Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “trending”

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 1,567 records · Page 87

Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections

This report helps to clarify the confusion surrounding different estimates of system pricing by distinguishing between past, current, and near-term projected estimates. It also discusses the different methodologies and factors that impact the estimated price of a PV system, such as system size, location, technology, and reporting methods. These factors, including timing, can have a significant impact on system pricing.

14 SOLAR ENERGY↗

Harnessing Light: Capitalizing on Optical Science Trends and Challenges for Future Research (Final Technical Report)

The committee has during the earlier period finalized their work on the report, Optics and Photonics: Essential Technologies for Our Nation (2013). The report did undergo review and initial editorial processing. The NRC released a pre-publication report on August 13, 2012. A final report is now available. The study director has been able to practice his skills in running a national academies committee. From a research perspective the grant has generated a report with recommendations to the government. The work itself is the meetings where the committee convened to hear presenters and to discuss the status of optics and photonics as well as writing the report.

36 MATERIALS SCIENCE↗

A Comprehensive System of Energy Intensity Indicators for the U.S.: Methods, Data and Key Trends

This report describes a comprehensive system of energy intensity indicators for the United States that has been developed for the Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) over the past decade. This system of indicators is hierarchical in nature, beginning with detailed indexes of energy intensity for various sectors of the economy, which are ultimately aggregated to an overall energy intensity index for the economy as a whole. The aggregation of energy intensity indexes to higher levels in the hierarchy is performed with a version of the Log Mean Divisia Index (LMDI) method. Based upon the data and methods in the system of indicators, the economy-wide energy intensity index shows a decline of about 14% in 2010 relative to a 1985 base year. Discussion of energy intensity indicators for each of the broad end-use sectors of the economy—residential, commercial, industrial, and transportation—is presented in the report. An analysis of recent changes in the efficiency of electricity generation in the U.S. is also included. A detailed appendix describes the data sources and methodology behind the energy intensity indicators for each sector.

Belzer, David B.↗

The evolving price of household LED lamps: Recent trends and historical comparisons for the US market

In recent years, household LED light bulbs (LED A lamps) have undergone a dramatic price decline. Since late 2011, we have been collecting data, on a weekly basis, for retail offerings of LED A lamps on the Internet. The resulting data set allows us to track the recent price decline in detail. LED A lamp prices declined roughly exponentially with time in 2011-2014, with decline rates of 28percent to 44percent per year depending on lumen output, and with higher-lumen lamps exhibiting more rapid price declines. By combining the Internet price data with publicly available lamp shipments indices for the US market, it is also possible to correlate LED A lamp prices against cumulative production, yielding an experience curve for LED A lamps. In 2012-2013, LED A lamp prices declined by 20-25percent for each doubling in cumulative shipments. Similar analysis of historical data for other lighting technologies reveals that LED prices have fallen significantly more rapidly with cumulative production than did their technological predecessors, which exhibited a historical decline of 14-15percent per doubling of production.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Intriguing Trends in Nuclear Physics Articles Authorship

A look at how authorship of physics publications (particularly nuclear publications) have changed throughout the decades by comparing data mined from the National Nuclear Data Center (NNDC) with observations.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Utility-Scale Solar 2013: An empirical analysis of project cost, performance, and pricing trends in the United States

Other than the SEGS I-IX parabolic trough projects built in the 1980s, virtually no large-scale or "utility-scale" solar projects-defined here to include any ground-mounted photovoltaic ("PV"), concentrating photovoltaic ("CPV"), or concentrating solar power ("CSP" or solar thermal) project larger than 5 MW AC -existed in the United States prior to 2007.

14 SOLAR ENERGY↗

Temperature Trends in Coal Char Combustion under Oxy-fuel Conditions for the Determination of Kinetics

Oxy-fuel combustion technology with carbon capture and storage could significantly reduce global CO 2 emissions, a greenhouse gas. Implementation can be aided by computational fluid dynamics (CFD) simulations, which require an accurate understanding of coal particle kinetics as they go through combustion in a range of environments. To understand the kinetics of pulverized coal char combustion, a heated flow reactor was operated under a wide range of experimental conditions. We varied the environment for combustion by modifying the diluent gas, oxygen concentration, gas flow rate, and temperature of the reactor/reacting gases. Measurements of reacting particle temperatures were made for a sub-bituminous and bituminous coal char, in environments with CO 2 or N 2 as the diluent gas, with 12, 24, and 36 vol-% oxygen concentration, at 50, 80, 100, and 200 standard liters per minute flowing through the reactor, reactor temperatures of 1200, 1400 K, at pressures slightly above atmospheric. The data shows consistent increasing particle temperature with increased oxygen concentration, reactor temperature and higher particle temperatures for N 2 diluent than CO 2 . We also see the effects of CO 2 gasification when different ranks of coal are used, and how the reduction in the temperature due to the CO 2 diluent is greater for the coal char that has higher reactivity. Quantitative measurements for temperature are not yet complete due to ongoing calibration of detection systems.

01 COAL, LIGNITE, AND PEAT↗

Photovoltaic (PV) Pricing Trends: Historical, Recent, and Near-Term Projections

The installed capacity of global and U.S. photovoltaic (PV) systems has soared in recent years, driven by declining PV prices and government incentives. The U.S. Department of Energy’s (DOE) SunShot Initiative aims to make PV cost competitive without incentives by reducing the cost of PV-generated electricity by about 75% between 2010 and 2020. This summary report—based on research at Lawrence Berkeley National Laboratory (LBNL) and the National Renewable Energy Laboratory (NREL)—examines progress in PV price reductions to help DOE and other PV stakeholders manage the transition to a market-driven PV industry, and to provide clarity surrounding the wide variety of potentially conflicting data available about PV system prices.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

IEA Wind Task 26. Wind Technology, Cost and Performance Trends in Denmark, Germany, Ireland, Norway, the European Union, and the United States. 2007 - 2012

This report builds from a similar previous analysis (Schwabe et al., 2011) exploring the differences in cost of wind energy in 2008 among countries participating in IEA Wind Task 26 at that time. The levelized cost of energy (LCOE) is a widely recognized metric for understanding how technology, capital investment, operations, and financing impact the life-cycle cost of building and operating a wind plant. Schwabe et al. (2011) apply a spreadsheet-based cash flow model developed by the Energy Research Centre of the Netherlands (ECN) to estimate LCOE. This model is a detailed, discounted cash flow model used to represent the various cost structures in each of the participating countries from the perspective of a financial investor in a domestic wind energy project. This model is used for the present analysis as well, and comparisons are made for those countries who contributed to both reports, Denmark, Germany, and the United States.

17 WIND ENERGY↗

2013 Market Trends Report: Geothermal Technologies Office

The potential geothermal energy resource base of the United States is a major natural asset, on the order of more than 100 gigawatts (GW) of clean renewable energy. Conventional hydrothermal technologies could be utilized for 6 GW of additional potential beyond what has already been developed. There are an estimated 30 GW of additional conventional resources yet to be discovered in the western United States. The next generation of geothermal technologies, enhanced geothermal systems (EGS), is positioned to access additional geothermal resources by adding either permeability or a heat exchange fluid to a geological formation with sufficient heat. A breakthrough in EGS could expand the U.S. geothermal resource base dramatically.

15 GEOTHERMAL ENERGY↗

Unit Price Scaling Trends for Chemical Products

To facilitate early-stage life-cycle techno-economic modeling of emerging technologies, here we identify scaling relations between unit price and sales quantity for a variety of chemical products of three categories - metal salts, organic compounds, and solvents. We collect price quotations for lab-scale and bulk purchases of chemicals from both U.S. and Chinese suppliers. We apply a log-log linear regression model to estimate the price discount effect. Using the median discount factor of each category, one can infer bulk prices of products for which only lab-scale prices are available. We conduct out-of-sample tests showing that most of the price proxies deviate from their actual reference prices by a factor less than ten. We also apply the bootstrap method to determine if a sample median discount factor should be accepted for price approximation. We find that appropriate discount factors for metal salts and for solvents are both -0.56, while that for organic compounds is -0.67 and is less representative due to greater extent of product heterogeneity within this category.

97 MATHEMATICS AND COMPUTING↗

Utility-Scale Solar 2014. An Empirical Analysis of Project Cost, Performance, and Pricing Trends in the United States

Other than the nine Solar Energy Generation Systems (“SEGS”) parabolic trough projects built in the 1980s, virtually no large-scale or “utility-scale” solar projects – defined here to include any groundmounted photovoltaic (“PV”), concentrating photovoltaic (“CPV”), or concentrating solar thermal power (“CSP”) project larger than 5 MW AC – existed in the United States prior to 2007. By 2012 – just five years later – utility-scale had become the largest sector of the overall PV market in the United States, a distinction that was repeated in both 2013 and 2014 and that is expected to continue for at least the next few years. Over this same short period, CSP also experienced a bit of a renaissance in the United States, with a number of large new parabolic trough and power tower systems – some including thermal storage – achieving commercial operation. With this critical mass of new utility-scale projects now online and in some cases having operated for a number of years (generating not only electricity, but also empirical data that can be mined), the rapidly growing utility-scale sector is ripe for analysis. This report, the third edition in an ongoing annual series, meets this need through in-depth, annually updated, data-driven analysis of not just installed project costs or prices – i.e., the traditional realm of solar economics analyses – but also operating costs, capacity factors, and power purchase agreement (“PPA”) prices from a large sample of utility-scale solar projects in the United States. Given its current dominance in the market, utility-scale PV also dominates much of this report, though data from CPV and CSP projects are presented where appropriate.

14 SOLAR ENERGY↗

A Comprehensive System of Energy Intensity Indicators for the U.S.: Methods, Data and Key Trends

This report describes a comprehensive system of energy intensity indicators for the United States that has been developed for the Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE) over the past decade. This system of indicators is hierarchical in nature, beginning with detailed indexes of energy intensity for various sectors of the economy, which are ultimately aggregated to an overall energy intensity index for the economy as a whole. The aggregation of energy intensity indexes to higher levels in the hierarchy is performed with a version of the Log Mean Divisia index (LMDI) method. Based upon the data and methods in the system of indicators, the economy-wide energy intensity index shows a decline of about 14% in 2011 relative to a 1985 base year.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Status and Trends in the U.S. Voluntary Green Power Market (2012 Data)

The "voluntary" or "green power" market is that in which consumers and institutions voluntarily purchase renewable energy to match all or part of their electricity needs. Voluntary action provides a revenue stream for renewable energy projects and raises consumer awareness of the benefits of renewable energy. There are numerous ways consumers and institutions can purchase renewable energy. Historically, the voluntary market has consisted of three market sectors: (1) utility green pricing programs (in states with regulated electricity markets), (2) competitive suppliers (in states with restructured electricity markets), and (3) unbundled renewable electricity certificate (REC) markets, where RECs are purchased by consumers separately from electricity ("unbundled").

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Mercury Content of Sediments in East Fork Poplar Creek: Current Assessment and Past Trends

This study provided new information on sediment mercury (Hg) and monomethylmercury (MMHg) content and chemistry. The current inventory of Hg in East Fork Poplar Creek (EFPC) bed sediments was estimated to be 334 kg, which represents a ~67% decrease relative to the initial investigations in 1984. MMHg sediment inventory was estimated to be 44.1 g, lower but roughly similar to past estimates. The results support the relevance and potential impacts of other active and planned investigations within the Mercury Remediation Technology Development for Lower East Fork Poplar Creek project (e.g., assessment and control of bank soil inputs, sorbents for Hg and MMHg removal, re-introduction of freshwater clams to EFPC), and identify gaps in current understanding that represent opportunities to understand controlling variables that may inform future technology development studies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

SWATS: Diurnal Trends in the Soil Temperature Report

During the processing of data for the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility ARMBE2D Value-Added Product (VAP), the developers noticed that the SWATS soil temperatures did not show a decreased temporal variability with increased depth with the new E30+ Extended Facilities (EFs), unlike the older EFs at ARM’s Southern Great Plains (SGP) site. The instrument mentor analyzed the data and reported that all SWATS locations have shown this behavior but that the magnitude of the problem was greatest at EFs E31-E38. The data were analyzed to verify the initial assessments of: 1. 5 cm SWATS data were valid for all EFs and 15 cm soil temperature measurements were valid at all EFs other than E31-E38, 2. Use only nighttime SWATS soil temperature measurements to calculate daily average soil temperatures, 3. Since it seems likely that the soil temperature measurements below 15cm were affected by the solar heating of the enclosure at all but E31-38, and at all depths below 5cm at E31-38, individual measurements of soil temperature at these depths during daylight hours, and daily averages of the same, can ot be trusted on most (particularly sunny) days.

58 GEOSCIENCES↗