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At least 865 records · Page 48

High Temperature Fluoride Salt Test Loop

Effective high-temperature thermal energy exchange and delivery at temperatures over 600°C has the potential of significant impact by reducing both the capital and operating cost of energy conversion and transport systems. It is one of the key technologies necessary for efficient hydrogen production and could potentially enhance efficiencies of high-temperature solar systems. Today, there are no standard commercially available high-performance heat transfer fluids above 600°C. High pressures associated with water and gaseous coolants (such as helium) at elevated temperatures impose limiting design conditions for the materials in most energy systems. Liquid salts offer high-temperature capabilities at low vapor pressures, good heat transport properties, and reasonable costs and are therefore leading candidate fluids for next-generation energy production. Liquid-fluoride-salt-cooled, graphite-moderated reactors, referred to as Fluoride Salt Reactors (FHRs), are specifically designed to exploit the excellent heat transfer properties of liquid fluoride salts while maximizing their thermal efficiency and minimizing cost. The FHR s outstanding heat transfer properties, combined with its fully passive safety, make this reactor the most technologically desirable nuclear power reactor class for next-generation energy production. Multiple FHR designs are presently being considered. These range from the Pebble Bed Advanced High Temperature Reactor (PB-AHTR) [1] design originally developed by UC-Berkeley to the Small Advanced High-Temperature Reactor (SmAHTR) and the large scale FHR both being developed at ORNL [2]. The value of high-temperature, molten-salt-cooled reactors is also recognized internationally, and Czechoslovakia, France, India, and China all have salt-cooled reactor development under way. The liquid salt experiment presently being developed uses the PB-AHTR as its focus. One core design of the PB-AHTR features multiple 20 cm diameter, 3.2 m long fuel channels with 3 cm diameter graphite-based fuel pebbles slowly circulating up through the core. Molten salt coolant (FLiBe) at 700°C flows concurrently (at significantly higher velocity) with the pebbles and is used to remove heat generated in the reactor core (approximately 1280 W/pebble), and supply it to a power conversion system. Refueling equipment continuously sorts spent fuel pebbles and replaces spent or damaged pebbles with fresh fuel. By combining greater or fewer numbers of pebble channel assemblies, multiple reactor designs with varying power levels can be offered. The PB-AHTR design is discussed in detail in Reference [1] and is shown schematically in Fig. 1. Fig. 1. PB-AHTR concept (drawing taken from Peterson et al., Design and Development of the Modular PB-AHTR Proceedings of ICApp 08). Pebble behavior within the core is a key issue in proving the viability of this concept. This includes understanding the behavior of the pebbles thermally, hydraulically, and mechanically (quantifying pebble wear characteristics, flow channel wear, etc). The experiment being developed is an initial step in characterizing the pebble behavior under realistic PB-AHTR operating conditions. It focuses on thermal and hydraulic behavior of a static pebble bed using a convective salt loop to provide prototypic fluid conditions to the bed, and a unique inductive heating technique to provide prototypic heating in the pebbles. The facility design is sufficiently versatile to allow a variety of other experimentation to be performed in the future. The facility can accommodate testing of scaled reactor components or sub-components such as flow diodes, salt-to-salt heat exchangers, and improved pump designs as well as testing of refueling equipment, high temperature instrumentation, and other reactor core designs.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

Laboratory Experiments and Modeling for Interpreting Field Studies of Secondary Organic Aerosol Formation Using an Oxidation Flow Reactor

This grant was originally funded for deployment of a suite of aerosol instrumentation by our group in collaboration with other research groups and DOE/ARM to the Ganges Valley in India (GVAX) to study aerosols sources and processing. Much of the first year of this grant was focused on preparations for GVAX. That campaign was cancelled due to political reasons and with the consultation with our program manager, the research of this grant was refocused to study the applications of oxidation flow reactors (OFRs) for investigating secondary organic aerosol (SOA) formation and organic aerosol (OA) processing in the field and laboratory through a series of laboratory and modeling studies. We developed a gas-phase photochemical model of an OFR which was used to 1) explore the sensitivities of key output variables (e.g., OH exposure, O 3 , HO 2 /OH) to controlling factors (e.g., water vapor, external reactivity, UV irradiation), 2) develop simplified OH exposure estimation equations, 3) investigate under what conditions non-OH chemistry may be important, and 4) help guide design of future experiments to avoid conditions with undesired chemistry for a wide range of conditions applicable to the ambient, laboratory, and source studies. Uncertainties in the model were quantified and modeled OH exposure was compared to tracer decay measurements of OH exposure in the lab and field. Laboratory studies using OFRs were conducted to explore aerosol yields and composition from anthropogenic and biogenic VOC as well as crude oil evaporates. Various aspects of the modeling and laboratory results and tools were applied to interpretation of ambient and source measurements using OFR. Additionally, novel measurement methods were used to study gas/particle partitioning. The research conducted was highly successful and details of the key results are summarized in this report through narrative text, figures, and a complete list of publications acknowledging this grant.

54 ENVIRONMENTAL SCIENCES↗

Accelerating Energy Efficiency in Indian Data Centers. Final Report for Phase I Activities

This report documents Phase 1 of the “Accelerating Energy Efficiency in Indian Data Centers” initiative to support the development of an energy efficiency policy framework for Indian data centers. The initiative is being led by the Confederation of Indian Industry (CII), in collaboration with Lawrence Berkeley National Laboratory (LBNL)-U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy, and under the guidance of Bureau of Energy Efficiency (BEE). It is also part of the larger Power and Energy Efficiency Working Group of the US-India Bilateral Energy Dialogue. The initiative consists of two phases: Phase 1 (November 2014 – September 2015) and Phase 2 (October 2015 – September 2016).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Report on the Sixth International Symposium on Isotopomers

The ISI 2012 met in Washington, DC, 18-22 June 2012, bringing together researchers and their students spanning an unusually wide range of disciplines including quantum and physical chemistry, cosmochemistry, atmospheric chemistry, chemical oceanography, biogeochemistry, organic and inorganic geochemistry. The diversity of subject matter was matched geographically with 92 attendees hailing from Canada, China, Finland, France, Germany, India, Israel, Japan, the Netherlands, Russia, Switzerland, Taiwan, the United Kingdom, and the USA. Although diverse, the group was united in its commitment to use the light stable isotopes of H, C, N, O, and S, with their equilibrium, kinetic, and intramolecular fractionations, to understand the material cycles and their dynamics between atmosphere, biosphere, hydrosphere, and lithosphere that make life possible on Earth. A distinct benefit of a small meeting like ISI 2012 is the opportunity for everyone to talk to each other. The historic rooms of the Carnegie Institution of Washington offered a cozy and warm atmosphere for participants in ISI 2012 to talk science and life in a casual, relaxed, and in-depth fashion. Graduate students and postdoctoral researchers were particularly appreciative of being able to spend five days together with old and new colleagues in comfortable quarters. Many commented that they had gained a lot more in building their life-long working relationships with colleagues at this meeting than at larger meetings.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

International Energy Outlook 2016 With Projections to 2040

The International Energy Outlook 2016 (IEO2016) presents an assessment by the U.S. Energy Information Administration (EIA) of the outlook for international energy markets through 2040. U.S. projections appearing in IEO2016 are consistent with those published in EIA’s Annual Energy Outlook 2015 (AEO2015). IEO2016 is provided as a service to energy managers and analysts, both in government and in the private sector. The projections are used by international agencies, federal and state governments, trade associations, and other planners and decisionmakers. They are published pursuant to the Department of Energy Organization Act of 1977 (Public Law 95-91), Section 205(c). The IEO2016 energy consumption projections are divided according to Organization for Economic Cooperation and Development members (OECD) and nonmembers (non-OECD). OECD members are divided into three basic country groupings: OECD Americas (United States, Canada, and Mexico/Chile), OECD Europe, and OECD Asia (Japan, South Korea, and Australia/New Zealand). Non-OECD countries are divided into five separate regional subgroups: non-OECD Europe and Eurasia (which includes Russia); non-OECD Asia (which includes China and India); Middle East; Africa; and non-OECD Americas (which includes Brazil). In some instances, the IEO2016 energy production models have different regional aggregations to reflect important production sources (for example, Middle East OPEC is a key region in the projections for liquids production). Complete regional definitions are listed in Appendix M. IEO2016 focuses exclusively on marketed energy. Nonmarketed energy sources, which continue to play an important role in some developing countries, are not included in the estimates. The IEO2016 projections are based on existing U.S. and foreign government laws and regulations. In general, IEO2016 reflects the effects of current policies—often stated through regulations—within the projections. EIA analysts attempt to interpret the likely effects of announced country targets when the implementation of those targets will require new policies that have not been formulated or announced.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Analysis of a Single Year of Performance Data for Thin Film Modules Deployed at NREL and NISE

The National Renewable Energy Laboratory (NREL) and National Institute of Solar Energy (NISE), located in the United States and India, respectively, have partnered to deploy and monitor modules of three different thin film technologies, to compare the performance and/or degradation between the two sites. This report analyzes a single year of performance data (May 2014 -- May 2015) for the three thin film technologies, exploring the modules' performance under standard test conditions and monthly performance ratios, as well as fill factors varying season, light level, and temperature.

14 SOLAR ENERGY↗

Applications of Antineutrino Monitoring to Nonproliferation

Antineutrinos are highly penetrating particles emitted by the fission process in operating nuclear power and research reactors. Their rate of emission and energy spectrum can provide useful information about reactor operations, including the existence of the reactor, its power level, and the fissile mass inventories in the core. Because the signal cannot be attenuated or masked, this information can be gathered at long standoff outside the core. Building on our group’s successful experimental demonstrations of plutonium content monitoring at 25 meters from a reactor core, the goal of this project is to demonstrate detectors for reactor monitoring and discovery detectors at increasing standoffs, out to a practical limit of about 1000 kilometers. Our two main goals for FY16 and 17 are: 1) design a detector capable of monitoring nuclear reactor operations at 25 kilometer standoff, and 2) engage in a cooperative effort to monitor a former plutonium production reactor in India (at close range).

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

China-Pakistan Economic Corridor.

International trade and related economic activities in Central and South Asia are increasing as developing economies, particularly India and Pakistan, grow. China continues to emerge as a major regional and global power and has embarked upon numerous regional economic and political initiatives . A major development is the China - Pakistan Economic Corridor (CPEC), a host of infrastructure and trade projects worth over 40 billion American dollars . This report analyzes CPEC a nd its potential regional effects, including the trade security implications of the port and land infrastructure developments . As trade increase s in the reg ion and the major CPEC infrastructure projects are completed, there will be numerous implications on trade security and geopolitics within South Asia. CPEC projects uniquely intersect numerous regional situations, including territorial disputes in Kashmir, the Afghanistan/Pakistan border, and Chinese foreign policy a mbitions. A nuanced understanding of these effects can influence future policy adjustments in this region . The views expressed in this report are those of the author and do not necessarily reflect the position of Sandia National Laboratories or the author's current and past institutions.

99 GENERAL AND MISCELLANEOUS↗

Achieving Tier 4 Emissions in Biomass Cookstoves

Previous literature on top-lit updraft (TLUD) gasifier cookstoves suggested that these stoves have the potential to be the lowest emitting biomass cookstove. However, the previous literature also demonstrated a high degree of variability in TLUD emissions and performance, and a lack of general understanding of the TLUD combustion process. The objective of this study was to improve understanding of the combustion process in TLUD cookstoves. In a TLUD, biomass is gasified and the resulting producer gas is burned in a secondary flame located just above the fuel bed. The goal of this project is to enable the design of a more robust TLUD that consistently meets Tier 4 performance targets through a better understanding of the underlying combustion physics. The project featured a combined modeling, experimental and product design/development effort comprised of four different activities: Development of a model of the gasification process in the biomass fuel bed; Development of a CFD model of the secondary combustion zone; Experiments with a modular TLUD test bed to provide information on how stove design, fuel properties, and operating mode influence performance and provide data needed to validate the fuel bed model; Planar laser-induced fluorescence (PLIF) experiments with a two-dimensional optical test bed to provide insight into the flame dynamics in the secondary combustion zone and data to validate the CFD model; Design, development and field testing of a market ready TLUD prototype. Over 180 tests of 40 different configurations of the modular TLUD test bed were performed to demonstrate how stove design, fuel properties and operating mode influences performance, and the conditions under which Tier 4 emissions are obtainable. Images of OH and acetone PLIF were collected at 10 kHz with the optical test bed. The modeling and experimental results informed the design of a TLUD prototype that met Tier 3 to Tier 4 specifications in emissions and Tier 2 in efficiency. The final prototype was field tested in India.

09 BIOMASS FUELS↗

Analysis of Supply Chains and Advanced Manufacturing of Small Hydropower Systems

Clean energy manufacturing is a sector of increasing importance both in the United States and worldwide. In the United States, it has been presented as an engine for job creation in a sector of the U.S. economy that was hit hard by the 2008-2009 recession. The Clean Energy Manufacturing Analysis Center (CEMAC), sponsored by the U.S. Department of Energy (DOE), conducts credible, objective, industry-relevant, recurring, and consistent analyses of clean energy technologies. In this project, the National Renewable Energy Laboratory (NREL) and the Oak Ridge National Laboratory (ORNL) collaborated in a hydropower manufacturing and supply chain analysis primarily for U.S. small hydropower (SHP) market to provide insights on supply chain constraints, manufacturing cost, location factors, and opportunities for hydropower using advanced manufacturing technologies. The goal of the project is to improve understanding of the manufacturing opportunities in the U.S. hydropower supply chain, specific competitive advantages, and factors for manufacturing location decisions for SHP. These insights could be used to inform investment and research strategies, policy, and other decisions that could promote economic growth and strengthen U.S. manufacturing capabilities. The project scope included a design for manufacturing and assembly (DFMA) costs analysis and a levelized cost of electricity (LCOE) sensitivity analysis of modular, representative SHP turbines. A representative SHP system was chosen to be made up of two 5 megawatt (MW) turbines, as these Kaplan style turbines could be useable for many non-powered dams (NPDs) across the U.S. The sensitivity analysis used the Integrated Design and Assessment (IDEA) tool, which has helped highlight the impact of the turbine equipment cost on the potential capital expenditure (CAPEX) and LCOE of the installed, representative system. In addition, the project team analyzed international tradeflows (e.g., export and import of hydropower turbines and the parts used in hydropower systems). As part of this project, hydropower stakeholder interviews were undertaken to help identify insights related to hydropower manufacturing opportunities for U.S. players in SHP, the country-specific manufacturing advantages in the United States and threats, and key factors behind manufacturing location decisions made by the SHP industry. Key opportunities for the US SHP market and industry include: Foreign export markets such as Chile, China, Columbia, India and Japan, have an estimated 71,795 MW of technical potential that could be serviced with SHP installations. Utilization of existing manufacturing capacity and expertise, along with economies of scale benefits, could result in increased global competitiveness through lower investment requirements and component costs, which could lead to increased U.S. strength in the export of SHP systems and components. Technology advances such as modular turbine designs, standardized units for conduit systems, precast systems, and improved powertrain technologies could help reduce costs, particularly for manufacturing a small number of units. The DOE is also exploring modular hydropower designs, which would integrate standard independently-produced components, validated to meet multiple specifications. Using modules in product design simplifies manufacturing activities such as inspection, testing, assembly, and purchasing, may increase economies of scale to lower total system cost. There are significant opportunities for the use of composites and Additive Manufacturing (AM) for hydropower components, when design changes are made to hydropower systems. By taking advantage of the corrosion resistance, light-weighting and structural benefits, composites and AM could help significantly alter hydropower structures and installations.

13 HYDRO ENERGY↗

Climate impact of a regional nuclear weapons exchange: Initial consideration of the Indian and East Asian Summer Monsoon

In Reisner et al. [2017] we reconsider the potential impact of a nuclear exchange between Pakistan and India on global climate, improving upon the result of Mills et al. [2014] with the inclusion of more realistic vertical distribution of black carbon. The change in global precipitation was found to be modest, as shown here in Figure 1. In this note, we examine the impacts on rainfall in somewhat more detail, examining changes in several of the great regional monsoons.

54 ENVIRONMENTAL SCIENCES↗

Impact of clays on the compressibility and permeability of sands during methane extraction from gas hydrate

Background: The quantity of methane potentially recoverable from gas hydrate is large enough to motivate federally-supported production tests in several countries, which in turn motivates studies of reservoir production efficiency. Evaluating long-term production well viability involves modeling permeability evolution in the reservoir sediments around the production well because processes reducing the flow of gas into the production well also reduce the long-term economic viability of the well. Fine particles, such as clays, exist nearly ubiquitously in the permafrost and marine settings that typically host gas hydrate, and fines reacting to fluid flow by migrating and clogging pore throats can reduce flow toward the production well. Many fines are sensitive to variations in pore-fluid chemistry, swelling in reaction to in situ pore brine being displaced by fresh water liberated from hydrates during dissociation. Additionally, fine particles tend to collect at gas/water interfaces created by the multiphase flow of gas and water. Thus, as methane and fresh water flow from the hydrate-dissociation front toward the production well, fine particles in the reservoir sands, interbedded fine-grained layers and seal layers can be swelled, migrated (or both), potentially clogging pathways and limiting flow to the production well. Objective: This project provides a quantitative basis for reservoir models to account for the impact of clays and other fine-grained material (“fines”) on reservoir compressibility and permeability, two key factors controlling the flow of gas and fluids toward a production well. This overall objective is addressed through a combination of site-specific and more generalized, fundamental science goals: Site-specific measurement goals: quantify the change in compressibility and permeability due to the reaction of fines to pore-water freshening in sediment collected during gas hydrates research expeditions (2010 UBGH2 expedition offshore eastern Korea; 2015 NGHP-02 expedition offshore eastern India). Fundamental measurements on pure fines goal: distinguish between, and quantify, mechanisms for sediment compressibility and permeability change due to physical and chemical responses of fines to the flow of freshened pore water and gas: 1) Chemical response: quantify and catalog the sensitivity of pure fines (fines with only a single component, or “endmember” fines) to pore-water chemistry, and 2) Physical response: quantify the link between fines migration and clogging during single and multiphase flow.

03 NATURAL GAS↗

Online mapping and forecasting of epidemics using open-source indicators

Open-source indicators have been proposed as a way of tracking and forecasting disease outbreaks. Some, such are meteorological data, are readily available as reanalysis products. Others, such as those derived from our online behavior (web searches, media article etc.) are gathered easily and are more timely than public health reporting. In this study we investigate how these datastreams may be combined to provide useful epidemiological information. The investigation is performed by building data assimilation systems to track influenza in California and dengue in India. The first does not suffer from incomplete data and was chosen to explore disease modeling needs. The second explores the case when observational data is sparse and disease modeling complexities are beside the point. The two test cases are for opposite ends of the disease tracking spectrum. We find that data assimilation systems that produce disease activity maps can be constructed. Further, being able to combine multiple open-source datastreams is a necessity as any one individually is not very informative. The data assimilation systems have very little in common except that they contain disease models, calibration algorithms and some ability to impute missing data. Thus while the data assimilation systems share the goal for accurate forecasting, they are practically designed to compensate for the shortcomings of the datastreams. Thus we expect them to be disease and location-specific.

42 ENGINEERING↗

XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019) (Final Report)

Supersymmetry (SUSY) is one of most elegant extensions of the Standard Model (SM) and explains the puzzles of the SM by providing a candidate to explain the dark matter content of the universe, allowing scientists to understand the origin of the electroweak scale requiring the top mass to be around 170 GeV and leading to the unification of forces at a grand unified scale. Further the minimal supersymmetric standard model (MSSM) predicts the Higgs boson mass to be less than 135 GeV. The discovery of the Higgs Boson with mass around 125 GeV at the LHC has provided a major support to SUSY ideas. Searches for SUSY are ongoing at the Large Hadron Collider (LHC). Direct and indirect dark matter experiments are searching for a particle dark matter candidate which arises most naturally in SUSY models. Proton decay predicted by SUSY grand unified theories is being searched for at deep underground experiments. In addition, recent advances in neutrino and dark matter physics, observational astrophysics, precision cosmology and the promising new window into the cosmos opened by the direct detection of gravitational waves, have brought new ideas on the potential connections between new fundamental particles and our understanding of their impact on the early universe and its evolution. At present, the major questions include: Is SUSY still the best candidate for models beyond the SM? Do we have any well motivated alternative to SUSY? Have we exhausted all possibilities to search for new physics at high and low energy scales? XXVIIth International Conference on Supersymmetry and Unification of Fundamental Interactions (SUSY 2019), hosted by Texas A&M University – Corpus Christi during May 20-24, 2019, provided a unique venue to discus and understand the status of SUSY, connection between particle physics and cosmology, supersymmetry and its alternative, Higgs sector, neutrino sector, flavor sector, dark matter, electroweak phase transition, astroparticle physics, gravitational waves and string theory. Discussion of results from the LHC, recent neutrino experiments and observations, direct and indirect dark matter detection experiments, detection of gravitational waves, data from particle colliders, as well as measurements of the CMB and Large Scale Structure were an integral part of SUSY 2019. To ensure the younger participants will benefit from the conference the most, the conference was preceded by the 4 day long pre-SUSY summer school for graduate students and postdocs. The invited speakers were leading scientists in the fields of SUSY interest. The school took place on Texas A&M University – Corpus Christi campus during the week prior the SUSY 2019 conference (May 15 – 18, 2019). Since its inception in 1993, SUSY has become one of the most important and widely attended international meetings in high energy physics, devoted to new ideas in fundamental particle physics. SUSY 2019 brought together approximately 250 scientists, theorists, phenomenologists, experimentalists and cosmologists, (including over 60 graduate students and 70 postdocs) representing 22 nations: Australia, Belgium, Canada, Chile, China, Colombia, France, Germany, India, Italy, Japan, Mexico, Peru, Portugal, Romania, South Korea, Spain, Sweden, Switzerland, Taiwan, United Kingdom and United States. SUSY 2019 provided a stimulating venue for the exchange of scientific ideas among experts in dark matter, neutrino physics, particle physics, astrophysics and cosmology. The following scientific topics were delivered during SUSY 2019 in form of 44 plenary talks and over 200 parallel talks: Unification of Forces; Electroweak, Top and Higgs Physics; Precision Calculations and MC tools; BSM in Flavor Physics; Neutrino Masses: Models and Phenomenology; Cosmology and Gravitational Waves; Dark Matter, Astroparticle Physics; Formal Field Theory and Strings; Alternatives to Supersymmetry; Quantum Information: Machine Learning/Big Data. 28 talks were given during the pre-SUSY program related to the following topics: Neutrino Physics; Big Data; Collider Physics & SUSY; String Phenomenology; Cosmology; Dark Matter; SUSY Models and Phenomenology

43 PARTICLE ACCELERATORS↗

Energy Information Systems: From the Basement to the Boardroom

A significant buildings energy reduction opportunity exists in the office sector, given that this market segment typically is an early adopter of new technology. There is a rising trend towards smart and connected offices through the internet of things (IoT) that provides new opportunities for operational efficiency and environmental sustainability practices. Leading commercial real estate companies have begun to shift from individual building automation systems (BAS) to partially integrated and automated systems such as energy information systems (EIS). In both the United States and India, organizations are seeking operational excellence, enhanced tenant relationships, and topline growth. Hence it is imperative to engage the executives with decision-making power, by tapping into their interest in sustainability, corporate social responsibility, and innovation. This expansion of interest can enable data-driven decisions, strong energy investments, and deeper energy benefits, and would drive innovation in this field. However, none of this would be possible without robust, consistent building energy information to provide visibility across all the levels of decision making, i.e. from the basement where the facilities staff take operational action to the boardroom where the executives make investment decisions. Price, security, and ease of use remain barriers to the adoption and pervasive use of promising EIS technologies in commercial office buildings. We believe that these barriers can be addressed through the development of ready, simplified, consistent, commercially available, low-cost EIS-in-a-box packages, that have a pre-defined set of hardware components and software features and functionality that are pertinent to a particular building sector. These simplified, sector-specific EIS packages can help to obviate the need for customization, and enhance ease of use, thereby enabling scale-up, in order to facilitate building energy savings. The EIS-in-a-box are adaptable in both U.S. and Indian office buildings, and potentially beyond these two countries.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

Regulatory Foundations for Cross-Border Electricity Trading: Nepal

Cross-border electricity trading (CBET) can reduce costs, improve reliability, and reduce emissions for all participating countries. Regulatory coordination is essential to making CBET successful. For Nepal, expanding CBET mechanisms could help accelerate development of the country’s large hydroelectric potential, especially if Nepal, India, and Bangladesh were parties to a comprehensive CBET framework. This report maps the regulatory issues Nepal might address if it elects to develop a national strategy for CBET with its neighbors in South Asia.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

AMS / BARC Joint Survey (Summary Report)

Report describes a series of joint aerial radiation survey flights at various locations in Southern Nevada and Colorado performed by AMS and BARC (U.S. and India). The flights were conducted over areas of well-characterized natural background in Nevada, at the Large-Area Calibration Pads at Grand Junction, CO, and over real ground contamination at the Nevada National Security Site. The intention of the joint surveys was to compare the responses, processes, and procedures of each country’s aerial radiation detection system. These systems can detect and map ground contamination that may result from a nuclear or radiological accident or incident, and play a significant role in the national radiological emergency response capabilities of both countries.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

Enhancement of Optical Efficiency of CSP Mirrors for Reducing O&M Cost via Near-Continuous Operation of Self-Cleaning Electrodynamic Screens (EDS). Final Report

Over the past decade, techno-economical advancements in solar energy systems, particularly the improvement in the conversion efficiency of PV modules made with mono-crystalline silicon solar cells from 12% to 20%, as well as the cost reduction in manufacturing by a factor of about 10%, have made it possible to achieve a levelized cost of electricity (LCOE) in PV plants that is comparable to, or less than, the cost of deriving electricity from fossil fuels. Operating PV plants in mid-latitude sun-belt regions, where the solar irradiance level is highest, provides a high annual energy-yield (kWh/kWp) due to two factors: (1) the availability of predictable high solar irradiance throughout the year with the fewest interruptions in solar flux from clouds and rain, and (2) the increased conversion efficiency of crystalline solar cells, as recombination loss has decreased with increased intensity of the sunlight that illuminates the silicon solar cells. Semi-arid and desert regions, however, are plagued by high atmospheric dust concentrations and frequent sand storms. The deposition of a layer of dust on the optical surfaces of solar collectors such as PV modules and concentrating mirrors reduces the transmission efficiency of sunlight that actually reaches the solar cells or receivers, resulting in high energy-yield soiling loss. There are two major cost components to operating a solar plant: (1) installation costs, and (2) operation-and-maintenance (O&M) costs. There is no fuel cost; hence operating a solar plant in a semi-arid or desert region provides high returns on investment if soiling losses are mitigated via efficient cleaning methods and optimized cleaning frequency. If solar collectors are not cleaned, the accumulation of dust layers on solar collectors may cause the operation of such plants in arid regions to become economically unviable. Washing solar collectors with water and detergent, as is most commonly done now, is an efficient method for cleaning. The conventional approach in utility-scale solar plants is to use a large truck with a water tank and pump system for spraying deionized water on the surface of the solar collectors. Robotic cleaning with brushes, used for many solar plants, requires lesser water for cleaning. The water consumed using semi-automated cleaning of PV modules in utility-scale solar plants is approximately 2 liters/m 2 per cleaning cycle. The total optical surface area of the solar collectors in 1 TW-scale solar installation will be more than 3 × 109 m 2 ; hence an enormous amount of water be needed for cleaning. There simply is not enough fresh water in the sun-belt areas of the world for predicted cleaning needs. In solar power plants, the estimated cost of cleaning solar collectors includes expenses related to the equipment used, labor, cost of transportation of water, the energy required for cleaning, plus ancillary costs whereas the cost of water is not considered. The water used is obtained from sources located close to plant sites, unmindful of the environmental and societal impact as the power plants are oftentimes located in regions that face severe drought. This practice is very similar to the cost calculations in deriving the levelized cost of electricity (LCOE) in conventional power plants based on burning fossil fuel such as coal and gas, while disregarding the cost of climate change and health effects. Unless a water-free or low-water cleaning method is established, the expansion of solar plants may lose public support in areas suffering long intervals of drought. The goal of this research project has been the development and application of the Electrodynamic Screen (EDS) as a means for a water-free, scalable cleaning process applicable to solar-power installations, including rooftop applications. We describe here the development of an EDS film-based cleaning process as an emerging method for use on PV modules, parabolic troughs, and heliostats. This report aims to show the feasibility of integrating or retrofitting EDS films onto the optical surfaces of solar collectors (both PV and CSP) while maintaining high transmission or reflection efficiency. The cleaning action provided by the EDS film is an active method to remove dust deposits by electrodynamic force. Current lab-scale prototype EDS films, retrofitted onto solar panels and mirrors, have shown to be capable of maintaining optical transmission or specular-reflection efficiencies higher than 90% of initial values under clean conditions. The optical surfaces of solar collectors laminated with EDS films can remove more than 90% of deposited dust when the EDS is activated for less than two minutes. As an electrodynamic dust removal process, the EDS film-based method is designed primarily for the removal of dust in solar installations located in semi-arid and desert areas, where the atmosphere is often dry and dusty and rainfall is infrequent. While EDS film application minimizes water consumption and facilitates cleaning as frequently as needed, it has limitations in removing contaminants such as soot, organic pollutants deposited as fine films on the surface, and bird droppings. The dust removal efficiency of the EDS is maximum at relative humidity RH is 40 to 50% and decreases at when RH > 65%. Many solar plant sites undergo diurnal and seasonal cycles of high ambient, early afternoon temperatures and an RH that reaches the dew point early in the morning. These variations in atmospheric conditions do not limit the operation of the EDS film. This report presents a brief review of the progress and the potential of EDS film technology for mitigating the impact of dust on solar collectors via water-free cleaning, as well as current technical challenges regarding efficiency and durability. Our experimental data on the performance of EDS films show that: (1) the dust-removal efficiency (DRE) can reach levels higher than 90%, (2) the specular reflectivity (SR) of EDS film-laminated second-surface mirrors reach levels in excess of 90%, (3) the specular reflectivity restoration (SRR) can exceed 90%, (4) the output-power restoration (OPR) of PV modules can exceed 95%, and (5) the optical transmission efficiency (TE) of the EDS films can be greater than 90%. Working with Sandia National Laboratories (NM), Corning Research and Development Corporation (NY), Eastman Kodak (NY), Tomark-Worthen Industries (NH), and EDS Chile SPA (Chile), we have produced EDS film-laminated PV modules and demonstrated their self-cleaning functions without requiring water. We have demonstrated that the operational range of EDS films will cover the expected ambient temperature of solar fields at RH cycling varying from 20 to 95% as long as the EDS films are activated in the RH range 20 to 50%. (Typical solar-field climates in deserts and semi-arid lands often reach near dew point in coastal areas.) Our experiments on the application of hydrophobic-fluorinated nanoparticle coatings on EDS film surfaces show that the EDS operational range can be extended to higher RH levels that approach the dew point. At Eastman Kodak, as one of our industrial partners, we were able to establish a process for manufacturing EDS films using flexographic printing of the electrodes onto transparent polymer films. This process utilizes an existing manufacturing line at Eastman Kodak that allows fabrication of medium-scale EDS films (26 cm × 30 cm). The manufacturing process has the capacity to produce EDS films at high production speeds. The medium-scale EDS films that have been printed at Kodak were evaluated in the lab at Boston University. The EDS films produced at Kodak were laminated at Tomark-Worthen using an industrial scale vacuum laminator to produce EDS film stacks, which can be affixed onto the optical surfaces of PV modules or concentrating mirrors. The EDS film stack consists of the EDS films that have Willow® Glass (WG) which has a thickness of 100 μm as the front surface. The WG sheets obtained from Corning Research and Development Corporation are customized in size and shape to cover the active area of the EDS films. The back surface of the EDS film stack is integrated onto the optical surface of the solar panel or mirror using optically clear adhesive (OCA) films or silicone adhesives. The OCA films (thickness 25 μm) are produced by 3M. The EDS film stacks have the architecture: WG/OCA/EDS Film/OCA/ over PV module or solar mirror. The power-supply units needed for activating the electrodes of the EDS film were designed and produced at Boston University. These power supply units provide three-phase, 1.2 kV voltage pulses at a very low current (micro-ampere) level and at a low frequency (≈ 5 Hz). The voltage pulses are applied to the electrodes in a sequence such that the train of pulses resembles a unidirectional traveling wave of electrical field on the surface of the EDS film. The dust particles on the surface become charged electrostatically and are levitated by the Coulomb force. The lateral sweeping action of the traveling electric field created by the three-phase voltages pulses then sweeps the dust off the surface. The energy consumed by the EDS electrodes is less than 0.2 Wh/m 2 /cleaning cycle, enabling energy-efficient restoration of output power (OPR) of PV module or specular reflectivity restoration (SRR) for solar mirrors. The EDS system consists of (1) an EDS film stack laminated onto the solar collectors, (2) connection of the EDS film to its power supply unit and (3) Interconnection of the power supply to PV modules or solar mirrors. Design, construction and assessment of field-testing units that have EDS stack laminated PV modules for evaluating the performance of the EDS films in solar fields is being carried out at BU. Our progress under this project, aimed at the advancement of EDS film technology, has reached DOE Technology Readiness Level (TRL) 6. Based on the extensive laboratory evaluations and limited field trials, as well as contacts with potential users, we believe that the technology has reached its commercial stage. We are conducting a cost analysis using the National Renewable Energy Laboratory (NREL) System Advisory Model (SAM) and are preparing for field trials of EDS films in different solar fields in the US, Chile, India and in the Middle East. A brief description of EDS film performance, construction and testing of the field-test unit, autonomous operation of the field-test unit for evaluating EDS performance in increasing energy yield, associated revenue savings, and water conservation is presented.

14 SOLAR ENERGY↗