In many commercial cells, long tabs at both cell sides, leading to uniform potentials along the spiral direction of wound jelly rolls, are rarely seen because of their high manufacturing cost. More often, several metal strips are welded at discrete locations along both current collector foils. With this design, the difference of electrical potentials is easily built up along current collectors in the spiral direction. Hence, the design features of the tabs, such as number, location and size, can be crucial factors for spiral-shaped battery cells. This paper presents a Li-ion battery cell model having a 3-dimensional spiral mesh involving a wound jellyroll structure. Further results and analysis will be given regarding impacts of tab location, number, and size.

Accelerated Testing and On-Sun Failure of CPV Die-attach. Presentation on CPV accelerated reliability testing.

Computer-aided engineering (CAE) is a proven pathway, especially in the automotive industry, to improve performance by resolving the relevant physics in complex systems, shortening the product development design cycle, thus reducing cost, and providing an efficient way to evaluate parameters for robust designs. Academic models include the relevant physics details, but neglect engineering complexities. Industry models include the relevant macroscopic geometry and system conditions, but simplify the fundamental physics too much. Most of the CAE battery tools for in-house use are custom model codes and require expert users. There is a need to make these battery modeling and design tools more accessible to end users such as battery developers, pack integrators, and vehicle makers. Developing integrated and physics-based CAE battery tools can reduce the design, build, test, break, re-design, re-build, and re-test cycle and help lower costs. NREL has been involved in developing various models to predict the thermal and electrochemical performance of large-format cells and has used in commercial three-dimensional finite-element analysis and computational fluid dynamics to study battery pack thermal issues. These NREL cell and pack design tools can be integrated to help support the automotive industry and to accelerate battery design.

Presentation about the National Renewable Energy Laboratory's analysis of hydrogen energy storage scenarios, including analysis framework, levelized cost comparison of hydrogen and competing technologies, analysis results, and conclusions drawn from the analysis.

This presentation summarizes ARRA fuel cell deployment and operation.

This presentation uses a vehicle simulator and economics model called the Battery Ownership Model to examine the levelized cost per mile of conventional (CV) and hybrid electric vehicles (HEVs) in comparison with the cost to operate an electric vehicle (EV) under a service provider business model. The service provider is assumed to provide EV infrastructure such as charge points and swap stations to allow an EV with a 100-mile range to operate with driving profiles equivalent to CVs and HEVs. Battery cost, fuel price forecast, battery life, and other variables are examined to determine under what scenarios the levelized cost of an EV with a service provider can approach that of a CV. Scenarios in both the United States as an average and Hawaii are examined. The levelized cost of operating an EV with a service provider under average U.S. conditions is approximately twice the cost of operating a small CV. If battery cost and life can be improved, in this study the cost of an EV drops to under 1.5 times the cost of a CV for U.S. average conditions. In Hawaii, the same EV is only slightly more expensive to operate than a CV.

This presentation summarizes Biogas Resources Characterization

This presentation summarizes biological systems for hydrogen photoproduction.

Presentation of Blade Testing at NREL's National Wind Technology Center for the 2010 Sandia National Laboratories Blade Testing Workshop.

Presentation about compressed natural gas in municipal fleets, assessing investment profitability, the VICE model, base-case scenarios, and pressing questions for fleet owners.

Presentation on shaded PV power loss, practical issues with modeling shaded PV, and methods of implementing partially shaded PV modeling.

This presentation was written and presented by Elizabeth Doris (NREL) at the November 17 TAP Webinar to provide background detail about how state policies are transforming the clean energy market in different regions of the country.

NREL and partners will investigate the reuse of retired lithium ion batteries for plug-in hybrid, hybrid, and electric vehicles in order to reduce vehicle costs and emissions and curb our dependence on foreign oil. A workshop to solicit industry feedback on the process is planned. Analyses will be conducted, and aged batteries will be tested in two or three suitable second-use applications. The project is considering whether retired PHEV/EV batteries have value for other applications; if so, what are the barriers and how can they be overcome?

Electric-drive vehicles enabled by power- and energy-dense batteries promise to improve vehicle efficiency and help reduce society's dependence on fossil fuels. Next generation plug-in hybrid vehicles and battery electric vehicles may also enable vehicles to be powered by electricity generated from clean, renewable resources; however, to increase the commercial viability of such vehicles, the cost, performance and life of the vehicles batteries must be further improved. This work illustrates a virtual design process to optimize the performance and life of large-format lithium ion batteries. Beginning with material-level kinetic and transport properties, the performance and life of multiple large-format cell designs are evaluated, demonstrating the impact of macroscopic design parameters such as foil thickness, tab location, and cell size and shape under various cycling conditions. Challenges for computer-aided engineering of large-format battery cells, such as competing requirements and objectives, are discussed.

This presentation summarizes controlled hydrogen fleet & infrastructure analysis undertaken for the DOE Fuel Cell Technologies Program.

Presentation about ARRA Early Fuel Cell Market Demonstrations, including an overview of the ARRE Fuel Cell Project, the National Renewable Energy Laboratory's data analysis objectives, deployment composite data products, and planned analyses.

This presentation describes a battery optimization and trade-off analysis for Li-ion batteries used in EVs and PHEVs to extend their life and/or reduce cost.

A review of NREL's FY10 work on hydrogen production via distributed bio-oil reforming.

This presentation summarizes the methodology and results for a probabilistic risk analysis of research, development, and demonstration work-primarily for enhanced geothermal systems (EGS)-sponsored by the U.S. Department of Energy Geothermal Technologies Program.

This presentation summarizes the approach used to update the U.S. geothermal supply curve.

This presentation was given December 14, 2010, as part of DOE's Webinar series. The presentation discusses geothermal heat pump retrofits, technology options, and an overview of geothermal energy and geothermal heat pumps.

This presentation reports the findings of NREL's screen test to characterize the durability of poly (methyl methacrylate) lenses used in concentrated photovoltaics.

Presentation about ethanol, specifications for E85, and market surveys of fuel quality.

This presentation summarizes Effect of System and Air Contaminants on PEMFC Performance and Durability.