841 Matching Results

Search Results

Advanced search parameters have been applied.

in creator/contributor: "Lawrence Berkeley National Laboratory. Environmental Energy Technologies Division."

open access

Using SPARK as a Solver for Modelica

Modelica is an object-oriented acausal modeling language that is well positioned to become a de-facto standard for expressing models of complex physical systems. To simulate a model expressed in Modelica, it needs to be translated into executable code. For generating run-time efficient code, such a translation needs to employ algebraic formula manipulations. As the SPARK solver has been shown to be competitive for generating such code but currently cannot be used with the Modelica language, we … more

Date: June 30, 2008

Creator: Wetter, Michael; Wetter, Michael; Haves, Philip; Moshier, Michael A. & Sowell, Edward F.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Summary of Workshop: Barriers to Energy Efficient Residential Ventilation

The objectives for this workshop were to bring together those with different viewpoints on the implementation of energy efficient ventilation in homes to share their perspectives. The primary benefit of the workshop is to allow the participants to get a broader understanding of the issues involved and thereby make themselves more able to achieve their own goals in this area. In order to achieve this objective each participant was asked to address four objectives from their point of view: (1) Dr… more

Date: January 10, 2008

Creator: Sherman, Max & Sherman, Max

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities

This paper assesses the accuracy of the simplified frame cavity conduction/convection and radiation models presented in ISO 15099 and used in software for rating and labeling window products. Temperatures and U-factors for typical horizontal window frames with internal cavities are compared; results from Computational Fluid Dynamics (CFD) simulations with detailed radiation modeling are used as a reference. Four different frames were studied. Two were made of polyvinyl chloride (PVC) and two of… more

Date: December 1, 2008

Creator: Gustavsen, Arlid; Kohler, Christian; Dalehaug, Arvid & Arasteh, Dariush

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Using RPS Policies to Grow the Solar Market in the United States

The market for photovoltaics in the United States remains small relative to the nation's solar resource potential. Nonetheless, annual grid-connected PV installations have grown from just 4 MW in 2000 to over 100 MW in 2006, fast enough to the catch the attention of the global solar industry. The state of California deserves much of the credit for this growth. The State's historical rebate programs resulted in roughly 75% of the nation's grid-connected PV additions from 2000 through 2006 being … more

Date: November 20, 2007

Creator: Wiser, Ryan H & Wiser, Ryan H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

EPA ENERGY STAR: Tackling Growth in Home Electronics and Small Appliances

Over a decade ago, the electricity consumption associated with home electronics and other small appliances emerged onto the global energy policy landscape as one of the fastest growing residential end uses with the opportunity to deliver significant energy savings. As our knowledge of this end use matures, it is essential to step back and evaluate the degree to which energy efficiency programs have successfully realized energy savings and where savings opportunities have been missed.For the pas… more

Date: November 17, 2008

Creator: Sanchez, Marla Christine; Brown, Richard & Homan, Gregory

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Experimental Determination of ETS Particle Deposition in a Low Ventilation Room

Deposition on indoor surfaces is an important removal mechanism for tobacco smoke particles. We report measurements of deposition rates of environmental tobacco smoke particles in a room-size chamber. The deposition rates were determined from the changes in measured concentrations by correcting for the effects of coagulation and ventilation. The air flow turbulent intensity parameter was determined independently by measuring the air velocities in the chamber. Particles with diameters smaller th… more

Date: May 1, 1993

Creator: Xu, M.; Nematollahi, M.; Sextro, R. G.; Gadgil, A. J. & Nazaroff, W. W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

RESIDENTIAL THERMOSTATS: COMFORT CONTROLS IN CALIFORNIA HOMES

This report summarizes results of a literature review, a workshop, and many meetings with demand response and thermostat researchers and implementers. The information obtained from these resources was used to identify key issues of thermostat performance from both energy savings and peak demand perspectives. A research plan was developed to address these issues and activities have already begun to pursue the research agenda.

Date: March 2, 2008

Creator: Meier, Alan K. & Walker, Iain

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

EnergyPlus Analysis Capabilities for Use in California Building Energy Efficiency Standards Development and Compliance Calculations

California has been using DOE-2 as the main building energy analysis tool in the development of building energy efficiency standards (Title 24) and the code compliance calculations. However, DOE-2.1E is a mature program that is no longer supported by LBNL on contract to the USDOE, or by any other public or private entity. With no more significant updates in the modeling capabilities of DOE-2.1E during recent years, DOE-2.1E lacks the ability to model, with the necessary accuracy, a number of bu… more

Date: March 28, 2008

Creator: Hong, Tianzhen; Buhl, Fred & Haves, Philip

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Effects of Temporal Wind Patterns on the Value of Wind-Generated Electricity in California and the Northwest

Wind power production is variable, but also has diurnal and seasonal patterns. These patterns differ between sites, potentially making electric power from some wind sites more valuable for meeting customer loads or selling in wholesale power markets. This paper investigates whether the timing of wind significantly affects the value of electricity from sites in California and the Northwestern United States. We use both measured and modeled wind data and estimate the time-varying value of wind po… more

Date: May 1, 2008

Creator: Wiser, Ryan H; Wiser, Ryan H & Fripp, Matthias

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Comparison groups on bills: Automated, personalized energy information

A program called ``Innovative Billing?? has been developed to provide individualized energy information for a mass audience?the entireresidential customer base of an electric or gas utility. Customers receive a graph on the bill that compares that customer?s consumption with othersimilar customers for the same month. The program aims to stimulate customers to make ef?ciency improvements. To group as many as severalmillion customers into small ``comparison groups??, an automated method must be d… more

Date: July 1, 2006

Creator: Iyer, Maithili; Kempton, Willett & Payne, Christopher

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Towards a Sustainable Energy Balance: Progressive Efficiency and the Return of Energy Conservation

We argue that a primary focus on energy efficiency may not be sufficient to slow (and ultimately reverse) the growth in total energy consumption and carbon emissions. Instead, policy makers need to return to an earlier emphasis on"conservation," with energy efficiency seen as a means rather than an end in itself. We briefly review the concept of"intensive" versus"extensive" variables (i.e., energy efficiency versus energy consumption), and why attention to both con… more

Date: August 13, 2007

Creator: Diamond, Rick; Harris, Jeff; Diamond, Rick; Iyer, Maithili; Payne, Christopher; Blumstein, Carl et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Supercomputers: Super-polluters?

Thanks to imperatives for limiting waste heat, maximizing performance, and controlling operating cost, energy efficiency has been a driving force in the evolution of supercomputers. The challenge going forward will be to extend these gains to offset the steeply rising demands for computing services and performance.

Date: April 8, 2008

Creator: Mills, Evan; Mills, Evan; Tschudi, William; Shalf, John & Simon, Horst

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Heating, Ventilating, and Air-Conditioning: Recent Advances in Diagnostics and Controls to Improve Air-Handling System Performance

The performance of air-handling systems in buildings needs to be improved. Many of the deficiencies result from myths and lore and a lack of understanding about the non-linear physical principles embedded in the associated technologies. By incorporating these principles, a few important efforts related to diagnostics and controls have already begun to solve some of the problems. This paper illustrates three novel solutions: one rapidly assesses duct leakage, the second configures ad hoc duct-st… more

Date: February 1, 2008

Creator: Wray, Craig; Wray, Craig P.; Sherman, Max H.; Walker, I. S.; Dickerhoff, D. J. & Federspiel, C. C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Ferromagnetism in GaN: Gd: A density functional theory study

First principle calculations of the electronic structure and magnetic interaction of GaN:Gd have been performed within the Generalized Gradient Approximation (GGA) of the density functional theory (DFT) with the on-site Coulomb energy U taken into account (also referred to as GGA+U). The ferromagnetic p-d coupling is found to be over two orders of magnitude larger than the s-d exchange coupling. The experimental colossal magnetic moments and room temperature ferromagnetism in GaN:Gd reported re… more

Date: February 4, 2008

Creator: Stevenson, Cynthia & Stevenson, Cynthia

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Calendar Year 2007 Program Benefits for ENERGY STAR Labeled Products

ENERGY STAR is a voluntary energy efficiency-labeling program operated jointly by the United States Department of Energy and the United States Environmental Protection Agency (US EPA). Since the program inception in 1992, ENERGY STAR has become a leading international brand for energy efficient products. ENERGY STAR's central role in the development of regional, national, and international energy programs necessitates an open process whereby its program achievements to date as well as projected… more

Date: October 31, 2008

Creator: Sanchez, Marla Christine; Homan, Gregory & Brown, Richard

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Secondary organic aerosol from ozone-initiated reactions with terpene-rich household products

We analyzed secondary organic aerosol (SOA) data from a series of small-chamber experiments in which terpene-rich vapors from household products were combined with ozone under conditions analogous to product use indoors. Reagents were introduced into a continuously ventilated 198 L chamber at steady rates. Consistently, at the time of ozone introduction, nucleation occurred exhibiting behavior similar to atmospheric events. The initial nucleation burst and growth was followed by a period in whi… more

Date: January 1, 2008

Creator: Coleman, Beverly; Coleman, Beverly K.; Lunden, Melissa M.; Destaillats, Hugo & Nazaroff, William W.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Report to Congress on Server and Data Center Energy Efficiency: Public Law 109-431

This report was prepared in response to the request from Congress stated in Public Law 109-431 (H.R. 5646),"An Act to Study and Promote the Use of Energy Efficient Computer Servers in the United States." This report assesses current trends in energy use and energy costs of data centers and servers in the U.S. (especially Federal government facilities) and outlines existing and emerging opportunities for improved energy efficiency. It also makes recommendations for pursuing these energ… more

Date: August 2, 2007

Creator: Energy, Alliance to Save; Incorporated, ICF; Incorporated, ERG; Agency, U.S. Environmental Protection; Brown, Richard E; Brown, Richard et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Advanced Coal Wind Hybrid: Economic Analysis

Growing concern over climate change is prompting new thinking about the technologies used to generate electricity. In the future, it is possible that new government policies on greenhouse gas emissions may favor electric generation technology options that release zero or low levels of carbon emissions. The Western U.S. has abundant wind and coal resources. In a world with carbon constraints, the future of coal for new electrical generation is likely to depend on the development and successful a… more

Date: November 28, 2008

Creator: Phadke, Amol; Goldman, Charles; Larson, Doug; Carr, Tom; Rath, Larry; Balash, Peter et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

NATURAL CONVECTION IN PASSIVE SOLAR BUILDINGS: EXPERIMENTS, ANALYSIS AND RESULTS

Computer programs have been developed to numerically simulate natural convection in two- and three-dimensional room geometries. The programs have been validated using published data from the literature, results from a full-scale experiment performed at the Massachusetts Institute of Technology, and results from a small-scale experiment performed at LBL. One of the computer programs has been used to study the influence of natural convection on the thermal performance of a single zone in a direct… more

Date: April 1, 1981

Creator: Gadgil, A.; Bauman, F. & Kammerud, R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Check-Testing of Manufacturer Self Reported Labeling Data & Compliance with MEPS

China first adopted minimum energy performance standards (MEPS) in 1989. Today, there are standards for a wide range of domestic, commercial and selected industrial equipment. In 1999, China launched a voluntary endorsement label, which has grown to cover over 40 products including water-saving products. Further, in 2005, China started a mandatory energy information label that initially covered two products and in 2007 was extended to cover four products total including: air conditioners; house… more

Date: March 1, 2008

Creator: Zhou, Nan; Zhou, Nan; Zheng, Nina; Fridley, David; Wang, Ruohong & Egan, Christine

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

China's Top-1000 Energy-Consuming Enterprises Program:Reducing Energy Consumption of the 1000 Largest Industrial Enterprises in China

In 2005, the Chinese government announced an ambitious goal of reducing energy consumption per unit of GDP by 20% between 2005 and 2010. One of the key initiatives for realizing this goal is the Top-1000 Energy-Consuming Enterprises program. The energy consumption of these 1000 enterprises accounted for 33% of national and 47% of industrial energy usage in 2004. Under the Top-1000 program, 2010 energy consumption targets were determined for each enterprise. The objective of this paper is to eva… more

Date: June 2, 2008

Creator: Price, Lynn; Price, Lynn; Wang, Xuejun & Yun, Jiang

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Report to Congress on Server and Data Center Energy Efficiency: Public Law 109-431: Appendices

This report is the appendices to a companion report, prepared in response to the request from Congress stated in Public Law 109-431 (H.R. 5646),"An Act to Study and Promote the Use of Energy Efficient Computer Servers in the United States." This report assesses current trends in energy use and energy costs of data centers and servers in the U.S. (especially Federal government facilities) and outlines existing and emerging opportunities for improved energy efficiency. It also makes rec… more

Date: August 2, 2007

Creator: Energy, Alliance to Save; Incorporated, ICF; Incorporated, ERG; Agency, U.S. Environmental Protection; Brown, Richard E; Brown, Richard et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

An Analysis of the Price Elasticity of Demand for Household Appliances

This report summarizes our study of the price elasticity of demand for home appliances, including refrigerators, clothes washers, and dishwashers. In the context of increasingly stringent appliance standards, we are interested in what kind of impact the increased manufacturing costs caused by higher efficiency requirements will have on appliance sales. We begin with a review of existing economics literature describing the impact of economic variables on the sale of durable goods.We then describ… more

Date: January 25, 2008

Creator: Fujita, Kimberly; Dale, Larry & Fujita, K. Sydny

Item Type: Report

Partner: UNT Libraries Government Documents Department

open access

Carbonyl Emissions from Gasoline and Diesel Motor Vehicles

Carbonyls from gasoline powered light-duty vehicles (LDVs) and heavy-duty diesel powered vehicles (HDDVs) operated on chassis dynamometers were measured using an annular denuder-quartz filter-polyurethane foam sampler with O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine derivatization and chromatography-mass spectrometry analyses. Two internal standards were utilized based on carbonyl recovery, 4-fluorobenzaldehyde for<C8 carbonyls and 6-fluoro-4-chromanone for>_C8 compounds. Gas- and partic… more

Date: December 1, 2007

Creator: Destaillats, Hugo; Jakober, Chris A.; Robert, Michael A.; Riddle, Sarah G.; Destaillats, Hugo; Charles, M. Judith et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department