Search NASA⌕ Search

SEARCH · Search NASA

Results for “Capacity Factor”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,729 records · Page 96
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Bench-Scale Development of a Novel Direct Air Capture Technology Using High-Capacity Structured Sorbents

The work performed under this project has resulted into development of a DAC technology utilizing a structured sorbent to capture CO 2 from ambient air with a key innovation of direct Joule heating of the sorbent for CO 2 desorption. A working SMA, fully integrated with an electrically resistive heating layer, high surface area support, and high CO 2 capacity sorbent coated onto a commercial ceramic monolithic substrate, was successfully developed and demonstrated over >200 adsorption-desorption cycles in a high-fidelity bench test unit directly using ambient air. A cordierite-based monolith was selected as a substrate owing to its high surface area, low bulk density, low heat capacity, and commercial availability. Reaction kinetics study conducted during this project led to development of a promoter for the base Na 2 CO 3 sorbent that could be incorporated into the sorbent to enhance to achieve higher CO 2 adsorption/desorption rates, greater working capacity, and reduced regeneration temperature. An accelerated aging study was conducted in a TGA to determine sorbent stability and no degradation in the sorbent performance was observed even after 250 adsorption-desorption cycles. An electrically resistive heating layer was developed with tunable electrical properties. The heating layer was coated onto the selected cordierite substrate. Aging studies performed showed the electrical properties and heating performance was stable after 500 heating and cooling cycles. The collective findings on the selected cordierite substrate, robust heating layer, promoter and sorbent selection were used to synthesize a full, 6”x6” SMA for bench-scale testing. The bench-scale DAC system was constructed to test full size SMAs using real ambient air for adsorption and joule heating for regeneration. After completing shakedown and commissioning of the 1 kg/day of CO 2 capacity DAC bench unit, an extended operation was performed to complete over 230 cycles with the full size SMA. This testing showed no observable degradation in sorbent performance. A detailed process model, TEA and LCA were developed for a conceptual 100,000 TPY CO 2 removal DAC facility. The LCA results show the net CO 2 e emissions from the DAC system are highly dependent on the electricity source. All other factors, including SMA manufacturing, materials for facility enclosure, etc., are minor cost contributors compared to the energy consumption required for CO 2 removal. With the successful development and validation of the SMA for the sustained performance for CO 2 removal from ambient air with joule heated regeneration in this project, a fully integrated 1 TPY bench-scale DAC system is currently in development with the support of DOE/FECM (DE-FE0032243). The project objective is to demonstrate the engineering design of the DAC system to produce a continuous, high purity CO 2 stream from ambient air. This project will address and validate key engineering features of the DAC system including the gas sealing mechanism and panels, enclosure and air contactor design, and automation sequence to achieve continuous CO 2 production.

42 ENGINEERING↗
NASA NTRS1980

Energy potential and early operational experience for large wind turbines

Projections for the total potential output of large wind turbines in the U.S. are reviewed. NASA has developed nine large windpowered generators, of 100 kW, 200 kW, 2 MW, and 2.5 MW capacities, with rotors 100-300 ft in diameter, and all with horizontal axes. Approximately 214,000 sq miles of the U.S. have been determined as having substantial wind regimes and terrain suitable for large wind turbine siting. This translates into 340,000 Mod 2 (2.5 MW) wind turbines producing 4.9 quads of electricity annually, equivalent to saving 2.5 billion barrels of oil/yr. The cost of electricity is seen as the critical factor in utility acceptance of large wind turbines, and the Mod 2 machines are noted to achieve the 2-4 cents/kWh (1977 dollars) COE which is necessary. Problems such as pollution, including visual, auditory, EM, and land use difficulties are considered, and solutions are indicated.

Robbins, W. H.↗
NASA NTRS1997

Design and Operational Evaluation of the Traffic Management Advisor at the Ft. Worth Air Route Traffic Control Center

NASA and the FAA have designed and developed and an automation tool known as the Traffic Management Advisor (TMA). The system was operationally evaluated at the Ft. Worth Air Route Traffic Control Center (ARTCC). The TMA is a time-based strategic planning tool that provides Traffic Management Coordinators and En Route Air Traffic Controllers the ability to efficiently optimize the capacity of a demand impacted airport. The TMA consists of trajectory prediction, constraint-based runway scheduling, traffic flow visualization and controllers advisories. The TMA was used and operationally evaluated for forty-one rush traffic periods during a one month period in the Summer of 1996. The evaluations included all shifts of air traffic operations as well as periods of inclement weather. Performance data was collected for engineering and human factor analysis and compared with similar operations without the TMA. The engineering data indicates that the operations with the TMA show a one to two minute per aircraft delay reduction during rush periods. The human factor data indicate a perceived reduction in en route controller workload as well as an increase in job satisfaction. Upon completion of the evaluation, the TMA has become part of the normal operations at the Ft. Worth ARTCC.

Swenson, Harry N.↗
NASA NTRS2017

Structural Health Management of Damaged Aircraft Structures Using the Digital Twin Concept

The development of multidisciplinary integrated Structural Health Management (SHM) tools will enable accurate detection, and prognosis of damaged aircraft under normal and adverse conditions during flight. As part of the digital twin concept, methodologies are developed by using integrated multiphysics models, sensor information and input data from an in-service vehicle to mirror and predict the life of its corresponding physical twin. SHM tools are necessary for both damage diagnostics and prognostics for continued safe operation of damaged aircraft structures. The adverse conditions include loss of control caused by environmental factors, actuator and sensor faults or failures, and structural damage conditions. A major concern in these structures is the growth of undetected damage/cracks due to fatigue and low velocity foreign object impact that can reach a critical size during flight, resulting in loss of control of the aircraft. To avoid unstable, catastrophic propagation of damage during a flight, load levels must be maintained that are below a reduced load-carrying capacity for continued safe operation of an aircraft. Hence, a capability is needed for accurate real-time predictions of damage size and safe load carrying capacity for structures with complex damage configurations. In the present work, a procedure is developed that uses guided wave responses to interrogate damage. As the guided wave interacts with damage, the signal attenuates in some directions and reflects in others. This results in a difference in signal magnitude as well as phase shifts between signal responses for damaged and undamaged structures. Accurate estimation of damage size, location, and orientation is made by evaluating the cumulative signal responses at various pre-selected sensor locations using a genetic algorithm (GA) based optimization procedure. The damage size, location, and orientation is obtained by minimizing the difference between the reference responses and the responses obtained by wave propagation finite element analysis of different representative cracks, geometries, and sizes.

Seshadri, Banavara R.↗
NASA NTRS2001

Long-term insulin-like growth factor-I expression in skeletal muscles attenuates the enhanced in vitro proliferation ability of the resident satellite cells in transgenic mice

Insulin-like growth factor-I (IGF-I) overexpression for 1-month in mouse skeletal muscle increases satellite cell proliferation potential. However, it is unknown whether this beneficial enhancement by IGF-I expression would persist over a longer-term duration in aged mice. This is an important issue to address if a prolonged course of IGF-I is to be used clinically in muscle-wasting conditions where satellite cells may become limiting. Using the IGF-I transgenic (IGF-I Tg) mouse that selectively expresses the IGF-I transgene in striated muscles, we found that 18-months of continuous IGF-I overexpression led to a loss in the enhanced in vitro proliferative capacity of satellite cells from Tg skeletal muscles. Also 18-month-old IGF-I Tg satellite cells lost the enhanced BrdU incorporation, greater pRb and Akt phosphorylations, and decreased p27(Kip1) levels initially observed in cells from 1-month-old IGF-I Tg mice. The levels of those biochemical markers reverted to similar values seen in the 18-months WT littermates. These findings, therefore, suggest that there is no further beneficial effect on enhancing satellite cell proliferation ability with persistent long-term expression of IGF-I in skeletal muscles of these transgenic mice.

Non-NASA Center↗
DOE OSTI2020

Intricate Genetic Programs Controlling Dormancy in Mycobacterium tuberculosis

Mycobacterium tuberculosis (MTB) displays the remarkable ability to transition in and out of dormancy, a hallmark of the pathogen’s capacity to evade the immune system and exploit susceptible individuals. Uncovering the gene regulatory programs that underlie the phenotypic shifts in MTB during disease latency and reactivation has posed a challenge. We develop an experimental system to precisely control dissolved oxygen levels in MTB cultures in order to capture the transcriptional events that unfold as MTB transitions into and out of hypoxia-induced dormancy. Using a comprehensive genome-wide transcription factor binding map and insights from network topology analysis, we identify regulatory circuits that deterministically drive sequential transitions across six transcriptionally and functionally distinct states encompassing more than three-fifths of the MTB genome. The architecture of the genetic programs explains the transcriptional dynamics underlying synchronous entry of cells into a dormant state that is primed to infect the host upon encountering favorable conditions.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2018

Cerium dioxide (CeO2) nanoparticles decrease arsenite (As(III)) cytotoxicity to 16HBE14o- human bronchial epithelial cells

Highlights: • CeO{sub 2} NPs display a high adsorption capacity for As(III). • As(III) is highly toxic to lung 16HBE14o- cells (81% inhibition at 0.5 mg As/L). • As(III) adsorption onto CeO{sub 2} NPs decreased As(III) cytotoxicity on 16HBE14o- cells. • Cell uptake of As(III)-loaded CeO{sub 2} NPs did not lead to enhanced cytotoxicity. The production and application of engineered nanoparticles (NPs) are increasing in demand with the rapid development of nanotechnology. However, there are concerns that some of these novel materials could lead to emerging environmental and health problems. Some NPs are able to facilitate the transport of contaminants into cells/organisms via a “Trojan Horse” effect which enhances the toxicity of the adsorbed materials. In this work, we evaluated the toxicity of arsenite (As(III)) adsorbed onto cerium dioxide (CeO{sub 2}) NPs to human bronchial epithelial cells (16HBE14o-) using the xCELLigence real time cell analyzing system (RTCA). Application of 0.5 mg/L As(III) resulted in 81.3% reduction of cell index (CI, an RTCA measure of cell toxicity) over 48 h when compared to control cells exposed to medium lacking As(III). However, when the cells were exposed to 0.5 mg/L As(III) in the presence of CeO{sub 2} NPs (250 mg/L), the CI was only reduced by 12.9% compared to the control. The CeO{sub 2} NPs had a high capacity for As(III) adsorption (20.2 mg/g CeO{sub 2}) in the bioassay medium, effectively reducing dissolved As(III) in the aqueous solution and resulting in reduced toxicity. Transmission electron microscopy was used to study the transport of CeO{sub 2} NPs into 16HBE14o- cells. NP uptake via engulfment was observed and the internalized NPs accumulated in vesicles. The results demonstrate that dissolved As(III) in the aqueous solution was the decisive factor controlling As(III) toxicity of 16HBE14o- cells, and that CeO{sub 2} NPs effectively reduced available As(III) through adsorption. These data emphasize the evaluation of mixtures when assaying toxicity.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2013

Study on glass-forming ability and hydrogen storage properties of amorphous Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0, 4) alloys

Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0, 4) amorphous alloys were prepared by rapid solidification, using a melt-spinning technique. X-ray diffraction and differential scanning calorimetry analysis were employed to measure their microstructure, thermal stability and glass-forming ability, and hydrogen storage properties were studied by means of PCTPro2000. Based on differential scanning calorimetry results, their glass-forming ability and thermal stability were investigated by Kissinger method, Lasocka curves and atomic cluster model, respectively. The results indicate that glass-forming ability, thermal properties and hydrogen storage properties in the Mg-rich corner of Mg–Ni–La–Co system alloys were enhanced by Co substitution for La. It can be found that the smaller activation energy (ΔΕ) and frequency factor (υ{sub 0}), the bigger value of B (glass transition point in Lasocka curves), and higher glass-forming ability of Mg–Ni–La–Co alloys would be followed. In addition, atomic structure parameter (λ), deduced from atomic cluster model is valuable in the design of Mg–Ni–La–Co system alloys with good glass-forming ability. With an increase of Co content from 0 to 4, the hydrogen desorption capacity within 4000 s rises from 2.25 to 2.85 wt.% at 573 K. - Highlights: • Amorphous Mg{sub 60}Ni{sub 30}La{sub 10−x}Co{sub x} (x = 0 and 4) alloys were produced by melt spinning. • The GFA and hydrogen storage properties were enhanced by Co substitution for La. • With an increase of Co content, the hydrogen desorption capacity rises at 573 K.

36 MATERIALS SCIENCE↗
DOE OSTI2019

Pathways for practical high-energy long-cycling lithium metal batteries

Lithium (Li)-ion batteries play a critical role in modern day technologies, but their specific energy (Wh kg-1) and energy density (Wh L-1) are approaching the maximum practically achievable values based on existing manufacturing processes with the conventional cathode and anode materials. Developing the next generation rechargeable batteries with a specific energy higher than 300 Wh kg-1, up to 500 Wh kg-1, is a significant challenge. This paper discusses the pathways to build the next generation 500 Wh kg-1 rechargeable Li battery based on Li metal anode and a high nickel-content lithium nickel-manganese-cobalt oxide (high-Ni NMC) cathode. The fundamental requirements and practical technical approaches will be explored to hopefully address this grand challenge. In particular, we discuss the detailed cell level requirements and parameters to achieve high energy density, as well as the significant scientific challenges and potential solutions, including but not limited to enable the direct utilization of Li metal anode with high efficiency and long-term cycling stability, dendrite-free Li metal deposition, high utilization of the cathode materials with high mass loading and reasonable electrode thickness along with minimum parasitic weight in the cathode side. The cell level understanding and validation of the materials properties for high performance and control of interfacial reactions across the whole cell will be explored. New concepts in emerging multifunctional materials and electrolytes/additives and their implications will also be discussed.

lithium metal anode, lithium nickel manganese coba↗
NASA NTRS1990

Life sciences research using a lunar laboratory

The necessity for life sciences research on the lunar surface in order to determine the consequences of returning from extended missions in various low gravity environments and of transiting through high multiple gravity forces during decelerations is discussed. The functions of a lunar gravitational biology laboratory are outlined. Lunar science objectives include investigations in developmental biology including the evaluation of the capacity of diverse organisms to undergo normal development and the evaluation of the use of the lunar environment to study specific developmental phenomena in ways that cannot be accomplished by earth-based research. The need for musculoskeletal studies to examine the dynamics of osteoclast and osteoblast formation and breakdown and to address bone and demineralization problems is discussed. Biological adaptation to hypogravic environments and the effects of radiation and electromagnetic environmental factors are also considered.

Cipriano, Leonard F.↗
DOE OSTI2016

Transient performance of accident tolerant fuel in design basis accidents

A set of transient analysis has been performed to assess the performance of candidate accident tolerant fuel (ATF) against reference UO{sub 2} fuel with Zircaloy cladding under design basis accident (DBA) conditions. This study examined two ATF options, U{sub 3}Si{sub 2} fuel with SiC cladding and UO{sub 2} fuel with APMT cladding. The accident analyses were conducted using the system code TRACE for a three-loop PWR plant. PARCS standalone full-core calculations were done for each fuel/cladding combination to provide inputs to the TRACE point-kinetics model. The design basis accidents analyzed were a reactivity insertion accident (RIA) and a large break loss-of-coolant accident (LBLOCA). The RIA was simulated by the insertion of a reactivity ramp of $1 (one dollar) in 0.1 s at hot full power (HFP) condition. The LBLOCA was a simulation of a double-ended pipe break in one of the cold legs of the primary loops. Differences in thermal responses of the fuel and the cladding are attributed to their thermal properties. The U{sub 3}Si{sub 2} fuel with its lower volumetric heat capacity and higher thermal conductivity (i.e. higher thermal diffusivity) generally results in a lower fuel temperature than the UO{sub 2} fuel and a correspondingly faster thermal response. Additional calculations for the U{sub 3}Si{sub 2} fuel shows that in a RIA the cladding material, SiC versus Zr, has little impact on the maximum fuel centerline temperature and the PCT (peak cladding temperature). An increase in the hot rod power factor is shown to raise the centerline fuel temperature in a RIA but has little impact on the PCT. The analysis results show that for a relatively fast decay heat driven transient, such as the LBLOCA, the thermal-hydraulics and fuel/cladding thermal properties dictate the overall response more so than the reactivity feedback. The results show that the PCTs in a LBLOCA are similar for all fuel/cladding combinations considered in this study. The LBLOCA analysis also notes the impact of the asymmetry in the system response. The fuel rods in the sector of the core connected to the hot leg of the broken loop (Sector 1 in the PWR model) is shown to have a much lower PCT than fuel rods in the other five sectors of the core. Results of this study indicate that for the two DBAs considered (RIA and LBLOCA) the transient behavior and the resulting peak cladding temperature of the two ATF options (U{sub 3}Si{sub 2} fuel with SiC cladding and UO{sub 2} fuel with APMT cladding) are similar to the standard light-water reactor fuel (UO{sub 2} fuel with Zircaloy cladding). (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS1957

A Study of the "toss Factor" in the Impact Testing of Cermets by the Izod Pendulum Test

The test method presented shows that the "toss energy" contributed by the apparatus for brittle materials is negligible. The total toss energy is considered to consist of two components. (a) recovered stored elastic energy and (b) kinetic energy contributed directly by the apparatus. The results were verified by high-speed motion pictures of the test in operation. From these photographs, velocities of tossed specimens were obtained and toss energy computed. In addition, impact energies of some titanium carbide base cermets and high-temperature alloys, as measured by the low-capacity Izod pendulum test, compare well with impact energies measured by the NACA drop test.

ALLOYS, HEAT-RESISTING↗
DOE OSTI2015

The Doomsday Equation and 50 years beyond: new perspectives on the human‐water system

In 1960, von Foerster et al. humorously predicted an abrupt transition in human population growth to occur in the mid‐21st century. Their so‐called ‘Doomsday’ emerged from either progressive degradation of a finite resource or faster‐than‐exponential growth of an increasingly resource‐use efficient population, though what constitutes this resource was not made explicit. At present, few dispute the claim that water is the most fundamental resource to sustainable human population growth. Multiple lines of evidence demonstrate that the global water system exhibits nontrivial dynamics linked to similar patterns in population growth. Projections of the global water system range from a finite carrying capacity regulated by accessible freshwater, or ‘peak renewable water,’ to punctuated evolution with new supplies and improved efficiency gained from technological and social innovation. These projections can be captured, to first order, by a single delay differential equation with human–water interactions parameterized as a delay kernel that links present water supply to the population history and its impacts on water resources. This kernel is a macroscopic representation of social, environmental, and technological factors operating in the human‐water system; however, the mathematical form remains unconstrained by available data. A related model of log‐periodic, power‐law growth confirms that global water use evolves through repeated periods of rapid growth and stagnation, a pattern remarkably consistent with historical anecdotes. Together, these models suggest a possible regime shift leading to a new phase of water innovation in the mid‐21st century that arises from delayed feedback between population growth and development of water resources. WIREs Water 2015, 2:407–414. doi: 10.1002/wat2.1080 This article is categorized under: Engineering Water > Planning Water

Parolari, Anthony J.↗
DOE OSTI2025

National serosurvey and risk mapping reveal widespread distribution of Coxiella burnetii in Kenya

Coxiella burnetii, the causative agent of Q fever, is an emerging pathogen that has the potential to cause severe chronic infections in animals and humans worldwide. The detrimental impact on public health is projected to be higher in the low- and middle-income countries given their lower capacity to sustain effective surveillance and response measures. We implemented a national serosurvey of cattle in Kenya to map the spatial distribution of the pathogen. The study used serum samples that were collected from randomly selected cattle in different ago-ecological zones across the country. These samples were screened for the pathogen using PrioCHECK Ruminant Q Fever AB Plate ELISA kit. The laboratory findings were analyzed using INLA package to identify risk factors for C. burnetii exposure from herd- and animal-level factors, area, and bioclimatic datasets accessed from online databases. A total of 6,593 cattle were recruited for the study; of these, 7.9% (95% CI; 7.2–8.5) were seropositive. Outputs from the multivariable analysis revealed that the animal age and some of the geographical variables including wind speed, area under shrubs and “petric calcisols” type of soil were significantly associated with C. burnetii seropositivity. Being a calf, weaner or subadult was associated with lower odds of exposure compared to being an adult by 0.24 (credibility interval: 2.5% and 97.5%), 0.41 (0.30–0.55) and 0.51 (0.38–0.69), respectively. In addition, a unit increase in the wind speed increased the odds of C. burnetii seropositivity by 1.27 (1.05–1.52) while an increase on the land area under shrubs was associated with lower odds of exposure (0.67 [0.47–0.69]). The effect of petric calcisols was non-linear; an increase of the land area with this soil type was associated with an exponential increase in C. burnetii seropositivity. This study provides new data on C. burnetii seroprevalence, information of its risk factors and a prevalence map that can be used for C. burnetii risk surveillance and control. The identification of environmental risk factors for C. burnetii exposure, and the increasing awareness of the zoonotic potential of the pathogen, calls for the need to enhance the existing collaborations for the surveillance and control of C. burnetii in line with the One Health framework. The evidence generated on the potential role of environmental factors can also be used to design nature-based interventions, such as replacement of vegetation in denuded areas, to reduce potential for the aerosolization of the pathogen. Livestock vaccination in the hotspots would also reduce animal infections and hence the contamination of the environment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Geometric consideration of nanostructures for energy storage systems

Battery performance and its fade are determined by various aspects such as the transport of ions and electrons through heterogeneous internal structures; kinetic reactions at the interfaces; and the corresponding interplay between mechanical, chemical, and thermal responses. The fundamental factor determining this complex multiscale and multiphysical nature of a battery is the geometry of active materials. In this work, we systematically consider the tradeoffs among a selection of limiting geometries of media designed to store ions or other species via a diffusion process. Specifically, we begin the investigation by considering diffusion in spheres, rods, and plates at the particle level, in order to assess the effects of geometry, diffusivity, and rate on capacity. Then, the study is extended to considering of the volume fraction and particle network, as well as kinetics at the interface with electrolyte. Our study suggests that, in terms of overall bulk level material performance, thin film batteries may generate the highest energy density with high power capability when they are implemented at nanoscales or with highly diffusion materials.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

An experimentally validated electro-thermal EV battery pack model incorporating cycle-life aging and cell-to-cell variations

Lithium-ion batteries are used in a wide variety of applications. To meet the power and energy demands of these applications battery packs are composed of hundreds to thousands of cells. The electrical and thermal interactions between cells introduce additional complexity in the pack dynamics. To capture these effects, a battery pack model composed of 192 cells based on a first-generation (2012) Nissan Leaf battery pack is developed in MATLAB/Simulink/Simscape. Here, with this model, we simulate the electrical dynamics (using a first-order equivalent-circuit model), the thermal dynamics (using a first-order lumped-parameter thermal model), and the aging dynamics (using a semi-empirical severity factor-based model) of every cell in the pack and we also create a pack thermal model that explicitly captures the heat exchange between the modules, and the cells contained within, during operation. The models are calibrated and validated, both at the cell and pack level, with experimental data. Two different case studies of this pack model are investigated. In the first case study, an initial, normally-distributed, cell-to-cell capacity variation is introduced and its effect on the pack voltage and module temperatures is studied. In the second case study, we deliberately insert cells with lower than nominal capacity into the pack and we investigate how this type of initial cell-to-cell capacity variation affects the pack’s ability to deliver energy over time. Finally, we also study how parallel-connected cells can reduce the effects of cell-to-cell variations at the expense of increased aging of the pack overall.

25 ENERGY STORAGE↗
DOE OSTI2015

Impacts of Demand-Side Resources on Electric Transmission Planning

Will demand resources such as energy efficiency (EE), demand response (DR), and distributed generation (DG) have an impact on electricity transmission requirements? Five drivers for transmission expansion are discussed: interconnection, reliability, economics, replacement, and policy. With that background, we review the results of a set of transmission studies that were conducted between 2010 and 2013 by electricity regulators, industry representatives, and other stakeholders in the three physical interconnections within the United States. These broad-based studies were funded by the US Department of Energy and included scenarios of reduced load growth due to EE, DR, and DG. While the studies were independent and used different modeling tools and interconnect-specific assumptions, all provided valuable results and insights. However, some caveats exist. Demand resources were evaluated in conjunction with other factors, and limitations on transmission additions between scenarios made understanding the role of demand resources difficult. One study, the western study, included analyses over both 10- and 20-year planning horizons; the 10-year analysis did not show near-term reductions in transmission, but the 20-year indicated fewer transmission additions, yielding a 36percent capital cost reduction. In the eastern study the reductions in demand largely led to reductions in local generation capacity and an increased opportunity for low-cost and renewable generation to export to other regions. The Texas study evaluated generation changes due to demand, and is in the process of examining demand resource impacts on transmission.

99 GENERAL AND MISCELLANEOUS↗