Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “CALIFORNIA”

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 631 records · Page 35
All sourcesNASA NTRSDOE OSTI
NASA NTRS2014

Airborne In-Situ Trace Gas Measurements of Multiple Wildfires in California (2013-2014)

Biomass burning emissions are an important source of a wide range of trace gases and particles that can impact local, regional and global air quality, climate forcing, biogeochemical cycles and human health. In the western US, wildfires dominate over prescribed fires, contributing to atmospheric trace gas budgets and regional and local air pollution. Limited sampling of emissions from wildfires means western US emission estimates rely largely on data from prescribed fires, which may not be a suitable proxy for wildfire emissions.We report here in-situ measurements of carbon dioxide, methane, ozone and water vapor from the plumes of a variety of wildfires sampled in California in the fire seasons of 2013 and 2014. Included in the analysis are the Rim Fire (August October 2013, near Yosemite National Park), the Morgan Fire (September 2013, near Clayton, CA), and the El Portal Fire (July August 2014, in Yosemite National Park), among others. When possible, fires were sampled on multiple days.Emission ratios and estimated emission factors will be presented and discussed in the context of fuel composition, plume structure, and fire phase. Correlations of plume chemical composition to MODISVIIRS Fire Radiative Power (FRP) and other remote sensing information will be explored. Furthermore, the role of plumes in delivery of enhanced ozone concentrations to downwind municipalities will be discussed.

Gas↗
NASA NTRS2020

Ensemble-Based Deep Learning for Estimating PM2.5 over California with Multisource Big Data Including Wildfire Smoke

Estimating PM2.5 concentrations and their prediction uncertainties at a high spatiotemporal resolution is important for air pollution health effect studies. This is particularly challenging for California, which has high variability in natural (e.g. wildfires, dust) and anthropogenic emissions, meteorology, topography (e.g. desert surfaces, mountains, snow cover) and land use.

air quality↗
NASA NTRSDate not supplied

On-ground Live Fuel Moisture Content Sampling Along California’s Central Coast Santa Lucia Preserve - Carmel Valley, CA

The ratio of water to dry mass within live plants is an important factor when determining the severity and intensity of potential wildfires. Currently, live fuel moisture content (LFMC) samples support wildland fire management, but are limited in number and spatial extent. In Monterey County, the only LFMC data to analyze spatial and temporal trends is collected by CalFire and the Los Padres National Forest Unit of the United States Forest Service across five long-term sampling sites. Our project aims to enhance the spatial coverage of current LFMC data being collected across Monterey County. Here, we share results from the ongoing work to monitor LFMC across Carmel Valley, CA. We evaluate LFMC data by environmental factors such as slope, aspect, topography, and species composition. We also place our LFMC samples in relation to nearby long-term sampling locations. We conclude by interpreting spatial and temporal trends in the preliminary data and discuss logistical challenges of establishing more long-term LFMC sampling sites to better represent the complex topography and vegetation composition of Central California.

On-ground↗
DOE OSTI2011

Do Photovoltaic Energy Systems Effect Residential Selling Prices? Results from a California Statewide Investigation.

An increasing number of homes in the U.S. have sold with photovoltaic (PV) energy systems installed at the time of sale, yet relatively little research exists that provides estimates of the marginal impacts of those PV systems on home sale prices. This research analyzes a large dataset of California homes that sold from 2000 through mid-2009 with PV installed. We find strong evidence that homes with PV systems sold for a premium over comparable homes without PV systems during this time frame. Estimates for this premium expressed in dollars per watt of installed PV range, from roughly $4 to $6.4/watt across the full dataset, to approximately $2.3/watt for new homes, to more than $6/watt for existing homes. A number of ideas for further research are suggested.

14 SOLAR ENERGY↗
DOE OSTI2011

An Analysis of the Effects of Photovoltaic Energy Systems on Residential Selling Prices in California.

An increasing number of homes with existing photovoltaic (PV) energy systems have sold in the U.S., yet relatively little research exists that estimates the marginal impacts of those PV systems on the sales price. A clearer understanding of these effects might influence the decisions of homeowners, home buyers and PV home builders. This research analyzes a large dataset of California homes that sold from 2000 through mid-2009 with PV installed. Across a large number of hedonic and repeat sales model specifications and robustness tests, the analysis finds strong evidence that homes with PV systems sold for a premium over comparable homes without. The effects range, on average, from approximately $3.9 to $6.4 per installed watt (DC), with most models coalescing near $5.5/watt, which corresponds to a premium of approximately $17,000 for a 3,100 watt system. The research also shows that, as PV systems age, the premium enjoyed at the time of home sale decreases. Additionally, existing homes with PV systems are found to have commanded a larger sales price premium than new homes with similarly sized PV systems. Reasons for this discrepancy are suggested, yet further research is warranted in this area as well as a number of other areas that are highlighted.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2011

Demand Response Opportunities in Industrial Refrigerated Warehouses in California

Industrial refrigerated warehouses that implemented energy efficiency measures and have centralized control systems can be excellent candidates for Automated Demand Response (Auto-DR) due to equipment synergies, and receptivity of facility managers to strategies that control energy costs without disrupting facility operations. Auto-DR utilizes OpenADR protocol for continuous and open communication signals over internet, allowing facilities to automate their Demand Response (DR). Refrigerated warehouses were selected for research because: They have significant power demand especially during utility peak periods; most processes are not sensitive to short-term (2-4 hours) lower power and DR activities are often not disruptive to facility operations; the number of processes is limited and well understood; and past experience with some DR strategies successful in commercial buildings may apply to refrigerated warehouses. This paper presents an overview of the potential for load sheds and shifts from baseline electricity use in response to DR events, along with physical configurations and operating characteristics of refrigerated warehouses. Analysis of data from two case studies and nine facilities in Pacific Gas and Electric territory, confirmed the DR abilities inherent to refrigerated warehouses but showed significant variation across facilities. Further, while load from California's refrigerated warehouses in 2008 was 360 MW with estimated DR potential of 45-90 MW, actual achieved was much less due to low participation. Efforts to overcome barriers to increased participation may include, improved marketing and recruitment of potential DR sites, better alignment and emphasis on financial benefits of participation, and use of Auto-DR to increase consistency of participation.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2011

The U.S. Department of Energy Office of Indian Energy Policy and Programs, Pala, California, Roundtable Summary

The Pala, California, DOE Tribal Roundtable convened at 5:30 p.m., Wednesday, March 23, at the Pala Resort. The meeting was hosted by the Department of Energy (DOE) Office of Indian Energy Policy and Programs (DOE Office of Indian Energy). Tracey LeBeau, Director of the DOE Office of Indian Energy and Pilar Thomas, Deputy Director-Policy of the DOE Office of Indian Energy, attended. Tribal leaders and representatives from five tribal communities also attended. There were thirteen participants. The meeting was facilitated by Debra Drecksel, Senior Program Manager, Senior Facilitator, Udall Foundation’s U.S. Institute for Environmental Conflict Resolution (U.S. Institute). She was assisted by Lindsey Sexton, Program Associate, U.S. Institute.

Pala, California, Indian Energy, tribe, wind energ↗
DOE OSTI2015

California Statewide PEV Infrastructure Assessment; NREL (National Renewable Energy Laboratory)

This presentation discusses how the California Statewide Plug-In Electric Vehicle (PEV) Infrastructure Assessment provides a framework for understanding the potential energy (kWh) and demand (MW) impacts of PEV market growth; how PEV travel simulations can inform the role of public infrastructure in future market growth; and how ongoing assessment updates and Alternative Fuels Data Center outreach can help coordinate stakeholder planning and decision making and reduce uncertainties.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2015

Building America Case Study: Zero Energy Ready Home Multifamily Project: Mutual Housing at Spring Lake, Woodland, California

Building cost effective, high performance homes that provide superior comfort, health, and durability is the goal of the Department of Energy's (DOE's) Zero Energy Ready Homes (ZERH) program. Through Building America research and other innovative programs throughout the country, many of the technical challenges to building to the ZERH standard have been addressed. This case study describes the development of a 62-unit multifamily community constructed by nonprofit developer Mutual Housing at the Spring Lake subdivision in Woodland, CA. The Spring Lake project is expected to be the first ZERH-certified multifamily project nationwide. Building America team Alliance for Residential Building Innovation worked with Mutual Housing throughout the project. The case study discusses challenges encountered, lessons learned, and how obstacles were overcome. An objective of this project was to gain a highly visible foothold for residential buildings built to the DOE ZERH specification that can be used to encourage participation by other California builders.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2017

Green Routing Fuel Saving Opportunity Assessment: A Case Study on California Large-Scale Real-World Travel Data: Preprint

New technologies, such as connected and automated vehicles, have attracted more and more researchers for improving the energy efficiency and environmental impact of current transportation systems. The green routing strategy instructs a vehicle to select the most fuel-efficient route before the vehicle departs. It benefits the current transportation system with fuel saving opportunity through identifying the greenest route. This paper introduces an evaluation framework for estimating benefits of green routing based on large-scale, real-world travel data. The framework has the capability to quantify fuel savings by estimating the fuel consumption of actual routes and comparing to routes procured by navigation systems. A route-based fuel consumption estimation model, considering road traffic conditions, functional class, and road grade is proposed and used in the framework. An experiment using a large-scale data set from the California Household Travel Survey global positioning system trajectory data base indicates that 31% of actual routes have fuel savings potential with a cumulative estimated fuel savings of 12%.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

South Lake Tahoe, California: Using Energy Data to Partner on Building Energy Efficiency Actions (City Energy: From Data to Decisions)

This fact sheet "South Lake Tahoe, California: Using Energy Data to Partner on Building Energy Efficiency Actions" explains how the City of South Lake Tahoe used data from the U.S. Department of Energy's Cities Leading through Energy Analysis and Planning (Cities-LEAP) and the State and Local Energy Data (SLED) programs to inform its city energy planning. It is one of ten fact sheets in the "City Energy: From Data to Decisions" series.

building energy efficiency actions↗
DOE OSTI2018

Remediation of a 3-Mile Hexavalent Chromium Plume in Hinkley, California - 18532

Pacific Gas and Electric Company (PG and E) is conducting assessment and cleanup of hexavalent chromium (Cr[VI]) in groundwater related to industrial activities from the 1950's and 1960's at the PG and E Hinkley Compressor Station near Barstow, California (the Site). The plume core undergoing remediation is approximately 4.8 kilometers long and 1.6 kilometers wide (3 miles long and one mile wide). In December 2015, a Cleanup and Abatement Order was issued which established cleanup requirements for the Site, including required cleanup time frames for the plume core undergoing remediation to reach 50 micrograms per liter (μg/L) across 90% of the plume by 2025 and to reach 10 μg/L across 80% of the plume by 2032. To reach the milestones at the scale of the site, remedy design includes a series of remedial system expansions and remedy implementation relies on an adaptive management scheme for continual performance evaluation and optimization. This presentation will detail the remedial approach, implementation and performance to date. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Coastal Upwelling Off the California Coast - A Satellite Perspective

The planning of offshore wind farms off the California coast, near Humboldt Bay in northern CA and Morro Bay in central CA, raises concerns about their potential influence on local wind patterns and, consequently, coastal upwelling dynamics. The coastal upwelling phenomenon is responsible for transporting cold, nutrient-rich waters from the deeper ocean to the surface, nurturing the area's ecosystems and fisheries that are deeply intertwined with the region's cultural identity. As stakeholders voice concerns about the impact of the wind farm developments, this study endeavors to shed light on the interactions between offshore wind conditions and coastal upwelling processes using satellite data. We aim to provide observational insights from a multi-decade time period that deepen the scientific understanding of coastal upwelling processes and eventually inform sustainable energy policies with broader implications for coastal ecosystems.

California↗
DOE OSTI2010

The Economic Value of PV and Net Metering to Residential Customers in California

In this paper, we analyze the bill savings from PV for residential customers of the California's two largest electric utilities, under existing net metering tariffs as well as under several alternative compensation mechanisms. We find that economic value of PV to the customer is dependent on the structure of the underlying retail electricity rate and can vary quite significantly from one customer to another. In addition, we find that the value of the bill savings from PV generally declines with PV penetration level, as increased PV generation tends to offset lower-priced usage. Customers in our sample from both utilities are significantly better off with net metering than with a feed-in tariff where all PV generation is compensated at long-run avoided generation supply costs. Other compensation schemeswhich allow customers to displace their consumption with PV generation within each hour or each month, and are also based on the avoided costs, yield similar value to the customer as net metering.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2025

Evaluating sulfurization as a blue carbon sink in a southern California salt marsh

Blue carbon ecosystems such as seagrass meadows, mangrove forests, and salt marshes are important carbon sinks that can store carbon for millennia. Recently, organic matter sulfurization and pyritization have been proposed as mechanisms of net carbon storage in blue carbon ecosystems. At our study site, organic sulfur that is resistant to acid hydrolysis (protokerogen) is an order of magnitude less abundant than pyrite sulfur, suggesting a dominance of pyritization over sulfurization. The C/N ratios and carbon isotope compositions suggest that nearly half of total organic carbon and ≥ 80% of protokerogen is composed of marsh plant material. Sediment protokerogen appears to be sulfurized based on its low δ 34 S values (− 10‰), abundance of disulfides, and higher S/C ratio (~ 1.0%) relative to potential biogenic sulfur sources. However, the interpretation of protokerogen δ 34 S values is complicated by the wide range in sulfur isotope compositions of marsh plants. Evidence for sulfurization occurs within the shallowest sediments across different vegetation zones, yielding consistent products, while pyritization appears to be more sensitive to alterations in sediment redox conditions. Based on organic sulfur and pyrite content, sulfurization may be a more spatially consistent process than pyritization, with implications for carbon storage. The relative abundance of pyrite and protokerogen organic sulfur indicates that pyritization is favored at our study site, but this is likely to vary across the spectrum of blue carbon ecosystems.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2015

Primary marine aerosol‐cloud interactions off the coast of California

Abstract Primary marine aerosol (PMA)‐cloud interactions off the coast of California were investigated using observations of marine aerosol, cloud condensation nuclei (CCN), and stratocumulus clouds during the Eastern Pacific Emitted Aerosol Cloud Experiment (E‐PEACE) and the Stratocumulus Observations of Los‐Angeles Emissions Derived Aerosol‐Droplets (SOLEDAD) studies. Based on recently reported measurements of PMA size distributions, a constrained lognormal‐mode‐fitting procedure was devised to isolate PMA number size distributions from total aerosol size distributions and applied to E‐PEACE measurements. During the 12 day E‐PEACE cruise on the R/V Point Sur , PMA typically contributed less than 15% of total particle concentrations. PMA number concentrations averaged 12 cm −3 during a relatively calmer period (average wind speed 12 m/s 1 ) lasting 8 days, and 71 cm −3 during a period of higher wind speeds (average 16 m/s 1 ) lasting 5 days. On average, PMA contributed less than 10% of total CCN at supersaturations up to 0.9% during the calmer period; however, during the higher wind speed period, PMA comprised 5–63% of CCN (average 16–28%) at supersaturations less than 0.3%. Sea salt was measured directly in the dried residuals of cloud droplets during the SOLEDAD study. The mass fractions of sea salt in the residuals averaged 12 to 24% during three cloud events. Comparing the marine stratocumulus clouds sampled in the two campaigns, measured peak supersaturations were 0.2 ± 0.04% during E‐PEACE and 0.05–0.1% during SOLEDAD. The available measurements show that cloud droplet number concentrations increased with >100 nm particles in E‐PEACE but decreased in the three SOLEDAD cloud events.

Modini, R. L.↗
DOE OSTI2015

Top-down estimate of methane emissions in California using a mesoscale inverse modeling technique: The South Coast Air Basin

Methane (CH 4 ) is the primary component of natural gas and has a larger global warming potential than CO 2 . Some recent top-down studies based on observations showed CH 4 emissions in California's South Coast Air Basin (SoCAB) were greater than those expected from population-apportioned bottom-up state inventories. In this study, we quantify CH 4 emissions with an advanced mesoscale inverse modeling system at a resolution of 8 km × 8 km, using aircraft measurements in the SoCAB during the 2010 Nexus of Air Quality and Climate Change campaign to constrain the inversion. To simulate atmospheric transport, we use the FLEXible PARTicle-Weather Research and Forecasting (FLEXPART-WRF) Lagrangian particle dispersion model driven by three configurations of the Weather Research and Forecasting (WRF) mesoscale model. We determine surface fluxes of CH 4 using a Bayesian least squares method in a four-dimensional inversion. Simulated CH4 concentrations with the posterior emission inventory achieve much better correlations with the measurements (R2 = 0.7) than using the prior inventory (U.S. Environmental Protection Agency's National Emission Inventory 2005, R 2 = 0.5). The emission estimates for CH 4 in the posterior, 46.3 ± 9.2 Mg CH 4 /h, are consistent with published observation-based estimates. Changes in the spatial distribution of CH 4 emissions in the SoCAB between the prior and posterior inventories are discussed. Missing or underestimated emissions from dairies, the oil/gas system, and landfills in the SoCAB seem to explain the differences between the prior and posterior inventories. Furthermore, we estimate that dairies contributed 5.9 ± 1.7 Mg CH 4 /h and the two sectors of oil and gas industries (production and downstream) and landfills together contributed 39.6 ± 8.1 Mg CH 4 /h in the SoCAB.

54 ENVIRONMENTAL SCIENCES↗