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Analysis of Buoyancy-Driven Ventilation of Hydrogen from Buildings: Preprint

Description: When hydrogen gas is used or stored within a building, as with a hydrogen-powered vehicle parked in a residential garage, any leakage of unignited H2 will mix with indoor air and may form a flammable mixture. One approach to safety engineering relies on buoyancy-driven, passive ventilation of H2 from the building through vents to the outside.
Date: August 1, 2007
Creator: Barley, C. D.; Gawlik, K.; Ohi, J. & Hewett, R.
Partner: UNT Libraries Government Documents Department

Test Protocol for Room-to-Room Distribution of Outside Air by Residential Ventilation Systems

Description: This test and analysis protocol has been developed as a practical approach for measuring outside air distribution in homes. It has been used successfully in field tests and has led to significant insights on ventilation design issues. Performance advantages of more sophisticated ventilation systems over simpler, less-costly designs have been verified, and specific problems, such as airflow short-circuiting, have been identified.
Date: December 1, 2007
Creator: Barley, C. D.; Anderson, R.; Hendron, B. & Hancock, E.
Partner: UNT Libraries Government Documents Department

Optimal control of remote hybrid power systems. Part 1: Simplified model

Description: In this two-part study, time-series models are used to determine optimal dispatch strategies, in conjunction with optimally-sized components, in remote hybrid power systems. The objective of the dispatch optimization is to minimize the costs associated with diesel fuel, diesel starts, and battery erosion, based on a thorough economic analysis of present worth life-cycle cost. An ideal predictive control strategy is used as a basis of comparison. In Part 1 (reported here), a simplified time-series model is used to obtain preliminary conceptual results. These results illustrate the nature of the optimal dispatch strategy and indicate that a simple SOC setpoint strategy can be practically as effective as the ideal predictive control. In Part 2 (at a later date), a more detailed model will be used to obtain more accurate, quantitative results. The authors anticipate that these results will be correlated to dimensionless economic, design, and performance parameters, rendering them useful as design guidelines over a wide variety of load profiles, climates, equipment specifications, and economic variables.
Date: April 1, 1995
Creator: Barley, C D; Winn, C B; Flowers, L & Green, H J
Partner: UNT Libraries Government Documents Department

Design and Performance of the Van Geet Off-Grid Home: Preprint

Description: The Van Geet home near Denver, Colorado, demonstrates the successful integration of energy conservation measures and renewable energy supply in a beautiful, comfortable, energy-efficient, 295-m2 (3,176-ft2) off-grid home in a cold, sunny climate. Features include a tight envelope, energy-efficient appliances, passive solar heating (direct gain and Trombe wall), natural cooling, solar hot water, and photovoltaics. In addition to describing this house and its performance, this paper describes the recommended design process of (1) setting a goal for energy efficiency at the outset, (2) applying rules of thumb, and (3) using computer simulation to fine-tune the design. Performance monitoring and computer simulation are combined for the best possible analysis of energy performance. In this case, energy savings are estimated as 89% heating and cooling, 83% electrical, and nearly 100% domestic water heating. The heating and cooling energy use is 8.96 kJ/Cdaym2 (0.44 Btu/Fdayft2).
Date: January 1, 2003
Creator: Barley, C. D.; Torcellini, P. & Van Geet, O.
Partner: UNT Libraries Government Documents Department

Field Test of a DHW Distribution System: Temperature and Flow Analyses

Description: This presentation discusses a field test of a DHW distribution system in an occupied townhome. It includes measured fixture flows and temperatures, a tested recirculation system, evaluated disaggregation of flow by measured temperatures, Aquacraft Trace Wizard analysis, and comparison.
Date: May 13, 2010
Creator: Barley, C. D.; Hendron, B. & Magnusson, L.
Partner: UNT Libraries Government Documents Department

Analysis of Buoyancy-Driven Ventilation of Hydrogen from Buildings

Description: The scope of work for this project includes safe building design, vehicle leak in residential garage, continual slow leak, passive, buoyancy-driven ventilation (versus mechanical), and steady-state concentration of hydrogen versus vent size.
Date: September 11, 2007
Creator: Barley, C. D.; Gawlik, K.; Ohi, J. & Hewett, R.
Partner: UNT Libraries Government Documents Department

Van Geet Off-Grid Home: An Integrated Approach to Energy Savings

Description: The Van Geet home near Denver, Colorado, exemplifies the effectiveness of coupling energy conservation measures with renewable energy utilization in a modern residence. The remote location, with no utility connections available, and the owner's interest in renewable energy motivated the ambitious design. This design attracted the interest of the Building America (BA) program and was studied as a research home. As a result, the BA program provided energy engineering throughout the design, construction, and performance evaluation phases. The American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) also recognized the success of this project by awarding it an ASHRAE Technology Award in 2001.
Date: August 1, 2004
Creator: Barley, C. D.; Torcellini, P. & Van Geet, O.
Partner: UNT Libraries Government Documents Department

Sizing Wind/Photovoltaic Hybrids for Households in Inner Mongolia

Description: Approximately 140,000 wind turbines currently provide electricity to about one-third of the non-grid-connected households in Inner Mongolia. However, these households often suffer from a lack of power during the low-wind summer months. This report describes an analysis of hybrid wind/photovoltaic (PV) systems for such households. The sizing of the major components is based on a subjective trade-off between the cost of the system and the percent unmet load, as determined by the Hybrid 2 software in conjunction with a simplified time-series model. Actual resource data (wind speed and solar radiation) from the region are processed so as to best represent the scenarios of interest. Small wind turbines of both Chinese and U.S. manufacture are considered in the designs. The results indicate that combinations of wind and PV are more cost-effective than either one alone, and that the relative amount of PV in the design increases as the acceptable unmet load decreases and as the average wind sp eed decreases.
Date: June 1, 1997
Creator: Barley, C. D.; Lew, D. J. & Flowers, L. T.
Partner: UNT Libraries Government Documents Department

Diesel plant retrofitting options to enhance decentralized electricity supply in Indonesia

Description: Over the last 20 years, the government of Indonesia has undertaken an extensive program to provide electricity to the population of that country. The electrification of rural areas has been partially achieved through the use of isolated diesel systems, which account for about 20% of the country`s generated electricity. Due to many factors related to inefficient power production with diesels, the National Renewable Energy Laboratory, in conjunction with PLN, the Indonesian national utility, Community Power Corporation, and Idaho Power Company, analyzed options for retrofitting existing diesel power systems. This study considered the use of different combinations of advanced diesel control, the addition of wind generators, photovoltaics and batteries to reduce the systems of overall cost and fuel consumption. This analysis resulted in a general methodology for retrofitting diesel power systems. This paper discusses five different retrofitting options to improve the performance of diesel power systems. The systems considered in the Indonesian analysis are cited as examples for the options discussed.
Date: September 1, 1997
Creator: Baring-Gould, E.I.; Barley, C.D. & Drouilhet, S.
Partner: UNT Libraries Government Documents Department

Feasibility of Hybrid Retrofits to Off-Grid Diesel Power Plants in the Philippines

Description: The Strategic Power Utilities Group (SPUG) of the National Power Corporation (NPC) in the Philippines owns and operates about 100 power plants, mostly fueled by diesel, ranging in energy production from about 15 kilowatt-hours (kWh)/day to 106,000 kWh/day. Reducing the consumption of diesel fuel in these plants, along with the associated financial losses, is a priority for SPUG. The purpose of this study is to estimate the potential fuel and cost savings that might be achieved by retrofitting hybrid power systems to these existing diesel plants. As used in this report, the term ''hybrid system'' refers to any combination of wind turbine generators (WTGs), photovoltaic (PV) modules, lead-acid batteries, and an AC/DC power converter (either an electronic inverter or a rotary converter), in addition to the existing diesel gensets. The resources available for this study did not permit a detailed design analysis for each of the plants. Instead, the following five-step process was used: (1) Tabulate some important characteristics of all the plants. (2) Group the plants into categories (six classes) with similar characteristics. (3) For each class of system, identify one plant that is representative of the class. (4) For each representative plant, perform a moderately detailed prefeasibility analysis of design options. (5) Summarize and interpret the results. The analysis of each representative plant involved the use of time-series computer simulation models to estimate the fuel usage, maintenance expenses, and cash flow resulting from various designs, and to search the domain of possible designs for the one leading to the lowest life-cycle cost. Cost items that would be unaffected by the retrofit, such as operator salaries and the capital cost of existing equipment, were not included in the analysis. Thus, the results are reported as levelized cost of energy (COE) savings: the difference between the cost of the existing ...
Date: August 1, 1999
Creator: Barley, C. D.; Flowers, L. T.; Benavidez, P. J.; Abergas, R. L. & Barruela, R. B.
Partner: UNT Libraries Government Documents Department