance components is investigated in the Snake River Basin (SRB) by coupling the Variable Infiltration Capacity (VIC) and MODFLOW models (VIC-MF) for the period of 1986 through 2042. A 4.4% increase in base flows and a 10.3% decrease in peak flows are estimated by VIC-MF compared to the VIC model in SRB. The VIC-MF model shows significant improvement in the streamflow simulation (Nash-Sutcliffe efficiency [NSE] of 0.84) at King Hill, where the VIC model could not capture the effect of spring discharge in the streamflow simulation (NSE of -0.30); however, the streamflow estimates show an overall decreasing trend. Two climate scenarios representing median and high radiative-forcings such as representative concentration pathways 4.5 and 8.5 show an average increase in the water table elevations between 2.1 and 2.6 m (6.9 and 8.5 feet) through the year 2042. The spatial patterns of these exchanges show a higher groundwater elevation of 15 m (50 feet) in the downstream area and a lower elevation of up to 3 m (10 feet) in the upstream area. Broadly, this study supports results of previous work demonstrating that integrated assessment of groundwater-surface water enables stakeholders to balance pumping, recharge and base flow needs and to manage the watersheds that are subjected to human pressures more sustainably. © 2017, National Ground Water Association.

  20. Financing the alternative: renewable energy in developing and transition countries

    OpenAIRE

    Brunnschweiler, Christa N.

    2006-01-01

    This paper examines the determinants of credit allocation to renewable energy firms in developing and transition countries. Using a simple en- dogenous growth model, we show that the development of the renewable energy sector, i.e. the diversification of renewable energy resources used in primary energy production, depends on the quality of financial intermedia- tion, debtor information costs to banks, and financing needs of renewable energy firms. Policies should aim at increasing financial ...

  1. Reliable low precision simulations in land surface models

    Science.gov (United States)

    Dawson, Andrew; Düben, Peter D.; MacLeod, David A.; Palmer, Tim N.

    2017-12-01

    Weather and climate models must continue to increase in both resolution and complexity in order that forecasts become more accurate and reliable. Moving to lower numerical precision may be an essential tool for coping with the demand for ever increasing model complexity in addition to increasing computing resources. However, there have been some concerns in the weather and climate modelling community over the suitability of lower precision for climate models, particularly for representing processes that change very slowly over long time-scales. These processes are difficult to represent using low precision due to time increments being systematically rounded to zero. Idealised simulations are used to demonstrate that a model of deep soil heat diffusion that fails when run in single precision can be modified to work correctly using low precision, by splitting up the model into a small higher precision part and a low precision part. This strategy retains the computational benefits of reduced precision whilst preserving accuracy. This same technique is also applied to a full complexity land surface model, resulting in rounding errors that are significantly smaller than initial condition and parameter uncertainties. Although lower precision will present some problems for the weather and climate modelling community, many of the problems can likely be overcome using a straightforward and physically motivated application of reduced precision.

  2. Water on hydrophobic surfaces: Mechanistic modeling of hydrophobic interaction chromatography.

    Science.gov (United States)

    Wang, Gang; Hahn, Tobias; Hubbuch, Jürgen

    2016-09-23

    Mechanistic models are successfully used for protein purification process development as shown for ion-exchange column chromatography (IEX). Modeling and simulation of hydrophobic interaction chromatography (HIC) in the column mode has been seldom reported. As a combination of these two techniques is often encountered in biopharmaceutical purification steps, accurate modeling of protein adsorption in HIC is a core issue for applying holistic model-based process development, especially in the light of the Quality by Design (QbD) approach. In this work, a new mechanistic isotherm model for HIC is derived by consideration of an equilibrium between well-ordered water molecules and bulk-like ordered water molecules on the hydrophobic surfaces of protein and ligand. The model's capability of describing column chromatography experiments is demonstrated with glucose oxidase, bovine serum albumin (BSA), and lysozyme on Capto™ Phenyl (high sub) as model system. After model calibration from chromatograms of bind-and-elute experiments, results were validated with batch isotherms and prediction of further gradient elution chromatograms. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. US Renewable Futures in the GCAM

    Energy Technology Data Exchange (ETDEWEB)

    Smith, S. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mizrahi, A. H. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Karas, J. F. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nathan, M. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2011-10-01

    This report examines renewable energy deployment in the United States using a version of the Global Change Assessment Model (GCAM) with a detailed representation of renewables; the GCAM-RE. Electricity generation was modeled in four generation segments and 12-subregions. This level of regional and sector detail allows a more explicit representation of renewable energy generation. Wind, solar thermal power, and central solar PV plants are implemented in explicit resource classes with new intermittency parameterizations appropriate for each technology. A scenario analysis examines a range of assumptions for technology characteristics, climate policy, and long distance transmission.

  4. Renewable energy in the race towards 2050

    International Nuclear Information System (INIS)

    Cleijne, H.; Ruijgrok, W.; Juffermans, P.

    1999-01-01

    Insight is given into the consequences of two visions on the use of renewable sources in the Netherlands: (1) a 'green' model in which the most important activity is to prevent undesired effects on nature, environment and local conditions; and (2) a 'grey' model in which the advantages of renewable sources (e.g. reduction of CO2 emission) outweigh the disadvantages in most cases. Also an overview is given of those renewable energy sources which are expected to break through in the next period to 202019 refs

  5. Metering Best Practices Applied in the National Renewable Energy Laboratory's Research Support Facility: A Primer to the 2011 Measured and Modeled Energy Consumption Datasets

    Energy Technology Data Exchange (ETDEWEB)

    Sheppy, M.; Beach, A.; Pless, S.

    2013-04-01

    Modern buildings are complex energy systems that must be controlled for energy efficiency. The Research Support Facility (RSF) at the National Renewable Energy Laboratory (NREL) has hundreds of controllers -- computers that communicate with the building's various control systems -- to control the building based on tens of thousands of variables and sensor points. These control strategies were designed for the RSF's systems to efficiently support research activities. Many events that affect energy use cannot be reliably predicted, but certain decisions (such as control strategies) must be made ahead of time. NREL researchers modeled the RSF systems to predict how they might perform. They then monitor these systems to understand how they are actually performing and reacting to the dynamic conditions of weather, occupancy, and maintenance.

  6. Iowa's renewable energy and infrastructure impacts

    Science.gov (United States)

    2010-04-01

    Objectives : Estimate traffic growth and pavement deterioration due to Iowas growing renewable energy industries in a multi-county area. : Develop a traffic and fiscal impact model to help assess the impact of additional biofuels plants on...

  7. Renewable energy integration challenges and solutions

    CERN Document Server

    Hossain, Jahangir

    2014-01-01

    This book examines challenges involved in the integration of renewable energy into existing electricity grids. It provides models of power systems to show how the integration will effect conventional grids and various solutions to minimize the impacts.

  8. Modelling and simulation of surface morphology driven by ion bombardment

    Energy Technology Data Exchange (ETDEWEB)

    Yewande, E.O.

    2006-05-02

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  9. Modelling and simulation of surface morphology driven by ion bombardment

    International Nuclear Information System (INIS)

    Yewande, E.O.

    2006-01-01

    Non-equilibrium surfaces, at nanometer length scales, externally driven via bombardment with energetic particles are known to exhibit well ordered patterns with a variety of applications in nano-technology. These patterns emerge at time scales on the order of minutes. Continuum theory has been quite successful in giving a general picture of the processes that interplay to give the observed patterns, as well as how such competition might determine the properties of the nanostructures. However, continuum theoretical descriptions are ideal only in the asymptotic limit. The only other theoretical alternative, which happens to be more suitable for the characteristic length-and time-scales of pattern formation, is Monte Carlo simulation. In this thesis, surface morphology is studied using discrete solid-on-solid Monte Carlo models of sputtering and surface diffusion. The simulations are performed in the context of the continuum theories and experiments. In agreement with the experiments, the ripples coarsen with time and the ripple velocity exhibits a power-law behaviour with the ripple wavelength, in addition, the exponent was found to depend on the simulation temperature, which suggests future experimental studies of flux dependence. Moreover, a detailed exploration of possible topographies, for different sputtering conditions, corresponding to different materials, was performed. And different surface topographies e.g. holes, ripples, and dots, were found at oblique incidence, without sample rotation. With sample rotation no new topography was found, its only role being to destroy any inherent anisotropy in the system. (orig.)

  10. Slag transport models for vertical and horizontal surfaces. [SLGTR code

    Energy Technology Data Exchange (ETDEWEB)

    Chow, L S.H.; Johnson, T R

    1978-01-01

    In a coal-fired MHD system, all downstream component surfaces that are exposed to combustion gases will be covered by a solid, liquid, or solid-liquid film of slag, seed, or a mixture of the two, the specific nature of the film depending on the physical properties of the slag and seed and on local conditions. An analysis was made of a partly-liquid slag film flowing on a cooled vertical or horizontal wall of a large duct, through which passed slag-laden combustion gases. The model is applicable to the high-temperature steam generators in the downstream system of an MHD power plant and was used in calculations for a radiant-boiler concept similar to that in the 1000-MWe Gilbert-STD Baseline Plant study and also for units large enough for 230 and 8 lb/s (104.3 and 3.5 kg/s) of combustion gas. The qualitative trends of the results are similar for both vertical and horizontal surfaces. The results show the effects of the slag film, slag properties, and gas emissivity on the heat flux to the steam tubes. The slag film does not reduce the rate of heat transfer in proportion to its surface temperature, because most of the heat is radiated from the gas and particles suspended in it to the slag surface.

  11. Minimal models on Riemann surfaces: The partition functions

    International Nuclear Information System (INIS)

    Foda, O.

    1990-01-01

    The Coulomb gas representation of the A n series of c=1-6/[m(m+1)], m≥3, minimal models is extended to compact Riemann surfaces of genus g>1. An integral representation of the partition functions, for any m and g is obtained as the difference of two gaussian correlation functions of a background charge, (background charge on sphere) x (1-g), and screening charges integrated over the surface. The coupling constant x (compacitification radius) 2 of the gaussian expressions are, as on the torus, m(m+1), and m/(m+1). The partition functions obtained are modular invariant, have the correct conformal anomaly and - restricting the propagation of states to a single handle - one can verify explicitly the decoupling of the null states. On the other hand, they are given in terms of coupled surface integrals, and it remains to show how they degenerate consistently to those on lower-genus surfaces. In this work, this is clear only at the lattice level, where no screening charges appear. (orig.)

  12. Minimal models on Riemann surfaces: The partition functions

    Energy Technology Data Exchange (ETDEWEB)

    Foda, O. (Katholieke Univ. Nijmegen (Netherlands). Inst. voor Theoretische Fysica)

    1990-06-04

    The Coulomb gas representation of the A{sub n} series of c=1-6/(m(m+1)), m{ge}3, minimal models is extended to compact Riemann surfaces of genus g>1. An integral representation of the partition functions, for any m and g is obtained as the difference of two gaussian correlation functions of a background charge, (background charge on sphere) x (1-g), and screening charges integrated over the surface. The coupling constant x (compacitification radius){sup 2} of the gaussian expressions are, as on the torus, m(m+1), and m/(m+1). The partition functions obtained are modular invariant, have the correct conformal anomaly and - restricting the propagation of states to a single handle - one can verify explicitly the decoupling of the null states. On the other hand, they are given in terms of coupled surface integrals, and it remains to show how they degenerate consistently to those on lower-genus surfaces. In this work, this is clear only at the lattice level, where no screening charges appear. (orig.).

  13. A model investigation of annual surface ultraviolet radiation in Iran

    International Nuclear Information System (INIS)

    Sabziparvar, A.-A.

    2003-01-01

    In recent years, there has been some concern regarding solar ultraviolet (UV) radiation received at the earth,s surface because of its biological hazards affecting living organisms. Although the geographical distribution of ground-based UV network is relatively good in some continents,but over Asia, the number of UV instruments are not sufficient for meteorological and biological purposes. Iran, as an Asian country, is also suffering from the lack of UV monitoring network with the exception of one ground-based UV spectrophotometer site (Brower III) at Esfahan. Using a complex radiative transfer model and various meteorological data (for 8 years) such as total column ozone, cloudiness, surface albedo, surface air pressure, relative humidity, visibility and daily total solar radiation (TSR), the geographical distribution of annual integrated biological surface UV irradiances such as UVB, erythema and cataracts are calculated. The comparison is made for cloud-free and all-sky conditions for eight selected cities distributed from the southern tip of the country (25 N-60 E) to the northern border (39 N-48 E). It is shown that the difference between the annual UV at south and north in all-sky condition is larger than the differences in cloud-free condition. The ratio of some biological UV irradiances at southern cities to the same component at northern cities shows a factor of two and more which is quite significant. The possible reasons which might cause such differences are discussed

  14. Allowing for surface preparation in stress corrosion cracking modelling

    International Nuclear Information System (INIS)

    Berge, P.; Buisine, D.; Gelpi, A.

    1997-01-01

    When a 600 alloy component is significantly deformed during installation, by welding, rolling, bending, its stress corrosion cracking in Pressurized Water Nuclear Reactor's primary coolant, is significantly changed by the initial surface treatment. Therefore, the crack initiated time may be reduced by several orders of magnitude for certain surfaces preparations. Allowing for cold working of the surface, for which modelling is proposed, depends less on the degree of cold work then on the depths of the hardened layers. Honing hardens the metal over depths of about one micron for vessel head penetrations, for example, and has little influence on subsequent behaviour after the part deforms. On the other hand, coarser turning treatment produces cold worked layers which can reach several tens of microns and can very significantly reduce the initiation time compared to fine honing. So evaluation after depths of hardening is vital on test pieces for interpreting laboratory results as well as on service components for estimating their service life. Suppression by mechanical or chemical treatment of these layers, after deformation, seems to be the most appropriate solution for reducing over-stressing connected with surface treatment carried out before deformation. (author)

  15. Design of a Three Surfaces R/C Aircraft Model

    Directory of Open Access Journals (Sweden)

    D. P. Coiro

    2002-01-01

    Full Text Available Design of a three lifting surfaces radio-controlled model has been carried out at Dipartimento di Progettazione Aeronautica (DPA by the authors in the last year. The model is intended to be a UAV prototype and is now under construction. The main goal of this small aircraft's design is to check the influence of the canard surface on the aircraft's aerodynamic characteristics and flight behavior, especially at high angles of attack. The aircraft model is also intended to be a flying platform to test sensors, measurement and acquisition systems for research purposes and a valid and low-cost teaching instrument for flight dynamics and flight maneuvering. The aircraft has been designed to fly with and without canard, and all problems relative to aircraft balance and stability have been carefully analyzed and solved. The innovative configuration and the mixed wooden-composite material structure has been obtained with very simple shapes and all the design is focused on realizing a low-cost model. A complete aerodynamic analysis of the configuration up to high angles of attack and a preliminary aircraft stability and performance prediction will be presented.

  16. Modeling land-surface/atmosphere dynamics for CHAMMP

    International Nuclear Information System (INIS)

    Gutowski, W.J. Jr.

    1993-01-01

    Project progress is described on a DOE CHAMP project to model the land-surface/atmosphere coupling in a heterogeneous environment. This work is a collaboration between scientists at Iowa State University and the University of New Hampshire. Work has proceeded in two areas: baseline model coupling and data base development for model validation. The core model elements (land model, atmosphere model) have been ported to the Principal Investigator's computing system and baseline coupling has commenced. The initial target data base is the set of observations from the FIFE field campaign, which is in the process of being acquired. For the remainder of the project period, additional data from the region surrounding the FIFE site and from other field campaigns will be acquired to determine how to best extrapolate results from the initial target region to the rest of the globe. In addition, variants of the coupled model will be used to perform experiments examining resolution requirements and coupling strategies for land-atmosphere coupling in a heterogeneous environment

  17. Developing the use of renewable heat

    International Nuclear Information System (INIS)

    Nifenecker, Herve

    2013-01-01

    The author reports a study in which he shows that the heat production by means of renewable energies is an efficient method to reach the objective of 23 per cent of renewable energies in the French final energy consumption. He browses the different techniques of renewable heat production (solar heat, wood-fuel, surface geothermal) and indicates the associated potential resources. He proposes a cost analysis which compares the use of gas and electricity with three techniques of production of renewable heat: solar heat to produce hot water, biomass combustion (more particularly wood), solar heat extracted with fuel cells. He also assesses tariffs and CO 2 emissions. Then, he elaborates a strategy to phase out fossil energies: a modification of the RT 2012 thermal regulation, to give up the purchase obligation for electricity produced by wind and photovoltaic energy, to extend the CSPE calculation basis, to put oil-fuel and gas boilers out of the market, to support the development of renewable heat production, to improve the competitiveness of the different techniques of renewable heat production. He finally gives a brief overview of industrial perspectives created by such a development of renewable heat

  18. Modelling of the initial stage of the surface discharge development

    International Nuclear Information System (INIS)

    Gibalov, V.; Pietsch, G.

    1998-01-01

    Computer modelling of the initial stage of the surface discharge was performed by solving numerically the coupled continuity, the Poisson and Townsend ionization equations and taking into account the ionization, attachment and detachment processes. The potential distribution at the dielectric surface and at the boundaries which surround the integration region have been calculated with the charge-image method in a 3D approach. In order to eliminate numerical diffusion effects, the solution of the continuity equation was corrected using a flux correction transport routine. At the positive voltage the development of the discharge channel is determined mainly by the shape of the electrode tip. At the negative voltage the following phases of the discharge may be distinguished: the initial phase, the cathode directed streamer phase resulting in the cathode layer formation, and the propagating phase. The physical processes governing each discharge phase are described in detail. (J.U.)

  19. Renewing Urban Schools.

    Science.gov (United States)

    Mayfield, John

    This paper describes an approach to urban renewal, called the Multi-Function Polis (MFP), which emphasizes education as a key factor in a renewal process that includes development of 21st century industries such as information technology, telecommunications, and environmental management. Focusing on Adelaide, Australia, as an example, the paper…

  20. Renewable Energy in Alaska

    Energy Technology Data Exchange (ETDEWEB)

    2013-03-01

    This report examines the opportunities, challenges, and costs associated with renewable energy implementation in Alaska and provides strategies that position Alaska's accumulating knowledge in renewable energy development for export to the rapidly growing energy/electric markets of the developing world.