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.

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 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.

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 work describes the development of a waste biomass fermentation process using cellulose-degrading bacteria for hydrogen production. This process is then integrated with an electrohydrogenesis process via the development of a microbial electrolysis cell reactor, during which fermentation waste effluent is further converted to hydrogen to increase the total output of hydrogen from biomass.

This presentation details how wind turbine gearboxes fail to meet 20-year design life and how the Gearbox Reliability Collaborative (GRC) is addressing the challenges.

Presentation on the execution of the first high-throughput thermochemical pretreatment/enzyme digestion pipeline for screening biomass for recalcitrance.

With support from General Motors, NREL researchers converted and tested a hybrid electric vehicle (HEV) with three energy storage configurations: a nickel metal-hydride battery and two ultracapacitor (Ucap) modules. They found that the HEV equipped with one Ucap module performed as well as or better than the HEV with a stock NiMH battery configuration. Thus, Ucaps could increase the market penetration and fuel savings of HEVs.

Overview of hydrogen for energy storage analysis presented at the National Hydrogen Association Conference & Expo, May 3-6, 2010, Long Beach, CA.

Discussion of the formation of CdTe thin-film PV junctions and optimization of CdTe thin-film PV solar cells.

Overview of nominal operating cell temperature research, hypothesis, and testing at NREL.

Invited Tutorial presented as part of AMS International Short Course Series.

This presentation describes the multi-physics behaviors of internal and external short circuits in large lithium-ion batteries.

The motivation for an increased scope and a more proactive effort in reliability research of photovoltaic modules and systems includes reducing the levelized cost of energy and gaining better confidence in the energy and financial payback for photovoltaic systems. This increased reliability and confidence will lead to greater penetration of photovoltaics in the energy portfolio and greater employment in photovoltaics and related industries. Present research needs include the fundamental degradation mechanisms of polymers, connectors and other module components, mapping of failure mechanisms observed in the field to those in accelerated lifetime tests, determining the acceleration factors, and improving standards for modules such that tests can appropriately be assigned to evaluate their long term durability. Specific mechanisms discussed are corrosion in module components, metastability in thin-film active layers, delamination and loss of elastic properties in module polymeric materials, and inverter failure. Presently, there is hiring of reliability scientists and engineers at many levels of the value chain for photovoltaics.

Renewable energy sources, such as wind and solar, have vast potential to reduce dependence on fossil fuels and greenhouse gas emissions in the electric sector. Climate change concerns, state initiatives including renewable portfolio standards, and consumer efforts are resulting in increased deployments of both technologies. Both solar photovoltaics (PV) and wind energy have variable and uncertain (sometimes referred to as "intermittent") output, which are unlike the dispatchable sources used for the majority of electricity generation in the United States. The variability of these sources has led to concerns regarding the reliability of an electric grid that derives a large fraction of its energy from these sources as well as the cost of reliably integrating large amounts of variable generation into the electric grid. In this report, we explore the role of energy storage in the electricity grid, focusing on the effects of large-scale deployment of variable renewable sources (primarily wind and solar energy).

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?

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