ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (369)
Collection
  • Articles  (369)
Publisher
Years
Journal
  • 1
    Publication Date: 2014-04-15
    Description: A photovoltaic-thermal water heating system is a hybrid energy conversion device transforming the incident solar radiation to yield electrical energy and thermal energy. Plane reflectors are found to be a convenient option for enhancing the solar radiation incident on the collector plane. The present work investigates the performance of a photovoltaic-thermal water heater integrated with a plane reflector mounted on the top edge of the collector for the tropical climate of Calicut (11.25°N, 75.78°E). Performance testing of the system has been carried out for the winter season of the location. The variations in thermal and electrical output are studied for various inclination angles of the reflector. The system performance is evaluated on the basis of system energy efficiency and exergetic efficiency. It is observed that there is a significant enhancement in the thermal and electrical output of the system with the integration of the reflector as compared to the system without the reflector. For the present system, the reflector tilt angle in the range of 85–100° has been found to be suitable in terms of enhanced system output and exergetic efficiency for the winter conditions of Calicut.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2014-03-28
    Description: This study presents a novel search algorithm of maximum power point tracking for photovoltaic power generation systems. The I-V characteristics and the P-V power output under specific irradiation and temperature conditions are simulated. The performance of the algorithm under fully shaded and sudden partially shaded conditions as well as variable insulations levels is investigated. The developed algorithm performs a wide-range search in order to detect rapidly changing weather conditions, and keeps the simulated stand-alone or grid-connected systems continuously operating close to the maximum power point. The performance of the developed algorithm, under extremely changing environmental conditions, is found to be superior compared to that of other conventional algorithms. The results of this study show that, under uniform radiations conditions, the developed algorithm takes only half of the time required by the Perturbation and Observe algorithms to reach maximum power point MMP. Furthermore, when PV is subjected to sudden partial shading conditions, the algorithm rapidly detects these changes and reaches the new MMP in less than a second.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2014-03-17
    Description: Microgrid became one of the key spot in research on distributed energy systems. Since the definition of the microgrid is paradigm of the first time, investigation in this area is growing continuously and there are numerous research projects in this moment all over the world. The increased infiltration of nonlinear loads and power electronic interfaced distribution generation system creates power quality issues in the distributed power system. In this paper, a comprehensive survey on microgrid to improve the power quality parameters is taken as the main objective. Furthermore, the detailed investigations are explored in this paper for the enhancement of power quality issues with the help of an optimization technique, filters, controllers, FACTS devices, compensators, and battery storage.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2014-03-11
    Description: A research on production of biodiesel from lipid of phytoplankton Porphyridium cruentum through ultrasonic method has been done. In this research, we carried out a series of phytoplankton cultures to determine the optimum time of growth and biodiesel synthesis process from phytoplankton lipids. Process of biodiesel synthesis consists of two steps, that is, isolation of phytoplankton lipids and biodiesel synthesis from those lipids. Oil isolation process was carried out by ultrasonic extraction method using ethanol 96%, while biodiesel synthesis was carried out by transesterification reaction using methanol and KOH catalyst under sonication. Weight of biodiesel yield per biomass Porphyridium cruentum is 40,27%. Characterization of biodiesel was well carried out in terms of physical properties which are density and viscosity and chemical properties which are FFA content, saponification value, and iodine value. These values meet the American Society for Testing and Materials (ASTM D6751) standard levels, except for the density value which was 0.9461 g·cm−3 and the FFA content which was 4.6671%.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2014-03-10
    Description: The implantation of wind turbines generally follows a wind potential study which is made using specific numerical tools; the generated expenses are only acceptable for great projects. The purpose of the present paper is to propose a simplified methodology for the evaluation of the wind potential, following three successive steps for the determination of (i) the mean velocity, either directly or by the use of the most occurrence velocity (MOV); (ii) the velocity distribution coming from the single knowledge of the mean velocity by the use of a Rayleigh distribution and a Davenport-Harris law; (iii) an appropriate approximation of the characteristic curve of the turbine, coming from only two technical data. These last two steps allow calculating directly the electric delivered energy for the considered wind turbine. This methodology, called the SWEPT approach, can be easily implemented in a single worksheet. The results returned by the SWEPT tool are of the same order of magnitude than those given by the classical commercial tools. Moreover, everybody, even a “neophyte,” can use this methodology to obtain a first estimation of the wind potential of a site considering a given wind turbine, on the basis of very few general data.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2014-02-27
    Description: The standard air density of 1.225 kg m−3 is often used in determining the energy output of a wind turbine although the energy output is dependent on a site's air density. By using measurements of temperature, dew-point temperature, and pressure, we calculate the monthly air density of moist tropical climates at two sites in the small-island state of Trinidad and Tobago. In addition, we calculate the energy output of a BOREAS 30 kW small wind turbine using the 10 m level wind speed distribution extrapolated to hub height. The average air densities at Crown Point and Piarco were 1.156 kg m−3 and 1.159 kg m−3, respectively, and monthly air densities at both sites were at most 6% less than standard air density. The difference in energy output of the BOREAS 30 kW calculated using standard air density over that using the local site's air density could provide electrical energy for the continuous monthly operation of 6 light bulbs rated at 50 W at Crown Point and 4 light bulbs at Piarco. Thus, communities interested in implementing wind turbine technologies must use the local air density of the site when sizing a wind turbine system for its needs.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2014-02-27
    Description: We present 11.7% efficient p-type crystalline silicon solar cells with a nanoscale textured surface and no dielectric antireflection coating. We propose nanocrystalline-like textured surface consisting of nanocrystalline columnar structures of diameters from 50 to 100 nm and depth of about 500 nm formed by reactive-ion etching (RIE) in multihollow cathode system. This novel nano textured surface acts as an antireflective absorbing surface of c-Si abbreviate as ARNAB (antireflective nanoabsorber). Light shining on the surface of RIE-etched silicon bounces back and forth between the spikes in such a way that most of it never comes back. Radio frequency (RF) hollow cathode discharge allows an improvement of plasma density by an order of magnitude in comparison to standard RF parallel-plate discharge. Desirable black silicon layer has been achieved when RF power of about 20 Watt per one hollow cathode glow is applied for our multihollow cathode system. The RF power frequency was 13.56 MHz. The antireflection property of ARNAB textured surface has been investigated and compared with wet-textured and PECVD coated silicon samples. Solar cell using low-cost spin-on coating technique has been demonstrated in this paper. We have successfully achieved 11.7% efficient large area (98 cm2) ARNAB textured crystalline silicon solar cell using low-cost spin-on coating (SOD) doping.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2014-02-27
    Description: The present rate of economic growth is unsustainable without saving of fossil energy like crude oil, natural gas, or coal. There are many alternatives to fossil energy such as biomass, hydropower, and wind energy. Also, suitable waste management strategy is another important aspect. Development and modernization have brought about a huge increase in the production of all kinds of commodities, which indirectly generate waste. Plastics have been one of the materials because of their wide range of applications due to versatility and relatively low cost. The paper presents the current scenario of the plastic consumption. The aim is to provide the reader with an in depth analysis regarding the recycling techniques of plastic solid waste (PSW). Recycling can be divided into four categories: primary, secondary, tertiary, and quaternary. As calorific value of the plastics is comparable to that of fuel, so production of fuel would be a better alternative. So the methods of converting plastic into fuel, specially pyrolysis and catalytic degradation, are discussed in detail and a brief idea about the gasification is also included. Thus, we attempt to address the problem of plastic waste disposal and shortage of conventional fuel and thereby help in promotion of sustainable environment.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2014-02-27
    Description: A key objective of this paper is to provide an assessment of the current and future situation on the “food versus fuel” debate and to contribute to possible alternatives to minimise or avoid future conflict. The debate has centred on three main areas: (i) food versus biofuel production, (ii) their positive and negative effects (i.e., GHG, climate change, and the broader environment), and (iii) a socioeconomic impact. The debate has been controversial because it has largely been driven by politics, ethical/moral considerations, and vested interests rather than by science. The paper focuses on food prices, land competition, GHG, energy balance, and energy subsidies and concerns with the rapid expansion of bioenergy for electricity and heat, climatic changes, the role of agriculture as a key factor, the potential of biomass energy resources, and the various alternatives to minimize or avoid conflict between food and fuel production. Biomass for energy is both “part of the problem and part of the solution.” It proposes a holistic approach: a new paradigm that takes full account of the diverse and complex nature of biomass energy sources and states that the fundamental underlying causes are social injustice, inequality, waste, and so forth, rather than land competition for food and fuel.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2014-02-27
    Description: Oscillating water column plants are one of the most popular wave energy device types. Prototype OWC units have been operating in various parts of the world since the mid-1980s and such developers have more field experience of this technology than any other relevant plant. The most common turbine used is the self-rectifying Well's turbine which has a rather low peak efficiency if compared to other designs but was preferred in terms of its simplicity and cycle performance. The present study exploits the merits of a new concept for the power extraction process, that of an encaged turbine for OWC plants, which allows conventional high-efficiency turbines to be employed in such plants. This is achieved by guiding the pressurized air into a sequence of three chambers, creating a unidirectional closed air circuit through the turbine. A theoretical model is deployed simulating the operation of the plant and a sensitivity analysis is carried out for the design and working parameters. Results indicate that the power extraction efficiency may exceed the 50% level in a real plant.
    Print ISSN: 2090-7451
    Electronic ISSN: 2090-746X
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Hindawi
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...