Vasilis M. Fthenakis Columbia University
and Brookhaven National Laboratory
Anne C. Dillon National Renewable Energy Laboratory
Nora Savage U. S. Environmental Protection Agency
R1: PV Energy Conversion
Monday PM, November 26, 2007
Room 301 (Hynes)
10:00 AM - **R1.1
Reduction of Environmental Impacts in Crystalline Silicon Photovoltaic Technology – An Analysis of Driving Forces and Opportunities.
Erik Alsema 1 , Mariska De Wild-Scholten 2 Show Abstract
1 Copernicus Institute, Utrecht University, Utrecht Netherlands, 2 Unit Solar Energy, Energy Research Centre of the Netherlands, Petten Netherlands
Over the past 10-15 years the environmental impacts of photovoltaic modules based on crystalline silicon have decreased substantially. Improved process technology has led to more efficient material use and lower energy consumption. This has for example led to a reduction of the energy payback time by 50% over the past 15 years. Also waste emissions have decreased significantly.In this paper we will investigate what the major driving forces for this improvement have been, whether it was to reduce material cost, to improve cell efficiency or other factors. To what extent has sustainability or eco-efficiency been a driving force in the technology improvement? After this historical perspective we will look into future prospects with respect to new c-Si cell concepts and future module production technology. Could another 50% reduction of energy payback be reached? We will investigate how, in terms of greenhouse gas emission and other environmental impacts, c-Si technology compares with thin film photovoltaics and with other sustainable energy options, like wind, biomass, nuclear and carbon sequestration. On which aspects can c-Si photovoltaics face the competition and on which aspects would improvements be necessary or helpful.Thirdly we will investigate which of the expected improvements in c-Si technology, driven by cost reduction objectives, will help to reduce environmental impacts further and which could even be counter-effective. Finally we will look at the question whether it is necessary to make environmental improvement a separate objective in R&D and in process optimization, and in what way this may be achieved.
10:30 AM - **R1.2
Key Projections on Future PV Performance, Market Penetration and Costs, with Special Reference to CdTe and Other Thin Film Technologies.
Marco Raugei 1 , Paolo Frankl 2 Show Abstract
1 , Ambiente Italia Research Institute, Rome Italy, 2 , International Energy Agency, Paris France
The authors have drafted three alternative scenarios for the technological improvement and market penetration of photovoltaics in the next four decades, based on the preliminary results of the EU FP6 Integrated Project NEEDS, Research Stream 1a.The long-term diffusion of PV is foreseen to depend on the achievable module efficiencies and on the maturity of the different technologies in terms of their manufacturing costs, energy pay-back times, additional BOS costs, and even raw material reserves. Last but not least, the co-evolution of a suitable energy storage network (e.g. hydrogen) is also foreseen to be a mandatory requirement.Cumulative installed capacity worldwide is projected to reach 9,000 GWp in 2050 in the most optimistic scenario, which is reduced to 2,400 GWp in the intermediate scenario. In the third “pessimistic” scenario the current economic incentives are not assumed to be sustained long enough to allow PV to become competitive with bulk electricity, resulting in a stunted market growth (500 GWp in 2050).The resulting predictions in terms of costs range from 0.50 to 1.50 €/Wp in 2050, respectively corresponding to 2 - 8 €-cents per kWh in Southern Europe and 4 - 14 €-cents per kWh in Northern Europe.Within the framework of these three general scenarios, special attention is then put to the role that is likely to be played by thin film technologies, namely amorphous Si, CdTe and CIS. These technologies are expected to collectively reach a market share of approximately 45% by as early as 2025 in all but the most pessimistic scenario, wherein the same goal is put off until 2050. Marked increases in module efficiencies and material and energy consumption are also expected, to varying degrees depending on the assumptions made in the three scenarios.
11:00 AM - R1:Photovoltaics
11:30 AM - R1.3
Life Cycle Assessment of Photovoltaics – Update of the Ecoinvent Database.
Niels Jungbluth 1 , Roberto Dones 2 Show Abstract
1 , ESU-services Ltd., Uster Switzerland, 2 , Paul Scherrer Institute, Villigen PSI Switzerland
11:45 AM - R1.4
Comparative Life-cycle Analysis of Photovoltaics Based on Nano-materials: A Proposed Framework.
Sandra Gualtero 1 , Rob van der Meulen 1 , Hyung Chul Kim 2 , Vasilis Fthenakis 1 2 Show Abstract
1 Center for Life Cycle Analysis, Columbia University, New York, New York, United States, 2 PV EH&S Research Center, Brookhaven National Laboratory, Upton, New York, United States
In academic and industrial institutes research on synthesizing nano-particle precursors and fabricating nano-structured solar cells is rapidly expanding. While nanotechnology potentially can greatly increase the efficiency of photovoltaic energy-conversion, there is a dearth of knowledge about the health and environmental impacts of using nanomaterials. Since many characteristics of nanomaterials are linked to their particle size, it is essential to investigate the benefits and risks due to their minuscule dimensions. For example, using nano-particle cadmium telluride (CdTe) for depositing/growing thin film photovoltaics may enable the growth of thin films at a lower temperature than when depositing comparably thin films with micro-particles, implying a reduced energy consumption during the former’s deposition process. However, nano-particle CdTe is likely to have completely different physical transport and toxicological properties than bulk CdTe. In this analysis, we describe a life-cycle analysis framework that will enable the comparisons of the health- and environmental-impacts of nanomaterials and bulk materials during the production of photovoltaics. The following parameters that distinguish nanotechnology from a conventional technologies will be investigated within the life-cycle framework: 1) method of synthesizing the nanoparticles; 2) physical specifications of the precursors, i.e., their purity and size; 3) material utilization rate/process efficiency; 4) deposition processes/conditions; 5) the energy-conversion efficiency of the solar cells; and 6) the life-time expectancy of the final product. We will introduce the application of this framework in comparing cadmium telluride and silicon thin-film technologies.
12:00 PM - **R1.5
Photovoltaic Panels Performance Assessment.
Antonia Moropoulou 1 , John Palyvos 1 , Maria Karoglou 1 , Panagopoulos Vasilis 1 Show Abstract
1 School of Chemical Engineering, National Technical University of Athens, Athens Greece
In this work infrared thermography is used for the assessment of the performance of photovoltaic panels at the façade of NTUA's Chemical Engineering building. On the southern façade and roof of the NTUA's Chemical Engineering building complex, under the Thermie Project (SE-142-97-GR-ES), it is installed a grid-connected 50 kWp solar photovoltaic array, in a standard and hybrid PV-Thermal configuration, meant to save conventional energy.The thermographic system used was of 8-12μ wavelength. The thermographs obtained during the day continuously, using a standard video PAL. The thermal images obtained showed that there are temperature differences on the PV panels, which may be attributed to PV material defects or PV malfunction.
R2: Nanomaterials and Hydrogen Storage
Monday PM, November 26, 2007
Room 301 (Hynes)
2:30 PM - **R2.1
Nano-Structured Materials to Address Challenges of the Hydrogen Initiative.
Mildred Dresselhaus 1 2 Show Abstract
1 EECS, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States, 2 Physics, Massachusetts Institute of Technology (MIT), Cambridge, Massachusetts, United States
One of the Grand Challenges of the 21st Century is to achieve a sustainable energy supply as the global demand per capita of energy consumption increases sharply, fossil fuel supplies decline and environmental concerns mount.In this talk the use of hydrogen as one possible approach to address the Grand Energy Challenge in part is considered, including hydrogen production, storage and utilization, with emphasis given to the large gap between present science and technology know-how and the requirements in efficiency and cost for a sustainable hydrogen economy. Opportunities for nanoscience andnanotechnology to narrow this gap will be discussed, and examples of recent progress will be presented.
3:00 PM - **R2.2
Low-Pressure, High-Capacity Storage of Alternative Fuels in Nanoporous Biocarbon: Natural Gas and Hydrogen.
Peter Pfeifer 1 , Jacob Burress 1 , Mikael Wood 1 , Sarah Barker 1 , John Flavin 1 , Cintia Lapilli 1 , Galen Suppes 2 , Parag Shah 2 , Phil Buckley 3 , Darren Radke 3 , Mike Benham 4 Show Abstract
1 Department of Physics, University of Missouri, Columbia, Missouri, United States, 2 Department of Chemical Engineering, University of Missouri, Columbia, Missouri, United States, 3 , Midwest Research Institute, Kansas City, Missouri, United States, 4 , Hiden Isochema Ltd., Warrington United Kingdom
The Alliance for Collaborative Research in Alternative Fuel Technology (http://all-craft.missouri.edu) is a multi-institutional partnership to develop low-pressure, high-capacity storage technologies for natural gas (methane, CH4) and hydrogen (H2) as fuels for advanced transportation. The immediate objective is to replace bulky cylindrical, heavy-walled compressed natural gas tanks (250 bar) in current natural-gas vehicles by a flat (conformable), lightweight tank, with storage as adsorbed natural gas (35 bar), in next-generation clean vehicles. An overview of achievements, since inception of the project in 2004, will be given. The core material is nanoporous carbon (activated carbon), fabricated from waste corncob in a multi-step process, which reversibly stores, by physisorption, 238 g CH4/kg carbon and 118 g CH4/liter carbon (180 times its own volume, 180 V/V) at 35 bar and 298 K, and 80 g H2/kg carbon at 47 bar and 77 K. The CH4 capacity reaches for the first time the DOE target for natural gas.Items of interest will include a prototype tank that is currently being road-tested on a natural-gas vehicle; detailed studies of the pore structure by ultra-small-angle x-ray scattering and other methods, experimental determination of CH4 and H2 binding energies; and strategies for achieving capacities of 60 g H2/kg carbon, or better, at 47 bar and 298 K.Research support: NSF (EEC-0438469), University of Missouri, Midwest Research Institute, U.S. Department of Education (GAANN), U.S. Department of Energy (W-31-109-Eng-38), U.S. Department of Energy (BES), and U.S. Department of Defense (NSWC-BAA-N0016407R6967).
3:30 PM - **R2.3
Impact of Coordinatively Unsaturated Metal Sites of MOFs on H2 Affinity and Surface Packing Density.
Yun Liu 1 2 , Houria Kabbour 3 , Craig Brown 1 4 , Dan Neumann 1 , Channing Ahn 3 Show Abstract
1 NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, United States, 2 Department of Materials and Engineering, University of Maryland, College Park, Maryland, United States, 3 Division of Engineering and Applied Science, California Institute of Technology, Pasadena, California, United States, 4 Indiana University Cyclotron Facility, Indiana University, Bloomington, Indiana, United States
Storing Hydrogen molecules in porous media based on a physisorption mechanism is one possible approach to reach the US Department of Energy targets for on-board hydrogen storage. Although the storage capacities of metal-organic frameworks (MOFs) have progressed significantly over recent years, some technological obstacles pose challenges for their future improvement: 1) The generally low H2 adsorption enthalpy limits the applications at room temperature; and 2) The lack of understanding of surface packing density (SPD) hinders the efficient improvement of H2 adsorption uptake. To improve the H2 affinity in MOFs, our previous work on Mn-BTT (1,3,5-benzenetristetrazolate), Cu-BTT, and HKUST-1, have shown that the coordinatively unsaturated metal centers (CUMCs) can greatly enhance the H2 binding strength. Our current study of MOF-74 will be presented, showing that its open Zn2+ ions bind H2 strongly and are identified as being responsible for the large initial H2 adsorption enthalpy of 8.4 kJ/mol. In all, there are four H2 adsorption sites in MOF-74 identified by neutron powder diffraction. These four hydrogen adsorption sites are closely packed in MOF-74 and form a one dimensional nanoscale tube structure. We also demonstrate an interesting correlation that MOFs with CUMCs generally show larger SPD than that of other MOFs without CUMCs. Since the total uptake is the product of the SPD and the available surface area, this may provide an avenue to improve gravimetric H2 uptake. A semi-quantum mechanical calculation is employed to estimate how close H2 molecules can approach each other in a simple model system. The estimated H2-H2 interaction distance thus poses an upper limit of the SPD available for physisorbed H2. Our study of MOF-74 with neutron powder diffraction together with the isotherm measurements show that MOF-74 exhibits the largest SPD of any MOF currently studied.
4:00 PM - R2:Nano-H2
4:30 PM - **R2.4
Energy and Environmental Issues Associated with Metal Hydrides for Hydrogen Storage.
Jason Graetz 1 , James Wegrzyn 1 , James Reilly 1 Show Abstract
1 Energy Sciences and Technology, Brookhaven National Laboratory, Upton, New York, United States
The emergence of a Hydrogen Economy will require the development of new media capable of safely storing hydrogen with high gravimetric and volumetric densities. Metal hydrides and complex metal hydrides, where hydrogen is chemically bonded to the metal atoms in the bulk, offer some hope of overcoming the challenges associated with hydrogen storage. Many of the more promising hydrogen materials are tailored to meet the unique demands of a low temperature automotive fuel cell and are therefore either entirely new (e.g. in structural or chemical composition) or in some new form (e.g. morphology, crystallite size, catalysts). An overview of the different methods and materials (metal hydrides) being investigated for on-board and off-board reversible hydrogen storage will be presented. Specific focus will be given to the energy requirements necessary to recover the hydride from the spent material (on-board or off-board) and potential environmental impact.
5:00 PM - **R2.5
Science and Prospects of Using Nanoporous Materials for Energy Absorption.
Xi Chen 1 , Yu Qiao 2 Show Abstract
1 Civil Engineering and Engineering Mechanics, Columbia University, New York, New York, United States, 2 Structural Engineering, University of California, San Diego, California, United States
With its ultra-large specific surface area, a nanoporous material is an ideal, yet relatively unexplored, platform for accepting or actuating liquids, with potential performance gains for energy dissipation and output typical of disruptive technologies. In the nanoporous energy absorption system (NEAS), liquids and lyphobic nanoporous materials are combined to form a new type of nanocomposite. By applying a quasi-hydrostatic or dynamic pressure (e.g. those from blast, vibration, wind load, ocean wave, etc.), liquids can be forced into lyophobic nanopores, nanochannels, or nanotubes, which converts the mechanical energy into interface energy and becomes an ideal platform for energy absorption (with performance gain of about 100J/g, orders of magnitude higher than most of today's commerical systems). In addition, the interface energy between the liquids and nanopores can be adjusted by electrical or thermal fields, which provides additional degree of freedom for system control and morphology adjustment. From the scientific aspect, nanofluidic behavior is of immense significance to energy conversion and exchange. Through molecular dynamics (MD) simulations and experiments, we show that the pressure-induced infiltration in nanopores is fundamentally different than that at the macroscale. Nano-scale mechanism-based theories are also proposed to model nanofluids.
5:30 PM - **R2.6
Novel Organometallic Fullerene Complexes for Vehicular Hydrogen Storage.
Erin Whitney 1 , Anne Dillon 1 , Chaiwat Engtrakul 1 , Calvin Curtis 1 , Kevin O'Neill 1 , Philip Parilla 1 , Lin Simpson 1 , Michael Heben 1 , Yufeng Zhao 1 , Yong-Hyun Kim 1 , Shengbai Zhang 1 , Kim Jones 1 Show Abstract
1 , National Renewable Energy Laboratory, Golden, Colorado, United States
A hydrogen-based energy economy could supply a pollution-free closed cycle that relies entirely on renewable resources. However, one of the biggest challenges in the development of a hydrogen economy is that of onboard vehicular hydrogen storage. To this end, new fullerene coordination chemistry and synthetic techniques have been demonstrated for Fe-C60 and Li-C60 complexes as potential hydrogen storage materials. This work is based on theoretical studies of Sc-C60 and Li12C60 structures that are predicted to have reversible hydrogen capacities of ~7 wt% and 9 wt%, respectively. These new complexes have been characterized with solid state nuclear magnetic resonance (NMR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), transmission electron microscopy (TEM), and temperature-programmed hydrogen desorption (TPD). Analysis of the iron-fullerene complex indicates the formation of C60-Fe-C60-Fe-C60 chain structures of an undetermined length, with a reversible hydrogen capacity of ~0.8 wt% at 77 K and 2 bar after degassing to 200 °C. Interestingly, BET surface area measurements yield a value of ~50 m2/g both before and after degassing, which is an order of magnitude less than expected given the measured experimental hydrogen capacity. For the lithium-fullerene complexes, several stoichiometries of Li and C60 have been synthesized, yielding different hydrogen capacities, and also suggesting the formation of a lithium hydride.
R3: Poster Session: Life Cycle Analysis of New Energy Conversion and Storage Systems
Tuesday AM, November 27, 2007
Exhibition Hall D (Hynes)
9:00 PM - R3.10
Effect of Water Vapor and SOx in Air on the Cathodes of Solid Oxide Fuel Cells.
Seon Kim 1 , Toshihiro Ohshima 1 , Yusuke Shiratori 1 , Kohei Itoh 1 , Kazunari Sasaki 1 2 Show Abstract
1 Faculty of Engineering, Kyushu university, Fukuoka Japan, 2 Hydrogen Technology Research Center, Kyushu University, Fukuoka Japan
Ambient air is used as an oxygen source in SOFCs to be commercialized. Various chemical species which can lead to poisoning of SOFC cathodes are included as minor constitutions in air, such as water vapor, SOx, NOx and NaCl etc. However, their effects on the cathode performance have not yet well known, even though they are expected to cause a degradation of the electrode performance and to reduce the long-term durability of SOFCs. Therefore, in this study, we focused on the poisoning caused by water vapor and SOx in the oxygen source to clarify their effects on SOFCs performances and to reveal the degradation mechanism of cathodes. SOFCs with typical electrolyte-supported structure were used in this work, which were composed with ScSZ (10 mol% Sc2O3, 1mol% CeO2, 89 mol% ZrO2) plate with the thickness of 200 µm as electrolyte, NiO-ScSZ (mixture of 56 wt% NiO and 44 wt% ScSZ) porous layer as anode, and two cathode layers of LSM ((La0.8Sr0.2)0.98MnO3) and LSM-ScSZ (mixture of 50 wt% LSM and 50 wt% ScSZ). Power generation characteristics of the cells had been analyzed by measuring cell voltage at a constant current density (200 mA/cm2) and by comparing changes in cell impedance, upon supplying the artificially-contaminated air with water vapor or SOx, to the SOFC cathodes at various operational temperatures. High-resolution FESEM (S-5200, Hitachi) was used to analyze microstructural changes caused by the impurities. Mg Kα radiation from a monochromatized X-ray source was used for XPS measurements (ESCA-3400, KRATOS). AC impedance was measured at various temperatures under the open circuit voltage condition by an impedance analyzer (Solatron 1255B/SI 1287, Solatron), in a frequency range from 0.1 to 105 Hz with an amplitude of 10 mV.
9:00 PM - R3.11
Compaction and Cold Crucible Induction Melting of Fine Poly Silicon Powders for Economical Production of Polycrystalline Silicon Ingot.
Daeseok Kim 1 , Jesik Shin 2 , Byungmoon Moon 2 , Bonghwan Kim 2 , Sangmok Lee 2 , Kiseung Park 2 , Kiyoung Kim 1 Show Abstract
1 Material Engineering, KOREA UNIVERSITY OF TECHNOLOGY AND EDCATION, Cheon-an Korea (the Republic of), 2 , Korea Institute of Industrial Technology, In-chon Korea (the Republic of)
In this study, the compaction and cold crucible induction melting of low-priced poly silicon powders with average diameter of 8 micrometer, by products of making high purity poly silicon rods in the current method (TCS), were systematically investigated to produce economically polycrystalline silicon ingot for solar cell. The silicon powders are required to obtain high purity and density ratio for the application as solar-grade feedstock. The poly silicon powders were chemically pre-conditioned by washing in an aqueous HF-ethanol solution to remove surface oxide. After subsequent rinsing with de-ionised water and ethanol to remove trace HF, the solutions are filtered through a Buckner vessel and then the powders were dried in a vacuum oven. The dried poly silicon powders were immediately subjected to uniaxial mechanical pressing at pressure of 700 MPa at room temperature under a vacuum of 3 torr. Finally, the poly silicon compacts were melted using a cold crucible induction melting method and the electrical resistivity was examined for purity assessment utilizing Hall effect measurement. Compactability and density ratio of the poly-Si powders were significantly improved without binder agents by the chemical pre-conditioning. The chemical pre-conditioning was observed to be effective for suppressing the formation of gas porosity, which precipitated during melting and casting processes of the poly-Si powders. After adequate chemical treatments of poly-Si powders, a sufficiently high purity above solar-grade was able to be achieved.
9:00 PM - R3.12
Enhanced Surface Area of Mutilwalled Carbon Nanotubes by using High Energy Ball Milling Method.
Wen-Feng Lu 1 , Chia-Feng Chang 1 , Yung-Ting Cho 1 , Tsing-Hai Wang 2 , Shi-Ping Teng 2 , Jiann-Ruey Chen 1 Show Abstract
1 Dept. Material Science and Engineering, national tsing hua university, Hsinchu Taiwan, 2 Dept. Engineering and System Science, National Tsing Hua Univ., Hsinchu Taiwan
9:00 PM - R3.2
Mechanical Effect on Oxygen Mobility in Yttria Stabilized Zirconia.
Wakako Araki 1 , Tadaharu Adachi 1 Show Abstract
1 Mechanical Sciences and Engineering, Tokyo Institute of Technology, Tokyo Japan
In this study, the mechanical effect on the oxygen mobility in polycrystalline zirconia stabilised with 8 mol% yttria (8YSZ) was investigated. The ionic conductivity was evaluated by the impedance analysis with alternating current (AC). The conductivity followed the Arrhenius equation so that the activation energy for the conductivity was derived.The dynamic modulus and mechanical loss were examined by the dynamic mechanical analysis (DMTA) and the activation energy for the mechanical relaxation was determined. The modulus gradually decreased with increasing temperature, especially around 440 and 540 K, while the mechanical loss had peaks at these temperatures. Both peaks had different activation energies due to different relaxation mechanisms. It can be considered, from the comparison of the activation energy for the ionic conductivity to that for the mechanical relaxation, that the oxygen mobility in 8YSZ was attributed to the immigration of an oxygen vacancy with a dopant cation in a form of simple complexes.The AC impedance analysis under mechanical tensile loads was carried out to examine the effect of the mechanical stress (strain) on the ionic conductivity. The tensile load improved the ionic conductivity by 6 % at maximum, and the improvement in the conductivity was remained for a while after unloading. The reason for the increase in the conductivity could be that the oxygen vacancies in the simple complexes were temporarily activated by the elastic stress (strain). The results of the present study proposed that the oxygen mobility in electrolyte, e.g. in solid oxide fuel cell, could be greatly improved by mechanical means and also suggested that the analyses for the performance and the life assessment must be conducted together allowing for the correlation between mechanical properties, stresses, and ionic conductivity.
9:00 PM - R3.3
Efficiency Improvement of Biofuel Cell for High Power Production based on Pt nanostructure Electrodes.
Minhee Yun 1 , Hoil Park 1 , David Sanchez 2 Show Abstract
1 Department of Electrical and Computer Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States, 2 Department of Civil and Environmental Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania, United States
Microbial fuel Cells (MFC) are devices that convert chemical energy into the form of electricity through the catalytic activity of microorganisms. MFC typically has had a lower efficiency of power generation compared to other types of fuel cells. Many researchers have studied MFC with Pt microstructure such as Pt-polymer or Pt-metal alloy electrodes using electrochemical deposition. However, electrochemical deposition had limited the efficiency improvement of the MFC because Pt is an expensive metal that leads to significant cost problems in fuel cell production. Additionally, electrochemical deposition method produces non-uniform metal deposition across electrodes and causes poor Pt activity due to poor adhesion. In this regard, we fabricated nanostructure electrodes using e-beam evaporation which enables to achieve reproducible and reliable Pt thin layers as well as other catalyst materials whose thicknesses range from tens of Å to thousands of µm. In particular, we applied the Pt nanostructures to both anode and cathode electrodes in the MFC, and to examine their performance in terms of current density and power generation. From the results, the Pt nanostructure electrodes only on the anode (carbon paper electrode on the cathode) and on both compartment (anode and cathode) produced the maximum current density of 0.42 A/m2 and 0.6 A/m2 respectively. The current density of the MFC with Pt nanostructure electrode on anode was above two times higher than when the Pt-black anode electrode or E-Tek commercial Pt anode electrode was used. The current density can be readily interpreted in relation to the power density. We achieved a maximum power density of 3600 mW/m2 using Pt nanostructure electrodes on both compartment. Therefore, our MFC with Pt nanostructure electrodes shows the highest electricity generation characteristics compared to other MFC designs. These results indicate that the MFC with Pt nanostructure electrodes for high power production would be an excellent, and Pt deposition using e-beam evaporation is a very effective technique to increase the MFC performance and decrease noble metal cost. Finally, DNA analysis of the bacteria has been conducted in this research. We have found that Aeromonas genus bacteria such as Aeromonas hydrophila, Aeromonas media, and Aeromonas molluscorum were dominant during our mediator-less MFC operation. In particular, Aeromonas hydrophila was electrochemically active bacterium in our MFC system and these bacteria were belonged to the γ-proteobacteria (90.7%) which contain glucose and glutamate fuel. Further DNA analysis and use of Pt nanoparticle electrodes for better approach that could improve MFC operation for practical use are under investigation.
9:00 PM - R3.5
Chemically Deposited Sb2Se3 Anode for Thin Film Lithium Batteries.
Arun Patil 1 , Vaishali Patil 1 , Ji-Won Choi 1 , Seok-Jin Yoon 1 Show Abstract
1 Thin Film Materials Research Centre, Korea Institute of Science and Technology, Seoul Korea (the Republic of)
Sb2Se3, an important member of V2VI3 compound semiconductor, is a layer-structured semiconductor of orthorhombic crystal structure which exhibits good photo-voltaic properties and high thermoelectric power (TEP) which makes it possess promising applications in photo-chemical devices, optical and thermoelectric cooling devices, decorative coatings and solar selective. However, there is no report on the electrochemical properties of Sb2Se3. Here first time we report that , Sb2Se3 thin film has been successfully fabricated by chemical deposition method which is a simple and cost effective method to deposit thin film and has the ability to control chemical composition and was investigated for its electrochemistry with lithium. The capacities of Sb2Se3 /Li cells cycled between 0.1 and 2.5V were measured for first 50 cycles. The electrochemical behavior, structure, composition and morphology of Sb2Se3 thin films before and after cycling were characterized by cyclic voltammetry (CV), X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The motivation of this work is to explore the possibility of using Sb2Se3 as anode material for thin film lithium batteries and to elucidate its electrochemical reaction mechanism with lithium. Here we also report the reaction mechanism includes both alloying/dealloying reaction of Sb and selenylation/reduction reaction between nanocrystalline Sb2Se3 and Sb was proposed. Nano-sized metal Sb particles formed after dealloying process should play an important role in enhancing its electrochemical activity. Sb2Se3 has high reversible capacity and good cycle performance, which makes it potential anode material for future lithium-ion batteries.
9:00 PM - R3.6
Electrochemical and Structural Behavior of LiCoO2 Thin Films Produced with Pulsed Laser Deposition.
Vaishali Patil 1 , Arun Patil 1 , Ji-Won Choi 1 , Yoon Pyo Lee 2 , Seok – Jin Yoon 1 Show Abstract
1 Thin Film Materials Research Center, Korea Institute of Science and Technology, Seoul Korea (the Republic of), 2 Thermal / Flow control Research Center, Korea Institute of Science and Technology , Seoul Korea (the Republic of)
AbstractThe lithium intercalation ability of LiCoO2 was discovered 20years ago by Goodenough and has been exploited by Sony with the introduction of their rechargeable C/LiCoO2 battery in 1991. Presently, this technology finds large-scale commercial application as a power source for numerous handheld devices. Extensive research has been conducted to explore alternative materials, which are more cost effective and less toxic. Until now, lithium cobalt oxide based electrodes exhibit superior properties in terms of cycle stability and energy density, a favorable combination for a reliable power source. The fabrication of lithiated intercalation oxides in thin film form is of great interest as a result of their possible use as positive electrode in all-solid-state lithium rechargeable microbatteries to power microelectronics. There is a growing interest in the production of secondary lithium batteries of smaller dimensions; microbatteries are very suitable to provide backup power for on-chip static memory modules. The present paper describes preparation and properties of dense, submicron films of polycrystalline LiCoO2 thin films on a platinum coated silicon wafer with pulsed laser deposition (PLD). Films of LiCoO2 were deposited onto substrates from a sintered composite target (LiCoO2 +Li2O). LiCoO2 thin films were investigated as a function of various growth conditions as substrate temperature, partial oxygen pressure in the deposition chamber, and target composition. Pulsed laser deposited LiCoO2 thin films obtained with polycrystalline morphology were successfully used as cathode materials in lithium microbatteries. The Li//LiCoO2 cells were tested by cyclic voltammetry and galvanostatic charge–discharge techniques in the potential range 2.0–4.2V. Specific capacity of deposited LiCoO2 thin films was measured. In this paper we also provide a structural and morphological characterization of the LiCoO2 thin films before and after cycling by XRD, SEM, and AFM.
9:00 PM - R3.7
Application of Nanoporous Carbon Materials in Energy Related Applications.
Ramakrishnan Rajagopalan 1 , Henry Foley 1 , Christopher Burket 1 , Anna Merritt 1 Show Abstract
1 , The Pennsylvania State University, University Park, Pennsylvania, United States
Nanoporous carbon (NPC) materials with tunable porosity and surface area have potential application across various fields that include electrochemical capacitors, membranes for gas separation, anode materials for lithium-ion batteries, adsorbents and catalyst supports. In this investigation, we report synthesis and application of nanoporous carbon derived from two different precursors (polyfurfuryl alcohol and coal tar pitch) with tunable physical properties such as electrical conductivity, porosity and surface areas. The work investigates the development of these physical properties using two different kinds of precursors namely graphitizing precursors (coal tar pitch) and non-graphitizing precursors (polyfurfuryl alcohol). We have been able to make NPC with narrow pore size distribution of 0.5 nm and significant pore volumes (0.8 cc/g) and surface areas (1500 – 2000 m2/g). We have also shown that the electrical conductivity of NPC derived from non-graphitizing precursor can be significantly increased by physical activation and thermal annealing of these carbons at high temperatures leading to the development of long-range order of aromatic domains. Electrochemical capacitors synthesized using these carbons show volumetric capacitances greater than 100 F/ml. We have also fabricated NPC as thin membranes on porous stainless steel supports and demonstrated O2/N2 permselectivity in the order of 5 -6 (SO2/N2) with O2 permeances in the order of 10-9 mol s-1 m-2 Pa-1.
9:00 PM - R3.8
Improvement of Rate Performance of LiCoO2 via Doping and Coating.
Chang-Sam Kim 1 , Seon Kim 3 , Kyung Han 2 Show Abstract
1 Battery Research Center, Korea Institute of Science and Technology, Seoul Korea (the Republic of), 3 Faculty of Engineering, Kyushu university, Fukuoka Japan, 2 Material Science and Technology Division, Korea Institute of Science and Technology, Seoul Korea (the Republic of)
Lithium cobalt oxide (LiCoO2) is one of the principal cathode materials for lithium-ion secondary batteries because of its high specific capacity, low self-discharge, and excellent cycle life. However, its structural and thermal stabilities are not enough at highly discharged state. Surface coating with metal oxide and doping of non-transition metals to this oxide have been intensively studied to solve the problems. Moreover, since there are demands to raise cut-off voltages and to reduce particle size of the oxide for higher capacity and higher power density of batteries, the coating and the doping should become an essential process to meet the demands. In this study, we prepared Zr4+ and divalent metal co-doped Li(M0.01Co0.98Zr0.01)O2 (M=Mg, Ni, Zn) powders by ultrasonic spray pyrolysis method and examined electrochemical properties. The all synthesized powders were pure phase of α-NaFeO2 and had a layered crystal structure. There was little particle size differences among the powders, but agglomeration of particles were increased with the co-doping. The initial discharge capacities of half-cells with the Zr/Mg, Zr/Ni, and Zr/Zn co-doped powders were 149, 147, and 143, respectively, in a voltage range of 3.0~4.3V. The capacities were 2~5% lower than that without doping. But the co-doped samples showed excellent capacity retention of more than 80% while 20% for the undoped after 40 cycles in the same voltage ranges. Among the co-doped, the Zr/Mg sample showed the highest cycle stability and rate performance even in a voltage range of 3.0-4.5V. To compare the difference between Mg-doping and MgO-coating, MgO was coated on LiCoO2, Zr doped LiCoO2 and Zr/Mg co-doped LiCoO2 powders using a sol-gel technique. Nano-sized MgO particles were homogeneously coated on the surface of the powders without segregation. The rate performance and cycle stability of the coated samples were improved and showed little difference among the samples in a voltage range of 3.5-4.5V.
9:00 PM - R3.9
New Processes and Characterization of LiCoO2 Chemistries for Li-Ion Batteries.
Jafar Al-Sharab 1 , Fredric Cosandey 1 , Glenn Amatucci 1 , Boris Yakshansky 1 , Nathalie Pierra 1 Show Abstract
1 Materials Science and Engineering, Rutgers University, Highland Park, New Jersey, United States
Vasilis M. Fthenakis Columbia University
and Brookhaven National Laboratory
Anne C. Dillon National Renewable Energy Laboratory
Nora Savage U. S. Environmental Protection Agency
R4: Environmentally Friendly Batteries
Tuesday AM, November 27, 2007
Room 301 (Hynes)
10:00 AM - R4.1
A Novel High Capacity, Environmental Benign Energy Storage System: Super-iron Boride Battery.
Xingwen Yu 1 , Stuart Licht 2 Show Abstract
1 Department of Chemical & Biological Engineering, University of British Columbia, Vancouver, British Columbia, Canada, 2 Department of Chemistry, University of Massachusetts, Boston, Massachusetts, United States
Alkaline Zn-MnO2 redox charge storage has been established for over a century and still playing the dominant share in primary alkaline battery market. However, this chemistry is increasingly limited in meeting the growing energy and power demands of contemporary optical, electromechanical, electronic, and medical consumer devices. Therefore, the search for new energy storage chemistry systems with higher capacity and energy density has been increasingly emphasized.In 1999, we introduced a novel environmental benign cathodic chemistry, which is based on a class of Fe(VI) or “super-iron” oxides with a 3e- intrinsic capacity (eg. K2FeO4: 406 mAh/g) higher than MnO2 (308 mAh/g), as described Eq. 1 and Eq. 2. FeO42- + 5/2H2O + 3e- → 1/2Fe2O3 + 5OH-, E = 0.60 V (1)MnO2 + 1/2H2O + e- → /2Mn2O3 + OH-, E =0.35V. (2)In 2004 it was reported that metal borides could be used as anodic alkaline charge storage materials. Representive transition metal borides include TiB2 and VB2 which can store several fold more charge than a zinc anode through multi-electron charge transfer:TiB2 + 12OH- → Ti(amorphous) + 2BO33- + 6H2O + 6e- (3)VB2 + 20OH- → VO43- + 2BO33- + 10H2O + 11e- (4)However, two obstacles were evident towards implementation of this alkaline boride (MB2, M=Ti or V) anodic chemistry. There is a significant domain in which the boride anode materials corroded spontaneously generating hydrogen gas, and the electrochemical potential of the boride anodes was more positive than that of zinc. Therefore a boride MnO2 cell was subject to decomposition, and secondly the voltage of this cell was low compared to the electrochemical potential of the pervasive Zn-MnO2 redox chemistry. In this paper, we introduce a novel battery chemistry system Fe(VI)-MB2, and both obstacles of the boride anode are overcome. The super-iron cathode provides the requisite additional electrochemical potential, and our recently demonstrated zirconia hydroxide-shuttle overlayer, which stabilizes alkaline cathodic charge transfer chemistry, also is demonstrated to prevent corrosion of the boride anode. Both Fe(VI) salts and borides are environmental benign materials and this Fe(VI)-MB2 alkaline battery chemistry system sustains much higher (two fold) electrochemical capacity than conventional MnO2-Zn battery.
10:15 AM - **R4.2
Metal Oxide Nanoparticles for Improved Lithium Ion Batteries.
Se-Hee Lee 1 , Rohit Deshpande 1 , Philip Parilla 1 , Erin Whitney 1 , Kim Jones 1 , A. Mahan 1 , Anne Dillon 1 Show Abstract
1 , National Renewable Energy Laboratory, Golden, Colorado, United States
10:45 AM - R4.3
Lithium Intercalation Capacity Of Mesoporous Titania Nanotube Arrays With Nitrogen Annealing Treatment.
Dawei Liu 1 , Peng Xiao 2 , Guozhong Cao 1 Show Abstract
1 Department of Materials Science and Engineering, University of Washington, Seattle, Washington, United States, 2 Physics, Chongqing University, Chongqing, Chongqing, China
Titanium dioxide, with its advantage of low cost and clean energy storage, has always been considered a favorable candidate for new energy storage devices in the new century.Recently, we have focused on the lithium intercalation investigation of titanium dioxide nanotube arrays. This mesoporous structure created a short lithium diffusion path and a large surface area. As a result, the amorphous nanotube arrays showed a high initial capacity around 270 mAh/g, corresponding to an intercalation ratio of 0.8 Li per Ti. Anatase TiO2 nanotube arrays fabricated by annealing in N2 for different temperature and different hours were also investigated for lithium intercalation capacity. Comparison of the data showed that the 300° C annealed sample whether 3 hours or 6 hours, showed as good initial capacity as the amorphous state. The 400 ° C 3 hours annealed sample showed an initial capacity of 165 mAh/g, and after 50 cycles the capacity still kept around 150 mAh/g. When the annealing temperature was raised to 500 ° C, this good stability was again destroyed. All of the samples were studied for impedance test and it was found that higher temperature and annealing time led to better conductivity, however, SEM images also showed that higher annealing temperature and time created larger wall thickness, which might be the obstacle for efficient lithium intercalation.
11:00 AM - R4: Batteries
11:30 AM - R4.4
An Evolutionary Overview of the Vehicle Recycling Partnership's Research Addressing End of Life Vehicle Recycling Challenges.
Nakia Simon 1 2 , Candace Wheeler 3 2 , Claudia Duranceau 4 2 Show Abstract
1 , DaimlerChrysler, Auburn Hills, Michigan, United States, 2 , Vehicle Recycling Partnership, Southfield, Michigan, United States, 3 , General Motors Corporation, Warren, Michigan, United States, 4 , Ford Motor Company, Dearborn, Michigan, United States
Every year about 15 million vehicles reach their end of life, and while 95% of those vehicles go through the recycling infrastructure, some of the materials still end up in landfills. The Vehicle Recycling Partnership (VRP) is consortium made up of DaimlerChrysler, General Motors Corporation, and Ford Motor Company, which is dedicated to finding economical recycling solutions for materials that would normally go to landfill, regardless of the manufacturer. The VRP has conducted research with numerous industrial partners in an attempt to address the challenges associated with recycling materials recovered from shredder residue. The various areas of recycling research include the mechanical separation of materials from shredder residue, substance of concern removal, the conversion of waste plastics into oil, hybrid battery recycling, and the conversion of polyurethane foam into a glycol. In addition, the VRP has preformed life cycle assessments on various recycling technologies. This paper will discuss the challenges in recycling materials recovered from shredder residue, as well as provide a general overview of VRP research activities, using specific projects and results as illustration.
11:45 AM - **R4.5
A Life Cycle Assessment of Converting Shredder Residue into Oil.
Candace Wheeler 1 2 , Nakia Simon 4 2 , Claudia Duranceau 3 2 Show Abstract
1 , General Motors Corporation, Warren, Michigan, United States, 2 , Vehicle Recycling Partnership, Southfield, Michigan, United States, 4 , DaimlerChrysler, Auburn Hills, Michigan, United States, 3 , Ford Motor Company, Dearborn, Michigan, United States
The availability of an affordable yet sustainable supply of energy is critical to the automotive industry. That is why we at General Motors, Ford, and DaimlerChrysler through the Vehicle Recycling Partnership (VRP) under the United States Council for Automotive Research are working together with our partners on a project to produce a light hydrocarbon oil from the residue, which is generated during the recycling of automobiles and other products. This project is part of the VRP’s long-term goal of promoting the sustainable recycling of all automotive materials using a life cycle approach. Each year approximately 15 million vehicles reach the end of their useful life and enter a complex infrastructure designed to recover usable parts and materials of value (primarily ferrous and nonferrous metals). The remaining mixture of glass, rubber, plastics, foam, and dirt is referred to as shredder residue (SR) and is currently sent to landfill for disposal. However, using a thermal chemical conversion process developed by Changing World Technologies, it is possible to thermal chemically recycle this waste into a light hydrocarbon oil, a fuel gas, and carbon ash, and, thereby, provide a sustainable source of hydrocarbon oil while recycling more of the vehicle. While the process has proven to be technically feasible, it is also important to understand what effects the process has on the environment. Therefore, a life cycle assessment was performed to better understand the environmental impact/benefits offered by this technology.
12:15 PM - R4.6
Effects of Processing Conditions and Sn Substitution in LiMn2O4 Thin Film Cathodes Prepared by Pulsed Laser Deposition.
Dong Wook Shin 1 2 , Ji-Won Choi 1 , Yong Soo Cho 2 , Seok-Jin Yoon 1 Show Abstract
1 , Korea Institute of Science and Technology, Seoul Korea (the Republic of), 2 , Yonsei University, Seoul Korea (the Republic of)
The processing conditions of pulsed laser deposition for preparing Sn-substituted LiMn2O4 thin films designed as a cathode of thin film lithium battery have been investigated mainly to avoid electrochemical degradations, which are known to be caused by structural collapse such as manganese dissolution and the Jahn-Teller phase transition. The thin films corresponding to LiSnx/2Mn2-xO4 (0≤x≤0.1) were prepared on Pt/Ti/SiO2/Si(100) substrate by the pulsed laser deposition method using targets which were synthesized by a conventional solid-state reaction method assuming the general coincidence in composition between the targets and deposited films. Substrate temperature, working pressure, distance between target and substrate, PLD power density, the amount of substituting Sn and so on was optimized mainly from phase evolution and microstructure analyses. The Sn-substituted thin films (x<0.1) showed the most reversible intercalation and de-intercalation of Li-ions into the spinel structure. Moreover, the Sn-substituted thin films showed more capacity than the non-substituted thin films, which is thought to be ascribed by the increase of Li intercalation site and the increase of diffusion coefficient of Li-ions and/or electrons in Mn-deficient LiSnx/2Mn2-xO4 structure. The evidence of substituting Sn into the LiMn2O4 spinel for physical and electrochemical enhancements will be discussed.
R5: Energy LCA Methodology
Tuesday PM, November 27, 2007
Room 301 (Hynes)
2:30 PM - **R5.1
Life Cycle Assessment and External Costs of Future Fossil Technologies with and without Carbon Capture and Storage.
Roberto Dones 1 , Christian Bauer 1 , Thomas Heck 1 , Oliver Mayer-Spohn 2 , Markus Blesl 2 Show Abstract
1 Laboratory of Energy Systems Analysis, Paul Scherrer Institut, Villigen PSI Switzerland, 2 IER, Universität Stuttgart, Stuttgart Germany
Fossil power remains crucial for covering a substantial part of the steadily increasing power demand in advanced countries as well as the dramatically increasing energy demand of fast developing countries. Therefore, improvements in fossil power technology likely to be implemented on a large scale in the next decades are important for contributing to control the emissions of greenhouse gas (GHG) by substitution of obsolete fossil plants, refurbishment of aging plants, and use of highly efficient units. An equal installation rate from renewable sources or nuclear seems not realistic in the short to medium term.The NEEDS project of the European Commission (2004-2008) continues the ExternE series, aiming at improving and integrating external cost assessment, LCA, and energy-economy modeling, using multi-criteria decision analysis for technology roadmap up to year 2050. The LCA covers power systems suitable for Europe in the first half of the 21st century. The paper presents environmental inventories and cumulative results for selected representative evolutionary fossil power technologies, namely for hard coal and lignite the Ultra-Supercritical Pulverized Combustion (USC-PC) and Integrated Gasification Combined Cycle (IGCC) technologies, and for natural gas the future generation of Combined Cycle (CC) technology. The power units are modeled with and without Carbon Capture and Storage (CCS). The three main technology paths for CO2 capture are represented, namely pre-combustion, post-combustion, and oxy-fuel combustion. Pipeline transport and storage in geological formations like saline aquifers and depleted gas reservoirs, which are the most likely solutions to be implemented in Europe, are modeled for assumed average conditions. The entire energy chains from fuel extraction through the fuel conversion in the power plant and, when applicable, the ultimate sequestration of CO2, are assessed, using ecoinvent as background LCA database.The results show that quantifying the total environmental burdens and external costs provides useful instruments to compare the sustainability of fossil options vs. alternatives in an objective way. Introduction of CCS, although resulting in a net decrease of the CO2 effluents to the atmosphere, still produces substantially more GHG than claimed by near-zero emission power plant promoters when the entire energy chain is accounted for, especially for post-combustion capture technologies and coal as a fuel. Furthermore, consideration of the full spectrum of environmental burdens additional to greenhouse gases results in a more pessimistic picture of the chain with CCS than obtained by just focusing on GHG reduction.Furthermore, the total external costs related to pollution are largely depending on the damage factor attributed to GHG, which greatly varies according to different modeling. Depending on this value, the fossil systems may be more or less penalized in comparison to renewable and nuclear energy.
3:00 PM - R5.2
Integration of Land Use Aspects into Life Cycle Assessment at the Example of Biofuels.
Michael Held 1 , Ulrike Bos 1 , Michael Faltenbacher 2 , Sabine Deimling 2 Show Abstract
1 Life cycle Engineering, University of Stuttgart, Echterdingen Germany, 2 , PE-International, Leinfelden Echterdingen Germany
It is well known that the transport sector causes significant environmental impacts worldwide and as a consequence influences the results of Life Cycle Assessment (LCA) studies. Today’s fuels are dominated by crude oil derived fuels. In Europe currently 98 % of the road transportation is based on such crude oil derived fuels. Similar ratios can be observed e.g. in the US and other countries. In addition to the environmental impacts, the high dependency on the imports of fossil fuels motivates most European countries to investigate in other than fossil fuel based transport systems. Therefore the European Commission presented an action plan including a strategy with the objective to substitute 20% of crude oil derived fuels by alternative fuel until 2020. To achieve these goals, actions to reduce the import dependency of fuels, the usage of non renewable (fossil) resources and the environmental burdens connected to the use of fuel / propulsion systems have to be addressed. Besides, the energy carrier mix has to be broadened. Especially alternative fuels from renewable resources, BTL (biomass to liquid) are supposed to have a high potentialRecent developments show, that there is a variety of options for fuels available as well as for propulsion technologies that utilise fuels based on renewable resources. It is therefore of key importance to select and promote the fuel/ propulsion system technology which is most beneficiary for a country or region from an environmental but also from an economic and social perspective. For such a sustainability evaluation it is essential to consider the local/regional boundary conditions such as availability of fuel resources, major pollution issues which need to be addressed, supply of secondary energy (e.g. power) etc. LCA is therefore a suitable approach to evaluate and compare different options, due to its transparent consideration of all life cycle stages. Besides the environmental impacts and resource consumption which are addressed in LCA considerations the needed land is another important aspect when talking about biomass as a resource. As land is a scarce resource that is used for all industry sectors there is a need to address this issue also in LCA. Up to now, no methods existed which allow the integration of Land Use aspects in a consistent way into LCA Software and Database. Currently at LBP-GaBi, University of Stuttgart together with PE International, a method was developed to integrate land use aspects into LCA. Backward processes are now implemented in an applicable way into a LCA database systemThe presentation will describe the method and will present results for the production and use of diesel in comparison to other fuels alternatives like biomass to liquid and bio diesel including land use aspects.
3:15 PM - R5.3
The Fuel Cycles of Electricity Generation: A Comparison of Land and Water Usage.
Hyung Chul Kim 1 , Vasilis Fthenakis 1 Show Abstract
1 PV EH&S Research Center, Brookhaven National Laboratory, Upton, New York, United States
In 1975, the amount of land committed to energy-related activities in the United States was 1.1 million acres (ANL, 1980). Although more recent data are unavailable, the present land use for energy generation is likely to be much higher as the production of electricity in this country has doubled during the last 30 years (EIA, 2006). Land use for extracting fossil fuel, processing it, operating power plants, and storing waste often significantly degrades and changes the adjacent local landscape in a variety of ways, including contaminating the water, eroding the soil, and releasing hazardous gasses. On the other hand, generating solar electricity often is portrayed as demanding large areas of land, especially for ground-mounted applications. In this article, we qualitatively and quantitatively compare land use for coal-, nuclear-, natural gas-, and photovoltaic-fuel cycles in the United States. Historical data, published values, and field measurements are the basis of our analysis. Our preliminary investigation reveals that comparable areas of land are committed to production across the fuel cycles, depending on specific fuel types, although the nature of land disturbance is quite unique for each fuel cycle. In particular, at the stage of mining for coal, the distinction between underground or surface mining, eastern versus western coal exhibits great variability in the area committed per kilowatt-hour generated. We also compare the aspects of land disturbance between renewable and non-renewable energy sources. The usage of water is problematic. Securing the water that is required for electricity generation in the United States is becoming increasingly important, as the quantity of freshwater is limited while the population, and their demand, is growing steadily. Estimates show that 48% of all freshwater and saline-water withdrawals, about 200 billion gallons per day, are withdrawn for thermoelectric power (USGS, 2004). A recent study by the DOE forecasts that, overall, freshwater withdrawal would be sufficient to meet the increasing capacity of thermoelectric power plants provided that modern plants adopted enhanced cooling systems. However, on a local basis, the increasing population of the states of the west and southeast presents a potential crisis of water supply for thermoelectric power plants, and moreover, they will have to compete for freshwater from other sectors like agriculture and industry. Abnormal drought conditions could pose a more significant threat (DOE, 2004). In this article, we also compare the life-cycle water withdrawal and consumption across fuel cycles. Possible future water shortages are discussed based on established models.
4:00 PM - R5.4
Multi-criteria Decision Analysis and LCA: Applications under High Uncertainty.
Kristin Rogers 1 , Thomas Seager 2 , Igor Linkov 3 Show Abstract
1 USDA Ecological Science and Engineering Research Fellow , Purdue University, West Lafayette, Indiana, United States, 2 , Rochester Institute of Technology, Rochester, New York, United States, 3 , Intertox Inc., Brookline, Massachusetts, United States
Assessment of environmental impact is one of the crucial steps in LCA. Nevertheless, uncertainty associated with quantification of environmental impact is in general very high. LCA tools such typically use a linear-weighted aggregation of normalized inventory data to compute an overall environmental impact score, but the results may be highly dependent upon the weights that determine the relative importance of incommensurate impacts, such as global warming, stratospheric ozone depletion or eutrophication. Moreover, where multiple stakeholder groups are engaged in a particular problem, there may be several different sets of weights that result in disparate scores or ranking. Finally, for many emerging threats (such as nanomaterials) the data on environmental impact though the product life cycle is largely unknown. We propose to supplement life cycle impact assessment tools with techniques for quantifying expert judgment developed in the field of Multi-criteria Decision Analysis (MCDA). This presentation will review MCDA tools and illustrate application of combined LCA and MCDA assessments for two case studies. The first case study will rank three diesel fuel alternatives (soy biodiesel, petroleum diesel, and Fischer-Tropsch diesel from coal) based on preference judgment of different stakeholder group. Sensitivity of the results to different weight distribution will be studied. EPA’s TRACI and GREET models will be used. The second case study will illustrate the use of MCDA methods to quantify expert judgment on nanomaterials impact through the product life cycle for LCA applications. In situations with high uncertainty we found thd Stochastic Multi-criteria Acceptability Analysis (SMAA) to be an ideal MCDA method. Other MCDA methods (e.g., MAUT) may be more appropriate for situations with more extensive data availability.
4:15 PM - **R5.5
Wise Energy Decisions--beyond LCA.
Lise Laurin 1 Show Abstract
1 , EarthShift, Eliot, Maine, United States
While the best energy solutions may seem obvious to the LCA community, we often see wind turbines voted down for aesthetics and policy makers leaning toward solutions that show poor return, kilojoule per kilojoule. If we are to move forward with wise energy solutions, we will need to broaden our perspective to include the social impacts that influence policy-makers and communities, creating a decision-system that encompasses both social and environmental impacts. Starting with LCA and Total Cost Assessment, a case study of a biodiesel facility in Vermont begins to incorporate social goals with reduced environmental impacts. We’ll then look at other energy systems and how these decision-making tools might be used to bring policy makers, environmentalists, and communities together making wise energy choices for our future.
4:45 PM - **R5.6
Standing the Test of Time: Signals and Noise From Environmental Assessments of Energy Technologies.
Bjorn Sanden 1 Show Abstract
1 Department of Energy & Enviroment, Chalmers Univ of Technology, Goteborg Sweden
The idea, that the intended application of the result of an assessment has consequences for methodological choices, is beginning to spread in the LCA research community. Standard LCA methodology is developed to answer questions about environmental impacts of the current production and use of one unit of a product or minor product or process changes. When this methodology is used to provide answers to questions about strategic technology choice, i.e. not decisions that aim at improving a process within an existing technological environment, but with the long-term goal of changing large-scale technological systems, the result could be of little value. To be frank, LCAs in many cases produce more noise than knowledge. In the worst case, interpretations of the results may be grossly misleading. This is particularly obvious in LCAs of energy technologies and the assessment of energy use in LCAs. A better structured approach could reveal the fundamental issues and reduce the noise. Examples are given from the technology fields of solar cells, fuel cells, batteries, renewable transport fuels and carbon nanoparticles.