The effects of different anti-reflective structures on the photovoltaic performance of the silicon solar cell were studied using finite-element modelling and numerical simulations for which experiment alone does not provide a full description. The front surface reflectivity may be mitigated...

The effects of different anti-reflective structures on the photovoltaic performance of the silicon solar cell were studied using finite-element modelling and numerical simulations for which experiment alone does not provide a full description. The front surface reflectivity may be mitigated...

Distributed generation with a combustion engine prime mover is still widely used to supply electric power in a variety of applications. These applications range from backup power supply systems and combined wind-diesel generation to providing power in places where grid connection is either...

This work is aimed at calculating the energy content of the residues from olive oil production. Olive pulp, olive husk and sludge (a mixture of olive pulp and husk) have been analyzed separately. Olive Mill Effluents (OME) are normally a problem for olive mill farms, yet they may be used as...

In metrology and standards, thermoelectricity is most often associated with thermometry. Therefore, this paper emphasizes thermoelectricity in thermometry and it focuses on the Seebeck effect. Yet, the thermoelectric terminology applies generally to all the diverse areas in which Seebeck,...

The paper illustrates some aspects of energy conversion processes during underground electric train operation. Energy conversion processes are explained using exergy, in order to support transport system sustainability. Loss of exergy reflects a loss of potential of energy to do work. Following...

In this paper we derive the dynamical model of a four-cylinder double-acting wobble-yoke Stirling engine. In addition to the classical thermodynamics methods that dominate the literature of Stirling mechanisms, we present a control systems viewpoint to analyze the dynamic properties of the...

This study is a contribution to the analysis of energy production by hybrid systems using renewable energy sources. It is realized within the framework of an isolated site, i.e., without any connection to an electrical network. Generally, with the conventional solutions for energy production,...

The present work considers a T-shaped standing-wave thermoacoustic system with an electrical heater confined in the bottom stem and two temperature-controllable heaters (TCHs) enclosed in the bifurcating branches. With the heater placed at the bottom stem set to 1100K and TCHs be adiabatic,...

Hybrid photovoltaic/thermal (PV/T) devices can simultaneously generate thermal and electrical energy, but have been limited to low temperature applications. This is done to avoid performance degradation of the PV cell at high temperatures. While the low temperature approach limits PV losses, it...

LED (Light Emitting Diode) has been expected as the next generation of lighting system due to its high efficiency. However, the hot spot problem of the LED is very critical for its lifetime and efficiency. TIMs (Thermal Interface Materials) have been used to enhance the cooling performance of...

The work focuses on energy conversion during the internal flow, discharge and formation of the spray from a pressure-swirl (PS) atomizer in the simplex as well as spill-return mode. Individual energy forms are described in general and assessed experimentally for a particular PS atomizer and...

Thermoelectric generators (TEGs) are being studied and developed for applications in which waste heat, for example, from the exhaust of motor vehicles is converted into usable electricity. TEGs consisting of TE elements integrated with an exhaust heat exchanger require optimization to produce...

This paper assesses the steady-state performance of cascaded IMs (induction motors) operating under voltage unbalance. Small sizes induction motors are connected in cascade instead of one big size induction motor to improve the electromagnetic system and to make the energy conversion process...

The Office of Energy Efficiency and Renewable Energy (EERE) has had a longstanding goal of introducing uncertainty into the analysis it routinely conducts in compliance with the Government Performance and Results Act (GPRA) and for strategic management purposes. The need to introduce some...

The National Energy Modeling System (NEMS) is a computer-based, energy-economy modeling system of US energy markets for the midterm period through 2020. NEMS projects the production, imports, conversion, consumption, and prices of energy, subject to assumptions on macroeconomic and financial...

Cost studies were done for Total Flow, double flash, and multistage flash binary systems for electric Energy production from the Salton Sea Geothermal Resource. The purpose was to provide the Department of energy's Division of Geothermal Energy with information by which to judge whether to...

The most important factors affecting the economics of geothermal electricity production are the wellhead temperature or enthalpy, the well flow rate, and the cost of the wells. The capital cost of the powerplant is significant, but not highly sensitive to these resource characteristics. The...

As part of a mission-oriented program for accelerating the commercialization of geothermal energy, research is sponsored which concerns the quantitative analysis of investment decisions by industries involved in the development of geothermal resources. The results of a quick-response study...

The analysis and modeling of investment behavior in the development of hydrothermal electric power facilities are reported. This investment behavior reflects a degree of sensitivity to public policy alternatives concerning taxation and regulation of the resource and its related energy conversion...

Theeconomic and technical factors involved in using geothermal energy at Ahuachapan are examined. The experience at Ahuachapan is evaluated in relation to conditions prevailing in El Salvador and to conditions in the U.S. technical characteristics considered are: geological characteristics, well...

This study is concerned with U.S. geothermal resources, their potential for commercial utilization by electric utilities between now and the year 2000, and their impact on the utility industry. USGS estimates of the resources in identified hydrothermal systems were extrapolated to the...

Purpose of the audit was to determine whether the Department's conditional commitment to UltraSystems, Inc. (UltraSystems) was in compliance with the Geothermal Energy Research, Development and Demonstration Act of 1974 and applicable regulations. It was found that the loan guaranty conditional...

A computer simulation model (GIRORA-Electric) is developed to study the economics of power generation from high temperature geothermal resources. GIRORA-Electric is a discounted cash flow investment model which evaluates the rate of return on producers' capital investment. This model consists of...

The degradation of fossil fuels and other non-renewable energy resources are the challenges faced by current and future generations. This trend requires humans to utilize, reuse, and transform energy efficiently, for the right applications and with the right timing. The low-grade heat from...

Undoubtedly, energy has a significant role in economic growth and technical developments. Renewable energy resources are becoming more important in recent years due to their tremendous contributions to the independence of power generation industry from traditional fossil energy resources. Wind...

Two novel crystalline compounds (1-C15H31NH3)2CdCl4(s) and (1-C16H33NH3)2CdCl4(s), which may be used as the solid–solid phase change materials, were synthesized. X-ray crystallography was applied to characterize crystal structures of the two compounds. Both of them are monoclinic, the space...

A thermoacoustic heat engine (TAHE) is one kind of new power system which can simply convert heat into mechanical power in forms of acoustic wave without any moving mechanical components. This article focuses on using variable acoustical load method to study the energy conversion characteristics...

We determine the threshold herd size at which a biomass waste to energy conversion system becomes commercially viable. The threshold herd size is found by optimisation of the biomass waste to energy conversion system for different herd sizes. Manure is co-digested with food waste. The...

The vapor-compression refrigeration systems have been one of the essential energy conversion systems for humankind and exhausting huge amounts of energy nowadays. Surrounding the energy efficiency promotion of the systems, there are lots of effectual optimization methods but mainly relied on...

Polygeneration systems are commonly found in chemical and energy industry. These systems often involve chemical conversions and energy conversions. Studies of these systems are interdisciplinary, mainly involving fields of chemical engineering, energy engineering, environmental science, and...

Energy conversion for conjugate conduction, convection and radiation analysis have been performed for free convection heat transfer with radiation effect of a steady laminar boundary-layer flow that pass a non-linearly flow field over extrusion stretching sheet by two kinds of boundary-layer...

The pulse tube engine represents the thermodynamic inversion of the pulse tube refrigerator used in cryogenic cooling applications. It has a high potential to be used as a prime mover for the conversion of low grade waste heat into mechanical or electrical energy. This paper describes an...

The pulse tube engine is a simple heat engine based on the pulse tube process. Due to its simplicity it has a high potential to be applicable in waste heat usage and energy harvesting purposes. In this work, mathematical and experimental design tools are developed to study a pressurized...

Organic Rankine cycles (ORCs) provide an alternative to traditional steam Rankine cycles for the conversion of low grade heat sources into power, where conventional steam power cycles are known to be inefficient. A large processing plant often has multiple low temperature waste heat streams...

Several rural farms have installed anaerobic digestion systems as manure management systems. Such systems are also used to provide electricity and heating. In these systems, biogas is generated from anaerobic digestion of biomass waste and combusted in a boiler and an engine-generator set, to...

This paper provides an insight to the feasibility of adopting hydrogen as a key energy carrier and fuel source in the near future. It is shown that hydrogen has several advantages, as well as few drawbacks in using for the above purposes. The research shows that hydrogen will be a key player in...

The energetic and exergetic performance of an updated ORC (organic Rankine cycle) is investigated. The thermal efficiencies of the ORC at different heat source temperatures of about 100, 90, 80, and 70 °C are explored. The thermodynamic irreversibility that takes place in the evaporator,...

Thermal energy storage is essential in solar cooling applications due to intermittent and uncontrollable availability of solar energy. Various technologies are available for low temperature energy storage. In the present work, a solar-assisted ejector cooling system with latent heat cold storage...

Volatile oil price and growing emphasis on environmental conservation have stimulated the development and utilisation of biomass as a vital source of renewable energy. In reducing the global dependency on fossil fuels, rice husk and rice straw which are the widely abundant agricultural wastes...

This article presents an overview on the research and development and application aspects for the hybrid photovoltaic/thermal (PV/T) collector systems. A major research and development work on the photovoltaic/thermal (PVT) hybrid technology has been done since last 30 years. Different types of...

Alkanes, aromates and linear siloxanes are considered as working fluids for high-temperature organic Rankine cycles (ORCs). Case studies are performed using the molecular based equations of state BACKONE and PC-SAFT. First, “isolated” ORC processes with maximum temperatures of 250°C and...