LDRD Seminar Series
2011 Archive

Soft X-ray spectroscopy of Lithium battery materials

August 18

One of the most crucial elements for electric vehicles is a high-performance low-cost battery system. Much of the optimism is based on the phenomenal progress in developing new materials to revolutionize the lithium battery technologies. With the extensive efforts on exploring lithium storage materials, most of the material breakthroughs have been experience based, and are slow comparing with the increasing demand of green energy applications and CO2 emission reduction nowadays. It is thus critical to enable a speedy development of desired energy materials through fundamentally understanding their relevant properties based on advanced analytic tools. Soft x-ray spectroscopy is one of such incisive tools, which probes the key electronic structures that are directly related to the battery performance.

This seminar will present some of our recent results of soft x-ray spectroscopy on lithium battery cathode, anode and/or electrolyte materials. The presentation will focus on X-ray absorption spectroscopy (XAS) and X-ray emission spectroscopy (XES) of the olivine LiFePO4 cathode materials, performed at the Advanced Light Source. The combination of the experimental techniques uncovers the in-depth information on both the occupied and unoccupied electron states in the vicinity of the Fermi level. A complete picture of such electronic structure shed new lights on understanding and optimizing the relevant properties including the lithium diffusion and electron conductivity. Further, we will briefly discuss both direct and indirect measurements of the lithium distribution through various soft x-ray techniques.

Figure 1

Wanli Yang image

NOTE: Please see the Lab Map (click here) for the location of Bldg 15.

Building Systems for Net Zero Energy

August 4

State and federal governments declared that by 2030 all new commercial buildings should be Net Zero Energy Buildings (NZEB). Depending on the climate and building type, a rule of thumb is that to achieve a cost‐effective NZEB, the energy demand needs to be reduced by about 70% to 80%, while the remaining energy will be provided by using on‐site or off‐site renewable energy sources. It is clear that for such an aggressive energy demand reduction, building system solutions need to adapt to the local availability of sources and sinks for thermal conditioning, ventilation, lighting and electricity production, while respecting constraints for occupant health and comfort, building service levels, building system maintainability and aesthetic considerations. As a result, the building becomes an integrated system of multi‐physics, multiscale heterogeneous systems. The underlying equations are nonlinear systems of ordinary differential equations, partial differential equations and algebraic equations with continuous and discrete states. Modeling, simulation and analysis of such systems pose new challenges as systems become increasingly integrated.

This seminar will present our recent research in the development of tools that support modeling, simulation, analysis and operation of complex building systems. To provide a tool for coherent design, fast modeling, dynamic simulation of building energy and control systems, we have developed a Modelica “Buildings” library. Modelica is an equation‐based modeling language for dynamic systems and it is based on separation of concerns between modeling physical systems and solving underlined differential algebra equation (DAE) systems. To facilitate the integrated simulation of programs for different domains, we are developing a standard interface for co‐simulation between various DAE solvers using the functional mockup interface. The integrated simulations of complex systems are demanding in computing power. To make them feasible for industrial applications in terms of computing time and financial cost, we are investigating high‐performance low‐cost computing solutions through the optimization of algorithms combined with the use of parallel computing on graphics processing units. Finally, we will discuss future research needs to apply our findings in a large scale for accelerating the implementation of NZEBs.

Download the flyer (pdf) »

Biological Soil Crusts: Element Cycling by Earth's Most Extensive Biofilm

July 28

Biological soil crusts are extensive but little-known topsoil microbial ecosystems that encompass complete terrestrial carbon cycles. They become biogeochemically relevant under extreme conditions of aridity, where plants falter. They constitute treatable model systems for the integrative deployment of "omics" approaches in search of a mechanistic understanding of microbial community functioning. If successful, this may lead us to an increased explanatory and predictive ability of biogeochemical cycling in the environment. They constitute the main study subject of a recently initiated LDRD at Lawrence Berkeley Lab.

I will review aspects of the basic ecology and microbiology of biological soil crusts, and speak to the potential of these communities as models for integrative carbon cycle research.

Hosted by: Trent Northen, Life Sciences Division

Geologic Carbon Sequestration and Subsurface Heterogeneity Tomography

July 14

Geologic carbon sequestration (GCS) has been investigated for more than two decades, from early concept studies in the late 1980’s to field pilot tests, and to a limited number of industrial-scale applications. In order for GCS to be an effective measure for climate change mitigation, we are facing three grand challenges: the storage capacity of the subsurface is constrained by pressure buildup and its adverse effects (e.g., caprock integrity damage, induced seismicity, and fault reactivation); monitoring methods for early warning and detection of CO2 leakage need improvement; and effects of subsurface heterogeneity on CO2 migration, long-term trapping, and storage efficiency need to be better quantified. The focus of this talk will be on the last challenge. A conceptual model is described for CO2 migration and trapping in heterogeneous formations. Laboratory and field evidence is then presented to demonstrate the effects of heterogeneity observed from centimeter-scale core flush experiments, to meter-scale laboratory experiments, to hundred meter-scale field pilot tests, and to kilometer-scale GCS application and demonstration projects. Finally, we discuss the methodology of subsurface heterogeneity tomography and its potential application to the Frio pilot test, a small scale CO2 storage experiment, which offers a wealth of perse monitoring data of hydraulic, thermal, tracer, and CO2 injection tests.

Artificial Photosynthesis and Novel Photovoltaics

June 30

Abstract: A practical method to use sunlight to generate liquid transportation fuels would yield a carbon-neutral energy source which could dramatically change the landscape of global energy generation. The fundamental steps involved in developing such an “artificial photosynthesis” scheme will be discussed, along with the scientific barriers which have prevented development of a feasible system to date. At LBNL, an approach based on inorganic light absorbers coupled to oxidation and reduction catalysts is being developed in the Joint Center for Artificial Photosynthesis (JCAP). This presentation will focus on the photovoltaic (PV) element of the fuel generating system. These PV systems are designed to provide the electrical driving force to enable catalysts to perform the desired oxidation and reduction chemistry. We are concentrating on photoanodes (O2 producing) and photocathodes (H2 or hydrocarbon producing) which can be formed from abundant elements with inexpensive and scalable processes.

While the thermodynamic minimum voltage required for photochemical water splitting into H2 and O2 is 1.23 V, in practice higher voltages are required to produce acceptable reaction rates (the constraints for reducing CO2 to methanol or to methane are similar). Two specific examples of PV approaches which can produce the required voltage for water splitting will be discussed. (1) An “aliovalent” alloy of GaN and ZnO is one of the few materials which has been reported to sustain spontaneous water splitting under visible illumination. Insights into the nature of the reduced bandgap compared to that of the endpoint compounds and efforts to synthesis and characterize the related AlN1-xZnOx system will be presented. (2) In a CC 2.0 LDRD project the origin of a new PV effect which occurs at the “domain walls” between regions of differing electrical polarizations in ferroelectric BiFeO3 is being investigated. Although the voltage generated by each domain wall is small, ca. 10 mV, the voltages can add in series, as in a tandem solar cell, so that a voltage of any chemically relevant magnitude can be produced. We have demonstrated photovoltages exceeding 10 V with a quantum efficiency per domain wall approaching 50%.

Graphene-based Nanostructured Composite Materials for High Energy Batteries

June 24

High energy density, low cost, and safe electrochemical energy storage devices are critical for enabling the use of renewable energy and the reduction of green house gas emission. The use of novel high capacity electrode materials in lithium batteries, however, faces great challenges due to the large volume change accompanying the insertion and retraction of lithium ions in/from such materials which leads to severe degradation of the electrodes upon cycling and dramatically shorten the cycle life of the cells. Using nanostructured composite materials could be a promising approach to solve this problem, though such structures should be carefully designed so that it will not cause new problems, such as the stability of solid-electrolyte-interphase layers. In our research, we use graphene and its derivatives as platform materials to synthesize nanostructured composites with various high-capacity anode (Si, Sn, Fe3O4) and cathode (Sulfur, Li2S) materials. The atomic thin graphene provides desirable properties as a matrix material for battery electrodes, such as light weight, high surface area, high mechanical strength, and high electrical conductivity. Improved lithium storage capacity, cycling life, and rate capability have been observed in lithium cells made from these nanocomposite electrodes.

Applications of Life-Cycle Assessment to Geologic Carbon Sequestration

June 2

Geologic Carbon Sequestration (GCS) entails the deep injection of CO2 captured from stationary point sources such as fossil-fuel power plants. Key targets for GCS in North America are brine-filled aquifers in large sedimentary basins. The motivating premise of this project is that pressure management by brine discharge will very likely be needed in future deployment of GCS. Life-cycle assessment (LCA) is a systematic assessment of the potential environmental, health, and resource impacts associated with a product, process, or service over its “life-cycle” based on an inventory of relevant energy and material inputs and environmental releases. I will introduce the LCA process for energy technologies and illustrate its application to options for managing the brine produced to reduce pressure in GCS storage reservoirs. The CO2 sequestered from a 1 GW coal-fired power plant can annually displace as much as 20 million m3 of brine. We will review brine management options that include brine reinjection in shallow aquifers, discharge to large rivers, evaporation pounds or desalination plants with staged mineral recovery, transport via pipeline to ocean, energy recover from hot brines, and supporting saline algae ponds.

Manipulating the plasmon resonance of metal oxide nanocrystals for dynamic window coatings

May 27

Plasmons are light-induced collective oscillations of the free electrons in a metal. In heavily doped metal oxide nanocrystals, they exist as localized surface plasmons that give rise to an optical absorption feature in the infrared spectral range. The wavelength of this absorption peak can be modified by varying the amount of dopant incorporated into the nanocrystals during their chemical synthesis.

I will overview our efforts to manipulate such plasmon resonance features, following an innovation cycle of new materials development, investigation of optical and structural properties, and integration into prototype devices. We have demonstrated that the surface plasmon absorption of a nanocrystal film can be dynamically and reversibly tuned across the near infrared spectrum while maintaining excellent transparency for visible light. These properties are of keen interest for a new breed of carbon-saving, dynamic window coatings that can modulate solar heating while consistently supplying daylight.

Probing Atmospheric Aerosols by Micro-Spectroscopic Methods

May 19

Understanding and characterizing the diversity of particulate matter produced from fossil fuel and biomass burn combustion is important for determining the magnitude and sign of radiative forcing by aerosols. In particular improved studies on the mixing state of atmospheric particles and their evolution in the atmosphere are needed.

We employ multiple single particle methods such as SEM/EDX and scanning transmission x-ray spectroscopy (STXM) with near edge x-ray absorption fine structure (NEXAFS) spectroscopy to explore the diversity of light absorbing particles. Information is presented on the percent of carbon involved in C=C double bonds (sp2 hybridization) and total atomic carbon/oxygen ratios. Light absorbing aerosols studied include numerous laboratory surrogates, spherical aged biomass burn particulates collected from laboratory burns of selected biomass fuels, and field samples collected from the MILAGRO field study in Mexico City and recent studies in California.

Towards Time Resolved Fluctuation Scattering

May 12

Fluctuation scattering is a multi-particle scattering experiment in which angular correlations within an image are averaged over many shots. Kam, Saldin, Spence and coworkers [1,2,3] have shown both theoretcially and experimentally that the correlation functions obtained from snapshot of multiple, identical particles converge towards the correlation function of a single particle. We show that this theory can be extended to heterogeneous particles mixtures and that, under certain circumstances, the correlation function of a series of mixtures with know stoichiometry can be used to recover the correlation functions of individual species. This analyses is an extension of time-resolved SAXS/WAXS methods successfully employed to determine intermediate solution structures of membrane proteins [4].

[1] Z. Kam. Macromolecules 10, 927 (1978).
[2] D. K. Saldin et al., New J. Phys. 12, 035014 (2010).
[3] D. K. Saldin et al., Phys. Rev. B 81, 174105 (2010).
[4] M. Andersson et al, Structure 17, 1265-1275 (2009).

Regional climate consequences of large-scale cool roof and photovoltaic array deployment

May 5

Modifications to the surface albedo through deployment of cool roofs and pavements (reflective materials) and photovoltaic (PV) arrays (low reflection) have the potential to change radiative forcing, surface temperatures, and regional weather patterns. In this work we investigate the regional climate and radiative effects of modifying surface albedo to mimic massive deployment of cool surfaces (roofs and pavements) and, separately, photovoltaic arrays across the United States using a fully coupled regional climate model, the Weather Research and Forecasting (WRF) model. With adoption of cool roofs, afternoon summertime temperatures in urban locations was reduced by 0.11 to 0.53 °C, although some urban areas showed no statistically significant temperature changes. Averaged over the full domain, the increase in outgoing radiation due to cool roofs and pavements was 0.16 W m-2. The annual emissions offset by this increase in outgoing radiation is calculated to be 127 Mt CO2, roughly 2% of total 2008 U.S. emissions. The hypothetical PVs were designed to be able to produce one terawatt of peak energy and were located in the Mojave Desert of California. To simulate the PVs the desert surface albedo was darkened, causing local afternoon temperature increases of up to +0.4 °C. Statistically significant but lower magnitude changes to temperature and radiation could be seen across the domain due to the introduction of PVs and this forcing was calculated to be equivalent to 4.7 kg emitted CO2 m-2 of PV panel, a penalty of ~4% of the carbon offset by the PV panels. Ongoing work will investigate the climate impact of changes in emissions when replacing fossil-fuel based energy sources with PVs and additionally associated economic and health impacts.

Ion Beam Driven Fusion

April 28

Inertial confinement fusion is the process of initiating nuclear fusion reactions by heating and compressing a fuel target with, for example, laser or ion beams. Applied to energy production, inertial fusion energy requires igniting fuel targets repeatedly, and using the released energy to generate electricity. We are exploring inertial fusion driven by energetic and intense heavy ion beams. Advantages of heavy ion driven inertial fusion energy (IFE) include attractive reactor designs allowing liquid wall protection and credible final optic protection. Induction particle accelerators are very efficient, which lead to attractive economics. The main goal is the development of accelerator concepts and designs leading to an attractive development path with fewer scientific uncertainties.

Why it may be important to link flow in fractured bedrock to ecologic and atmospheric processes

April 21

Models of hillslope hydrology, ecology and the climate are currently limited because of the lack of information about moisture in fractured rock that underlies hillslopes. Missing are data that document the rates and mechanisms of water flow in weathered bedrock that lies between the soil and groundwater. In effect, this unsaturated zone, which links atmospheric, hydrologic, geochemical, ecological, and geomorphic processes in many regions of the world remains unmeasured and poorly understood.

We have used an array of deep and shallow water-level and moisture-detection devices to document how pulses of rainwater pass through a hillslope in Northern California. We have observed rapid flow through the soil, into underlying weathered fractured rock, where it is either stored or transmitted to the underlying water table. We found no evidence of surface flow or of a conductivity barrier forming between soil and the underlying bedrock, to force lateral flow through the soil—a key assumption in most models of hillslope hydrology. These observations suggest that models treating soil as containing the water available for evaporation and transpiration need to consider moisture dynamics in the underlying bedrock to better explain land-atmosphere interactions.

Physically–based Accounting for Resource Use in New Energy Pathways

April 15

This talk describes the development of a new approach to the problem of allocating finite natural resources to diverse ends, which is used here to investigate the potential scale of output of a group of biofuel production pathways. The approach is organized around an energy production web, analogous to the food web models used in ecology. The base of the production web is composed of natural resources including land, water, fossil fuels, and the finite capacity of the environment to act as a sink for pollutants. Within this framework, various physical constraints are used to estimate limitations on the efficiency of different steps in the biofuel production process. We show that estimates of the scale of total output, which are largely independent of the process details, can be derived from the requirements that (1) emissions from fuel are balanced by carbon uptake in the growth of the feedstock, (2) water must be diverted from current uses, and (3) the biorefinery production process must be energetically self-sufficient. We also provide a brief discussion of how the biorefinery process energy use can be estimated based on simple thermodynamic arguments, using the JBEI corn stover model as an example.

Structural Characterization of Energy Related Materials Using Laue Micro-Diffraction

April 7

Materials science plays a central role in the quest for reducing the green house gas emissions of modern societies. Novel materials are sought for energy storage, energy conversion, green house gas capture and inertialization as well as replacements for energy intensive raw materials (e.g. cement production).

One of the fundamental steps when characterizing new materials is an understanding of its atomic structure. This is commonly achieved by employing diffraction methods. Modern material more often than not distinguish themselves by complicated hierarchical, composite or other secondary structures which by one way or the other make the application of traditional monochromatic single crystal diffraction technique impossible. Laue micro-diffraction is a possible alternative technique applicable to such problems, since it combines very high spatial resolution with tolerance to immobile samples. This requires proper interpretation of Laue diffraction intensities, which for most material with small unit cells is a non-trivial task.

In our LDRD project we develop hard- and software tools to enable interpretation of white beam diffraction data. One of the cruxes to be solved was a proper assessment of the effective incident flux since small deviations from the theoretical curve led to significant deviations on some of the energy ranges. This was achieved by comparing the measured intensity of a well-characterized standard crystal with its calculated structure factors. A very accurate quantification of the thermal motion of the atoms of the standard crystal proved to be very important, due to the particular experimental geometry of Laue diffraction. Some examples based on the proper intensity quantification will be shown as well as remaining tasks to be solved.

Interfacial reactions in the environment, energy production, and catalysis investigated with synchrotron-based spectroscopy

March 31

Whether it is the removal of carbon monoxide from automotive exhaust gases, the interaction of trace gases with droplets and ice particles in clouds, or the reaction of hydrocarbons and air with fuel cell electrodes, all of these processes are governed by the fundamental chemistry of gas/solid and gas/liquid interfaces. The investigation of these phenomena on the molecular scale has gained increasing importance over the last decade.

In this talk we will discuss basic approaches to in situ measurements of gas/liquid and gas/solid interfaces, with emphasis on synchrotron-based spectroscopies.

Multi-tracer Measurements and Inversions Quantifying California’s GHG Emissions Budget

March 18

A sustainable global environmental energy future will require mutually agreed upon verifiable commitments to reducing anthropogenic greenhouse gas (GHG) emissions to the atmosphere. Supporting a vision for verified emissions reductions, LBNL is conducting research to quantify net GHG emissions at local to regional scales in California. The spatial distribution and temporal variations in emissions are estimated using a combination of atmospheric measurements and inverse model optimizations that quantify emissions by balancing information in the measurements against information supplied by atmospheric transport simulations, each weighted by their respective uncertainties. In collaboration with university, state, and federal partners, multi-species measurements are made over California from tower networks, aircraft campaigns, and satellite platforms. GHG transport simulations are computed using high-resolution data-driven a priori GHG emission maps and a carefully evaluated model for atmospheric transport. Measurements at select locations include all major GHG species (CO2, CH4, N2O, and industrial gases with high global warming potential (HGWP)), selected isotopes (13CO2, 14CO2, 13CH4), and combustion and transport tracers (e.g., CO, VOCs, and 222Rn). Work from a growing Central Valley network of CH4 measurements suggests that the ratio of actual-to-inventory CH4 emissions varies by region from 1 to 2 with typical statistical uncertainties of 10-20% (1 sigma) in well-sampled regions. A more limited data set from a single tower suggests N2O emissions are significantly higher (factor of 3 +/- 1 ) than inventory estimates. The combination of periodic radiocarbon 14CO2 and continuous CO2, and CO measurements suggest it may be possible to track fossil fuel derived CO2 to distinguish biospheric and fossil CO2 exchange. In an initial application of this technique, we find approximate agreement between inventory estimates of fossil fuel CO2 emissions from Sacramento and those inferred from atmospheric measurements. Initial comparison of selected industrial GHGs (e.g., SF6 and halo carbons) with CO show high correlations, suggesting it will also be possible to quantify HGWP GHG emissions. Taken together, this body of work shows the potential for comprehensive regional GHG emissions measurements for mixed rural and urban areas in California, and by extension, eventually other regions of the world.

More thin films for less carbon: Developing and applying high rate plasma technology

March 10

Energy conservation and renewable energies are surprisingly related to thin films in many ways. Whether photovoltaics, low friction machinery, smart windows, thin films are key. I will consider the size of the area being coated and the size of the markets - which are impressive and bound to grow. Efforts are being made to providing low cost coatings using abundant materials for high quality films. Here is where the deposition process comes in: it should be of high rate, well controlled and reproducible, yet flexible to address the needs of various applications. We have developed processes that involve metal and gas plasmas plasma including arc and advanced sputtering technology. Transparent conducting films are selected as an example of how plasma technology can advance low-carbon energy technologies.

Uncovering the mechanistic basis for soil microbial community response to altered precipitation patterns

February 24

Microbial communities are characterized by hundreds of thousands of diverse species and metabolic functions yet are still represented as a single ‘black box’ in many current global climate models forecasting climate change impacts on ecosystems. This simplification overlooks the fact that microbes are the dominant mediators of carbon and nutrient transformations. Therefore, the ability to accurately predict the response of soil microbial communities to a changing climate is crucial to understanding potential changes in the biological productivity and biogeochemistry of terrestrial ecosystems. In previous work, a phylogenetic signal to drought tolerance was identified suggesting that soil microbial response to altered precipitation could be predictable.

The goal of this project is to provide a mechanistic understanding of why soil microbial communities change in composition and metabolic function in response to altered precipitation patterns. We are examining three soil microbial populations (desert, Mediterranean grassland, tropical rainforest) that have evolved under vastly different rainfall regimes that allow for an initial comparison of whether climate history or evolutionary constraints (related to phylogeny) are the primary factors controlling adaptation of microbial communities to altered precipitation. Using a combination of next-generation sequencing and targeted isolation of bacteria, we have examined the response of whole communities and individual organisms to reduced rainfall.

Across these contrasting ecosystems an organism’s adaptive capacity to water potential stress is seemingly governed more by recent climate history than by evolutionary relatedness and bacterial diversity decreases with decreased precipitation. Such biodiversity loss may have important implications for ecosystem function and the biogeochemical response of the tropical site microbial community was measured following a period of decreased precipitation. Although soil respiration and methane flux remained unchanged, soils that had experienced decreased precipitation became a nitrous oxide source. We are currently investigating the molecular mechanisms behind this switch.

Agave: a biofuel feedstock for arid and semi-arid environments

February 17

Efficient production of plant-based, lignocellulosic biofuels relies upon continued improvement of existing biofuel feedstock species, as well as the introduction of new feedstocks capable of growing on marginal lands to avoid conflicts with existing food production and minimize use of water and nitrogen resources. To this end, species within the plant genusAgave have recently been proposed as new biofuel feedstocks. Many agave species are adapted to hot and arid environments generally unsuitable for food production, yet have biomass productivity rates comparable to other second-generation biofuel feedstocks such as switchgrass and Miscanthus. Agaves achieve remarkable heat tolerance and water use efficiency in part through a Crassulacean Acid Metabolism (CAM) mode of photosynthesis, but the genes and regulatory pathways enabling CAM and thermotolerance in agaves remain poorly understood. We seek to accelerate the development of agave as a new biofuel feedstock through genomic approaches using massively-parallel sequencing technologies. First, we plan to sequence the transcriptome of A. tequilana to provide a database of protein-coding genes to the agave research community. Second, we will compare transcriptome-wide gene expression of agaves under different environmental conditions in order to understand genetic pathways controlling CAM, water use efficiency, and thermotolerance. Finally, we aim to compare the transcriptome of A. tequilana with that of other agave species to gain further insight into molecular mechanisms underlying traits desirable for biofuel feedstocks. These genomic approaches will provide sequence and gene expression information critical to the breeding and domestication of Agave species suitable for biofuel production.

Mapping Genes and Acres: Engineering Switchgrass Lines for Large-scale Biofuel Production on Marginal Lands

February 10

To minimize conflicts between production of biofuels and food, research is proceeding on two converging fronts. 1) To what extent can genetic manipulation lead to drought- and salt-tolerance in lignocellulosic feedstocks, e.g., rice straw and switchgrass, and what is the productivity of genetically-modified biofuel crops? 2) what is the total land area that may be accessible to biofuel production as a function of land characteristics, including salinity and water availability? Combining genetic research with analysis of land characteristics contributes to a life-cycle economic and environmental assessment of potential biofuel production.

Materials Innovations for Energy Efficient Electronics

February 4

Information processing equipment, including data centers and servers, computers, consumer electronics, and network equipment consume a significant fraction of the total electricity production in the US, and it is growing dramatically with time. There is a need to address this growing component of energy consumption through the development of new device schemes and their associated materials. In this talk, I will discuss the materials challenges and opportunities associated with nanoscale semiconductors for low power electronics. Specifically, a new platform for the integration of high mobility, ultrathin layers (a few atomic layers thick) of III-V compound semiconductors on Si substrates will be discussed. This work enables fundamental studies of the size effects, surfaces/interfaces, contacts, and transport physics in low dimensional materials without the constraints of the original growth substrates. I will also discuss the challenges associated with dopant profiling of nanoscale semiconductors and the various approaches towards deterministic control of dopant positioning.

Enabling low-carbon technology development through integrated energy systems analysis

January 26

A primary aim of CC2.0 is to accelerate LBNL’s development and delivery of advanced technologies for sustainable, low-carbon energy systems. Integrated energy systems analysis can support this goal by providing credible, science-based assessments of the potential of emerging technologies for reducing energy and resource use, carbon emissions, environmental impacts, and societal costs when these technologies are deployed at scale. This presentation will provide an overview of a project to expand LBNL's integrated energy systems analysis capabilities and to build collaborations across LBNL's analysis, applied research, and basic research activities for early technology assessment. Key tasks include assessing market potentials, performing life-cycle assessments, conducting risk and uncertainty analyses, and developing improved analysis approaches for assessing the net environmental, climate, and economic impacts of LBNL technologies over different scales of time and space. Some example analyses will be presented to illustrate the key methods and goals of this project.

Eric Masanet is Deputy Leader of the International Energy Studies Group at Lawrence Berkeley National Laboratory. He holds a joint research appointment at the University of California, Berkeley, where he currently serves as Program Manager for the Engineering and Business for Sustainability Certificate Program. His research foci include life-cycle assessment of products and industrial systems, regional modeling of industrial energy demand, and analysis of industrial energy efficiency and greenhouse gas mitigation potentials. He is also Associate Editor of the journal Resources, Conservation & Recycling. He holds a Ph.D. in mechanical engineering from UC Berkeley, with a specialization in environmentally-conscious design and manufacturing.

CO2 as Cushion Gas for Compressed Air Energy Storage

January 21

Multiple approaches are needed to reduce global CO2 emissions to mitigate anthropogenic climate change. Among the approaches available are geologic carbon sequestration (GCS) and much greater use of renewable energy sources such as solar and wind. Because wind and solar energy are intermittent, energy storage is required to ensure a smooth electricity supply that can match demand.

In this research, we are investigating the potential beneficial coupling of GCS with compressed air energy storage (CAES). CAES is normally conceived as using air as both the working gas and the cushion gas. A coupling of GCS and CAES can be achieved if CO2 is used as the cushion gas in porous media (aquifer or gas-reservoir) CAES systems. Such use has dual benefits. First, upon emplacement of the CO2 cushion, an operator could receive payments for sequestering CO2 under the various carbon-pricing policies under consideration. Second, CO2 has an advantage as a cushion gas because of the large increase in density as it transitions from its gaseous to supercritical (liquid-like) form as the pressure increases above 7.4 MPa (1070 psi) at temperatures just above the critical temperature 31 °C (88 °F). As the CAES reservoir is cycled around the critical pressure by injection of air (working gas), the CO2 cushion gas will compress non-linearly and act like a super-cushion. This behavior of CO2 as a cushion gas will allow the storage of more energy for a given reservoir size.

We have modeled the coupled hydrologic and two-phase flow aspects of standard aquifer CAES including coupled reservoir and wellbore flow using numerical simulation approaches. To investigate the use of CO2 as cushion gas, we have carried out initial simulations of gas-reservoir CAES including the initial fill with CO2 to enhance the CH4 recovery. With CO2 subsequently occupying the majority of the reservoir, we have simulated air injection which raised the reservoir pressure above Pcrit resulting in the predicted super-compression of CO2. Upon production of air in the recovery cycle, the CO2 decompresses as expected to drive air out. Future work will add in the wellbore flow component, and more fully analyze the benefits and drawbacks of the use of CO2 as cushion gas.

Download the slides (pdf) »

Advanced Materials and Building Energy Efficiency: Nano- solutions with Gigaton Carbon Impacts

January 13

Buildings consume 40% of total US energy and carbon emissions and 71% of all electricity use. Buildings have been the fastest growing energy end use sector. The most cost effective method to rapidly reduce carbon emissions is to aggressively address “end use”; the point at which energy is converted into useful products and services. Although significant progress has been made in reducing the growth of energy use in the building sector, neither the savings to date, nor the projected future actions, are sufficient to achieve the bold greenhouse gas emission goals set by various state and federal agencies.

There are many new opportunities to capture enhanced savings from energy efficiency and LBNL has 30+ year track record of innovation and success in this field. One of the lab’s strengths is that across its R&D divisions it has world class expertise in both the basic and applied science that drives innovation in the commercial sector, and in the supporting policy innovations that both underlie and enable a transition to a low carbon society driven by a “green tech” revolution. Several new LDRD multi-divisional, coordinated efforts are now underway between scientists throughout the lab to capture these opportunities.

This talk will explore the building technologies and systems that are responsible for major energy end use today and the opportunities for making significant reductions in future use. It will focus on glass and window systems in buildings as an example where past R&D has dramatically reduced energy and new R&D promises to extend these savings further. A key element in these efficiency gains is the ability to control heat transfer with the use of multifunctional coatings. Multilayer low-emissivity coatings that transmit sunlight but reflect long wave infrared energy have revolutionized the energy performance of windows and provided a roadmap of how additional savings can be captured with other window system innovations. The current focus of global window R&D is “smart coatings”; coatings whose solar-optical properties can be dynamically and reversibly altered. Research to date has focused in the narrow class of materials that exhibit reversible electrochromism. The ability to work with nano-structured materials opens up additional promising pathways for both materials development as well as for high rate deposition processes needed to make cost effective products. The latest LBNL development effort looks to dynamic control of the microstructure of coatings as a means to redirect sunlight and daylight into rooms to dramatically reduce building lighting energy consumption. The LDRD partnerships linking EETD, MSD and AFRD staff promise to bring a new round of innovation to the energy savings in the building sector.

Highly parallelized synthesis of microbial genes using oligonucleotides arrays

January 6

Deep sequencing of environmental samples is revealing an increasingly large number of novel proteins, many of which have potential applications in “Green Biotechnologies”, such as biocatalysts for biomass degradation, biofuel synthesis, bioremediation and carbon capture. However, converting “Digital” sequence information into proteins that can be characterized biochemically has been challenging, since template DNA is almost always unavailable. Synthetic Biology, allows genes to be re-constructed in a template independent manner, essentially converting digital information into a biological information, that can be readily used for downstream applications. The goal of this project is to develop a high-throughput, low cost method for gene synthesis, using of oligonucleotide microarrays, which will allow the functional screening of large numbers of novel genes for activities of interest. Our initial test case is focused on synthesizing and testing 200 predicted GH1 cellulases which participate in the last step of degradation of biomass, an important step for the development of cellulosic biofuels.

Laboratory Directed Research and Development Program

Berkeley Lab seeds a number of innovative, creative and original research proposals to encourage innovative science and new research directions. The Laboratory Directed Research & Development (LDRD) program at Berkeley Lab is aligned with the Department of Energy’s strategic mission of applying world-class research to important national problems.

A number of these research projects are in research areas relating to the Carbon Cycle 2.0 initiative.

Carbon Cycle 2.0 hosts a weekly seminar series at Berkeley Lab in which recipients of Laboratory Directed Research & Development grants speak about work pertaining to their LDRD project.

In March 2011, the 2011 Carbon Cycle 2.0 LDRD projects prepared one-page summaries of their six-month research progress. LBNL personnel can log in to view the full list.