The development impact of solar cookers: A review of solar cooking impact research in South Africa

International Nuclear Information System (INIS)

Wentzel, Marlett; Pouris, Anastassios

2007-01-01

Solar cooking is often considered 'a solution looking for a problem'. Solar cookers have long been presented as an interesting solution to the world's problem of dwindling fuel wood sources and other environmental problems associated with wood fuel demand for cooking. However, recent GTZ field work in South Africa showed different benefits instead: the use of solar cookers resulted in appreciable fuel and time savings as well as increased energy security for households using commercial fuels. These observations are based on field tests in South Africa that started in 1996 to investigate the social acceptability of solar cookers and to facilitate local production and commercialisation of the technology. Impact studies and use rate studies have been carried out by a number of different organisations since the inception of the project and although commercialisation of the technology has not been achieved to its fullest potential, impact studies indicate that solar cookers have a positive development impact on households through fuel-, energy- and time savings. The article aims to summarise the findings of the various studies and present an overview of use rates and impact data. A variety of factors influence solar cooker use rates, which in turn determine impacts. Some factors are related to the user, some to the environment in which the cooker is used and some to the cooker itself. Ultimately, the data shows that on average, only 17% of solar cooker owners do not use their stoves after purchase and that active solar cooker users utilise their stoves on average for 31% of their cooking incidences. Since the majority of solar stove buyers actually use their stoves and obtain real benefits, this suggests that that solar cookers are indeed not a solution looking for a problem but a solution worth promoting

Numerical simulation of the performance and economical study of three cookers: solar, hybrid (solar and natural gas) and a LPG (Liquefied Petroleum Gases) cooker for one typical year in Fortaleza-Brazil; Simulacao numerica da performance e estudo da viabilidade economica de tres tipos de fogoes: solar, hibrido (solar e gas natural) e a GLP (Gas Liquefeito do Petroleo) para um ano em Fortaleza

Energy Technology Data Exchange (ETDEWEB)

Silva, Maria Eugenia Vieira da; Santana, Lana Ludmila Pinheiro [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Lab. de Energia Solar e Gas Natural (LESGN); Schwarzer, Klemens [Universidade de Ciencias Aplicadas de Aachen (Germany). Solar Institute Juelich; Miller, Francisco Mateus [PETROBRAS, Rio de Janeiro, RJ (Brazil); Baratelli Junior, Fernando [PETROBRAS, Rio de Janeiro, RJ (Brazil). Gerencia de Gas e Energia

2004-07-01

Alternative energy sources can represent viable economical solutions for the energy supply problems and also minimize damages to the environment. This research paper presents an economical and technical study of three different types of cookers: a solar cooker, a hybrid cooker and a conventional LPG cooker, through simulation for one typical year in Fortaleza. The solar cooker used in the experiments is composed of two pots, an oven, a tank of storage and 2m{sup 2} of solar collector area. The hybrid cooker has the same structure of the solar one with an additional natural gas burner, and the LPG stove can be easily found in the market. To find the value of the necessary energy to make food in a solar cooker, the amount of solar radiation was measured, as well as the sensible and latent efficiencies of the used stove. In the hybrid, it was considered that the natural gas is used only in the periods of the day when the amount of solar energy is not enough to heat the system up to the desired temperature. The results show an economical and technical comparison of the three different types of cookers. (author)

Solar cookers with and without thermal storage - A review

International Nuclear Information System (INIS)

Muthusivagami, R.M.; Velraj, R.; Sethumadhavan, R.

2010-01-01

The continuous increase in the level of green house gas emissions and the increase in fuel prices are the main driving forces behind efforts to more effectively utilize various sources of renewable energy. In many parts of the world, direct solar radiation is considered to be one of the most prospective sources of energy. Among the different energy end uses, energy for cooking is one of the basic and dominant end uses in developing countries. Energy requirement for cooking accounts for 36% of total primary energy consumption in India. Hence, there is a critical need for the development of alternative, appropriate, affordable mode of cooking for use in developing countries. However, the large scale utilization of this form of energy is possible only if the effective technology for its storage can be developed with acceptable capital and running costs. Thermal energy storage is essential whenever there is a mismatch between the supply and consumption of energy. Latent heat storage in a phase change material is very attractive because of its high storage density with small temperature swing. The choice of PCM plays an important role in addition to heat transfer mechanism in the PCM. In this present work a review has been made to study all the research and development work carried out in the field of solar cooker in particular the storage type solar cookers. A novel concept of PCM-based storage type solar cooker is also presented which is under experimental investigation. (author)

Design and Realisation of a Parabolic Solar Cooker

International Nuclear Information System (INIS)

Ouannene, M; Chaouachi, B; Gabsi, S

2009-01-01

The sun s energy is really powerful. Solar energy is renewable and it s free. We can use it to make electricity, to heat buildings and to cook. The field of cooking consumes many fossil fuels such as gas and wood. Million people cannot find enough gas and/or wood to cook, so using solar cookers is a good idea. During this work, we designed, built and studied a parabolic solar cooker. The characteristic equations and the experimental results are given

Solar cooker of the portable parabolic type incorporating heat storage based on PCM

International Nuclear Information System (INIS)

Lecuona, Antonio; Nogueira, José-Ignacio; Ventas, Rubén; Rodríguez-Hidalgo, María-del-Carmen; Legrand, Mathieu

2013-01-01

Highlights: ► A portable utensil for commercial paraboloid type solar cookers is proposed. ► It includes heat storage with phase change materials (PCMs). ► The utensil is stored indoors in a thermally insulating box after charging. ► A thermal 1-D model predicts its performance in sunny days. ► The set allows cooking lunch, dinner and next day the breakfast for a family. - Abstract: This paper reviews relevant issues on solar cooking in order to define and evaluate an innovative layout of a portable solar cooker of the standard concentrating parabolic type that incorporates a daily thermal storage utensil. This utensil is formed by two conventional coaxial cylindrical cooking pots, an internal one and a larger external one. The void space between the two coaxial pots is filled with a phase change material (PCM) forming an intermediate jacket. The ensemble is thermally simulated using 1-D finite differences. A lumped elements model with convective heat transfer correlations is used for the internal behavior of the utensil, subjected to external radiation. This numerical model is used to study its transient behavior for the climatic conditions of Madrid, and validated with experimental data. Two options have been checked as possible PCMs: technical grade paraffin and erythritol. The results indicate that cooking the lunch for a family is possible simultaneously with heat storage along the day. Keeping afterwards the utensil inside an insulating box indoors allows cooking the dinner with the retained heat and also the next day breakfast. This expands the applicability of solar cooking and sustains the possibility of all the day around cooking using solar energy with a low inventory cost

Prediction and experimental validation of stagnation temperature attained by a solar cooker of hot box type

Energy Technology Data Exchange (ETDEWEB)

Narasimha Rao, A. V; Srikrishna, D. V. N [Warangal (India)

2000-07-01

A hot box type solar cooker, having double glass covers and a plane mirror reflector, is tested for stagnation temperature. A computer code is developed based on the analytical model proposed by Vaishya et. al. The global and beam components of solar radiation measured at Warangal are made use to predict the stagnation temperature of the cooker. The observed values of stagnation temperature at Warangal are compared with those of predicted values. A good agreement of the measured and observed values of the stagnation temperature is observed during the afternoon period. The lag in the observed values during the forenoon may be due to thermal inertia of the cooker. [Spanish] Se probo una estufa solar de tipo caja caliente con cubiertas dobles de vidrio y un espejo reflector plano para medir la temperatura de estancamiento. Se desarrollo un codigo de computacion basado en el modelo analitico propuesto por Vaishya et. al. Los componentes de la radiacion solar globales y de rayo medidos en Warangal se usan para predecir la temperatura de estancamiento de la estufa. Los valores observados de la temperatura de estancamiento en Warangal se comparan con los valores predichos. Se aprecia una buena concidencia de los valores medidos y observados de la temperatura de estancamiento durante el periodo de la tarde. El retraso de los valores observados durante la manana puede ser debido a la inercia termica de la estufa.

Design, construction and performance evaluation of aBox type solar cooker with a glazing wiper mechanism

Directory of Open Access Journals (Sweden)

Zeleke Ademe

2018-01-01

Full Text Available This research work describes the performance evaluation of a double-glazed box-type solar oven with three reflectors and with a vapor wiper mechanism fabricated using locally available materials. The box cooker has external box dimensions of 600 mm × 600 mm × 250 mm and pyramidal internal box dimensions of 460 mm × 460 mm top face and 300 mm × 300 mm bottom face with depth of 150 mm. The thermal performance was tested as per the ASAE International Test procedure and Bureau of Indian Standards (BIS for testing the thermal performance of a box-type solar cooker. The obtained test results after employing required calculations were figures of merit F1 = 0.123 Km2/W, F2 = 0.540, the standard cooking power P50 = 36 W and the cumulative efficiency to be 22%, whereas with the application of the wiper mechanism, it was found that F1 = 0.123, F2 = 0.827, the standard cooking power (P50 = 51 W, and the cumulative efficiency to be 31.4%. The standard boiling time of 1.43 kg of water was calculated to be 53.54 and 88.84 minutes for the cooker with and without the application of wiper mechanism respectively. The thermal distribution of the cooker was modeled using interior box geometry as a boundary condition with ANSYS 15.0. The temperature distribution inside the box was simulated and the maximum wall temperature was found to be 139 ℃. This was lower than the experimental results by 22 ℃. The method of modeling and simulation of the cooker with and without a wiper mechanism is similar except for the variation of the transmittance of the glass due to shading of vapor which can be deducted from the cumulative efficiency for the latter case. The results show that using the vapor wiper mechanism increases the cumulative efficiency by 9.4% and reduces the boiling time by 35.3 minutes. Finally, the techno-economic analysis shows that the cooker with a vapor wiper mechanism has a good reliability for outdoor cooking of food and is economically feasible.

Benefits and constraints in the use of solar cooker

International Nuclear Information System (INIS)

Ilyas, S.Z.

2008-01-01

Women in Pakistan have been overlooked during and after the planning anti implementation of household energy projects for decades. The immediate impact of domestic household energy projects falls on the women first. Since women are the ones who deal mostly with energy at the domestic level A sample of 100 women users of solar cookers was selected randomly. Majority of the respondents were in the age group 30-55 years (80%) and possessed solar cooker for more than one year (74%). Nutritional aspects (preserving nutritive value and food flavors) environmental aspects (keeping environment clean) and economical aspects (saving fuel and money) were perceived at most beneficial. Personal benefits (saving of time me and convenience) ranked low under benefit. Situational constraints like no cooking after evening find seasonal use of the cooker were perceived as severe constraints followed by technical constraints (device not being durable) and personal constraints (shifting of device). The paper also highlights the modification desired in the design of the solar cooker. (author)

Prediction and experimental verification of performance of box type solar cooker - Part I. Cooking vessel with central cylindrical cavity

International Nuclear Information System (INIS)

Reddy, Avala Raji; Rao, A.V. Narasimha

2007-01-01

The performance of conventional box type solar cookers can be improved by better designs of cooking vessels with proper understanding of the heat flow to the material to be cooked. An attempt has been made in this article to arrive at a mathematical model to understand the heat flow process to the cooking vessel and thereby to the food material. The mathematical model considers a double glazed hot box type solar cooker loaded with two different types of vessels, kept either on the floor of the cooker or on lugs. The performance of the cooking vessel with a central cylindrical cavity is compared with that of a conventional cylindrical cooking vessel. It is found from the experiments and modeling that the cooking vessel with a central cylindrical cavity on lugs results in a higher temperature of the thermic fluid than that of a conventional vessel on the floor or on lugs. The average improvement of performance of the vessel with a central cylindrical cavity kept on lugs is found to be 5.9% and 2.4% more than that of a conventional cylindrical vessel on the floor and on lugs, respectively

Artificial neural networks approach on solar parabolic dish cooker

International Nuclear Information System (INIS)

Lokeswaran, S.; Eswaramoorthy, M.

2011-01-01

This paper presents heat transfer analysis of solar parabolic dish cooker using Artificial Neural Network (ANN). The objective of this study to envisage thermal performance parameters such as receiver plate and pot water temperatures of the solar parabolic dish cooker by using the ANN for experimental data. An experiment is conducted under two cases (1) cooker with plain receiver and (2) cooker with porous receiver. The Back Propagation (BP) algorithm is used to train and test networks and ANN predictions are compared with experimental results. Different network configurations are studied by the aid of searching a relatively better network for prediction. The results showed a good regression analysis with the correlation coefficients in the range of 0.9968-0.9992 and mean relative errors (MREs) in the range of 1.2586-4.0346% for the test data set. Thus ANN model can successfully be used for the prediction of the thermal performance parameters of parabolic dish cooker with reasonable degree of accuracy. (authors)

Solar cooking in Mozambique—an investigation of end-user's needs for the design of solar cookers

International Nuclear Information System (INIS)

Otte, Pia Piroschka

2014-01-01

Sub-Saharan Africa is characterized by insufficient access to modern energy. One solution to this problem could be the use of solar energy to satisfy the current energy demand. However, solar energy technologies have shown limited success up to now. In the literature it is argued that solar cookers are often implemented as a “solution looking for a problem”, without consideration of the end-user needs. This study contributes to this debate by investigating the energy patterns and cooking profiles of public institutions for the design and implementation of solar cookers in the case of Mozambique. Interviews were conducted with 12 health institutions in Maputo and Sofala province in Mozambique. The paper concludes that solar cooking presents one solution to overcome the energy crisis in Sub-Saharan Africa but not the only solution. Solar cookers could improve the current cooking situation if combined with heat storage, back up, or a hybrid system that ensures reliability also during evening hours and rainy days. In general we could see that solar cookers should fulfill a variety of requirements related to cooking habits, schedule of daily routine and performance that are considered to enhance levels of use. - Highlights: • The study investigates energy patterns of public health institutions in Mozambique. • The aim is to find out how a solar cooker should be designed for implementation. • Solar cookers should be reliable and lead to economic savings. • Users are skeptical towards the use of solar cookers during the rainy season. • Solar cookers need to be combined with other energy sources to be successful

Numerical heat transfer studies of PCMs used in a box-type solar cooker

Energy Technology Data Exchange (ETDEWEB)

Chen, C.R.; Sharma, Atul [Department of Mechanical Engineering, Kun Shan University, 949 Da-Wan Road, Yung-Kung City, Tainan Hsien 710 (China); Tyagi, S.K. [Department of Building Services Engineering, The Hong Kong Polytechnic University, Hung Hom, Kowloon (China); Buddhi, D. [Thermal Energy Storage Laboratory, School of Energy and Environmental Studies, Khandwa Road Campus, Devi Ahilya University, Indore 452017 (India)

2008-05-15

Theoretical investigations on the phase change materials (PCMs) used as the heat storage media for box-type solar cookers have been conducted in this study. The selected PCMs are magnesium nitrate hexahydrate, stearic acid, acetamide, acetanilide and erythritol. For a two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Different materials such as glass, stainless steel, tin, aluminum mixed, aluminum and copper are used as the heat exchanger container materials in the numerical calculations. The large value of thermal conductivity of heat exchanger container material did not make a significant contribution on the melt fraction except for at very low thermal conductivities. Based on the theoretical results, stearic acid and acetamide are found to be good compatibility with latent heat storage system. It is also found that the initial temperature of PCM does not have very important effects on the melting time, while the boundary wall temperature plays an important role during the melting and has a strong effect on the melt fraction. The results also show that the effect of thickness of container material on the melt fraction is insignificant. The results obtained in this paper show that in a box-type solar cooker, acetamide and stearic acid should be used as a latent heat storage materials. (author)

Ultra-light solar cooker; Cuiseur solaire ultra-leger

Energy Technology Data Exchange (ETDEWEB)

Goetz, M.

2006-07-01

The aim of this project was the development of a solar cooker for travellers. The cooker shouldn't weight more than 2 kg including the cooking pot, it should be easy to handle and it should cook for two within an hour. The first project phase was an intense theoretical study of the market, patents, competitors and mirror geometries. The result were two innovating ideas: A 'linear Fresnel geometry' and a 'section of a parabola'. Both geometries allow the cooking pot to be near the ground. In the second phase, prototypes were built and tested. A first series allowed to choose which technology to follow and gave us ideas for the advanced models of the second series. These models (of the 'linear Fresnel' type) are foldable due to a scissor structure, they can slightly change their shape according to the sun's height and the cooking pot has its windshield. We reached the goal of an innovative solar cooker weighting less than our limit. It takes a reasonable time to set up, it is well transportable and its stability to wind is sufficient. The cooking power is a bit lower than planned, but rice, vegetables and even a small bread have been successfully cooked. (author)

Experimental characterization of a solar cooker with thermal energy storage based on solar salt

Science.gov (United States)

Coccia, G.; Di Nicola, G.; Tomassetti, S.; Gabrielli, G.; Chieruzzi, M.; Pierantozzi, M.

2017-11-01

High temperature solar cooking allows to cook food fast and with good efficiency. An unavoidable drawback of this technology is that it requires nearly clear-sky conditions. In addition, evening cooking is difficult to be accomplished, particularly on the winter season during which solar radiation availability is limited to a few hours in the afternoon in most of countries. These restrictions could be overcome using a cooker thermal storage unit (TSU). In this work, a TSU based on solar salt was studied. The unit consists of two metal concentric cylindrical vessels, connected together to form a double-walled vessel. The volume between walls was filled with a certain amount of nitrate based phase change material (solar salt). In order to characterize the TSU, a test bench used to assess solar cooker performance was adopted. Experimental load tests with the TSU were carried out to evaluate the cooker performance. The obtained preliminary results show that the adoption of the solar salt TSU seems to allow both the opportunity of evening cooking and the possibility to better stabilize the cooker temperature when sky conditions are variable.

Solar cooker effect test and temperature field simulation of radio telescope subreflector

International Nuclear Information System (INIS)

Chen, Deshen; Wang, Huajie; Qian, Hongliang; Zhang, Gang; Shen, Shizhao

2016-01-01

Highlights: • Solar cooker effect test of a telescope subreflector is conducted for the first time. • The cause and temperature distribution regularities are analyzed contrastively. • Simulation methods are proposed using light beam segmentation and tracking methods. • The validity of simulation methods is evaluated using the test results. - Abstract: The solar cooker effect can cause a local high temperature of the subreflector and can directly affect the working performance of the radio telescope. To study the daily temperature field and solar cooker effect of a subreflector, experimental studies are carried out with a 3-m-diameter radio telescope model for the first time. Initially, the solar temperature distribution rules, especially the solar cooker effect, are summarized according to the field test results under the most unfavorable conditions. Then, a numerical simulation for the solar temperature field of the subreflector is studied by light beam segmentation and tracking methods. Finally, the validity of the simulation methods is evaluated using the test results. The experimental studies prove that the solar cooker effect really exists and should not be overlooked. In addition, simulation methods for the subreflector temperature field proposed in this paper are effective. The research methods and conclusions can provide valuable references for thermal design, monitoring and control of similar high-precision radio telescopes.

Determination of Performance Measuring Parameters of an Improved Dual Paraboloid Solar Cooker

Directory of Open Access Journals (Sweden)

Suhail Zaki Farooqui

2017-01-01

Full Text Available An experimental investigation into the performance evaluation of an improved dual reflector foldable paraboloid solar cooker has been reported, along with its energy and exergy analysis. The best attribute of this lightweight and low-cost solar cooker is its high performance coupled with the ease of handling. The cooker utilizes two paraboloid reflectors made out of Mylar-coated fiberglass dishes, each having a diameter of 90 cm and focal length of 105 cm. The total intercepted radiation energy is 1.08 kW under standard test conditions. Stagnation temperatures of up to 330°C and cooking temperatures of up to 290°C have been attained with load. Altogether, 9 experiments have been performed with and without load. Loaded tests have been conducted with water and vegetable oil. Results indicate an average cooking power of 485 W, peak exergy gain of 60.53 W, quality factor of 0.077, and a high product of temperature difference gap at half peak power to peak power of 4364.33 W·K. The maximum exergy output power attained was 70 W, while maximum exergy efficiency was 8–10%. All performance measuring parameters indicate that it is a high performance solar cooker for rural and urban communities and is suitable for all types of oil- and water-based cooking.

The use of paraffin wax in a new solar cooker with inner and outer reflectors

Directory of Open Access Journals (Sweden)

Arabacigil Bihter

2015-01-01

Full Text Available In this paper, the potential use and effectiveness of paraffin wax in a new solar cooker was experimentally investigated during daylight and late evening hours. For these experiments, a cooker having an inner reflecting surface was designed, constructed by filling paraffin wax and metal shavings. The side- and sub-surface temperatures of the paraffin wax in the cooker are measured in the summer months of June and July. The thermal efficiency of the cooker was tested on different conditions. The results show that the optimum angle of the outer reflector is 30°. Here, the peak temperature of the paraffin wax in the solar cooker was 83.4 °C. The average solar radiation reflected makes a contribution of 9.26% to the temperature of paraffin wax with the outer reflector. The solar cooker with the outer reflector angle of 30° receives also reflected radiation from the inner reflectors. Besides, the heating time is decreased to approximately 1 hour. The designed solar cooker can be effectively used with 30.3% daily thermal efficiency and paraffin wax due to the amount of energy stored.

Heat Transfer Convection in The Cooking of Apple Using a Solar Cooker Box-Type

International Nuclear Information System (INIS)

Terres, H; Chávez, S; Lizardi, A; López, R; Vaca, M; Flores, J; Salazar, A

2015-01-01

In this work, experimental results to determine the convection heat transfer coefficient in the cooking process of apple using a solar cooker box-type are presented. Experimental data of temperatures for water, surface and central point of the apple were used. To determine the convection coefficient, the apple was modelled as a sphere. The temperatures evolution was defined using thermocouples located at water, surface and central point in the vegetables. Using heat transfer convection equations in transitory state and the temperatures measured, the Biot number and the convection coefficient were determined

Heat Transfer Convection in The Cooking of Apple Using a Solar Cooker Box-Type

Science.gov (United States)

Terres, H.; Chávez, S.; Lizardi, A.; López, R.; Vaca, M.; Flores, J.; Salazar, A.

2015-01-01

In this work, experimental results to determine the convection heat transfer coefficient in the cooking process of apple using a solar cooker box-type are presented. Experimental data of temperatures for water, surface and central point of the apple were used. To determine the convection coefficient, the apple was modelled as a sphere. The temperatures evolution was defined using thermocouples located at water, surface and central point in the vegetables. Using heat transfer convection equations in transitory state and the temperatures measured, the Biot number and the convection coefficient were determined.

Solar cookers in developing countries—What is their key to success?

International Nuclear Information System (INIS)

Otte, Pia Piroschka

2013-01-01

In developing countries households and institutions heavily rely on biomass to satisfy their energy needs. The unsustainable use of biomass is accompanied by several negative health and environmental impacts. As a clean energy source, solar cooking presents one alternative solution. In spite of its multiple benefits; however, solar cookers have experienced little success. Curiously, there has been little discussion about this in academic circles. Most research concerns technical improvements of solar cookers, rather than on the reasons why these cookers are not actually adopted in the field. This paper fills the gap by developing a comprehensive list of variables that influence the adoption of solar cooking: (1) economic, (2) social, (3) cultural, (4) environmental, (5) political and (6) technical. Furthermore, we can see that some solar cooking promoters are able to control for some of the variables (e.g., environmental factors), but not others (e.g. technical, social and cultural factors). The latter can only be captured through a needs assessment of the target group. This sort of assessment is a demanding but necessary step for the successful outcome of a solar cooking project. - Highlights: • The paper elaborates a list of variables influencing the adoption of solar cookers. • The interrelations of the variables are illustrated in a flow chart. • Environmental factors are easiest to control for by solar cooking organizations. • Technical, social and cultural variables can be captured through a needs assessment

From Solar Cookers Towards Viable Solar Cooking Technology

DEFF Research Database (Denmark)

Ahmad, Bashir

1997-01-01

A broader concept of technology encompassing the technical and the societal aspects is introduced. Viability of technology and technological development process from a socio-technical view- point is discussed. Based on the above, the question of securing viability of solar cooking technology...... is taken up. It is discussed that actor- approach can operationally relate the abstract societal factors with those of technical aspects. Some concrete measures regarding application of solar cooker projects are drawn from the discussion: solar cooking projects should a) be based on user and producer...

Experimental investigation of novel indirect solar cooker with indoor PCM thermal storage and cooking unit

International Nuclear Information System (INIS)

Hussein, H.M.S.; El-Ghetany, H.H.; Nada, S.A.

2008-01-01

In the present study, a novel indirect solar cooker with outdoor elliptical cross section, wickless heat pipes, flat-plate solar collector and integrated indoor PCM thermal storage and cooking unit is designed, constructed and tested under actual meteorological conditions of Giza, Egypt. Two plane reflectors are used to enhance the insolation falling on the cooker's collector, while magnesium nitrate hexahydrate (T m = 89 deg. C, latent heat of fusion 134 kJ/kg) is used as the PCM inside the indoor cooking unit of the cooker. It is found that the average daily enhancement in the solar radiation incident on the collector surface by the south and north facing reflectors is about 24%. Different experiments have been performed on the solar cooker without load and with different loads at different loading times to study the possibility of benefit from the virtues of the elliptical cross section wickless heat pipes and PCMs in indirect solar cookers to cook food at noon and evening and to keep food warm at night and in early morning. The results indicate that the present solar cooker can be used successfully for cooking different kinds of meals at noon, afternoon and evening times, while it can be used for heating or keeping meals hot at night and early morning

Solar Cooker Study under Oman Conditions for Late Evening Cooking Using Stearic Acid and Acetanilide as PCM Materials

Directory of Open Access Journals (Sweden)

Nagaraj Nayak

2016-01-01

Full Text Available Solar energy is an alternative source of nonrenewable energy in Oman. Sultanate of Oman government showed initiation into utilization of solar energy for domestic applications. Conversion of solar radiation into useful heat is the simplest application of solar energy, in which it can be used for late evening cooking. In this context, present work highlighted the design and development of solar cooker for Oman climatic conditions. The current work signifies usage of solar cooker for late evening cooking using stearic acid and acetanilide as phase change materials (PCM. Solar cooker parts are developed in-house and connected to water heating system compounded with evacuated tubes solar collector and storage tank. The circumference of cooker unit is incorporated with spiral stainless steel heat exchanger and annulus area of the pot is filled with PCM material. PCM releases heat at late evening and effective cooking up to 7:30 PM is noticed. The experimental results indicated the cooker efficiency of 30% and collector efficiency of 60–65% during the study. Overall, experiments showed satisfactory performance on the developed cooker.

Use of solar parabolic cookers (SK-14) in Nepal

Energy Technology Data Exchange (ETDEWEB)

Shrestha, S. [Asia Network for Small Scale Bioresources, Kathmandu (Nepal)

2000-07-01

Solar Cooker is a device that uses only sunlight to cook food and pasteurise water. Solar cooker can be used along with other cooking devices to save cost, fuel and the time spent in gathering fuelwood. Solar cooking enables individual families to do without commercially sold fuel and help save money. In Nepal, supply of energy is one of the major problems for both urban and rural households. Increase in population, high migration, expensive fuel bills, environmental degradation, and unsafe drinking water have resulted in the keen interest from people of Nepal in the use of solar energy. The increasing number of tourists and trekkers are now one of the major sources of income and many people are engaged in running hotels, lodges, and restaurants. This has also increased the fuel demand. This paper highlights the current energy situation of Nepal, the technical details of solar parabolic cooker (SK-14), its uses throughout Nepal, strategies adopted by various organisations for its promotion. A lot of effort have been made by various organisations, educational, governmental and health related institutions in order to introduce solar cooking programs in villages of Nepal. The parameters, which have influenced the adoption of this technology in Nepal are also mentioned. Various awareness programs and the government subsidy program are playing considerable role in dissemination of such technologies. The promotion activities with the objective of mass awareness have long term effect and sustainable rather than instant business. Continued efforts to create awareness, development of models as well as proper promotion and dissemination are required. (au)

Development of a household solar box cooker | Fumen ...

African Journals Online (AJOL)

About 60 - 80% Nigerians live in the rural areas and rely heavily on firewood as the main household energy source. A solar cooker or solar oven that uses direct sunlight, the cheapest and the most sustainable source of energy could be introduced in rural communities to help reduce the amount of firewood used by rural ...

Performance and potential of community solar cooker in agroindustries

Energy Technology Data Exchange (ETDEWEB)

Nahar, N. M; Sharma, P [Central Arid Zone Research Institute (India)

2000-07-01

Performance and testing of a community solar cooker having absorber area 3.2 m{sup 2} has been described. The cooker is based on hot box principle having a single reflector. The width to length ratio of reflector is four so that azimuthal tracking is not required. Therefore cooker is kept fixed, facing equator. The maximum stagnation temperature inside cooking chamber during summer is 146 Celsius degrees and 136 Celsius degrees in winter. The efficiency of the cooker is 28.4%. The cooker can be used twice a day for about 254 days and once a day for about 67 days in a year. The cooker can be used in cottage industries for Aanwala, ber et cetera for jam and jelly making. The cost of the cooker is only Rs. 18,000.00 (1.0 US $=Rs. 44.00) that can be recovered in less than a year and one can earn about Rs. 10,000.00 per month. [Spanish] Se describe el rendimiento y la prueba de una estufa solar con un absorbedor en una comunidad con un area de 3.2 m{sup 2}. La estufa esta basada en el principio de la caja caliente que tiene un solo reflector. La proporcion del ancho a largo de reflector es de manera que el seguimiento azimutal no se requiere. Por lo que la estufa se mantiene fijo dando frente al ecuador. La maxima temperatura de estancamiento dentro de la camara de cocimiento durante el verano es de 146 grados celsius y de 136 grados celsius en invierno. La eficiencia de la estufa es de 28.4% la estufa puede usarse 2 veces por dia durante alrededor de 254 dias y una vez por dia durante aproximadamente 67 dias en un ano. La estufa puede usarse en industrias queseras y de cerveza, etc., para la manufactura de jamon y gelatina en Anwala. El costo de la estufa es de solamente 18,000 Rs(rupias) (un US dolar = 44.00 rupias) el cual puede ser recuperado en menos de un ano y se pueden ganar aproximadamente 10,000.00 rupias por mes.

Efficient solar energy conversion in a low cost flat-plate solar cooker fabricated for use in rural areas of the south asian countries

International Nuclear Information System (INIS)

Jamil, Y.; Raza, M.; Muhammad, N.

2008-01-01

Solar flat plate cooker has been designed and fabricated for use in the rural areas of the South Asian countries. Indigenous low cost materials have been utilized for the fabrication of the cooker. The manufacturing cost of the cooker is less than US$ 150. The aim of this work is to utilize direct solar energy for cooking purpose. A flat plate absorber made of copper is used to absorb the heat energy from the sun. The maximum recorded plate temperature of the cooker was 110 degree C at an ambient temperature of 37 degree C. At this temperature sufficient steam is produced which is channeled to the cooking region though copper pipes. The cooker is found to be effective for cooking traditional food items like pulses, vegetables, meat, eggs, etc. It may be used as an alternative of fossil fuels in the rural areas of the South Asian countries, particularly by the rural women. (author)

Experimental studies on solar parabolic dish cooker with porous medium

International Nuclear Information System (INIS)

Lokeswaran, S.; Eswaramoorthy, M.

2012-01-01

The solar cooking is the alternate method of cooking to reduce consumptions of fossil fuels. An affordable, energy efficient solar cooking technology is much need due to the fossil fuels increasing cost and it is the hottest research topic in all over the world. This paper presents an experimental analysis of the heat transfer enhancement of solar parabolic dish cookers by a porous medium made of scrap material. Using the stagnation temperature test and water boiling test are conducted on the cooking vessel with and without porous medium. Experimental results are compared for both cases in terms of thermal performance, optical efficiency, heat loss factor and cooking power. (authors)

Multi-criteria evaluation of cooking energy alternatives for promoting parabolic solar cooker in India

Energy Technology Data Exchange (ETDEWEB)

Pohekar, S.D. [Birla Institute of Technology and Science, Pilani (India). CREED; Ramachandran, M. [Birla Institute of Technology and Science, Dubai (United Arab Emirates)

2004-07-01

The policy formulation for cooking energy substitution by renewables is addressed in multi-criteria context. A survey is conducted to know the perceptions of different decision making groups on present dissemination of various cooking energy alternatives in India. Nine cooking energy alternatives are evaluated on 30 different criteria comprising of technical, economic, environmental/social, behavioural and commercial issues. Preference Ranking Organization METHod for Enrichment Evaluation (PROMETHEE), a multi-criteria decision making method of outranking nature is used to rank the alternatives. It is found that liquefied petroleum gas (LPG) stove is the most preferred device, followed by kerosene stove, solar box cooker and parabolic solar cooker (PSC) in that order. A sensitivity analysis is also carried out for identifying potential areas for improvement for PSC. On the basis of results, strategies for promoting wide spread use of PSC are formulated. (author)

Daily heat storage for a concentrating solar cooker; Tages-Hitzespeicher fuer einen konzentrierenden Solarkocher

Energy Technology Data Exchange (ETDEWEB)

Goetz, M.

2002-07-01

This report for the Swiss Federal Office of Energy (SFOE) describes a project that concerned the development and testing of two storage heating elements for automatic parabolic solar cookers. The first variant is made of solid aluminium and stores sensible heat; the second one is filled with tin and uses the latent heat of the solid-liquid phase-change of the tin as well as the storage of sensible heat, too. Various materials for use in heat storage - metals and salts - were examined. Tin was finally chosen for further experiments. The author concludes that the storage units work well, whereby the tin variant was more flexible for changing-weather conditions because of its latent heat storage. Because of their weight, however, the mobile use of the units is restricted. Suggestions for further development are made, including the integration of the units in the bases of solar cookers and the simplification of their construction. The article also reviews the development and application of concentrating-mirror solar cooking systems in India, where large-scale use can be found.

Thermal performance evaluation of a latent heat storage unit for late evening cooking in a solar cooker having three reflectors

Energy Technology Data Exchange (ETDEWEB)

Buddhi, D.; Sharma, A. [Devi Ahilya University, Indore (India). School of Energy and Environmental Studies, Thermal Energy Storage Laboratory; Sharma, S.D. [Mie University, Tsu (Japan). Faculty of Engineering, Department of Architecture

2003-04-01

In this paper, a phase change material (PCM) storage unit for a solar cooker was designed and developed to store energy during sunshine hours. The stored energy was utilised to cook food in the late evening. Commercial grade acetanilide (melting point 118.9 {sup o}C, latent heat of fusion 222 kJ/kg) was used as a latent heat storage material. Evening cooking experiments were conducted with different loads and loading times during the winter season. The experimental results showed that late evening cooking is possible in a solar cooker having three reflectors to enhance the incident solar radiation with the PCM storage unit. (author)

WHY ARE SOLAR COOKERS STILL UNPOPULAR AMONG DEVELOPMENT EXPERTS?

Directory of Open Access Journals (Sweden)

PAUL KRÄMER

2010-03-01

Full Text Available The household energy problem in countries of the South remains critical. Solar cookers can contribute to a solution; however, their potential is seldom realized by the academic and political world. By contrast, bio-energy as a replacement for fossil fuels is increasingly popular in Europe. With regard to tropical developing countries, this European enthusiasm implies unrealistic views about the renewability of woody biomass in drylands under conditions of climate change and increasing population pressure. Another reason of error is a too narrow concept of modernization of energy supplies, neglecting affordable cooking energies and focusing nearly exclusively on electricity. Cheap solar cooking appliances with a low thermal output are useful in extreme situations like refugee camps to allow survival of large numbers of individuals or mini-groups. Under normal circumstances, families need appliances which can cope with the volume of staple food needed, which is the number of people times about 1 litre/person/day.

Fast thermal cycling of acetanilide and magnesium chloride hexahydrate for indoor solar cooking

International Nuclear Information System (INIS)

El-Sebaii, A.A.; Al-Amir, S.; Al-Marzouki, F.M.; Faidah, Adel S.; Al-Ghamdi, A.A.; Al-Heniti, S.

2009-01-01

Solar cookers are broadly divided into a direct or focusing type, indirect or box-type and advanced solar cookers. The focusing and box-type solar cookers are for outdoor applications. The advanced solar cookers have the advantage of being usable indoors and thus solve one of the problems, which impede the social acceptance of solar cookers. The advanced type solar cookers are employing additional solar units that increase the cost. Therefore, the solar cooker must contain a heat storage medium to store thermal energy for use during off-sunshine hours. The main aim of this study is to investigate the influence of the melting/solidification fast cycling of the commercial grade acetanilide C 8 H 9 NO (T m = 116 deg. C) and magnesium chloride hexahydrate MgCl 2 .6H 2 O (T m = 116.7 deg. C) on their thermo-physical properties; such as melting point and latent heat of fusion, to be used as storage media inside solar cookers. Five hundred cycles have been performed. The thermo-physical properties are measured using the differential scanning calorimetric technique. The compatibility of the selected phase change materials (PCMs) with the containing material is also studied via the surface investigation, using the SIM technique, of aluminum and stainless steel samples embedded in the PCM during cycling. It is inferred that acetanilide is a promising PCM for cooking indoors and during law intensity solar radiation periods with good compatibility with aluminum as a containing material. However, MgCl 2 .6H 2 O is not stable during its thermal cycling (even with the extra water principle) due to the phase segregation problem; therefore, it is not recommended as a storage material inside solar cookers for cooking indoors. It is also indicated that MgCl 2 .6H 2 O is not compatible with either aluminum or stainless steel.

Fast thermal cycling of acetanilide and magnesium chloride hexahydrate for indoor solar cooking

Energy Technology Data Exchange (ETDEWEB)

El-Sebaii, A.A.; Al-Amir, S.; Al-Marzouki, F.M.; Faidah, Adel S.; Al-Ghamdi, A.A.; Al-Heniti, S. [Physics Dept., Faculty of Science, King Abdul Aziz Univ., P.O. Box 80203, Jeddah 21589 (Saudi Arabia)

2009-12-15

Solar cookers are broadly divided into a direct or focusing type, indirect or box-type and advanced solar cookers. The focusing and box-type solar cookers are for outdoor applications. The advanced solar cookers have the advantage of being usable indoors and thus solve one of the problems, which impede the social acceptance of solar cookers. The advanced type solar cookers are employing additional solar units that increase the cost. Therefore, the solar cooker must contain a heat storage medium to store thermal energy for use during off-sunshine hours. The main aim of this study is to investigate the influence of the melting/solidification fast cycling of the commercial grade acetanilide C{sub 8}H{sub 9}NO (T{sub m} = 116 C) and magnesium chloride hexahydrate MgCl{sub 2}.6H{sub 2}O (T{sub m} = 116.7 C) on their thermo-physical properties; such as melting point and latent heat of fusion, to be used as storage media inside solar cookers. Five hundred cycles have been performed. The thermo-physical properties are measured using the differential scanning calorimetric technique. The compatibility of the selected phase change materials (PCMs) with the containing material is also studied via the surface investigation, using the SIM technique, of aluminum and stainless steel samples embedded in the PCM during cycling. It is inferred that acetanilide is a promising PCM for cooking indoors and during low intensity solar radiation periods with good compatibility with aluminum as a containing material. However, MgCl{sub 2}.6H{sub 2}O is not stable during its thermal cycling (even with the extra water principle) due to the phase segregation problem; therefore, it is not recommended as a storage material inside solar cookers for cooking indoors. It is also indicated that MgCl{sub 2}.6H{sub 2}O is not compatible with either aluminum or stainless steel. (author)

Techno-economic evaluation of masonry type animal feed solar cooker in rural areas of an Indian state Rajasthan

International Nuclear Information System (INIS)

Panwar, N.L.; Kothari, Surendra; Kaushik, S.C.

2013-01-01

Utilisation of animal draft power in agricultural operation and milk production is highly dependent on the feed and fodder. Properly cooked feed is digestive in nature and enhance milk production. Solar energy is promising option for slow cooking. Keeping this in view a masonry animal feed solar cooker (AFSC) was developed. It helps in the number of ways to improve the living standard of rural farmers and also reduce the CO 2 emission by replacing conventional fossil fuel. The AFSC can replace the 100 per cent biomass and save about 424.80 kg of CO 2 on annual basis and save about 24 INR per day. Usually women prepare animal feed in rural areas, hence cooking with AFSC save time and this time can be spear to take care of her family or in agricultural operation. This paper presents fuel replacement and reduction of carbon dioxide on annual basis and economic evaluation of AFSC. - Highlights: ► Considerable amount of energy can be saved on annual basis. ► This also helps to save the time and money of rural farmer. ► AFSC helps to reduce the greenhouse gas.

Performance Test of Parabolic Trough Solar Cooker for Indoor ...

African Journals Online (AJOL)

Bheema

mm diameter copper pipe is the optimum size for the absorber. Maximum temperatures of ... This paper deals with improving and testing performance of a concentrating cooker for indoor cooking with ... bean oil Soya bean oil. Coating material.

A Little Solar Story

DEFF Research Database (Denmark)

Ahmad, Bashir

1997-01-01

Experiences from use of solar cookers in India and many other places are different. But the story which is based on a field study in Gujarat state of India shows that during last twenty years there has been a tendency that many families do not continue to use their solar cookers. The study shows...... that the tendency is related with the lack of compatibility of this new technology (solar cooker) with the everyday real-life conditions of the families. In principle the findings are supported by an evaluation report on a solar cooker project in Burkina Faso. The conclusion is that the user should be involved...... in the solar cooker technological development process....

Sustainable implementation of solar tunnel dryers, water heaters and cookers in Nepal

Energy Technology Data Exchange (ETDEWEB)

Kovacs, Peter [Danish Energy Management, DEM for Renewable Energy Project, REP, Dhobighat, Lalitpur (Nepal); Shrestha, Niraj; Shakya, Prajwal Raj [Renewable Energy Project, REP, Dhobighat, Lalitpur (Nepal); Pokharel, Govind [Alternative Energy Promotion Centre (AEPC), Lalitpur (Nepal)

2008-07-01

The Renewable Energy Project (REP) is a joint effort of the European Union and the Government of Nepal. Main objectives of the project are to create renewable energy infrastructure and services for the benefit of rural people in remote districts of Nepal. The REP will provide solar energy systems for public services in remote districts, as well as for income generating activities e.g. agro business and tourism. The REP focuses on the installation of institutional PV systems with a total capacity of 0.850 MWp. Concurrently, a number of solar thermal systems are being provided to community organizations (COs) in rural areas of Nepal. The priority applications for the solar thermal part are solar tunnel dryers for small industries drying vegetables. fruits and herbs, solar water heaters for community centers in trekking areas and large scale solar cookers in schools. The paper describes the Renewable Energy Project's implementation program for solar thermal technology and in particular the implications on design and usefulness of the solar tunnel dryer from on-site feasibility studies carried out by the project team. REP provides a framework for a sustainable implementation of these systems by carrying out the whole process from dissemination of information to demand collection, feasibility studies, design, procurement, commissioning and user training. Hand over of ownership will take place once the equipment is installed and successfully commissioned. Monitoring during the first year of operation should conclude the project. REP is co-funded by the European Union and the Government of Nepal. (orig.)

Solar cooking and baking in Central Europe; Kochen mit der Sonne. Solar kochen und backen in Mitteleuropa

Energy Technology Data Exchange (ETDEWEB)

Behringer, Rolf; Goetz, Michael

2008-07-01

Even in the Western and Central European climate, solar cookers can enable environment-friendly cooking and baking on about 100 to 150 days of the year. Some foods taste better when cooked more carefully, and vitamins and nutrients will be better preserved than in conventionally cooked food. After a short historical outline, the authors present some commercial solar cookers suited for our climate. This is followed by a detailed guide on how to construct a simple wooden solar cooker box from commercially available materials. Examples of solar cooking initiatives illustrate the many applications of solar cookers and parabolic trough cookers. The text is supplemented by practical hints and recipes.

Investigation of Bioethanol Productivity from Sargassum sp. (Brown Seaweed) by Pressure Cooker and Steam Cooker Pretreatments

International Nuclear Information System (INIS)

Yu Yu Wah; Kyaw Nyein Aye; Tint Tint Kyaw; Moe Moe Kyaw

2011-12-01

Production of biothanol from Sargassum sp. (Brown seaweed) is more suitable than using any other raw materials because it can easily collect on Chaung Tha Beach in Myanmar without any environmental damages. In this regard an attempt for bioethanol production from sargassum sp. by separation hydrolysis and fermentation (SHF) with saccharomyces cerevisiae was made. Sargassum sp. was pretreated with steam cooker at 120 C and 1 bar for 30 min and pressure cooker at 65 C for 2 hour. The pretreated sargassum sp. was liquefied with the crude enzyme from Trichoderma sp. at the temperature of 50 C and pH of 4 for the first liquefaction step and 95 C, pH of 5 and enzyme of SPEZYME FERD were employed for the second liquefaction step. OPTIDEX L-400 was used as saccharified enzyme with the temperature of 65 C and pH of 4.5 at saccharification step. The process of fermentation was followed by distillation at 78 C for alcohol extraction. Concentrations of crude ethanol were about 1.8% by using steam cooker and 2% for pressure cooker treatment with enzyme mediated saccharification followed by yeast fermentation. Yields of bioethanol were 23% for pressure cooker treatment and 21% for steam cooker treatment at SHF process.

One thousand thermal cycles of magnesium chloride hexahydrate as a promising PCM for indoor solar cooking

International Nuclear Information System (INIS)

El-Sebaii, A.A.; Al-Heniti, S.; Al-Agel, F.; Al-Ghamdi, A.A.; Al-Marzouki, F.

2011-01-01

Research highlights: → Solar cookers must contain a PCM for cooking indoors. → MgCl 2 .6H 2 O when it cycled in a sealed container. → MgCl 2 .6H 2 O shows maximum of 0.1-3.5 o C of supercooling. → MgCl 2 .6H 2 O is a promising PCM for thermal energy storage. -- Abstract: Cooking is the major necessity for people all over the world. It accounts for a major share of energy consumption in developing countries. There is a critical need for the development of alternative, appropriate, affordable methods of cooking for use in developing countries. There is a history for solar cooking since 1650 where they are broadly divided into direct or focusing type, box-type and indirect or advanced solar cookers. The advanced solar cookers have the advantage of being usable indoors and thus solve one of the problems, which impede the social acceptance of solar cookers. The advanced type solar cookers are employing additional solar units that increase the cost. Therefore, the solar cooker must contain a heat storage medium to store thermal energy for use during off-sunshine hours. The main aim of this paper is to investigate the influence of the melting/solidification fast thermal cycling of commercial grade magnesium chloride hexahydrate (MgCl 2 .6H 2 O) on its thermo-physical properties; such as melting point and latent heat of fusion, to be used as a storage medium inside solar cookers. One thousand cycles have been performed in a sealed container under the extra water principle. The thermo-physical properties are measured using the differential scanning calorimetric technique. It is indicated that MgCl 2 .6H 2 O with the extra water principle and hermetically sealing of the container is a promising phase change material (PCM) for cooking indoors and during law intensity solar radiation periods. It is also found from the melting/solidification behavior of MgCl 2 .6H 2 O that it is solidify almost without supercooling; except in few cases where it showed maximum of 0

Nuclear research center looks for 4000 pressure-cookers

International Nuclear Information System (INIS)

Anon.

2013-01-01

The CEA/Valduc research center has recently made a strange bid for the purchase of 4000 stainless steel pressure-cookers. In fact pressure-cookers are economical containers perfectly fitted for keeping radioactive materials. About 10.000 pressure-cookers have been bought in the last 50 years by CEA/Valduc. (A.C.)

A High Rated Solar Water Distillation Unit for Solar Homes

Directory of Open Access Journals (Sweden)

Abhishek Saxena

2016-01-01

Full Text Available India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC and solar water heater (SWH to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP has been estimated around 1.16 years of the present system.

Performance Evaluation of Various Phase Change Materials for Thermal Energy Storage of A Solar Cooker via Numerical Simulation

Directory of Open Access Journals (Sweden)

Dede Tarwidi

2016-11-01

Full Text Available In this paper, thermal performance of various phase change materials (PCMs used as thermal energy storage in a solar cooker has been investigated numerically. Heat conduction equations in cylindrical domain are used to model heat transfer of the PCMs. Mathematical model of phase change problem in the PCM storage encompasses heat conduction equations in solid and liquid region separated by moving solid-liquid interface. The phase change problem is solved by reformulating heat conduction equations with emergence of moving boundary into an enthalpy equation. Numerical solution of the enthalpy equation is obtained by implementing Godunov method and verified by analytical solution of one-dimensional case. Stability condition of the numerical scheme is also discussed. Thermal performance of various PCMs is evaluated via the stored energy and temperature history. The simulation results show that phase change material with the best thermal performance during the first 2.5 hours of energy extraction is shown by erythritol. Moreover, magnesium chloride hexahydrate can maintain temperature of the PCM storage in the range of 110-116.7°C for more than 4 hours while magnesium nitrate hexahydrate is effective only for one hour with the PCM storage temperature around 121-128°C. Among the PCMs that have been tested, it is only erythritol that can cook 10 kg of the loaded water until it reaches 100°C for about 3.5 hours. Article History: Received June 22nd 2016; Received in revised form August 26th 2016; Accepted Sept 1st 2016; Available online How to Cite This Article: Tarwidi, D., Murdiansyah, D.T, Ginanja, N. (2016 Performance Evaluation of Various Phase Change Materials for Thermal Energy Storage of A Solar Cooker via Numerical Simulation. Int. Journal of Renewable Energy Development, 5(3, 199-210. http://dx.doi.org/10.14710/ijred.5.3.199-210

Energy Efficient Cooking - The EffiCooker

DEFF Research Database (Denmark)

Schjær-Jacobsen, Jørgen

2011-01-01

Substantial energy savings in moist heat cooking may be achieved by employing a pan with integrated electric heating element rather than an ordinary pan on a conventional electric range. The electric pan should be thermally insulated and equipped with an "intelligent" controller and timer....... A working prototype of a saucepan, dubbed the EffiCooker, has been constructed according to these guidelines. The EffiCooker has demonstrated energy savings in the range from 28% to 81% compared to conventional equipment when performing ordinary cooking tasks. The user need not be particularly aware...... of energy conservation to realize such savings; even those who are more concerned with their culinary achievements than with energy efficiency are likely to benefit. Besides being energy efficient the EffiCooker is user friendly. Many cooking tasks, once initiated, are performed automatically without any...

Household appliances using solar energy technology

International Nuclear Information System (INIS)

Gul, H.

2000-01-01

Many solar energy technologies are now sufficiently developed to make it possible to use these to replace some of our conventional energy sources, but still need improvement and reduction in cost. It is, therefore, necessary to focus attention on household uses of solar energy. This paper describes the recent developments and current position in respect of several such devices, which include; solar cooker, with curved concentrator, Panel Cooker, Solar Dryer, solar water heater, Solar Still, Solar Water Pump, Solar Water Disinfection, Solar space Heating and greenhouse solar Reflectors, Development and Extension activities on these should be taken up at various levels. (author)

The Design and Construction of a Portable Kerosene Pressure-Cooker

African Journals Online (AJOL)

African Research Review ... The existing cookers and the problems associated with them were analyzed. ... Using the principles of fluid dynamics, this work was able to establish that the power of the cooker is 179.922KW, and that under a constant pressure of IMPa the cooker will discharge and burn 1 litre of kerosene in 3.5 ...

Solar cooking in Senegalese villages: An application of best–worst scaling

International Nuclear Information System (INIS)

Vanschoenwinkel, Janka; Lizin, Sebastien; Swinnen, Gilbert; Azadi, Hossein; Van Passel, Steven

2014-01-01

Dissemination programs of nontraditional cookstoves often fail. Nontraditional cookstoves aim to solve problems associated with biomass fuel usage in developing countries. Recent studies do not explain what drives user's cookstove choice. This study therefore builds a holistic framework that centralizes product-specific preferences or needs. The case study identifies product-specific factors that influence rural Senegalese inhabitants to switch to solar cooking, using best–worst scaling. Looking at the preferences, the case study classified 126 respondents, in three distinct market segments with different solar cooking expectations. The paper identifies socio-demographic characteristics that explain these differences in the respondents' preferences. Finally, the respondent sample is divided in two groups: solar cooker owners and non-owners. When studied with regard to the same issue, solar cooker owners appear to value benefits of the solar cooker lower than non-owners. This is due to program factors (such as formations, after-sales network) and miscommunication (such as a wrong image of the solar cooker) that highly influenced the respondents' cookstove choice. As a conclusion, solar cookers and solar cooking programs are not always adapted to the needs and requirements of the end-users. Needs-oriented and end-user adopted strategies are necessary in order to successfully implement nontraditional cookstoves programs. - Highlights: • Current solar cookers and their programs do not sufficiently fit end-users' needs. • We centralize product-specific preferences in a framework integrating all variables. • Looking at these preferences, three distinct market segments are identified. • Preferences are influenced by both socio-demographic and program characteristics

ENERGY STAR Certified Commercial Steam Cookers

Data.gov (United States)

U.S. Environmental Protection Agency — Certified models meet all ENERGY STAR requirements as listed in the Version 1.2 ENERGY STAR Program Requirements for Commercial Steam Cookers that are effective as...

Solar India - 82: national solar energy convention

Energy Technology Data Exchange (ETDEWEB)

1982-01-01

This document is the proceedings of the Solar India - 82 conference, which was held 17-19 December 1982. The papers are organized into functional groupings which include: (1) solar radiation, (2) flat plate solar collectors and solar water heaters, (3) solar concentrators, (4) solar air heaters and dryers, (5) solar ponds and energy storage, (6) solar cookers, (7) solar stills, (8) selective coatings, (9) photovoltaics, (10) space heating and cooling, (11) bio-energy, and (12) miscellaneous papers. The vast majority of the papers describe work carried out in India, the vast majority of the papers also contain relatively readable abstracts.

Life Cycle Assessment of two Electrolux electric cookers: ELK8200AL and EKV5600

DEFF Research Database (Denmark)

Hansen, Morten Søes; Wenzel, Henrik; Frees, Niels

A life cycle assessment of two electrical cookers was made for the company Electrolux A/S. A number of valid conclusions can be drawn from the study. The conclusions are supported by a sensitivity analysis covering essential parameter variations and showing that quite robust conclusions can...... issue for the resource consumption of the cookers over their life cycle • Transportation of the cookers over their life cycle is insignificant Environmentally, the main perspectives for improvements lie in the optimisation of the use stage, including better efficiency in transformation of the energy...

The pedagogy of building solar devices in architecture schools

Energy Technology Data Exchange (ETDEWEB)

Lee, T. G. [Calgary Univ., Faculty of Environmental Design, AB (Canada)

1999-11-01

Education and training of students of architecture, industrial design, planning and environmental sciences in solar energy utilization, as practiced at the University of Calgary, is described. Classes are relatively small, which allows for considerable flexibility in terms of the different modes of instruction. Lectures, case studies, field trips and workshops all have their place, although the most effective and most popular mode of instruction is the hands-on approach in building and installing a solar heating system. During the course, the students build various types of solar cookers and concentrating solar collectors, including air-type and water-type flat plate collectors. Usually one solar component is built by each class, but previous projects are available for examination and monitoring. This paper elaborates upon the pedagogical basis of shop experience for architectural students. In this context it addresses issues related to shop space, materials, construction, installation testing and monitoring, as well as safety and performance of the student-constructed solar systems. 3 refs., 9 figs.

The pedagogy of building solar devices in architecture schools

Energy Technology Data Exchange (ETDEWEB)

Lee, T. G. (Calgary Univ., Faculty of Environmental Design, AB (Canada))

1999-01-01

Education and training of students of architecture, industrial design, planning and environmental sciences in solar energy utilization, as practiced at the University of Calgary, is described. Classes are relatively small, which allows for considerable flexibility in terms of the different modes of instruction. Lectures, case studies, field trips and workshops all have their place, although the most effective and most popular mode of instruction is the hands-on approach in building and installing a solar heating system. During the course, the students build various types of solar cookers and concentrating solar collectors, including air-type and water-type flat plate collectors. Usually one solar component is built by each class, but previous projects are available for examination and monitoring. This paper elaborates upon the pedagogical basis of shop experience for architectural students. In this context it addresses issues related to shop space, materials, construction, installation testing and monitoring, as well as safety and performance of the student-constructed solar systems. 3 refs., 9 figs.

Solar oven for intertropical zones: Optogeometrical design

Energy Technology Data Exchange (ETDEWEB)

Jaramillo, O.A.; Huelsz, G.; Hernandez-Luna, G.; del Rio, J.A. [Centro de Investigacion en Energia. Universidad Nacional Autonoma de Mexico. Priv. Xochicalco S/N. Col. Centro. Temixco, Morelos 62580 (Mexico); Acosta, R. [Universidad de Quintana Roo, Boulevard Bahia s/n Esq. I. Comonfort, Chetumal Quintana Roo 77019 (Mexico); Arriaga, L.G. [Instituto de Investigaciones Electricas, Av. Reforma 113, Col. Palmira, Cuernavaca, Morelos 62490 (Mexico)

2007-10-15

In this paper, a novel design of a solar oven for the intertropical zones is presented. The oven box has seven faces instead of the six faces of most common designs reported in the literature, two of them are alternatively used as bases. This oven has four fixed mirrors to concentrate solar energy.The main advantage of this novel design is that the oven needs only four simple movements in order to obtain an adequate solar concentration throughout the year. This feature has been possible due to the optogeometrical design that is presented. A simple theoretical model of the oven concentration is developed. According to the model, the concentration achieved by the oven at noon is greater than 1.95 for all days of the year. In order to analyze the optical performance of the solar cooker, an experimental evaluation was conducted by using a scale model of the solar cooker and a heliodon. (author)

Solar oven for intertropical zones: Optogeometrical design

International Nuclear Information System (INIS)

Jaramillo, O.A.; Huelsz, G.; Hernandez-Luna, G.; Rio, J.A. del; Acosta, R.; Arriaga, L.G.

2007-01-01

In this paper, a novel design of a solar oven for the intertropical zones is presented. The oven box has seven faces instead of the six faces of most common designs reported in the literature, two of them are alternatively used as bases. This oven has four fixed mirrors to concentrate solar energy.The main advantage of this novel design is that the oven needs only four simple movements in order to obtain an adequate solar concentration throughout the year. This feature has been possible due to the optogeometrical design that is presented. A simple theoretical model of the oven concentration is developed. According to the model, the concentration achieved by the oven at noon is greater than 1.95 for all days of the year. In order to analyze the optical performance of the solar cooker, an experimental evaluation was conducted by using a scale model of the solar cooker and a heliodon

Performance and analysis by particle image velocimetry (PIV) of cooker-top burners in Thailand

International Nuclear Information System (INIS)

Makmool, U.; Jugjai, S.; Tia, S.; Vallikul, P.; Fungtammasan, B.

2007-01-01

Cooker-top burners are used extensively in Thailand because of the rapid combustion and high heating-rates created by an impinging flame, which is characteristic of these types of burners. High thermal efficiency with low level of CO emissions is the most important performance criteria for these burners. The wide variation in reported performances of the burners appears to be due to the ad hoc knowledge gained through trial and error of the local manufacturers rather than sound scientific principles. This is extremely undesirable in view of safety, energy conservation and environmental protection. In the present work, a nationwide cooker-top burner performance survey and an implementation of a PIV technique to analyze the burner performance as well as advising local manufacturers were carried out. Experimental data were reported for the base line value of thermal efficiency of all the burners. The thermal performance parameters and dynamic properties of the flow field at a flame impingement area, i.e. velocity magnitude, turbulent intensity, vorticity and strain rate were also reported as a function of burner type, which was categorized into four types based on the configuration of the burner head: radial flow burners, swirling flow burners, vertical flow burners and porous radiant burners

Study on Pot Forming of Induction Heater Type Rice Cookers by Forging Cast Process

Science.gov (United States)

Ohnishi, Masayuki; Yamaguchi, Mitsugi; Ohashi, Osamu

This paper describes a study result on pot fabrication by the forging cast process of stainless steel with aluminum. Rice cooked with the new bowl-shaped pot for the induction heater type rice cookers is better tasting than rice cooked with the conventional cylindrical one, due to the achievement of better heat conduction and convection. The conventional pot is made of the clad sheet, consisting of stainless steel and aluminum. However, it is rather difficult to form a bowl shape from the clad sheet, primarily due to the problem of a material spring back. The fabrication of a new type of a pot was made possible by means of the adoption of a forging cast process instead of the clad sheet. In this process, iron powder is inserted between stainless steel and aluminum in order to alleviate the large difference on the coefficient of expansion between each material. It was made clear that the application of two kinds of iron particle, namely 10 μm size powder on the stainless steel side and 44 μm on the aluminum side, enables the joints to become strong enough. The joint strength of the new pot by this fabrication process was confirmed by the tests of the shear strength and the fatigue tests together with the stress analysis.

A feedforward IMC structure for controlling the charging temperature of a TES system of a solar cooker

International Nuclear Information System (INIS)

Mawire, A.; McPherson, M.

2008-01-01

A feedforward internal model control (IMC) structure for controlling and maintaining the outlet charging temperature of a thermal energy storage (TES) system of a solar cooker is presented. The TES system consists of a packed pebble bed in thermal contact with a heat transfer oil contained in a storage tank. An electrical hot plate simulates the collector/concentrator which heats up the oil circulating in a hollow copper spiral coil thus charging the storage. A model for the collector/concentrator system is developed to enable simulation of the feedforward IMC structure. Using a Simulink block model, the simulation results reveal that a feedforward IMC structure performs better than a feedforward structure. The feedforward IMC structure is tested experimentally and the performance of the control structure is acceptable within a few degrees of the set temperatures. Experimental results are also compared with the simulation results. The simulated responses are found to relate closely to the experimental ones and any discrepancies between the two are discussed. Furthermore, the feedforward IMC structure is also compared experimentally with a combined feedforward and PID feedback structure. Results of the comparison indicate that the feedforward IMC structure performs better than the combined feedforward and PID feedback structure. The thermal profile of the storage during the charging experiment with the feedforward IMC structure is also presented and the results obtained from the storage profile indicate that the storage tank is thermally stratified

Design and Construction of Power System for Induction Heating (IH) Cooker Using Resonant Converter

International Nuclear Information System (INIS)

Soe Thiri Thandar; Clement Saldanah; Win Khaing Moe

2008-06-01

Induction Heating (IH) systems using electromagnetic induction are developed in many industrial applications in Myanmar. Many industries have benefited from this new breakthrough by implementing induction heating for melting, hardening, and heating. Induction heating cooker is based on high frequency induction heating,electrical and electronic technologies. From the electronic point of view, induction heating cooker is composed of four parts.They are rectifier, filter, high frequency inverter, and resonant load. The purpose of this research is mainly objected to developed an induction heating cooker. The rectifier module is considered as full-bridge rectifier. The second protion of the system is a capacitive filter. The ripple components are minimized by this filter. The third is a high frequency converter to convert the constant DC to high frequency AC by switching the devices alternately. In this research, the Insulated Gate Bipolar Transistor (IGBT) will be used as a power source, and can be driven by the pulse signals from the pulse transformer circuit. In the resonant load, the power consumption is about 500W. Construction and testing has been carried out. The merits of this research work is that IH cooker can be developed because of having less energy consumption, safe, efficient, quick heating, and having efficiency of 90% or more

Some applications of solar energy in Thailand. Research report No. 61

Energy Technology Data Exchange (ETDEWEB)

Htun, M N; Aftab, M P; Ramachandran, P N

1976-06-01

Solar energy for process heat is identified as the application with potential for widescale use in rural areas rather than urban centres of Thailand. Three applications of solar energy, namely distillation, drying, and cooking are investigated. The units for the study are designed with low cost, flexibility and durability as the aim. The production efficiency of a conventional solar still is improved by the use of internal or external mirrors. To improve the production and efficiency of a solar still, a suspension of activated carbon particles is introduced into the still. However, the most significant improvement in efficiency and production occurs when the solar still is filled and operated with a static bed of burnt rice husk. The solar dryer, drying tapioca chips can reduce moisture content of around 71% down to 14% within 8 hours of operation. The solar dryer performs more efficiently and effectively than open floor drying. The solar cooker is inconvenient to use and operate and the potential for widescale use is concluded to be remote unless social habits change and the cooker made more comfortable to utilize.

Solar Energy Education. Home economics: student activities. Field test edition

Energy Technology Data Exchange (ETDEWEB)

1981-03-01

A view of solar energy from the standpoint of home economics is taken in this book of activities. Students are provided information on solar energy resources while performing these classroom activities. Instructions for the construction of a solar food dryer and a solar cooker are provided. Topics for study include window treatments, clothing, the history of solar energy, vitamins from the sun, and how to choose the correct solar home. (BCS)

Solar thermal utilization--an overview

International Nuclear Information System (INIS)

Chen Deming; Xu Gang

2007-01-01

Solar energy is an ideal renewable energy source and its thermal utilization is one of its most important applications. We review the status of solar thermal utilization, including: (1) developed technologies which are already widely used all over the world, such as solar assisted water heaters, solar cookers, solar heated buildings and so on; (2) advanced technologies which are still in the development or laboratory stage and could have more innovative applications, including thermal power generation, refrigeration, hydrogen production, desalination, and chimneys; (3) major problems which need to be resolved for advanced utilizaiton of solar thermal energy. (authors)

RADIATION MODEL FOR PREDICTING TEMPERATURE EVOLUTION IN SOLAR COOKER

Directory of Open Access Journals (Sweden)

FARID CHEJNE

2011-01-01

Full Text Available Un modelo matemático que describe y simula el comportamiento térmico de una estufa solar fue desarrollado en base en la analogía de resistencias aléctricas. El modelo matemático incluye los tres diferentes mecanismos de transferencia de calor entre las diferentes superfi cies de la cocina solar y su entorno. El modelo matemático se utilizó para predecir la generación de entropía y de su efi ciencia; tambien, fue utilizado para evaluar los parametros de diseño de una estufa solar tipo caja. Los datos experimentales y teóricos fueron comparados satisfactoriamente.

Particle Emissions from Domestic Gas Cookers

DEFF Research Database (Denmark)

Glarborg, Peter; Livbjerg, Hans; Wagner, Ayten Yilmaz

2010-01-01

The authors experimentally studied the formation of submicron particles from a domestic gas cooker in a compartment free from external particle sources. The effects of fuel (methane, natural gas, odorant-free natural gas), primary aeration, flow rate, and fuel sulphur content on particle emissions...... of the emitted particles were found to have a mean value of about 7 nm for partially premixed flames, increasing to ∼10 nm for nonpremixed flames. The quantity of primary air had a strong impact on the particle emissions, showing a minimum at a primary aeration level of 60-65%. Presence of sulphur in small...... quantities may enhance particle formation under some conditions, but results were not conclusive....

What’s cooking? Unverified assumptions, overlooking of local needs and pro-solution biases in the solar cooking literature

NARCIS (Netherlands)

Iessa, L.; Vries, de Y.A.; Swinkels, C.E.; Smits, M.; Butijn, C.A.A.

2017-01-01

Solar cookers have been tested and studied in various settings, but despite their envisioned benefits – reduction of deforestation, economic benefits, improved health, and empowerment of women – results have been modest at best. This article performs a critical review of the literature on solar

Pre- and post-natal exposure of children to EMF generated by domestic induction cookers

Science.gov (United States)

Kos, Bor; Valič, Blaž; Miklavčič, Damijan; Kotnik, Tadej; Gajšek, Peter

2011-10-01

Induction cookers are a type of cooking appliance that uses an intermediate-frequency magnetic field to heat the cooking vessel. The magnetic flux density produced by an induction cooker during operation was measured according to the EN 62233 standard, and the measured values were below the limits set in the standard. The measurements were used to validate a numerical model consisting of three vertically displaced coaxial current loops at 35 kHz. The numerical model was then used to compute the electric field (E) and induced current (J) in 26 and 30 weeks pregnant women and 6 and 11 year old children. Both E and J were found to be below the basic restrictions of the 2010 low-frequency and 1998 ICNRIP guidelines. The maximum computed E fields in the whole body were 0.11 and 0.66 V m-1 in the 26 and 30 weeks pregnant women and 0.28 and 2.28 V m-1 in the 6 and 11 year old children (ICNIRP basic restriction 4.25 V m-1). The maximum computed J fields in the whole body were 46 and 42 mA m-2 in the 26 and 30 weeks pregnant women and 27 and 16 mA m-2 in the 6 and 11 year old children (ICNIRP basic restriction 70 mA m-2).

Pre- and post-natal exposure of children to EMF generated by domestic induction cookers

International Nuclear Information System (INIS)

Kos, Bor; Miklavcic, Damijan; Kotnik, Tadej; Valic, Blaz; Gajsek, Peter

2011-01-01

Induction cookers are a type of cooking appliance that uses an intermediate-frequency magnetic field to heat the cooking vessel. The magnetic flux density produced by an induction cooker during operation was measured according to the EN 62233 standard, and the measured values were below the limits set in the standard. The measurements were used to validate a numerical model consisting of three vertically displaced coaxial current loops at 35 kHz. The numerical model was then used to compute the electric field (E) and induced current (J) in 26 and 30 weeks pregnant women and 6 and 11 year old children. Both E and J were found to be below the basic restrictions of the 2010 low-frequency and 1998 ICNRIP guidelines. The maximum computed E fields in the whole body were 0.11 and 0.66 V m -1 in the 26 and 30 weeks pregnant women and 0.28 and 2.28 V m -1 in the 6 and 11 year old children (ICNIRP basic restriction 4.25 V m -1 ). The maximum computed J fields in the whole body were 46 and 42 mA m -2 in the 26 and 30 weeks pregnant women and 27 and 16 mA m -2 in the 6 and 11 year old children (ICNIRP basic restriction 70 mA m -2 ).

Pre- and post-natal exposure of children to EMF generated by domestic induction cookers

Energy Technology Data Exchange (ETDEWEB)

Kos, Bor; Miklavcic, Damijan; Kotnik, Tadej [Laboratory of Biocybernetics, Faculty of Electrical Engineering, University of Ljubljana, Trzaska 25, SI-1000 Ljubljana (Slovenia); Valic, Blaz; Gajsek, Peter, E-mail: bor.kos@fe.uni-lj.si, E-mail: damijan.miklavcic@fe.uni-lj.si, E-mail: tadej.kotnik@fe.uni-lj.si, E-mail: blaz.valic@inis.si, E-mail: p.gajsek@inis.si [Institute of Non-Ionizing Radiation, Pohorskega Bataljona 215, SI-1000 Ljubljana (Slovenia)

2011-10-07

Induction cookers are a type of cooking appliance that uses an intermediate-frequency magnetic field to heat the cooking vessel. The magnetic flux density produced by an induction cooker during operation was measured according to the EN 62233 standard, and the measured values were below the limits set in the standard. The measurements were used to validate a numerical model consisting of three vertically displaced coaxial current loops at 35 kHz. The numerical model was then used to compute the electric field (E) and induced current (J) in 26 and 30 weeks pregnant women and 6 and 11 year old children. Both E and J were found to be below the basic restrictions of the 2010 low-frequency and 1998 ICNRIP guidelines. The maximum computed E fields in the whole body were 0.11 and 0.66 V m{sup -1} in the 26 and 30 weeks pregnant women and 0.28 and 2.28 V m{sup -1} in the 6 and 11 year old children (ICNIRP basic restriction 4.25 V m{sup -1}). The maximum computed J fields in the whole body were 46 and 42 mA m{sup -2} in the 26 and 30 weeks pregnant women and 27 and 16 mA m{sup -2} in the 6 and 11 year old children (ICNIRP basic restriction 70 mA m{sup -2}).

Accelerated stress testing of terrestrial solar cells

Science.gov (United States)

Lathrop, J. W.; Hawkins, D. C.; Prince, J. L.; Walker, H. A.

1982-01-01

The development of an accelerated test schedule for terrestrial solar cells is described. This schedule, based on anticipated failure modes deduced from a consideration of IC failure mechanisms, involves bias-temperature testing, humidity testing (including both 85-85 and pressure cooker stress), and thermal-cycle thermal-shock testing. Results are described for 12 different unencapsulated cell types. Both gradual electrical degradation and sudden catastrophic mechanical change were observed. These effects can be used to discriminate between cell types and technologies relative to their reliability attributes. Consideration is given to identifying laboratory failure modes which might lead to severe degradation in the field through second quadrant operation. Test results indicate that the ability of most cell types to withstand accelerated stress testing depends more on the manufacturer's design, processing, and worksmanship than on the particular metallization system. Preliminary tests comparing accelerated test results on encapsulated and unencapsulated cells are described.

Pasteurization of naturally contaminated water with solar energy.

OpenAIRE

Ciochetti, D A; Metcalf, R H

1984-01-01

A solar box cooker (SBC) was constructed with a cooking area deep enough to hold several 3.7-liter jugs of water, and this was used to investigate the potential of using solar energy to pasteurize naturally contaminated water. When river water was heated either in the SBC or on a hot plate, coliform bacteria were inactivated at temperatures of 60 degrees C or greater. Heating water in an SBC to at least 65 degrees C ensures that the water will be above the milk pasteurization temperature of 6...

Final report - Sundyne Company

Energy Technology Data Exchange (ETDEWEB)

Long, J.B.

1994-09-27

Solar cookers offer a viable alternative to conventional cooking methods in many areas, and can be an effective tool in the fight against the deforestation and desertification that plague many developing countries. However, there have been numerous obstacles to the successful dissemination of solar cookers in the past. The purpose of this paper is to identify opportunities, review constraints and develop a marketing strategy to disseminate the Sundyne Solar Cooker (SSC) in developing countries.

Seawater desalination with solar-energy-integrated vacuum membrane distillation system

Directory of Open Access Journals (Sweden)

Fang Wang

2017-03-01

Full Text Available This study designed and tested a novel type of solar-energy-integrated vacuum membrane distillation (VMD system for seawater desalination under actual environmental conditions in Wuhan, China. The system consists of eight parts: a seawater tank, solar collector, solar cooker, inclined VMD evaporator, circulating water vacuum pump, heat exchanger, fresh water tank, and brine tank. Natural seawater was used as feed and a hydrophobic hollow-fiber membrane module was used to improve seawater desalination. The experiment was conducted during a typical summer day. Results showed that when the highest ambient temperature was 33 °C, the maximum value of the average solar intensity was 1,080 W/m2. The system was able to generate 36 kg (per m2 membrane module distilled fresh water during 1 day (7:00 am until 6:00 pm, the retention rate was between 99.67 and 99.987%, and electrical conductivity was between 0.00276 and 0.0673 mS/cm. The average salt rejection was over 90%. The proposed VMD system shows favorable potential application in desalination of brackish waters or high-salt wastewater treatment, as well.

Traumatic brain injury due to pressure cooker explosion in a child: case report

Directory of Open Access Journals (Sweden)

Calderon-Miranda Willem Guillermo

2016-06-01

Full Text Available Traumatic brain injury is a common condition in the emergency services, affecting the pediatric and adult population significantly. Patterns of head injury as well as management principles in children are important differences compared to adults. Traumatic brain injury by Domestic pressure cooker is rare and has not been described in children, which to our knowledge is the first report in the literature of this nature.

Experimental study of multipurpose solar hot box at Freiburg, Germany

Energy Technology Data Exchange (ETDEWEB)

Nandwani, S.S. [Iowa State University, Ames (United States). International Inst. of Theoretical and Applied Physics; Steinhart, J.; Henning, H.M.; Rommel, M.; Wittwer, V. [Fraunhofer-Institut fuer Solare Energiesysteme (ISE), Freiburg im Breisgau (Germany)

1997-12-31

With the aim to test an compare some properties of materials and common geometries that are used for designing solar cookers, water heaters, etc. we have made a solar hot box with two similar compartments. In the present study this hot box has been used for, (a) comparing the behavior of a metallic slab filled with a phase change material for short term heat storage, with a conventional absorbing sheet, (b) the use of a selectively coated, as compared to a normal black painted, cooking pot, and (c) for finding the overall heat loss coefficient and thermal capacity of the box. Experiments with the solar hot box will yield valuable information on solar systems that are to be constructed. Besides its use for research this multi-purpose device has been used both to pasteurize up to 14-16 l of water and for cooking. (author)

Direct observations of low-energy solar electrons associated with a type 3 solar radio burst

Science.gov (United States)

Frank, L. A.; Gurnett, D. A.

1972-01-01

On 6 April 1971 a solar X-ray flare and a type 3 solar radio noise burst were observed with instrumentation on the eccentric-orbiting satellite IMP 6. The type 3 solar radio noise burst was detected down to a frequency of 31 kHz. A highly anisotropic packet of low-energy solar electron intensities arrived at the satellite approximately 6000 seconds after the onset of the solar flare. This packet of solar electron intensities was observed for 4200 seconds. Maximum differential intensities of the solar electrons were in the energy range of one to several keV. The frequency drift rate of the type 3 radio noise at frequencies below 178 kHz also indicated an average particle speed corresponding to that of a 3-keV electron. The simultaneous observations of these solar electron intensities and of the type 3 solar radio burst are presented, and their interrelationships are explored.

Ulog: Solar cooker made in southern Baden, Germany; Ulog: Solarkocher aus Suedbaden

Energy Technology Data Exchange (ETDEWEB)

Hartenstein, Silke

2008-09-17

Ulog Freiburg, a sole trader business, and Verein Fast are cooperating with the intention to enhance solar energy use in Europe, Asia, and Africa. They have received several awards for their commitment to this cause. (orig.)

Uses of solar energy in Costa Rica

Energy Technology Data Exchange (ETDEWEB)

Nandwani, Shyam S. [Laboratorio de Energia Solar, Departamento de Fisica, Universidad Nacional Heredia, P.O. Box 728, 3000 Heredia (Costa Rica)

2006-04-15

Costa Rica, a small country with the population of 4 million, and without military and hence no military expenditure, promotes the use of renewable sources like Hydro, Mini hydro, Wind, Geothermal and Sun, mainly for electricity generation. Almost 90% of the electricity is produced from these renewable sources. Through different policies and some incentives, etc., private generation is also encouraged and there are some decentralized systems like solar water heaters, swimming pool heaters, cookers, dryers and stills and also photo voltaic panels. The last ones are mostly for the population where there is no electric grid. Depending on the province, 91-99.5% of the population is electrified. Government also encourages the use of energy saving devices specially at domestic and industrial sector. In addition to provide these data, some of the solar energy systems are mentioned. [Author].

Design, construction and operation of spherical solar cooker with automatic sun tracking system

International Nuclear Information System (INIS)

Abu-Malouh, Riyad; Abdallah, Salah; Muslih, Iyad M.

2011-01-01

In this work, the effect of two axes tracking on a solar cooking system was studied. A dish was built to concentrate solar radiation on a pan that is fixed at the focus of the dish. The dish tracks the sun using a two axes sun tracking system. This system was built and tested. Experimental results obtained show that the temperature inside the pan reached more than 93 o C in a day where the maximum ambient temperature was 32 o C. This temperature is suitable for cooking purposes and this was achieved by using the two axes sun tracking system.

Numerical study on the effects of absorptivity on performance of flat plate solar collector of a water heater

Science.gov (United States)

Tambunan, D. R. S.; Sibagariang, Y. P.; Ambarita, H.; Napitupulu, F. H.; Kawai, H.

2018-03-01

The characteristics of absorber plate of a flat plate solar collector play an important role in the improvement of the performance. In this work, a numerical analysis is carried out to explore the effect of absorptivity and emissivity of absorber plate to the performance of the solar collector of a solar water heater. For a results comparison, a simple a simple solar box cooker with absorber area of 0.835 m × 0.835 m is designed and fabricated. It is employed to heat water in a container by exposing to the solar radiation in Medan city of Indonesia. The transient governing equations are developed. The governing equations are discretized and solved using the forward time step marching technique. The results reveal that the experimental and numerical results show good agreement. The absorptivity of the plate absorber and emissivity of the glass cover strongly affect the performance of the solar collector.

Observing the gender condition during technology transfer of solar oven training in Indonesia

International Nuclear Information System (INIS)

Herliyani Suharta; Abdullah, K.

2006-01-01

Indonesian Sun Cooking via skill-training Technology Transfer of Solar Cooker has been undertaken since 1995. This community educational approach is expected could raise the local awareness on the need of gender equity for a better sustainable development. Quantitative survey with a multiple choices system is selected. Questionnaire was designed to investigate in depth the attitude of the participants. This questionnaire comes up with a positive result on gender equity. Therefore, it is proposed to disseminate this training as widely as possible as a vehicle for changing people ideas about their conventional role

Environmental and solar energy techniques

International Nuclear Information System (INIS)

Zaidi, Z.I.

2003-01-01

Technologies for fossil fuel extraction, transportation, processing and their use have harmful impact on the environment which cause direct and indirect negative impact on human heath, animals, crops and structure etc. The end use of all the fossil fuels is combustion irrespective of the final purpose i.e. heating, electricity production and motive power for transportation. The main constituents of fossil fuels are carbon and hydrogen but some other ingredients, which are originally in the fuel e.g. sulfur or are added during refining e.g. lead, alcohol etc. Combustion of the fossil fuel produces various gases (CO/sub x/, SO/sub x/ NO/sub x/, CH,), soot, ash, droplets of tar and other organic compounds, which are all released into the atmosphere. High rate of population growth and industrialization in the developing countries are causing unsustainable use of forest resources and fossil fuels, hence, are serious hurdles in environmental improvement. The situation in Pakistan is even worse as it has very limited fossil fuels and 40% of its commercial energy requirement are to be imported every year. Renewable energy technologies on the other hand, can play a vital role in improving the environmental condition globally. Pakistan Council of Renewable Energy Technologies (PCRET) is working in the field of renewable energy technologies. The Council has developed solar modules and solar thermal devices including solar cookers, solar dryers, solar stills and solar water heaters. The paper describes these devices and contribution they can make towards the improvement of environment. (author)

Observations spotted solar type stars in Pleiades

International Nuclear Information System (INIS)

Magnitskij, A.K.

1987-01-01

The september - october 1986 observations discovered periodic light variations in three solar type stars in the Pleiades cluster: Hz 296 (0.8 M Sun ), Hz152(0.91 M Sun ) and Hz739(1.15 M Sun ). Periods and amplitudes are accordingly 2 d and 0 m .11, 4 d .12 and 0 m .07, 2 d .70 and 0 m .05. Considerable light variations of these stars in Pleiades are due to the rotation of spotted stars. Contrast spots of solar type stars likely exist when stars are young and rapidly rotate

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

Science.gov (United States)

Duffin, R. T.; White, S. M.; Ray, P. S.; Kaiser, M. L.

2015-09-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena.

Type III-L Solar Radio Bursts and Solar Energetic Particle Events

International Nuclear Information System (INIS)

Duffin, R T; White, S M; Ray, P S; Kaiser, M L

2015-01-01

A radio-selected sample of fast drift radio bursts with complex structure occurring after the impulsive phase of the associated flare (“Type III-L bursts”) is identified by inspection of radio dynamic spectra from 1 to 180 MHz for over 300 large flares in 2001. An operational definition that takes into account previous work on these radio bursts starting from samples of solar energetic particle (SEP) events is applied to the data, and 66 Type III-L bursts are found in the sample. In order to determine whether the presence of these radio bursts can be used to predict the occurrence of SEP events, we also develop a catalog of all SEP proton events in 2001 using data from the ERNE detector on the SOHO satellite. 68 SEP events are found, for 48 of which we can identify a solar source and hence look for associated Type III-L emission. We confirm previous work that found that most (76% in our sample) of the solar sources of SEP events exhibit radio emission of this type. However, the correlation in the opposite direction is not as strong: starting from a radio-selected sample of Type III-L events, around 64% of the bursts that occur at longitudes magnetically well-connected to the Earth, and hence favorable for detection of SEPs, are associated with SEP events. The degree of association increases when the events have durations over 10 minutes at 1 MHz, but in general Type III-L bursts do not perform any better than Type II bursts in our sample as predictors of SEP events. A comparison of Type III-L timing with the arrival of near-relativistic electrons at the ACE spacecraft is not inconsistent with a common source for the accelerated electrons in both phenomena. (paper)

Alternative energy in Nepal

Energy Technology Data Exchange (ETDEWEB)

Tiwari, H.B.; Bhandari, K.P.

2011-05-15

Renewable energy Technology (RET) becomes the mainstream option for rural Nepal to access modern source of energy. It focuses on the trend of RET applications consisting of biogas technology, solar thermal, micro and Pico hydropower, biomass technology bio fuel technology, wind power technology etc. The RET's which provide both electricity based as well as non electricity based services, have been shown to most immediately meet the needs of a cleaner indoor environment, better quality lightning for education and income generating, activities, alternative cooking fuels and agro processing as well as rural industries. Improved cooking stoves and much more beneficial than other technologies. Wind energy utilization is still not popular. Solar thermal to generate thermal energy to cook, warm and dry, biogas for lighting and cooking services. Micro hydropower for electric as well as mechanical use and solar PV mainly for domestic lighting may become choice. The most important Renewable Energy Technology (RET's) in Nepal are related to Pico hydropower and micro-hydropower, biomass energy (biogas, briquettes, gasifies, improved cooking stoves, bio-fuels etc.) solar photovoltaic energy, solar PV water pumping, solar thermal energy (solar heater, solar dryers, solar cookers etc.) and wind energy (such as wind generators, wind mills etc.). One renowned Non-governmental organization has been established in the Jhapa and Mornag Bhutanese refugee camp. Two families from all the seven camps in Nepal received one solar cooker, one hay box and two cooking posts to each family. Under this programme, a total of 6,850 solar cookers, 12600 hay boxes and 25,200 cooking pots have been distributed 2009. The number of beneficiaries from this program has reached 85,000. Before the distribution of the cookers and the utensils, the instruction and orientation training for the maintenance and repair and operation method was improved. The refugees were divided in 315 groups of 40

p-type Mesoscopic nickel oxide/organometallic perovskite heterojunction solar cells.

Science.gov (United States)

Wang, Kuo-Chin; Jeng, Jun-Yuan; Shen, Po-Shen; Chang, Yu-Cheng; Diau, Eric Wei-Guang; Tsai, Cheng-Hung; Chao, Tzu-Yang; Hsu, Hsu-Cheng; Lin, Pei-Ying; Chen, Peter; Guo, Tzung-Fang; Wen, Ten-Chin

2014-04-23

In this article, we present a new paradigm for organometallic hybrid perovskite solar cell using NiO inorganic metal oxide nanocrystalline as p-type electrode material and realized the first mesoscopic NiO/perovskite/[6,6]-phenyl C61-butyric acid methyl ester (PC61BM) heterojunction photovoltaic device. The photo-induced transient absorption spectroscopy results verified that the architecture is an effective p-type sensitized junction, which is the first inorganic p-type, metal oxide contact material for perovskite-based solar cell. Power conversion efficiency of 9.51% was achieved under AM 1.5 G illumination, which significantly surpassed the reported conventional p-type dye-sensitized solar cells. The replacement of the organic hole transport materials by a p-type metal oxide has the advantages to provide robust device architecture for further development of all-inorganic perovskite-based thin-film solar cells and tandem photovoltaics.

Solar-Type Activity in Main-Sequence Stars

CERN Document Server

Gershberg, Roald E

2005-01-01

Solar-type activity over the whole range of the electromagnetic spectrum is a phenomenon inherent in the majority of low- and moderate-mass main sequence stars. In this monograph observational results are summarized in a systematic and comprehensive fashion. The analysis of the various manifestations of such stellar activity leads to the identification of these phenomena with macroscopic non-linear processes in a magnetized plasma. Comparative study of flare stars and the Sun has become increasingly fruitful and is presently an active field of research involving stellar and solar physicists, experts in plasma physics and high-energy astrophysicists. This book will provide them with both an introduction and overview of observational results from the first optical photometry and spectroscopy, from the satellite telescopes International Ultraviolet Explorer to Hubble Space Telescope, XMM-Newton and Chandra, as well as with the present physical interpretation of solar-type activity in main sequence stars. Gershbe...

Efficiency Improvement of HIT Solar Cells on p-Type Si Wafers.

Science.gov (United States)

Wei, Chun-You; Lin, Chu-Hsuan; Hsiao, Hao-Tse; Yang, Po-Chuan; Wang, Chih-Ming; Pan, Yen-Chih

2013-11-22

Single crystal silicon solar cells are still predominant in the market due to the abundance of silicon on earth and their acceptable efficiency. Different solar-cell structures of single crystalline Si have been investigated to boost efficiency; the heterojunction with intrinsic thin layer (HIT) structure is currently the leading technology. The record efficiency values of state-of-the art HIT solar cells have always been based on n-type single-crystalline Si wafers. Improving the efficiency of cells based on p-type single-crystalline Si wafers could provide broader options for the development of HIT solar cells. In this study, we varied the thickness of intrinsic hydrogenated amorphous Si layer to improve the efficiency of HIT solar cells on p-type Si wafers.

Evaluation of usage and fuel savings of solar ovens in Nicaragua

International Nuclear Information System (INIS)

Bauer, Gordon

2016-01-01

Solar cooking technology has been promoted as a solution to both global poverty and environmental degradation, but relatively little research exists on the impact of solar oven usage on biomass fuel consumption. This study evaluates solar oven usage and wood consumption in northern Nicaragua during both the rainy and dry seasons, using surveys, temperature dataloggers, and direct measurements of fuelwood use. Solar oven owners reported usage on 79% of days during the dry season, and 41% of days during the rainy season. Comparison with oven temperature records confirmed usage on 50% of days during the dry season, and 16% of days during the rainy season. However, wood consumption measurements showed no statistically significant difference between days with solar oven usage and days without, suggesting that frequency of usage alone is not an appropriate proxy for fuel savings. Survey results suggest that a large part of solar oven usage came in addition to biomass cooking, as opposed to replacing it. These results suggest a need for further study of wood consumption in situ and more focus on the specific kinds of foods prepared in solar cookers, as well as local cultural and climatic conditions. - Highlights: • Solar oven usage reported on most days during dry season. • No statistically significant fuelwood savings can be attributed to solar oven use. • Usage reported on surveys differs substantially from solar oven temperature data. • Possible causes of lack of wood savings range from weather to diet and gender norms.

Modelling radiative heat transfer inside a basin type solar still

International Nuclear Information System (INIS)

Madhlopa, A.

2014-01-01

Radiative heat transfer inside a basin type solar still has been investigated using two models with (model 1) and without (model 2) taking into account optical view factors. The coefficient of radiative heat exchange (h r,w-gc ) between the water and cover surfaces of a practical solar still was computed using the two models. Simulation results show that model 1 yields lower values of h r,w-gc and the root mean square error than model 2. It is therefore concluded that the accuracy of modelling the performance of a basin-type solar still can be improved by incorporating view factors. - Highlights: • Radiative heat transfer in a basin type solar still has been investigated. • Two models with and without view factors were used. • The model with view factors exhibits a lower magnitude of root mean square error. • View factors affect the accuracy of modelling the performance of the solar still

Status and outlook of solar energy use in Pakistan

International Nuclear Information System (INIS)

Mirza, U.K.

2003-01-01

Pakistan is an energy deficient country, where a large fraction of the population still does not have access to modern day energy services such as electricity. This is due to very limited fossil fuel resources and poor economy, which restrains the import of fossil fuels on a large scale. To overcome energy shortage, Pakistan needs to develop its indigenous energy resources like hydropower, solar and wind. Pakistan lies in an area of one of the highest solar insolation in the world. This vast potential can be exploited to produce electricity, which could be provided to off-grid communities in the northern hilly area and the southern and western deserts. Applications other than electricity production such as solar water heaters and solar cookers also have vast applications. All this will help in both reducing the import of fossil fuels and dependency of people on fuel wood, which in turn will provide some respite for the dwindling forest reserves of Pakistan. Accordingly, the status and outlook of solar energy use in Pakistan is discussed in this paper. In addition, the role of R and D organizations in the promotion of solar energy technologies in Pakistan is also presented including a description of some proposed projects. It is concluded that the current infrastructure has not been able to advance the status of solar energy of Pakistan. Significant efforts are needed to effectively utilize this cheap renewable energy source. (author)

Industrial n-type solar cells with >20% cell efficiency

Energy Technology Data Exchange (ETDEWEB)

Romijn, I.G.; Anker, J.; Burgers, A.R.; Gutjahr, A.; Koppes, M.; Kossen, E.J.; Lamers, M.W.P.E.; Heurtault, Benoit; Saynova-Oosterling, D.S.; Tool, C.J.J. [ECN Solar Energy, Petten (Netherlands)

2013-03-15

To realize high efficiencies at low costs, ECN has developed the n-Pasha solar cell concept. The n-Pasha cell concept is a bifacial solar cell concept on n-Cz base material, with which average efficiencies of above 20% have been demonstrated. In this paper recent developments at ECN to improve the cost of ownership (lower Euro/Wp) of the n-Pasha cell concept are discussed. Two main drivers for the manufacturing costs of n-type solar cells are addressed: the n-type Cz silicon material and the silver consumption. We show that a large resistivity range between 2 and 8 cm can be tolerated for high cell efficiency, and that the costs due to the silver metallization can be significantly reduced while increasing the solar cell efficiency. Combining the improved efficiency and cost reduction makes the n-Pasha cell concept a very cost effective solution to manufacture high efficient solar cells and modules.

Modeling and experimental study of a corrugated wick type solar still: Comparative study with a simple basin type

International Nuclear Information System (INIS)

Matrawy, K.K.; Alosaimy, A.S.; Mahrous, A.-F.

2015-01-01

Highlights: • Performance of corrugated wick type solar still is compared with simple type. • Corrugated porous surface contributes by about 75% of the total productivity. • Productivity of corrugated solar still was 34% more than that for simple type. - Abstract: In the present work, the productivity of a solar still is modified by forming the evaporative surface as a corrugated shape as well as by decreasing the heat capacity with the use of a porous material. This target has been achieved by using black clothes in a corrugated shape that are immersed in water where the clothes absorbs water and get saturated by capillary effect. Along with the proposed corrugated wick type solar still, a simple basin still type was fabricated and tested to compare the enhancement accomplished by the developed solar still. Inclined reflectors were used to augment the solar radiation incident on the plane of the developed solar stills. The energy balance in the developed mathematical models takes into consideration the glass covers, the porous material, along with the portion of water exposed to the transmitted solar radiation as well as the portion of water shaded by the corrugated surface. The developed mathematical model was validated by fabricating and testing two models for the proposed and simple basin solar stills under the same conditions. Good agreement between the simulated and experimental results has been detected. It has been found that an improvement of about 34% in the productivity for the proposed wick type solar still is gained as compared to the simple basin case. Also, the best tilt angle for the inclined reflector has been found to be about 30° with respect to the vertical direction of the setup under consideration.

Characteristics of coronal shock waves and solar type 2 radio bursts

Science.gov (United States)

Mann, G.; Classen, H.-T.

1995-01-01

In the solar corona shock waves generated by flares and/or coronal mass ejections can be observed by radio astronomical methods in terms of solar type 2 radio bursts. In dynamic radio spectra they appear as emission stripes slowly drifting from high to low frequencies. A sample of 25 solar type 2 radio bursts observed in the range of 40 - 170 MHz with a time resolution of 0.1 s by the new radiospectrograph of the Astrophvsikalisches Institut Potsdam in Tremsdorf is statistically investigated concerning their spectral features, i.e, drift rate, instantaneous bandwidth, and fundamental harmonic ratio. In-situ plasma wave measurements at interplanetary shocks provide the assumption that type 2 radio radiation is emitted in the vicinity of the transition region of shock waves. Thus, the instantaneous bandwidth of a solar type 2 radio burst would reflect the density jump across the associated shock wave. Comparing the inspection of the Rankine-Hugoniot relations of shock waves under coronal circumstances with those obtained from the observational study, solar type 2 radio bursts should be regarded to be generated by weak supercritical, quasi-parallel, fast magnetosonic shock waves in the corona.

Performance of indigenously fabricated pyramid type solar desalination unit at Nawabshah

International Nuclear Information System (INIS)

Memon, A.H.; Rajpar, A.H.; Memon, N.A.

2010-01-01

The performance of locally fabricated pyramid type solar desalination unit was studied and compared with the conventional basin type solar still. Both stills were initially filled with same quantity of brackish water. Their performance was studied in terms of the quality of water produced, quantity of water desalinated per hour and total quantity of water desalinated per day during the time under study. The experiments were conducted and various parameters were recorded from 9-15 hours daily. These results showed that pyramid solar still produced 20% higher desalinated water as compared to the conventional double slope basin type solar still. This study showed that the productivity rate of soar still is dependent upon geometrical configuration of solar still. It was observed that the units can highly reduce the salinity, TDS (Total Dissolved Solids) and EC (Electrical Conductivity) of the saline ground water providing the availability of safe drinking water. (author)

The Electricity Usage Pattern for Cooker Manufacturing in Three European Countries. A Benchmarking Study of Electrolux Factories

Energy Technology Data Exchange (ETDEWEB)

Nord-Aagren, Elisabet

2002-12-01

The European electricity market became deregulated by January 1999 and it is now free to trade electricity across borders. The price of electricity varies to a great extent among the countries within the European Union. Swedish electricity will increasingly be an export product on the European electricity market, due to the lower price compared with other countries in Europe. Energy statistics and studies indicate a clear relation between electricity price and electricity use. For the industrial sector in countries with low electricity prices, electricity is a major energy source. Electricity is the dominant energy source, not only for industrial processes but also for support processes, e.g. process heating and heating of the premises. The situation is quite different for industry in countries with high electricity prices. Electricity is sparingly used and only for electricity-specific processes. This thesis presents a benchmarking study of the electricity usage pattern for Electrolux cooker manufacturing in three European cities, i.e. Fredericia in Denmark, Spennymoor in England and Motala in Sweden. The basic idea is to investigate the relation between electricity price and use for cooker manufacturing and explain the differences. The results show that a high electricity price corresponds to a low electricity use and vice versa. Motala has the highest electricity use and the lowest electricity price. Spennymoor's electricity use is half of Motala's and the electricity price is about double Motala's. Spennymoor and Fredericia have about the same electricity price. They differ mainly in which energy source is used for process heating. The total energy use per cooker at Motala is rather close to that of Fredericia. They use less energy than Spennymoor, which has a high gas use. The total energy cost for Fredericia is 45.9 SEK/unit, Motala is 23.7 SEK/unit and Spennymoor is 40.9 SEK/unit. In this study the unit process method was used. The method is a

F I N A L CS1_31012007.indd

African Journals Online (AJOL)

It explains advantages and disadvantages of solar cook- ing and the ... rural areas by using renewable energies. ... Teaching the population to use the solar cooker .... Translation to English by: Michael Spiess, Albisstrasse 37, CH-8038 Zurich,.

Performance comparisons of dish type solar concentrator with mirror arrangements and receiver shapes

Energy Technology Data Exchange (ETDEWEB)

Seo, Joo Hyun; Kim, Yong; Ma, Dae Sung; Seo, Tae Beom [Graduate School, Dept. of Mechanical Engineering, Inha Univ., Inchon (Korea, Republic of); Kang, Yong Heack [Korea Inst. of Energy Research, Daejeon (Korea, Republic of)

2008-07-01

The performance comparisons of dish type solar concentrators are numerically investigated. The dish type solar concentrator considered in this paper consists of a receiver and multi-faceted mirrors. In order to investigate the performance comparisons of dish type solar concentrators, six different mirror arrangements and four different receivers are considered. A parabolic-shaped perfect mirror of which diameter is 1.40 m is considered as the reference for the mirror arrangements. The other mirror arrangements consist of twelve identical parabolic-shaped mirror facets of which diameter are 0.405 m. Their total collecting areas, which are 1.545 m{sup 2}, are the same. Four different solar receiver shapes are a conical, a dome, a cylindrical, and a unicorn type. In order to investigate the thermal performance of the dish type solar concentrator, the radiative heat loss in the receiver should be calculated. For calculation, the net radiation method and the Monte-Carlo method are used. Also, because the thermal performance of the dish type solar concentrator can vary as the receiver surface temperature, the various surface temperatures are considered. Based on the calculation, the unicorn type has the best performance in receiver shapes and the STAR has the best performance in mirror arrangements except the perfect mirror. (orig.)

Inorganic p-Type Semiconductors: Their Applications and Progress in Dye-Sensitized Solar Cells and Perovskite Solar Cells

Directory of Open Access Journals (Sweden)

Ming-Hsien Li

2016-04-01

Full Text Available Considering the increasing global demand for energy and the harmful ecological impact of conventional energy sources, it is obvious that development of clean and renewable energy is a necessity. Since the Sun is our only external energy source, harnessing its energy, which is clean, non-hazardous and infinite, satisfies the main objectives of all alternative energy strategies. With attractive features, i.e., good performance, low-cost potential, simple processibility, a wide range of applications from portable power generation to power-windows, photoelectrochemical solar cells like dye-sensitized solar cells (DSCs represent one of the promising methods for future large-scale power production directly from sunlight. While the sensitization of n-type semiconductors (n-SC has been intensively studied, the use of p-type semiconductor (p-SC, e.g., the sensitization of wide bandgap p-SC and hole transport materials with p-SC have also been attracting great attention. Recently, it has been proved that the p-type inorganic semiconductor as a charge selective material or a charge transport material in organometallic lead halide perovskite solar cells (PSCs shows a significant impact on solar cell performance. Therefore the study of p-type semiconductors is important to rationally design efficient DSCs and PSCs. In this review, recent published works on p-type DSCs and PSCs incorporated with an inorganic p-type semiconductor and our perspectives on this topic are discussed.

Investigations of combustion process in combined cooker-boiler fired on solid fuels

Directory of Open Access Journals (Sweden)

Stojiljković Dragoslava D.

2006-01-01

Full Text Available The aim of the investigation was to make some reconstructions on the existing stove used for cooking and baking and to obtain the combined cooker-boiler which will fulfill the demands of European standard EN 12815. Implementation of modern scientific achievements in the field of combustion on stoves and furnaces fired on solid fuels was used. During the investigations four various constructions were made with different fresh air inlet and secondary air supply with the intention to obtain more complete combustion with increased efficiency and reduced CO emission. Three different fuels were used: firewood, coal, and wood briquette. A numerous parameters were measured: fuel weight changes during the combustion process, temperature of inlet and outlet water, flue gas composition (O2, CO, SO2, CO2, NOx, flue gas temperature, ash quantity etc. The result of the investigations is the stove with the efficiency of more than 75% - boiler Class 1 (according EN 12815 and CO emission of about 1% v/v. The results obtained during the measurements were used as parameters for modeling of combustion process. .

Solar Distillation System Based on Multiple-Effect Diffusion Type Still

KAUST Repository

Huang, Bin-Juine; Chong, Tze-Ling; Chang, Hsien-Shun; Wu, Po-Hsien; Kao, Yeong-Chuan

2014-01-01

The present study intends to develop a high-performance solar-assisted desalination system (SADS) using multi-effect diffusion type still (MEDS) and the vacuum tube solar collector (VTSC). A MEDS prototype was designed and built. The measured result

Cheap type solar bioclimatic individual houses for residential areas

Directory of Open Access Journals (Sweden)

Mihailescu Teofil

2016-01-01

Full Text Available In the Romanian architectural practice for individual houses in residential areas, designing the architectural object in order to function together with the nature is neglected in the majority of the situations. This happens despite of a great variety of the solar bioclimatic solutions materialized in the traditional houses of all the Romanian geographical regions in a history of over 2000 years of traditional architecture. Unfortunately, in the local real estate realities, other choices are preferred in instead those of the solar bioclimatic architecture. The approach starts with a historical approach, analyzing several examples of traditional houses from all the regions of Romania, in order to identify the traditional bioclimatic solutions used to better adapt to the environment. This constitutes the source of inspiration for the modern cheap type solar bioclimatic houses presented. But a way of thinking should be changed for it, with the help of the Romanian state transformed in financial and legislative realities. These cheap type solar bioclimatic individual houses are destined for the middle class families and involve minimum costs for building and living, creating the best premises to efficiently use one or all of the complementary systems for producing, storage and/or transforming the energy from the environment (using solar, wind, water and/or earth energy.

Finite element modelling and simulation of free convection heat transfer in solar oven

Energy Technology Data Exchange (ETDEWEB)

Sobamowo, M.G.; Ogunmola, B.Y.; Ayerin A.M. [Department of Mechanical Engineering, University of Lagos, Akoka, Lagos (Nigeria)

2013-07-01

The use of solar energy for baking, heating or drying represents a sustainable way of solar energy applications with negligible negative effects. Solar oven is an alternative to conventional oven that rely heavily on coal and wood or Electric oven that uses the power from the National grid of which the end users have little or no control. Since the Solar oven uses no fuel and it costs nothing to run, it uses are widely promoted especially in situations where minimum fuel consumption or fire risks are considered highly important. As useful as the Solar Oven proved, it major setback in the area of applications has been its future sustainability. For the use of Solar Oven/Cookers to be sustained in the future, the design and development of solar oven must rely on sound analytical tools. Therefore, this work focused on the design and development of the solar oven. To test the performance of the Small Solar Oven a 5000cm3 beaker of water was put into the Oven and the temperature of the water was found to reach 810C after about 3hrs under an average ambient temperature of 300C. On no load test, the oven reached a maximum temperature of 112oC in 6hrs. In order to carry out the parametric studies and improve the performance of the Solar Oven, Mathematical models were developed and solved by using Characteristics-Based Split (CBS) Finite Element Method. The Model results were compared with the Experimental results and a good agreement was found between the two results.

Renewable energy

International Nuclear Information System (INIS)

Yoon, Cheon Seok

2009-09-01

This book tells of renewable energy giving description of environment problem, market of renewable energy and vision and economics of renewable energy. It also deals with solar light like solar cell, materials performance, system and merit of solar cell, solar thermal power such as solar cooker and solar collector, wind energy, geothermal energy, ocean energy like tidal power and ocean thermal energy conversion, fuel cell and biomass.

Statistical Studies of Solar White-light Flares and Comparisons with Superflares on Solar-type Stars

Science.gov (United States)

Namekata, Kosuke; Sakaue, Takahito; Watanabe, Kyoko; Asai, Ayumi; Maehara, Hiroyuki; Notsu, Yuta; Notsu, Shota; Honda, Satoshi; Ishii, Takako T.; Ikuta, Kai; Nogami, Daisaku; Shibata, Kazunari

2017-12-01

Recently, many superflares on solar-type stars have been discovered as white-light flares (WLFs). The statistical study found a correlation between their energies (E) and durations (τ): τ \\propto {E}0.39, similar to those of solar hard/soft X-ray flares, τ \\propto {E}0.2{--0.33}. This indicates a universal mechanism of energy release on solar and stellar flares, i.e., magnetic reconnection. We here carried out statistical research on 50 solar WLFs observed with Solar Dynamics Observatory/HMI and examined the correlation between the energies and durations. As a result, the E–τ relation on solar WLFs (τ \\propto {E}0.38) is quite similar to that on stellar superflares (τ \\propto {E}0.39). However, the durations of stellar superflares are one order of magnitude shorter than those expected from solar WLFs. We present the following two interpretations for the discrepancy: (1) in solar flares, the cooling timescale of WLFs may be longer than the reconnection one, and the decay time of solar WLFs can be elongated by the cooling effect; (2) the distribution can be understood by applying a scaling law (τ \\propto {E}1/3{B}-5/3) derived from the magnetic reconnection theory. In the latter case, the observed superflares are expected to have 2–4 times stronger magnetic field strength than solar flares.

IUE observations of solar-type stars in the Pleiades and the Hyades

Science.gov (United States)

Caillault, Jean-Pierre; Vilhu, Osmi; Linsky, Jeffrey L.

1991-01-01

An extensive set of IUE observations of solar-type stars (spectral types F5-G5) in the Pleiades is presented. Spectra were obtained in January and August 1988 for both the transition region and chromospheric emission wavelength regions, respectively. Mg II fluxes were detected for two out of three Pleiades stars and C IV upper limits for two of these stars. Long-wavelength high-resolution spectra were also obtained for previously unobserved solar-type stars in the Hyades. With the inclusion of spectra of additional Hyades stars obtained from the IUE archives, surface fluxes and fractional luminosities for both clusters' solar-type stars are calculated; these values provide a better estimate for the Mg II saturation line for single stars.

Solar Distillation System Based on Multiple-Effect Diffusion Type Still

KAUST Repository

Huang, Bin-Juine

2014-03-01

The present study intends to develop a high-performance solar-assisted desalination system (SADS) using multi-effect diffusion type still (MEDS) and the vacuum tube solar collector (VTSC). A MEDS prototype was designed and built. The measured result is very close to the estimation. The 10-effect MEDS will produce pure water at about 13.7 L/day/m2 collector area at a solar irradiation of 600 W/m2 and 19.7 L/day/m2 collector area at solar irradiation 800 W/m2. For 20-effect still, the yield rate increase is 32% compared to 10-effect still.

Modified basin-type solar still

International Nuclear Information System (INIS)

El-Mously, M.K.; El-Ashry, M.Y.; El-Iraqi, M.H.

1981-07-01

A modified basin-type solar still (BTSS) has been developed. The new idea introduced is to re-use the latent heat due to condensation for increasing the temperature of saline water flowing into the device. A new term had been introduced in the balance of equation of conventional BTSS leading to the increase of the efficiency. According to the suggested model, a modified BTSS had been constructed and tested. It is found that the increase in the efficiency is about 14%. (author)

Effect of Installation of Solar Collector on Performance of Balcony Split Type Solar Water Heaters

Directory of Open Access Journals (Sweden)

Xu Ji

2015-01-01

Full Text Available The influences of surface orientation and slope of solar collectors on solar radiation collection of balcony split type solar water heaters for six cities in China were analyzed by employing software TRNSYS. The surface azimuth had greater effect on solar radiation collection in high latitude regions. For deviation of the surface slope angle within ±20° around the optimized angle, the variation of the total annual collecting solar radiation was less than 5%. However, with deviation of 70° to 90°, the variation was up to 20%. The effects of water cycle mode, reverse slope placement of solar collector, and water tank installation height on system efficiency were experimentally studied. The thermal efficiencies of solar water heater with single row horizontal arrangement all-glass evacuated tubular collector were higher than those with vertical arrangement at the fixed surface slope angle of 90°. Compared with solar water heaters with flat-plate collector under natural circulation, the system thermal efficiency was raised up to 63% under forced circulation. For collector at reverse slope placement, the temperature-based water stratification in water tank deteriorated, and thus the thermal efficiency became low. For improving the system efficiency, an appropriate installation height of the water tank was suggested.

Geomagnetic storm related to intense solar radio burst type II and III ...

African Journals Online (AJOL)

The strong energetic particles ejected during sun's activity will propagate towards earth and contribute to solar radio bursts. These solar radio bursts can be detected using CALLISTO system. The open website of the NASA provides us the data including CALLISTO, TESIS, solar monitor, SOHO and space weather. The type ...

Solar Flares, Type III Radio Bursts, Coronal Mass Ejections, and Energetic Particles

Science.gov (United States)

Cane, Hilary V.; Erickson, W. C.; Prestage, N. P.; White, Nicholas E. (Technical Monitor)

2002-01-01

In this correlative study between greater than 20 MeV solar proton events, coronal mass ejections (CMEs), flares, and radio bursts it is found that essentially all of the proton events are preceded by groups of type III bursts and all are preceded by CMEs. These type III bursts (that are a flare phenomenon) usually are long-lasting, intense bursts seen in the low-frequency observations made from space. They are caused by streams of electrons traveling from close to the solar surface out to 1 AU. In most events the type III emissions extend into, or originate at, the time when type II and type IV bursts are reported (some 5 to 10 minutes after the start of the associated soft X-ray flare) and have starting frequencies in the 500 to approximately 100 MHz range that often get lower as a function of time. These later type III emissions are often not reported by ground-based observers, probably because of undue attention to type II bursts. It is suggested to call them type III-1. Type III-1 bursts have previously been called shock accelerated (SA) events, but an examination of radio dynamic spectra over an extended frequency range shows that the type III-1 bursts usually start at frequencies above any type II burst that may be present. The bursts sometimes continue beyond the time when type II emission is seen and, furthermore, sometimes occur in the absence of any type II emission. Thus the causative electrons are unlikely to be shock accelerated and probably originate in the reconnection regions below fast CMEs. A search did not find any type III-1 bursts that were not associated with CMEs. The existence of low-frequency type III bursts proves that open field lines extend from within 0.5 radius of the Sun into the interplanetary medium (the bursts start above 100 MHz, and such emission originates within 0.5 solar radius of the solar surface). Thus it is not valid to assume that only closed field lines exist in the flaring regions associated with CMEs and some

Seminar on the news energy utilization in rural area of April 3 to March 24 , 1980 in Reo, Upper Volta

International Nuclear Information System (INIS)

1980-04-01

The access to energy by the populations remains a primary preoccupation for the Government of Upper Volta (currently Burkina Faso). Due to this reason, a seminar on the utilization of renewable energy in rural area has been organized under the sponsorship of the Economic Community of West Africa (CEAO), the Canadian Agency of International Expansion and the Scout Movement. The goal of this seminar was to teach participants of several countries on how to put into practice the use of new sources of energy such as the cooker with closed fire, biological gas, the solar water-heater and the solar drier. The adoption of these new sources of energy by the populations would help mitigate problems of desertification caused by the intensive deforestation in the country. All the participants in this meeting are thus sensitized so that they will be able to positively contribute, along with their community, for a better conservation of the available natural resources. This can be done through the erection of closed fire cookers which can help get two sources of energy. This type of cooker is of easy construction and can be usable only three days after its construction. It helps avoid the loss of energy which has characterized the traditional way of cooking (around 95% of energy loss); this comes to rhyme with consuming less wood while ensuring an output of about 60 to 70%. It was question for the participants in this seminar to be initiated to the installation of gas by following Chinese and Indian models. They have been thus initiated to the realization of technologies of biological gas production throughout mastering the general diagram of the process of discontinuous fermentation. In the same way, they have acquired the know-how on the techniques of installation of the solar-fired heater by solar furnace and the solar drier. These tools help not only save energy but also the solar drier is a conservation tool which allows a bigger storage capacity of dry products and a

Desalination of effluent using fin type solar still

Energy Technology Data Exchange (ETDEWEB)

Velmurugan, V. [Department of Mechanical Engineering, Infant Jesus College of Engineering, Thoothukudi, Tamil Nadu 628 851 (India); Deenadayalan, C.K.; Vinod, H.; Srithar, K. [Department of Mechanical Engineering, Thiagarajar College of Engineering, Madurai, Tamil Nadu 625 015 (India)

2008-11-15

In this work, an attempt is made to produce potable water from industrial effluents. An ordinary basin type solar still integrated with fins at the basin plate is used for experimentation. Since industrial effluent is used as feed, before this still, an effluent settling tank is provided to get clarified effluent. This effluent settling tank is fabricated with three chambers, consists of pebble, coal and sand for settling the impurities and removing the bacteria in the effluents. Sponges, pebbles, black rubber and sand are used in the fin type single basin solar still for enhancing the yield. Results show that the productivity increases considerably due to this modification. A theoretical analysis is also carried out which, closely converges with experimental results. The economic analysis proved that the approximate payback period of such kinds of still is 1 year. (author)

Registered manufacturers of renewable energy devices

International Nuclear Information System (INIS)

Anon.

1992-01-01

Registered manufacturers of renewable energy devices in India are listed. The list is arranged under the headings : solar water heating system, solar cooker, solar still and water pumping wind mill. In all 38 manufacturers are listed. The list gives the postal address, name of the contact person and phone number of each manufacturer. (M.G.B.)

Absorber design for a Scheffler-Type Solar Concentrator

International Nuclear Information System (INIS)

Ruelas, José; Palomares, Juan; Pando, Gabriel

2015-01-01

Highlights: • Receiver and absorber design methodology based in a solar image in the focal surface. • Stirling absorber dimensions based in a solar image in the focal surface of a STSC. • Comparative study of a solar image in the focal surface from different optical model. • A Monte-Carlo ray-tracing method was used to set STSC cavity receiver aperture. - Abstract: Ray tracing software, digital close range photogrammetry and the Monte-Carlo ray-tracing method have proven to be precise and efficient measurement techniques for the assessment of the shape accuracies of solar concentrators and their components. This paper presents a new method and results for the geometric aspect of a focal image for a Scheffler-Type Solar Concentrator (STSC) using ray tracing, digital close range photogrammetry and the Monte-Carlo ray-tracing method to establish parameters that allow for the design of the most suitable absorber and receiver geometry for coupling the STSC to a Stirling engine. The results of the ray tracing software, digital close range photogrammetry and Monte-Carlo ray tracing technique in STSC are associated with a Stirling receiver. When using the method to perform simulations, we found that the most suitable solar image geometry has an elliptical shape and area of 0.0065 m 2 on average. Although this result is appropriate, the geometry of the receiver is modified to fit an absorber and cavity receiver to improve the heat transfer by radiation

Study on the Fabrication of Paint-Type Si Quantum Dot-Sensitized Solar Cells

Science.gov (United States)

Seo, Hyunwoong; Son, Min-Kyu; Kim, Hee-Je; Wang, Yuting; Uchida, Giichiro; Kamataki, Kunihiro; Itagaki, Naho; Koga, Kazunori; Shiratani, Masaharu

2013-10-01

Quantum dots (QDs) have attracted much attention with their quantum characteristics in the research field of photochemical solar cells. Si QD was introduced as one of alternatives to conventional QD materials. However, their large particles could not penetrate inside TiO2 layer. Therefore, this work proposed the paint-type Si QD-sensitized solar cell. Its heat durability was suitable for the fabrication of paint-type solar cell. Si QDs were fabricated by multihollow discharge plasma chemical vapor deposition and characterized. The paste type, sintering temperature, and Si ratio were controlled and analyzed for better performance. Finally, its performance was enhanced by ZnS surface modification and the whole process was much simplified without sensitizing process.

Pasteurization of naturally contaminated water with solar energy.

Science.gov (United States)

Ciochetti, D A; Metcalf, R H

1984-02-01

A solar box cooker (SBC) was constructed with a cooking area deep enough to hold several 3.7-liter jugs of water, and this was used to investigate the potential of using solar energy to pasteurize naturally contaminated water. When river water was heated either in the SBC or on a hot plate, coliform bacteria were inactivated at temperatures of 60 degrees C or greater. Heating water in an SBC to at least 65 degrees C ensures that the water will be above the milk pasteurization temperature of 62.8 degrees C for at least an hour, which appears sufficient to pasteurize contaminated water. On clear or partly cloudy days, with the SBC facing magnetic south in Sacramento, bottom water temperatures of at least 65 degrees C could be obtained in 11.1 liters of water during the 6 weeks on either side of the summer solstice, in 7.4 liters of water from mid-March through mid-September, and in 3.7 liters of water an additional 2 to 3 weeks at the beginning and end of the solar season. Periodic repositioning of the SBC towards the sun, adjusting the back reflective lid, and preheating water in a simple reflective device increased final water temperatures. Simultaneous cooking and heating water to pasteurizing temperatures was possible. Additional uses of the SBC to pasteurize soil and to decontaminate hospital materials before disposal in remote areas are suggested.

Interplanetary Type III Bursts and Electron Density Fluctuations in the Solar Wind

Science.gov (United States)

Krupar, V.; Maksimovic, M.; Kontar, E. P.; Zaslavsky, A.; Santolik, O.; Soucek, J.; Kruparova, O.; Eastwood, J. P.; Szabo, A.

2018-04-01

Type III bursts are generated by fast electron beams originated from magnetic reconnection sites of solar flares. As propagation of radio waves in the interplanetary medium is strongly affected by random electron density fluctuations, type III bursts provide us with a unique diagnostic tool for solar wind remote plasma measurements. Here, we performed a statistical survey of 152 simple and isolated type III bursts observed by the twin-spacecraft Solar TErrestrial RElations Observatory mission. We investigated their time–frequency profiles in order to retrieve decay times as a function of frequency. Next, we performed Monte Carlo simulations to study the role of scattering due to random electron density fluctuations on time–frequency profiles of radio emissions generated in the interplanetary medium. For simplification, we assumed the presence of isotropic electron density fluctuations described by a power law with the Kolmogorov spectral index. Decay times obtained from observations and simulations were compared. We found that the characteristic exponential decay profile of type III bursts can be explained by the scattering of the fundamental component between the source and the observer despite restrictive assumptions included in the Monte Carlo simulation algorithm. Our results suggest that relative electron density fluctuations /{n}{{e}} in the solar wind are 0.06–0.07 over wide range of heliospheric distances.

Simulation of a solar collector array consisting of two types of solar collectors, with and without convection barrier

DEFF Research Database (Denmark)

Bava, Federico; Furbo, Simon; Perers, Bengt

2015-01-01

The installed area of solar collectors in solar heating fields is rapidly increasing in Denmark. In this scenario even relatively small performance improvements may lead to a large increase in the overall energy production. Both collectors with and without polymer foil, functioning as convection...... barrier, can be found on the Danish market. Depending on the temperature level at which the two types of collectors operate, one can perform better than the other. This project aimed to study the behavior of a 14 solar collector row made of these two different kinds of collectors, in order to optimize...... the composition of the row. Actual solar collectors available on the Danish market (models HT-SA and HT-A 35-10 manufactured by ARCON Solar A/S) were used for this analysis. To perform the study, a simulation model in TRNSYS was developed based on the Danish solar collector field in Braedstrup. A parametric...

PERFORMANCE & ANALYSIS AND OPTIMIZATION OF STEPPED TYPE SOLAR STILL (A REVIEW)

OpenAIRE

Mr. Mujahid Ahmed Khan Abdul Sayeed Khan*1, Prof. A .G. Bhuibhar2 & Prof. P. P. Pande3

2018-01-01

The availability of drinking water is reducing day by day; where as the requirement of drinking water is increasing rapidly. To overcome this problem there is a need for some sustainable source for the water distillation (purification). Solar still is a useful device that can be used for the distilling of brackish water for the drinking purposes Solar still is a simple way of distilling water using the heat of the sun. The performance of stepped type solar still with internal and external ref...

Acoustic glitches in solar-type stars from Kepler

DEFF Research Database (Denmark)

Mazumdar, A.; Monteiro, M. J. P. F. G.; Ballot, J

2012-01-01

We report the measurement of the acoustic locations of layers of sharp variation in sound speed in the interiors of 19 solar-type stars observed by the Kepler mission. The oscillatory signal in the frequencies arising due to the acoustic glitches at the base of the convection zone and the second...

CARBON-TO-OXYGEN RATIOS IN M DWARFS AND SOLAR-TYPE STARS

International Nuclear Information System (INIS)

Nakajima, Tadashi; Sorahana, Satoko

2016-01-01

It has been suggested that high C/O ratios (>0.8) in circumstellar disks lead to the formation of carbon-dominated planets. Based on the expectation that elemental abundances in the stellar photospheres give the initial abundances in the circumstellar disks, the frequency distributions of C/O ratios of solar-type stars have been obtained by several groups. The results of these investigations are mixed. Some find C/O > 0.8 in more than 20% of stars, and C/O > 1.0 in more than 6%. Others find C/O > 0.8 in none of the sample stars. These works on solar-type stars are all differential abundance analyses with respect to the Sun and depend on the adopted C/O ratio in the Sun. Recently, a method of molecular line spectroscopy of M dwarfs, in which carbon and oxygen abundances are derived respectively from CO and H 2 O lines in the K band, has been developed. The resolution of the K- band spectrum is 20,000. Carbon and oxygen abundances of 46 M dwarfs have been obtained by this nondifferential abundance analysis. Carbon-to-oxygen ratios in M dwarfs derived by this method are more robust than those in solar-type stars derived from neutral carbon and oxygen lines in the visible spectra because of the difficulty in the treatment of oxygen lines. We have compared the frequency distribution of C/O distributions in M dwarfs with those of solar-type stars and have found that the low frequency of high-C/O ratios is preferred.

CARBON-TO-OXYGEN RATIOS IN M DWARFS AND SOLAR-TYPE STARS

Energy Technology Data Exchange (ETDEWEB)

Nakajima, Tadashi [Astrobiology Center, 2-21-1, Osawa, Mitaka, Tokyo, 181-8588 (Japan); Sorahana, Satoko, E-mail: tadashi.nakajima@nao.ac.jp, E-mail: sorahana@astron.s.u-tokyo.ac.jp [Department of Astronomy, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033 (Japan)

2016-10-20

It has been suggested that high C/O ratios (>0.8) in circumstellar disks lead to the formation of carbon-dominated planets. Based on the expectation that elemental abundances in the stellar photospheres give the initial abundances in the circumstellar disks, the frequency distributions of C/O ratios of solar-type stars have been obtained by several groups. The results of these investigations are mixed. Some find C/O > 0.8 in more than 20% of stars, and C/O > 1.0 in more than 6%. Others find C/O > 0.8 in none of the sample stars. These works on solar-type stars are all differential abundance analyses with respect to the Sun and depend on the adopted C/O ratio in the Sun. Recently, a method of molecular line spectroscopy of M dwarfs, in which carbon and oxygen abundances are derived respectively from CO and H{sub 2}O lines in the K band, has been developed. The resolution of the K- band spectrum is 20,000. Carbon and oxygen abundances of 46 M dwarfs have been obtained by this nondifferential abundance analysis. Carbon-to-oxygen ratios in M dwarfs derived by this method are more robust than those in solar-type stars derived from neutral carbon and oxygen lines in the visible spectra because of the difficulty in the treatment of oxygen lines. We have compared the frequency distribution of C/O distributions in M dwarfs with those of solar-type stars and have found that the low frequency of high-C/O ratios is preferred.

Biaxial-Type Concentrated Solar Tracking System with a Fresnel Lens for Solar-Thermal Applications

Directory of Open Access Journals (Sweden)

Tsung Chieh Cheng

2016-04-01

Full Text Available In this paper, an electromechanical, biaxial-type concentrated solar tracking system was designed for solar-thermal applications. In our tracking system, the sunlight was concentrated by the microstructure of Fresnel lens to the heating head of the Stirling engine and two solar cells were installed to provide the power for tracking system operation. In order to obtain the maximum sun power, the tracking system traces the sun with the altitude-azimuth biaxial tracing method and accurately maintains the sun’s radiation perpendicular to the plane of the heating head. The results indicated that the position of heating head is an important factor for power collection. If the sunlight can be concentrated to completely cover the heating head with small heat loss, we can obtain the maximum temperature of the heating head of the Stirling engine. Therefore, the temperature of heating head can be higher than 1000 °C in our experiment on a sunny day. Moreover, the results also revealed that the temperature decrease of the heating head is less than the power decrease of solar irradiation because of the latent heat of copper and the small heat loss from the heating head.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Wang, Yundong [Department of Chemical Engineering, Tsinghua University, State Key Lab of Chemical Engineering, Beijing 100084 (China); Fan, Xing, E-mail: foxcqdx@cqu.edu.cn [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China); Tao, Changyuan [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030 (China)

2016-02-15

Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm{sup 2} was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm{sup 2} could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

International Nuclear Information System (INIS)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

2016-01-01

Graphical abstract: - Highlights: • Fabric-type flexible solar cells have been assembled on Zn-plated wires and meshes. • Metal Zn can improve the carriers transfer over the metal/ZnO nanoarrays interface. • A current increase by ∼6 mA/cm"2 was realized by plating Zn on various metal substrates. • All-solid fabric-type DSSC was also assembled on Zn-plated metal wires. - Abstract: Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm"2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Stimulation of auroral kilometric radiation by type III solar radio bursts

International Nuclear Information System (INIS)

Calvert, W.

1981-01-01

It has been found that the onset of auroral kilometric radiation (AKR) frequently coincides with the arrival of type III solar radio bursts. Although the AKR onsets are usually abrupt and appear to be spontaneous, they sometimes develop from a discrete frequency near the leading edge of a type III burst or sometimes occur at progressively lower frequencies following that edge. From this, and the absence of the related solar electrons in specific cases, it was concluded that the incoming type III waves were sometimes responsible for stimulating auroral kilometric radiation. It was estimated that intense, isolated type III bursts were capable of stimulating AKR roughly one third of the time, and that at least ten percent of the observed AKR onsets could be attributed to these and weaker bursts, including some barely detectable by the ISEE plasma wave receivers

Solar Cells Based on Inks of n-Type Colloidal Quantum Dots

KAUST Repository

Ning, Zhijun; Dong, Haopeng; Zhang, Qiong; Voznyy, Oleksandr; Sargent, Edward H.

2014-01-01

© 2014 American Chemical Society. New inorganic ligands including halide anions have significantly accelerated progress in colloidal quantum dot (CQD) photovoltaics in recent years. All such device reports to date have relied on halide treatment during solid-state ligand exchanges or on co-treatment of long-aliphatic-ligand-capped nanoparticles in the solution phase. Here we report solar cells based on a colloidal quantum dot ink that is capped using halide-based ligands alone. By judicious choice of solvents and ligands, we developed a CQD ink from which a homogeneous and thick colloidal quantum dot solid is applied in a single step. The resultant films display an n-type character, making it suitable as a key component in a solar-converting device. We demonstrate two types of quantum junction devices that exploit these iodide-ligand-based inks. We achieve solar power conversion efficiencies of 6% using this class of colloids.

Solar Cells Based on Inks of n-Type Colloidal Quantum Dots

KAUST Repository

Ning, Zhijun

2014-10-28

© 2014 American Chemical Society. New inorganic ligands including halide anions have significantly accelerated progress in colloidal quantum dot (CQD) photovoltaics in recent years. All such device reports to date have relied on halide treatment during solid-state ligand exchanges or on co-treatment of long-aliphatic-ligand-capped nanoparticles in the solution phase. Here we report solar cells based on a colloidal quantum dot ink that is capped using halide-based ligands alone. By judicious choice of solvents and ligands, we developed a CQD ink from which a homogeneous and thick colloidal quantum dot solid is applied in a single step. The resultant films display an n-type character, making it suitable as a key component in a solar-converting device. We demonstrate two types of quantum junction devices that exploit these iodide-ligand-based inks. We achieve solar power conversion efficiencies of 6% using this class of colloids.

Silk cocoon drying in forced convection type solar dryer

International Nuclear Information System (INIS)

Singh, Panna Lal

2011-01-01

The thin layer silk cocoon drying was studied in a forced convection type solar dryer. The drying chamber was provided with several trays on which the cocoons loaded in thin layer. The hot air generated in the solar air heater was forced into drying chamber to avoid the direct exposure of sunlight and UV radiation on cocoons. The drying air temperature varied from 50 to 75 o C. The cocoon was dried from the initial moisture content of about 60-12% (wb). The drying data was fitted to thin layer drying models. Drying behaviour of the silk cocoon was best fitted with the Wang and Singh drying model. Good agreement was obtained between predicted and experimental values. Quality of the cocoons dried in the solar dryer was at par with the cocoons dried in the conventional electrical oven dryer in term of the silk yield and strength of the silk. Saving of electrical energy was about 0.75 kWh/kg cocoons dried. Economic analysis indicated that the NPV of the solar dryer was higher and more stable (against escalation rate of electricity) as compare to the same for electrical oven dryer. Due to simplicity in design and construction and significant saving of operational electrical energy, solar cocoon dryer seems to be a viable option.

Operational Augmentation of Forced Circulation Type Solar Dryer System Using CFD Analysis

OpenAIRE

Atul Patel; Gaurav Patel

2014-01-01

Solar drying is basically heat and mass transfer process in which the liquid water from the surface and the vapour removed by draft. The efficiency of a solar drying system is affected by the properties of drying materials.e.g. size, shape and geometry as well as ambient conditions. In this research article, the authors have done the CFD analysis of a Forced Circulation type Solar Dryer used conventionally for dehydrating vegetables and fruits. Using CFD analysis, the limiting...

Non-uniform Solar Temperature Field on Large Aperture, Fully-Steerable Telescope Structure

Science.gov (United States)

Liu, Yan

2016-09-01

In this study, a 110-m fully steerable radio telescope was used as an analysis platform and the integral parametric finite element model of the antenna structure was built in the ANSYS thermal analysis module. The boundary conditions of periodic air temperature, solar radiation, long-wave radiation shadows of the surrounding environment, etc. were computed at 30 min intervals under a cloudless sky on a summer day, i.e., worstcase climate conditions. The transient structural temperatures were then analyzed under a period of several days of sunshine with a rational initial structural temperature distribution until the whole set of structural temperatures converged to the results obtained the day before. The non-uniform temperature field distribution of the entire structure and the main reflector surface RMS were acquired according to changes in pitch and azimuth angle over the observation period. Variations in the solar cooker effect over time and spatial distributions in the secondary reflector were observed to elucidate the mechanism of the effect. The results presented here not only provide valuable realtime data for the design, construction, sensor arrangement and thermal deformation control of actuators but also provide a troubleshooting reference for existing actuators.

Forecasting the demand on solar water heating systems and their energy savings potential during the period 2001-2005 in Jordan

International Nuclear Information System (INIS)

Kablan, M.M.

2003-01-01

Jordan is an example of a developing country that depends almost exclusively on imported oil. Luckily, Jordan is blessed with good solar energy resources. However, only 24% of Jordanian families are installing solar water heating systems (SWHS). The objective of this research is to forecast the yearly demand on SWHS by the household sector during the period 2001-2005 and to compute the potential energy savings throughout the investigated period due to the use of SWHS. It is found that the net energy collected over the entire investigated period is about 1454.4 million kW h. In addition, the capital savings over the entire investigated period is estimated to be 46.28 million US$ if SWHS are used to heat water instead of the commonly used LPG gas cookers. The results of the research may assist decision makers in the energy sector to implement more comprehensive plans that encourage more families to install SWHS and save on imported oil

SOLAR RADIO TYPE-I NOISE STORM MODULATED BY CORONAL MASS EJECTIONS

International Nuclear Information System (INIS)

Iwai, K.; Tsuchiya, F.; Morioka, A.; Misawa, H.; Miyoshi, Y.; Masuda, S.; Shimojo, M.; Shiota, D.; Inoue, S.

2012-01-01

The first coordinated observations of an active region using ground-based radio telescopes and the Solar Terrestrial Relations Observatory (STEREO) satellites from different heliocentric longitudes were performed to study solar radio type-I noise storms. A type-I noise storm was observed between 100 and 300 MHz during a period from 2010 February 6 to 7. During this period the two STEREO satellites were located approximately 65° (ahead) and –70° (behind) from the Sun-Earth line, which is well suited to observe the earthward propagating coronal mass ejections (CMEs). The radio flux of the type-I noise storm was enhanced after the preceding CME and began to decrease before the subsequent CME. This time variation of the type-I noise storm was directly related to the change of the particle acceleration processes around its source region. Potential-field source-surface extrapolation from the Solar and Heliospheric Observatory/Michelson Doppler Imager (SOHO/MDI) magnetograms suggested that there was a multipolar magnetic system around the active region from which the CMEs occurred around the magnetic neutral line of the system. From our observational results, we suggest that the type-I noise storm was activated at a side-lobe reconnection region that was formed after eruption of the preceding CME. This magnetic structure was deformed by a loop expansion that led to the subsequent CME, which then suppressed the radio burst emission.

Advancements in n-type base crystalline silicon solar cells and their emergence in the photovoltaic industry.

Science.gov (United States)

ur Rehman, Atteq; Lee, Soo Hong

2013-01-01

The p-type crystalline silicon wafers have occupied most of the solar cell market today. However, modules made with n-type crystalline silicon wafers are actually the most efficient modules up to date. This is because the material properties offered by n-type crystalline silicon substrates are suitable for higher efficiencies. Properties such as the absence of boron-oxygen related defects and a greater tolerance to key metal impurities by n-type crystalline silicon substrates are major factors that underline the efficiency of n-type crystalline silicon wafer modules. The bi-facial design of n-type cells with good rear-side electronic and optical properties on an industrial scale can be shaped as well. Furthermore, the development in the industrialization of solar cell designs based on n-type crystalline silicon substrates also highlights its boost in the contributions to the photovoltaic industry. In this paper, a review of various solar cell structures that can be realized on n-type crystalline silicon substrates will be given. Moreover, the current standing of solar cell technology based on n-type substrates and its contribution in photovoltaic industry will also be discussed.

Available online Efficiency potential of indirectly heated solar reforming with different types of solar air receivers

International Nuclear Information System (INIS)

Storch, Henrik von; Roeb, Martin; Stadler, Hannes; Sattler, Christian; Hoffschmidt, Bernhard

2016-01-01

Highlights: • A process for indirectly heated solar reforming of natural gas with air as heat transfer fluid is proposed. • Different solar receivers are modeled and implemented into the reforming process. • The overall efficiency of the process with different solar receivers is determined. • Optimum solar receiver characteristics for application in a solar reforming process are determined. - Abstract: In solar reforming, the heating value of natural gas is increased by utilization of concentrated solar radiation. Hence, it is a process for storing solar energy in a stable and transportable form that also permits further conversion into liquid fuels like methanol. This process has the potential to significantly decrease the natural gas consumption and the associated CO_2-emissions of methanol production with only few open questions to be addressed prior to commercialization. In the medium and long term, it has the potential to generate methanol as an environmentally friendly fuel for both transport as well as flexible electricity production in combined cycle gas turbines, when biogas is used as reactant. In a previous study the high potential of indirectly heated solar reforming with solar air receivers was shown; however, the efficiency is limited when using state of the art open volumetric receivers. Therefore, different types of air receivers are implemented into an indirectly heated solar reforming process and the overall efficiency potential is assessed in the present study. The implemented receivers are an open volumetric cavity receiver, a closed volumetric cavity receiver and a tubular cavity receiver. The open volumetric cavity receiver and tubular cavity receiver achieve the best results due to their capability of operating efficiently at temperatures well above 700 °C. For these receivers peak efficiencies up to 29% and 27% respectively are predicted. As the utilization of an open volumetric cavity receiver constitutes an open heat transfer

Substorm Occurrence and Intensity Associated With Three Types of Solar Wind Structure

Science.gov (United States)

Liou, Kan; Sotirelis, Thomas; Richardson, Ian

2018-01-01

This paper presents the results of a study of the characteristics of substorms that occurred during three distinct types of solar wind: coronal mass ejection (CME) associated, high-speed streams (HSS), and slow solar wind (SSW). A total number of 53,468 geomagnetic substorm onsets from 1983 to 2009 is used and sorted by the three solar wind types. It is found that the probability density function (PDF) of the intersubstorm time can be fitted by the combination of a dominant power law with an exponential cutoff component and a minor lognormal component, implying that substorms are associated with two distinctly different dynamical processes corresponding, perhaps, to the "externally driven" and "internally driven" processes, respectively. We compare substorm frequency and intensity associated with the three types of solar wind. It is found that the intersubstorm time is the longest during SSW and shortest during CME intervals. The averaged intersubstorm time for the internally driven substorms is 3.13, 3.15, and 7.96 h for CME, HSS, and SSW, respectively. The substorm intensity PDFs, as represented by the peak value of |SML| (the generalization of AL), can be fitted by two lognormal distribution functions. The averaged substorm intensity for either component is largest for CME (292 and 674 nT) and smallest for SSW (265 and 434 nT). We argue that the externally driven substorms are more intense than those driven internally. We conclude that the dynamical process of substorms is controlled mainly by the direct solar wind-magnetosphere coupling, whereas the internally driven process only plays a very modest minor role.

The performance of solar collector CPC (compound parabolic concentrator) type with three pipes covered by glass tubes

Science.gov (United States)

Gaos, Yogi Sirodz; Yulianto, Muhamad; Juarsa, Mulya; Nurrohman, Marzuki, Edi; Yuliaji, Dwi; Budiono, Kabul

2017-03-01

Indonesia is a tropical country that has potential energy of solar radiation worth of 4.5 until 4.8 kWh/m2. However, this potential has not been utilized regularly. This paper will discuss the performance of solar collector compound parabolic concentrator (CPC) type with water as the working fluid. This CPC solar collector utilized three pipes covered by glass tubes. This paper has contribution to provide the temperature achievement between three pipes covered by glass tubes with and without glass cover of solar collector CPC type. The research conducted by varying the water flow rate of 1 l/m up to 6 l/m with three pipes arranged in series and parallel. From the results, the used of solar collector CPC type in the current study shows that the decrease of solar radiation, which was caused by climate change, did not influence the heat absorbance by water in the pipe. Therefore, the design of the solar collector in this research has potential to be used in future when solar radiation are used as the energy source.

Estimation of monthly solar exposure on horizontal surface by Angstrom-type regression equation

International Nuclear Information System (INIS)

Ravanshid, S.H.

1981-01-01

To obtain solar flux intensity, solar radiation measuring instruments are the best. In the absence of instrumental data there are other meteorological measurements which are related to solar energy and also it is possible to use empirical relationships to estimate solar flux intensit. One of these empirical relationships to estimate monthly averages of total solar radiation on a horizontal surface is the modified angstrom-type regression equation which has been employed in this report in order to estimate the solar flux intensity on a horizontal surface for Tehran. By comparing the results of this equation with four years measured valued by Tehran's meteorological weather station the values of meteorological constants (a,b) in the equation were obtained for Tehran. (author)

Simulation optimizing of n-type HIT solar cells with AFORS-HET

Science.gov (United States)

Yao, Yao; Xiao, Shaoqing; Zhang, Xiumei; Gu, Xiaofeng

2017-07-01

This paper presents a study of heterojunction with intrinsic thin layer (HIT) solar cells based on n-type silicon substrates by a simulation software AFORS-HET. We have studied the influence of thickness, band gap of intrinsic layer and defect densities of every interface. Details in mechanisms are elaborated as well. The results show that the optimized efficiency reaches more than 23% which may give proper suggestions to practical preparation for HIT solar cells industry.

Low-cost zinc-plated photoanode for fabric-type dye-sensitized solar cells

Science.gov (United States)

Kong, Lingfeng; Bao, Yunna; Guo, Wanwan; Cheng, Li; Du, Jun; Liu, Renlong; Wang, Yundong; Fan, Xing; Tao, Changyuan

2016-02-01

Fabric-type flexible solar cells have been recently proposed as a very promising power source for wearable electronics. To increase the photocurrent of fabric-type flexible solar cells, low-cost zinc-plated wire and mesh photoanodes are assembled for the first time through a mild wet process. Given the protection of the compact protection layer, the DSSC device could benefit from the low work function of Zn and self-repairing behavior on the Zn/ZnO interface. An evident current increase by ∼6 mA/cm2 could be observed after coating a layer of metal Zn on various metal substrates, such as traditional stainless steel wire. Given the self-repairing behavior on Zn/ZnO interface, the Zn layer can help to improve the interfacial carrier transfer, leading to better photovoltaic performance, for both liquid-type and solid-type cells.

Analyse technico-économique et évaluation de l’impact environnemental de la cuisson solaire directe au Maroc

Directory of Open Access Journals (Sweden)

Ndiaga MBODJI

2017-09-01

Full Text Available The objective of this study is to present a design methodology, carry out economic analysis and evaluate the environmental impact of direct solar cooking systems in Morocco. To satisfy the energy needs of a 5 people household, consuming a 3 kg meal at noon for a cooking time of 2.5 hours, a parabolic concentrator having a diameter of 1.4 m (useful area of 1.6 m² is required. At the household level, the economic analysis revealed that the payback period of a direct solar cooker compared to butane varies from 4 to 10 years, depending on the rate of public subsidy. Where firewood is used, the payback period varies from 0.6 to 10 years, depending on the stove performance and the firewood price. At the national level, a 50% subsidy of direct solar cookers with a penetration rate of 50% in rural areas requires a budget of 1.61 billion dirhams (1$US=10 Dirhams. This investment will allow the government to save 185 million dirhams a year in butane subsidies reduction, which corresponds to a payback period of about 8.7 years and a total profit of 1.45 billion dirhams over the cookers 15-year lifetime. On the ecological aspect, the area of forest saved would be about 10 000 ha/year, and the annual amount of CO2 emissions avoided would be 1.08 Mt/year.

A study of the drying effect on lemon slices using a closed-type solar dryer

Energy Technology Data Exchange (ETDEWEB)

Ho-Hsien Chen; Hernandez, C.E.; Tzou-Chi Huang [National Pingtung University of Science and Technology (China). Dept. of Food Science

2005-01-01

An experimental closed-type dryer associated with a photovoltaic system (PV) was developed. The transparent drying cabinet was designed with high transmittance glass to decrease the reflection of direct sunlight and to offer extra direct solar heating on the raw material during drying. Parallel wiring with a local electrical grid was necessary for switching purposes if there is insufficient battery backup during peak operation. Lemon slices were dried using the closed-type solar dryer and results were compared with hot air drying at 60{sup o}C. The results indicate that the dried lemon slices using a closed-type solar dryer has better general levels of quality in terms of sensory parameters. (author)

Performance Evaluation of a Solar Adsorption Refrigeration System with a Wing Type Compound Parabolic Concentrator

OpenAIRE

Umair, Muhammad; Akisawa, Atsushi; Ueda, Yuki

2014-01-01

Simulation study of a solar adsorption refrigeration system using a wing type compound parabolic concentrator (CPC) is presented. The system consists of the wing type collector set at optimum angles, adsorption bed, a condenser and a refrigerator. The wing type collector captures the solar energy efficiently in the morning and afternoon and provides the effective temperature for a longer period of time compared to that achieved by a linear collector. The objectives of the study were to evalua...

Spectral irradiance curve calculations for any type of solar eclipse

International Nuclear Information System (INIS)

Deepak, A.; Merrill, J.E.

1974-01-01

A simple procedure is described for calculating the eclipse function (EF), alpha, and hence the spectral irradiance curve (SIC), (1-alpha), for any type of solar eclipse: namely, the occultation (partial/total) eclipse and the transit (partial/annular) eclipse. The SIC (or the EF) gives the variation of the amount (or the loss) of solar radiation of a given wavelength reaching a distant observer for various positions of the moon across the sun. The scheme is based on the theory of light curves of eclipsing binaries, the results of which are tabulated in Merrill's Tables, and is valid for all wavelengths for which the solar limb-darkening obeys the cosine law: J = /sub c/(1 - X + X cost gamma). As an example of computing the SIC for an occultation eclipse which may be total, the calculations for the March 7, 1970, eclipse are described in detail. (U.S.)

Asteroseismic modelling of the solar-type subgiant star β Hydri

DEFF Research Database (Denmark)

Brandão, I.M.; Dogan, Gülnur; Christensen-Dalsgaard, Jørgen

2011-01-01

Context. Comparing models and data of pulsating stars is a powerful way to understand the stellar structure better. Moreover, such comparisons are necessary to make improvements to the physics of the stellar models, since they do not yet perfectly represent either the interior or especially...... the surface layers of stars. Because β Hydri is an evolved solar-type pulsator with mixed modes in its frequency spectrum, it is very interesting for asteroseismic studies. Aims: The goal of the present work is to search for a representative model of the solar-type star β Hydri, based on up-to-date non...... frequencies of β Hydri: (i) we assume that the best model is the one that reproduces the star's interior based on the radial oscillation frequencies alone, to which we have applied the correction for the near-surface effects; (ii) we assume that the best model is the one that produces the lowest value...

Simulation design of P–I–N-type all-perovskite solar cells with high efficiency

International Nuclear Information System (INIS)

Du Hui-Jing; Wang Wei-Chao; Gu Yi-Fan

2017-01-01

According to the good charge transporting property of perovskite, we design and simulate a p–i–n-type all-perovskite solar cell by using one-dimensional device simulator. The perovskite charge transporting layers and the perovskite absorber constitute the all-perovskite cell. By modulating the cell parameters, such as layer thickness values, doping concentrations and energy bands of n-, i-, and p-type perovskite layers, the all-perovskite solar cell obtains a high power conversion efficiency of 25.84%. The band matched cell shows appreciably improved performance with widen absorption spectrum and lowered recombination rate, so weobtain a high J sc of 32.47 mA/cm 2 . The small series resistance of the all-perovskite solar cell also benefits the high J sc . The simulation provides a novel thought of designing perovskite solar cells with simple producing process, low production cost and high efficient structure to solve the energy problem. (paper)

Association of solar flares with coronal mass ejections accompanied by Deca-Hectometric type II radio burst for two solar cycles 23 and 24

Science.gov (United States)

Kharayat, Hema; Prasad, Lalan; Pant, Sumit

2018-05-01

The aim of present study is to find the association of solar flares with coronal mass ejections (CMEs) accompanied by Deca-Hectometric (DH) type II radio burst for the period 1997-2014 (solar cycle 23 and ascending phase of solar cycle 24). We have used a statistical analysis and found that 10-20∘ latitudinal belt of northern region and 80-90∘ longitudinal belts of western region of the sun are more effective for flare-CME accompanied by DH type II radio burst events. M-class flares (52%) are in good association with the CMEs accompanied by DH type II radio burst. Further, we have calculated the flare position and found that most frequent flare site is at the center of the CME span. However, the occurrence probability of all flares is maximum outside the CME span. X-class flare associated CMEs have maximum speed than that of M, C, and B-class flare associated CMEs. We have also found a good correlation between flare position and central position angle of CMEs accompanied by DH type II radio burst.

Polycyclic aromatic hydrocarbons in disks around young solar-type stars

NARCIS (Netherlands)

Geers, Vincent Carlo

2007-01-01

In this thesis we study the dust around solar-type young stars. In particular, we focus on one specific species of dust, namely the Polycyclic Aromatic Hydrocarbons (PAHs), a family of large molecules, or small grains, that are widely observed in nearby star-forming regions. We address the following

A support approach for the conceptual design of energy-efficient cooker hoods

International Nuclear Information System (INIS)

Cicconi, Paolo; Landi, Daniele; Germani, Michele; Russo, Anna Costanza

2017-01-01

Highlights: •An eco-innovation approach to support the design of household appliances. •The research is focused on the energy labelling for kitchen hoods. •A software platform provides tools to configure and optimize new solutions. •A tool can calculate the energy efficiency indexes of a product configuration. -- Abstract: In Europe, kitchen hoods currently come with an energy label showing their energy efficiency class and other information regarding the energy consumption and noise level, as established by the European Energy Labelling Directive. Because of recent regulations, designs of cooker hoods must consider new issues, such as the evaluation of the energy efficiency, analysis of the energy consumption, and product lifecycle impact. Therefore, the development of eco-driven products requires Ecodesign tools to support eco-innovation and related sustainability improvements. The scope of the proposed research is to define a method and an agile and affordable platform tool that can support designers in the early estimation of product energy performance, including the calculation of energy efficiency indexes. The approach also considers the use of genetic algorithm methods to optimize the product configuration in terms of energy efficiency. The research context concerns large and small productions of kitchen hoods. The paper describes the methodological approach within the developed tool. The results show a good correlation between real efficiency values and calculated ones. A validation activity has been described, and a test case shows how to apply the proposed approach for the design of a new efficient product with an A-class Energy Efficiency Index.

JPRS Report, Science & Technology, China: Energy.

Science.gov (United States)

1988-02-10

bedrock growth anticlines, buried hill fault blocks, rolling anticlines, compression anticlines, draped anticlines, volcanic diapers and others. The...development and utilization of solar , wind, geothermal and other energy resources, the energy conservation capacity and newly-added energy resources were...equivalent to 20 million tons of standard coal. The firewood-saving capacity in wood and coal-saving stoves, biogas pits and solar cookers alone was

Silicon heterojunction solar cells with novel fluorinated n-type nanocrystalline silicon oxide emitters on p-type crystalline silicon

Science.gov (United States)

Dhar, Sukanta; Mandal, Sourav; Das, Gourab; Mukhopadhyay, Sumita; Pratim Ray, Partha; Banerjee, Chandan; Barua, Asok Kumar

2015-08-01

A novel fluorinated phosphorus doped silicon oxide based nanocrystalline material have been used to prepare heterojunction solar cells on flat p-type crystalline silicon (c-Si) Czochralski (CZ) wafers. The n-type nc-SiO:F:H material were deposited by radio frequency plasma enhanced chemical vapor deposition. Deposited films were characterized in detail by using atomic force microscopy (AFM), high resolution transmission electron microscopy (HRTEM), Raman, fourier transform infrared spectroscopy (FTIR) and optoelectronics properties have been studied using temperature dependent conductivity measurement, Ellipsometry, UV-vis spectrum analysis etc. It is observed that the cell fabricated with fluorinated silicon oxide emitter showing higher initial efficiency (η = 15.64%, Jsc = 32.10 mA/cm2, Voc = 0.630 V, FF = 0.77) for 1 cm2 cell area compare to conventional n-a-Si:H emitter (14.73%) on flat c-Si wafer. These results indicate that n type nc-SiO:F:H material is a promising candidate for heterojunction solar cell on p-type crystalline wafers. The high Jsc value is associated with excellent quantum efficiencies at short wavelengths (<500 nm).

Transient theory of double slope floating cum tilted - wick type solar still

International Nuclear Information System (INIS)

Balan, R.; Chandrasekaran, J.; Janarthanan, B.; Kumar, S.

2011-01-01

A double slope floating cum tilted-wick solar still has been fabricated and transient theory of floating cum tilted-wick type solar still has been proposed. Analytical expressions have been derived for the different temperatures components of the proposed system. For elocution of the analytical results, numerical calculations have been carried out using the meteorological parameters for a typical summer day in Coimbatore. Analytical expression results are found to be in the close agreement with the experimental results. (authors)

Heterojunction solar cell with 6% efficiency based on an n-type aluminum-gallium-oxide thin film and p-type sodium-doped Cu2O sheet

Science.gov (United States)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2015-02-01

In this paper, we describe efforts to enhance the efficiency of Cu2O-based heterojunction solar cells fabricated with an aluminum-gallium-oxide (Al-Ga-O) thin film as the n-type layer and a p-type sodium (Na)-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing copper sheets. The optimal Al content [X; Al/(Ga + Al) atomic ratio] of an AlX-Ga1-X-O thin-film n-type layer was found to be approximately 2.5 at. %. The optimized resistivity was approximately 15 Ω cm for n-type AlX-Ga1-X-O/p-type Cu2O:Na heterojunction solar cells. A MgF2/AZO/Al0.025-Ga0.975-O/Cu2O:Na heterojunction solar cell with 6.1% efficiency was fabricated using a 60-nm-thick n-type oxide thin-film layer and a 0.2-mm-thick Cu2O:Na sheet with the optimized resistivity.

Solar cell array for driving MOS type FET gate. MOS gata EFT gate kudoyo taiyo denchi array

Energy Technology Data Exchange (ETDEWEB)

Murakami, S; Yoshida, K; Yoshiki, T; Yamaguchi, Y; Nakayama, T; Owada, Y

1990-03-12

There has been a semiconductor relay utilizing MOS type FET (field effect transistor). Concerning the solar cells used for a semiconductor relay, it is required to separate the cells by forming insulating oxide films first and to form semiconductor layers by using many mask patterns, since a crystal semiconductor is used. Thereby its manufacturing process becomes complicated and laminification as well as thin film formation are difficult, In view of the above, this invention proposes a solar cell array for driving a MOS type FET gate consisting of amorphous silicon semiconductor cells, which are used for a semiconductor relay with solar cells generating electromotive power by the light of a light emitting diode and a MOS type FET that the power output of the above solar cells is supplied to its gate, and which are connected in series with many steps. 9 figs.

North–South Asymmetry in Rieger-type Periodicity during Solar Cycles 19–23

International Nuclear Information System (INIS)

Gurgenashvili, Eka; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil; Oliver, Ramon; Ballester, Jose Luis; Dikpati, Mausumi; McIntosh, Scott W.

2017-01-01

Rieger-type periodicity has been detected in different activity indices over many solar cycles. It was recently shown that the periodicity correlates with solar activity having a shorter period during stronger cycles. Solar activity level is generally asymmetric between northern and southern hemispheres, which could suggest the presence of a similar behavior in the Rieger-type periodicity. We analyze the sunspot area/number and the total magnetic flux data for northern and southern hemispheres during solar cycles 19–23, which had remarkable north–south asymmetry. Using wavelet analysis of sunspot area and number during the north-dominated cycles (19–20), we obtained the periodicity of 160–165 days in the stronger northern hemisphere and 180–190 days in the weaker southern hemisphere. On the other hand, south-dominated cycles (21–23) display the periodicity of 155–160 days in the stronger southern hemisphere and 175–188 days in the weaker northern hemisphere. Therefore, the Rieger-type periodicity has the north–south asymmetry in sunspot area/number data during solar cycles with strong hemispheric asymmetry. We suggest that the periodicity is caused by magnetic Rossby waves in the internal dynamo layer. Using the dispersion relation of magnetic Rossby waves and observed Rieger periodicity, we estimated the magnetic field strength in the layer as 45–49 kG in more active hemispheres (north during cycles 19–20 and south during cycles 21–23) and 33–40 kG in weaker hemispheres. The estimated difference in the hemispheric field strength is around 10 kG, which provides a challenge for dynamo models. Total magnetic flux data during cycles 20–23 reveals no clear north–south asymmetry, which needs to be explained in the future.

North–South Asymmetry in Rieger-type Periodicity during Solar Cycles 19–23

Energy Technology Data Exchange (ETDEWEB)

Gurgenashvili, Eka; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil [Abastumani Astrophysical Observatory at Ilia State University, Tbilisi, Georgia (United States); Oliver, Ramon; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain); Dikpati, Mausumi; McIntosh, Scott W., E-mail: Eka.gurgenashvili.1@iliauni.edu.ge [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307 (United States)

2017-08-20

Rieger-type periodicity has been detected in different activity indices over many solar cycles. It was recently shown that the periodicity correlates with solar activity having a shorter period during stronger cycles. Solar activity level is generally asymmetric between northern and southern hemispheres, which could suggest the presence of a similar behavior in the Rieger-type periodicity. We analyze the sunspot area/number and the total magnetic flux data for northern and southern hemispheres during solar cycles 19–23, which had remarkable north–south asymmetry. Using wavelet analysis of sunspot area and number during the north-dominated cycles (19–20), we obtained the periodicity of 160–165 days in the stronger northern hemisphere and 180–190 days in the weaker southern hemisphere. On the other hand, south-dominated cycles (21–23) display the periodicity of 155–160 days in the stronger southern hemisphere and 175–188 days in the weaker northern hemisphere. Therefore, the Rieger-type periodicity has the north–south asymmetry in sunspot area/number data during solar cycles with strong hemispheric asymmetry. We suggest that the periodicity is caused by magnetic Rossby waves in the internal dynamo layer. Using the dispersion relation of magnetic Rossby waves and observed Rieger periodicity, we estimated the magnetic field strength in the layer as 45–49 kG in more active hemispheres (north during cycles 19–20 and south during cycles 21–23) and 33–40 kG in weaker hemispheres. The estimated difference in the hemispheric field strength is around 10 kG, which provides a challenge for dynamo models. Total magnetic flux data during cycles 20–23 reveals no clear north–south asymmetry, which needs to be explained in the future.

Possible influence of the polarity reversal of the solar magnetic field on the various types of arrhythmias

International Nuclear Information System (INIS)

Giannaropoulou, E; Papailiou, M; Mavromichalaki, H; Preka-Papadema, P; Gigolashvili, M; Tvildiani, L; Janashia, K; Papadima, Th

2013-01-01

Over the last few years various researches have reached the conclusion that cosmic ray variations and geomagnetic disturbances are related to the condition of the human physiological state. In this study medical data concerning the number of incidents of different types of cardiac arrhythmias for the time period 1983 – 1992 which refer to 1902 patients in Tbilisi, Georgia were used. The smoothing method and the Pearson r-coefficients were used to examine the possible effect of different solar and geomagnetic activity parameters and cosmic ray intensity variations on the different types of arrhythmias. The time interval under examination was separated into two different time periods which coincided with the polarity reversal of the solar magnetic field that occurred in the years 1989-1990 and as a result a different behavior of all the above mentioned parameters as well as of the different types of arrhythmias was noticed during the two time intervals. In addition, changing of polarity sign of the solar magnetic field was found to affect the sign of correlation between the incidence of arrhythmias and the aforementioned parameters. The primary and secondary maxima observed in the solar parameters during the solar cycle 22, also appeared in several types of arrhythmias with a time lag of about five months.

Solar radio bursts of spectral type II, coronal shocks, and optical coronal transients

Science.gov (United States)

Maxwell, A.; Dryer, M.

1981-01-01

An examination is presented of the association of solar radio bursts of spectral type II and coronal shocks with solar flare ejecta observed in H-alpha, the green coronal line, and white-light coronagraphs. It is suggested that fast-moving optical coronal transients should for the most part be identified with piston-type phenomena well behind the outward-traveling shock waves that generate type II radio bursts. A general model is presented which relates type II radio bursts and coronal shocks to optically observed ejecta and consists of three main velocity regimes: (1) a quasi-hemispherical shock wave moving outward from the flare at speeds of 1000-2000 km/sec and Alfven Mach number of about 1.5; (2) the velocity of the piston driving the shock, on the order of 0.8 that of the shock; and (3) the regime of the slower-moving H-alpha ejecta, with velocities of 300-500 km/sec.

p-Type semiconducting nickel oxide as an efficiency-enhancing anodal interfacial layer in bulk heterojunction solar cells

Science.gov (United States)

Irwin, Michael D; Buchholz, Donald B; Marks, Tobin J; Chang, Robert P. H.

2014-11-25

The present invention, in one aspect, relates to a solar cell. In one embodiment, the solar cell includes an anode, a p-type semiconductor layer formed on the anode, and an active organic layer formed on the p-type semiconductor layer, where the active organic layer has an electron-donating organic material and an electron-accepting organic material.

Dependence of the cross polar cap potential saturation on the type of solar wind streams

OpenAIRE

Nikolaeva, N. S.; Yermolaev, Yu. I.; Lodkina, I. G.

2013-01-01

We compare of the cross polar cap potential (CPCP) saturation during magnetic storms induced by various types of the solar wind drivers. By using the model of Siscoe-Hill \\citep{Hilletal1976,Siscoeetal2002a,Siscoeetal2002b,Siscoeetal2004,Siscoe2011} we evaluate criteria of the CPCP saturation during the main phases of 257 magnetic storms ($Dst_{min} \\le -50$ nT) induced by the following types of the solar wind streams: magnetic clouds (MC), Ejecta, the compress region Sheath before MC ($Sh_{M...

Solar wind interaction with type-1 comet tails

International Nuclear Information System (INIS)

Ershkovich, A.I.

1977-01-01

A comet tail is considered as a plasma cylinder separated by a tangential discontinuity surface from the solar wind. Under typical conditions a comet tail boundary is shown to undergo the Kelvin-Helmholtz instability. With infinite amplitude the stabilizing effect of the magnetic field increases, and waves become stable. The proposed model supplies the detailed quantitative description of helical waves observed in type-1 comet tails. This theory enables the evaluation of the comet tail magnetic field by means of the observations of helical waves. The magnetic field in the comet tail turns out to be of the order of the interplanetary field. This conclusion seems to be in accordance with Alfven's idea that the magnetic field in type-1 comet tails is a captured interplanetary field. (Auth.)

EFFICIENCY OF THE CAPACITY-TYPE SOLAR WATER HEATER WITH THE FLEXIBLE POLYMER ABSORBER.

Directory of Open Access Journals (Sweden)

Ermuratschii V.V.

2008-08-01

Full Text Available Energetic indexes of solar capacity-type water heaters with flexible polymer absorbers and different constructions of enclosures using the refined method of calculus were obtained.

Development of alternative/renewable sources of energy in Pakistan

International Nuclear Information System (INIS)

Sharif, M.

2005-01-01

The depleting Conventional Energy Resources and highly raised prices of fuel oil, coal, firewood and such other fossil fuels, have forced the mankind to think about the utilization of Alternative / Renewable Sources of Energy. Alternative / Renewable Energy is very attractive, reliable and cost competitive energy. Sun is readily available to provide a clean, abundant and virtually infinite energy to meet the significant portion of mankind's energy-needs. The possible use of renewable-energy sources is discussed in this paper, in order to fill the estimated gap between the available energy-sources and energy-needs of our country in the near future. Designing, Fabrication and Installation of different renewable-energy devices by PCSIR are also discussed in this paper. Different renewable-energy devices such as, solar water heaters, solar cookers, solar dehydrators, solar water-desalination plants, solar heating and cooling of buildings, solar operated absorption-type chiller, solar furnace, solar architecture, developed by PCSIR are discussed in some detail so that the role of renewable-energy sources for their direct use (as heat and power) can be determined. Various technical aspects are discussed to reduce the unit cost with improved efficiency. (author)

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells.

Science.gov (United States)

Sahin, Mehmet

2018-05-23

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p-n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy ([Formula: see text]) of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same [Formula: see text]. The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same [Formula: see text], become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

Effect of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal solar cells

Science.gov (United States)

Sahin, Mehmet

2018-05-01

In this study, the effects of the shell material and confinement type on the conversion efficiency of core/shell quantum dot nanocrystal (QDNC) solar cells have been investigated in detail. For this purpose, the conventional, i.e. original, detailed balance model, developed by Shockley and Queisser to calculate an upper limit for the conversion efficiency of silicon p–n junction solar cells, is modified in a simple and effective way to calculate the conversion efficiency of core/shell QDNC solar cells. Since the existing model relies on the gap energy () of the solar cell, it does not make an estimation about the effect of QDNC materials on the efficiency of the solar cells, and gives the same efficiency values for several QDNC solar cells with the same . The proposed modification, however, estimates a conversion efficiency in relation to the material properties and also the confinement type of the QDNCs. The results of the modified model show that, in contrast to the original one, the conversion efficiencies of different QDNC solar cells, even if they have the same , become different depending upon the confinement type and shell material of the core/shell QDNCs, and this is crucial in the design and fabrication of the new generation solar cells to predict the confinement type and also appropriate QDNC materials for better efficiency.

Ensemble Asteroseismology of Solar-Type Stars with the NASA Kepler Mission

DEFF Research Database (Denmark)

Chaplin, William J.; Kjeldsen, Hans; Christensen-Dalsgaard, Jørgen

2011-01-01

In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar...

Ensemble asteroseismology of solar-type stars with the NASA Kepler mission

NARCIS (Netherlands)

Chaplin, W.J.; Kjeldsen, H.; Christensen-Dalsgaard, J.; Basu, S.; Miglio, A.; Appourchaux, T.; Bedding, T.R.; Elsworth, Y.; Garcia, R.A.; Gilliland, R.L.; Girardi, L.; Houdek, G.; Karoff, C.; Kawaler, S.D.; Metcalfe, T.S.; Molenda-Zakowicz, J.; Monteiro, M.J.P.F.G.; Thompson, M.J.; Verner, G.A.; Ballot, J.; Bonanno, A.; Brandao, I.M.; Broomhall, A.M.; Bruntt, H.; Campante, T.L.; Corsaro, E.; Creevey, O.L.; Esch, L.; Gai, N.; Gaulme, P.; Hale, S.J.; Handberg, R.; Hekker, S.; Huber, D.; Jimenez, A.; Mathur, S.; Mazumdar, A.; Mosser, B.; New, R.; Pinsonneault, M.H.; Pricopi, D.; Quirion, P.O.; Regulo, C.; Salabert, D.; Serenelli, A.M.; Silva Aguirre, V.; Sousa, S.G.; Stello, D.; Stevens, I.R.; Suran, M.D.; Uytterhoeven, K.; White, T.R.; Borucki, W.J.; Brown, T.M.; Jenkins, J.M.; Kinemuchi, K.; Van Cleve, J.; Klaus, T.C.

2011-01-01

In addition to its search for extrasolar planets, the NASA Kepler mission provides exquisite data on stellar oscillations. We report the detections of oscillations in 500 solar-type stars in the Kepler field of view, an ensemble that is large enough to allow statistical studies of intrinsic stellar

Nonuniform Effect of Carrier Separation Efficiency and Light Absorption in Type-II Perovskite Nanowire Solar Cells

Science.gov (United States)

Wang, Weiping; He, Jialun; Cao, Yiyan; Kong, Lijing; Zheng, Xuanli; Wu, Yaping; Chen, Xiaohong; Li, Shuping; Wu, Zhiming; Kang, Junyong

2017-03-01

Coaxial structures exhibit great potential for the application of high-efficiency solar cells due to the novel mechanism of radial charge separation. Here, we intensively investigate the nonuniform effect of carrier separation efficiency (CSE) and light absorption in perovskite-based type-II coaxial nanowire solar cells (ZnO/CH3NH3PbI3). Results show that the CSE rapidly decreases along the radial direction in the shell, and the value at the outer side becomes extremely low for the thick shell. Besides, the position of the main light absorption gradually moves to the outer side with the increase of the shell thickness. As a result, the external quantum efficiency shows a positional dependence with a maximal value close to the border of the nanowire. Eventually, in our case, it is found that the maximal power conversion efficiency of the solar cells reduces from 19.5 to 17.9% under the effect of the nonuniformity of CSE and light absorption. This work provides a basis for the design of high-efficiency solar cells, especially type-II nanowire solar cells.

A Novel Method for Age Estimation in Solar-Type Stars Through GALEX FUV Magnitudes

Science.gov (United States)

Ho, Kelly; Subramonian, Arjun; Smith, Graeme; Shouru Shieh

2018-01-01

Utilizing an inverse association known to exist between Galaxy Evolution Explorer (GALEX) far ultraviolet (FUV) magnitudes and the chromospheric activity of F, G, and K dwarfs, we explored a method of age estimation in solar-type stars through GALEX FUV magnitudes. Sample solar-type star data were collected from refereed publications and filtered by B-V and absolute visual magnitude to ensure similarities in temperature and luminosity to the Sun. We determined FUV-B and calculated a residual index Q for all the stars, using the temperature-induced upper bound on FUV-B as the fiducial. Plotting current age estimates for the stars against Q, we discovered a strong and significant association between the variables. By applying a log-linear transformation to the data to produce a strong correlation between Q and loge Age, we confirmed the association between Q and age to be exponential. Thus, least-squares regression was used to generate an exponential model relating Q to age in solar-type stars, which can be used by astronomers. The Q-method of stellar age estimation is simple and more efficient than existing spectroscopic methods and has applications to galactic archaeology and stellar chemical composition analysis.

SolarChill - a solar PV refrigerator without battery

Energy Technology Data Exchange (ETDEWEB)

Pedersen, P.H.; Poulsen, S.; Katic, I. [Danish Technological Inst., Taastrup (Denmark)

2004-07-01

A solar powered refrigerator (SolarChill) has been developed in an international project involving Greenpeace International, GTZ, UNICEF, UNEP, WHO, industrial partners and Danish Technological Institute. The refrigerator is able to operate directly on solar PV panels, without battery or additional electronics, and is therefore suitable for locations where little maintenance and reliable operation is mandatory. The main objective of the SolarChill Project is to help deliver vaccines and refrigeration to the rural poor. To achieve this objective, the SolarChill Project developed - and plans to make freely available a versatile refrigeration technology that is environmentally sound, technologically reliable, and affordable. SolarChill does not use any fluorocarbons in its cooling system or in the insulation. For domestic and small business applications, another type of solar refrigerator is under development. This is an upright type, suitable for cool storage of food and beverages in areas where grid power is non-existent or unstable. The market potential for this type is thus present in industrialised countries as well as in countries under development. The unique feature of SolarChill is that energy is stored in ice instead of in batteries. An ice compartment keeps the cabinet at desired temperatures during the night. The paper describes the product development, possible SolarChill applications and experience with the two types of solar refrigerators, as well as results from the laboratory and field test. (orig.)

EFFECTS OF ALFVEN WAVES ON ELECTRON CYCLOTRON MASER EMISSION IN CORONAL LOOPS AND SOLAR TYPE I RADIO STORMS

Energy Technology Data Exchange (ETDEWEB)

Zhao, G. Q.; Chen, L.; Wu, D. J. [Purple Mountain Observatory, CAS, Nanjing 210008 (China); Yan, Y. H., E-mail: djwu@pmo.ac.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, CAS, Beijing 100012 (China)

2013-06-10

Solar type I radio storms are long-lived radio emissions from the solar atmosphere. It is believed that these type I storms are produced by energetic electrons trapped within a closed magnetic structure and are characterized by a high ordinary (O) mode polarization. However, the microphysical nature of these emissions is still an open problem. Recently, Wu et al. found that Alfven waves (AWs) can significantly influence the basic physics of wave-particle interactions by modifying the resonant condition. Taking the effects of AWs into account, this work investigates electron cyclotron maser emission driven by power-law energetic electrons with a low-energy cutoff distribution, which are trapped in coronal loops by closed solar magnetic fields. The results show that the emission is dominated by the O mode. It is proposed that this O mode emission may possibly be responsible for solar type I radio storms.

Low-Frequency Type III Bursts and Solar Energetic Particle Events

Science.gov (United States)

Gopalswamy, Nat; Makela, Pertti

2010-01-01

We analyzed the coronal mass ejections (CMEs), flares, and type 11 radio bursts associated with a set of six low frequency (15 min) normally used to define these bursts. All but one of the type III bursts was not associated with a type 11 burst in the metric or longer wavelength domains. The burst without type 11 burst also lacked a solar energetic particle (SEP) event at energies >25 MeV. The 1-MHz duration of the type III burst (28 min) is near the median value of type III durations found for gradual SEP events and ground level enhancement (GLE) events. Yet, there was no sign of SEP events. On the other hand, two other type III bursts from the same active region had similar duration but accompanied by WAVES type 11 bursts; these bursts were also accompanied by SEP events detected by SOHO/ERNE. The CMEs were of similar speeds and the flares are also of similar size and duration. This study suggests that the type III burst duration may not be a good indicator of an SEP event.

Progress in N-type Si Solar Cell and Module Technology for High Efficiency and Low Cost

Energy Technology Data Exchange (ETDEWEB)

Song, Dengyuan; Xiong, Jingfeng; Hu, Zhiyan; Li, Gaofei; Wang, Hongfang; An, Haijiao; Yu, Bo; Grenko, Brian; Borden, Kevin; Sauer, Kenneth; Cui, Jianhua; Wang, Haitao [Yingli Green Energy Holding Co., LTD, 071051 Boading (China); Roessler, T. [Yingli Green Energy Europe GmbH, Heimeranstr. 37, 80339 Munich (Germany); Bultman, J. [ECN Solar Energy, P.O. Box 1, NL-1755 ZG Petten (Netherlands); Vlooswijk, A.H.G.; Venema, P.R. [Tempress Systems BV, Radeweg 31, 8171 Vaassen (Netherlands)

2012-06-15

A novel high efficiency solar cell and module technology, named PANDA, using crystalline n-type CZ Si wafers has moved into large-scale production at Yingli. The first commercial sales of the PANDA modules commenced in mid 2010. Up to 600MW of mass production capacity from crystal-Si growth, wafer slicing, cell processing and module assembly have been implemented by the end of 2011. The PANDA technology was developed specifically for high efficiency and low cost. In contrast to the existing n-type Si solar cell manufacturing methods in mass production, this new technology is largely compatible with a traditional p-type Si solar cell production line by conventional diffusion, SiNx coating and screen-printing technology. With optimizing all technologies, Yingli's PANDA solar cells on semi-square 6-inch n-type CZ wafers (cell size 239cm{sup 2}) have been improved to currently have an average efficiency on commercial production lines exceeding 19.0% and up to 20.0% in pilot production. The PANDA modules have been produced and were certified according to UL1703, IEC 61215 and IEC 61730 standards. Nearly two years of full production on scale-up lines show that the PANDA modules have a high efficiency and power density, superior high temperature performance, near zero initial light induced degradation, and excellent efficiency at low irradiance.

Type II GaSb quantum ring solar cells under concentrated sunlight.

Science.gov (United States)

Tsai, Che-Pin; Hsu, Shun-Chieh; Lin, Shih-Yen; Chang, Ching-Wen; Tu, Li-Wei; Chen, Kun-Cheng; Lay, Tsong-Sheng; Lin, Chien-Chung

2014-03-10

A type II GaSb quantum ring solar cell is fabricated and measured under the concentrated sunlight. The external quantum efficiency confirms the extended absorption from the quantum rings at long wavelength coinciding with the photoluminescence results. The short-circuit current of the quantum ring devices is 5.1% to 9.9% more than the GaAs reference's under various concentrations. While the quantum ring solar cell does not exceed its GaAs counterpart in efficiency under one-sun, the recovery of the open-circuit voltages at higher concentration helps to reverse the situation. A slightly higher efficiency (10.31% vs. 10.29%) is reported for the quantum ring device against the GaAs one.

EUV and Magnetic Activities Associated with Type-I Solar Radio Bursts

Science.gov (United States)

Li, C. Y.; Chen, Y.; Wang, B.; Ruan, G. P.; Feng, S. W.; Du, G. H.; Kong, X. L.

2017-06-01

Type-I bursts ( i.e. noise storms) are the earliest-known type of solar radio emission at the meter wavelength. They are believed to be excited by non-thermal energetic electrons accelerated in the corona. The underlying dynamic process and exact emission mechanism still remain unresolved. Here, with a combined analysis of extreme ultraviolet (EUV), radio and photospheric magnetic field data of unprecedented quality recorded during a type-I storm on 30 July 2011, we identify a good correlation between the radio bursts and the co-spatial EUV and magnetic activities. The EUV activities manifest themselves as three major brightening stripes above a region adjacent to a compact sunspot, while the magnetic field there presents multiple moving magnetic features (MMFs) with persistent coalescence or cancelation and a morphologically similar three-part distribution. We find that the type-I intensities are correlated with those of the EUV emissions at various wavelengths with a correlation coefficient of 0.7 - 0.8. In addition, in the region between the brightening EUV stripes and the radio sources there appear consistent dynamic motions with a series of bi-directional flows, suggesting ongoing small-scale reconnection there. Mainly based on the induced connection between the magnetic motion at the photosphere and the EUV and radio activities in the corona, we suggest that the observed type-I noise storms and the EUV brightening activities are the consequence of small-scale magnetic reconnection driven by MMFs. This is in support of the original proposal made by Bentley et al. ( Solar Phys. 193, 227, 2000).

Three year review

Energy Technology Data Exchange (ETDEWEB)

1980-01-01

Since 1977 research and development activities include various biotechnology systems: algal systems, microbial systems, water hyacinth utilization systems, pisciculture biogas systems; food, fodder and forestry systems (including algal systems), cattle feeding with water hyacinth, biodynamic-intensive vegetable gardening, hydroponic raft culture in stagnant water, small-lot energy-food forestry, and energy plantations; wind and solar energy systems including a bidirectional horizontal-axis down-wind sail-wing windmill, a horizontal-axis down-wind sail-wing windmill, solar crop and fish dryers, solar cookers and water sterilizers; appropriate-construction systems including pond-construction systems, passive solar-building techniques and pond roofing; and communication systems.

Sources of type III solar microwave bursts

Directory of Open Access Journals (Sweden)

Zhdanov D.A.

2016-06-01

Full Text Available Microwave fine structures allow us to study plasma evolution in an energy release region. The Siberian Solar Radio Telescope (SSRT is a unique instrument designed to examine fine structures at 5.7 GHz. A complex analysis of data from RATAN-600, 4–8 GHz spectropolarimeter, and SSRT, simultaneously with EUV data, made it possible to localize sources of III type microwave bursts in August 10, 2011 event within the entire frequency band of burst occurrence, as well as to determine the most probable region of primary energy release. To localize sources of III type bursts from RATAN-600 data, an original method for data processing has been worked out. At 5.7 GHz, the source of bursts was determined along two coordinates, whereas at 4.5, 4.7, 4.9, 5.1, 5.3, 5.5, and 6.0 GHz, their locations were identified along one coordinate. The size of the burst source at 5.1 GHz was found to be maximum as compared to those at other frequencies.

Atlas of fine structures of dynamic spectra of solar type IV-dm and some type II radio bursts

International Nuclear Information System (INIS)

Slottje, C.

1982-01-01

The author presents an atlas of spectral fine structures of solar radio bursts of types IV and II around 1 m wavelength, as obtained with a multichannel spectrograph at Dwingeloo. The structures form largely a collection of observations of these events during late 1968 through 1974, thus covering almost entirely the declining branch of solar cycle 20. The spectrograph has an extra enhanced contrast output with properties quite different from those of the commonly used swept frequency spectrographs. The corresponding instrumental characteristics and effects are discussed. A classification of fine structures and an analysis of their statistical properties and of those of the pertinent radio events are also given. (Auth.)

Peculiarities of frequency dependence of type 3 solar radio bursts duration

International Nuclear Information System (INIS)

Tsybko, Ya.G.

1989-01-01

From the averaged data of type 3 bursts at the fixed frequencies in the range 12.5-25 MHz and out of this limit it is concluded that there exist two branges of the burst duration dependence on the frequency. This splitting allows to distinguish bursts occurring at the fundamental and the second harmonics of the plasma frequency decreasing with height in the solar corona. The type 3b radiation is characterized by a separate diagram of the mean duration versus frequency of the stria-bursts at the fundamental harmonic

Continued Kinematic and Photometric Investigations of Hierarchical Solar-type Multiple Star Systems

Energy Technology Data Exchange (ETDEWEB)

Roberts, Lewis C. Jr.; Marinan, Anne D. [Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena CA 91109 (United States); Tokovinin, Andrei [Cerro Tololo Inter-American Observatory, Casilla 603, La Serena (Chile); Mason, Brian D., E-mail: lewis.c.roberts@jpl.nasa.gov [U.S. Naval Observatory, 3450 Massachusetts Avenue, NW, Washington, DC 20392-5420 (United States)

2017-03-01

We observed 15 of the solar-type binaries within 67 pc of the Sun previously observed by the Robo-AO system in the visible, with the PHARO near-infrared camera and the PALM-3000 adaptive optics system on the 5 m Hale telescope. The physical status of the binaries is confirmed through common proper motion and detection of orbital motion. In the process, we detected a new candidate companion to HIP 95309. We also resolved the primary of HIP 110626 into a close binary, making that system a triple. These detections increase the completeness of the multiplicity survey of the solar-type stars within 67 pc of the Sun. Combining our observations of HIP 103455 with archival astrometric measurements and RV measurements, we are able to compute the first orbit of HIP 103455, showing that the binary has a 68 year period. We place the components on a color–magnitude diagram and discuss each multiple system individually.

Impulsiveness and energetics in solar flares with and without type II radio bursts - A comparison of hard X-ray characteristics for over 2500 solar flares

Science.gov (United States)

Pearson, Douglas H.; Nelson, Robert; Kojoian, Gabriel; Seal, James

1989-01-01

The hard X-ray characteristics of more than 2500 solar flares are used to study the relative size, impulsiveness, and energetics of flares with and without type II radio bursts. A quantitative definition of the hard X-ray impulsiveness is introduced, which may be applied to a large number of events unambiguously. It is found that the flares with type II bursts are generally not significantly larger, more impulsive, or more energetic than those without type II bursts. Also, no evidence is found to suggest a simple classification of the flares as either 'impulsive' or 'gradual'. Because type II bursts are present even in small flares with relatively unimpulsive energy releases, it is concluded that changes in the ambient conditions of the solar atmosphere causing an unusually low Alfven speed may be important in the generation of the shock wave that produces type II radio bursts.

The convective noise floor for the spectroscopic detection of low mass companions to solar type stars

Science.gov (United States)

Deming, D.; Espenak, F.; Jennings, D. E.; Brault, J. W.

1986-01-01

The threshold mass for the unambiguous spectroscopic detection of low mass companions to solar type stars is defined here as the time when the maximum acceleration in the stellar radial velocity due to the Doppler reflex of the companion exceeds the apparent acceleration produced by changes in convection. An apparent acceleration of 11 m/s/yr in integrated sunlight was measured using near infrared Fourier transform spectroscopy. This drift in the apparent solar velocity is attributed to a lessening in the magnetic inhibition of granular convection as solar minimum approaches. The threshold mass for spectroscopic detection of companions to a one solar mass star is estimated at below one Jupiter mass.

Predicting the Detectability of Oscillations in Solar-type Stars Observed by Kepler

DEFF Research Database (Denmark)

Chaplin, William J.; Kjeldsen, Hans; Bedding, Timothy R.

2011-01-01

Asteroseismology of solar-type stars has an important part to play in the exoplanet program of the NASA Kepler Mission. Precise and accurate inferences on the stellar properties that are made possible by the seismic data allow very tight constraints to be placed on the exoplanetary systems. Here,...

Modelling the autocovariance of the power spectrum of a solar-type oscillator

DEFF Research Database (Denmark)

Campante , T.L.; Karoff, Christoffer

2010-01-01

tool in the analysis of the more than 1000 solar-type stars expected to be observed as part of the Kepler Asteroseismic Investigation (KAI). We apply the aforementioned procedure to simulations of the Sun. Assuming different apparent magnitudes, we address the issues of how accurately and how precisely...

Proposal of a neutron transmutation doping facility for n-type spherical silicon solar cell at high-temperature engineering test reactor.

Science.gov (United States)

Ho, Hai Quan; Honda, Yuki; Motoyama, Mizuki; Hamamoto, Shimpei; Ishii, Toshiaki; Ishitsuka, Etsuo

2018-05-01

The p-type spherical silicon solar cell is a candidate for future solar energy with low fabrication cost, however, its conversion efficiency is only about 10%. The conversion efficiency of a silicon solar cell can be increased by using n-type silicon semiconductor as a substrate. This study proposed a new method of neutron transmutation doping silicon (NTD-Si) for producing the n-type spherical solar cell, in which the Si-particles are irradiated directly instead of the cylinder Si-ingot as in the conventional NTD-Si. By using a 'screw', an identical resistivity could be achieved for the Si-particles without a complicated procedure as in the NTD with Si-ingot. Also, the reactivity and neutron flux swing could be kept to a minimum because of the continuous irradiation of the Si-particles. A high temperature engineering test reactor (HTTR), which is located in Japan, was used as a reference reactor in this study. Neutronic calculations showed that the HTTR has a capability to produce about 40t/EFPY of 10Ωcm resistivity Si-particles for fabrication of the n-type spherical solar cell. Copyright © 2018 Elsevier Ltd. All rights reserved.

Measurement of solar ultraviolet radiation intensity type A and B in Qazvin (2013-14

Directory of Open Access Journals (Sweden)

SAR. Babaee

2016-08-01

Full Text Available Background: Solar ultraviolet radiation (UVR is considered one of the most important biological risk factors in the world. Most health damages from solar ultraviolet radiation at ground level are mainly caused by UVA and UVB spectrums. Objective: The aim of this study was to Measure the solar ultraviolet radiation intensity type A and B in Qazvin city. Methods: In this cross-sectional study, the intensity of solar ultraviolet radiation type A and B was measured in Qazvin on years of 2013-14 (during one year every monthly at three times, in the morning, afternoon and evening by using a UV Radiometer. Data were analyzed using descriptive statistics. Findings: The maximum average intensity of UVA and UVB rays during the one year with 28.36±1.88 W/m2 and 0.156±0.035 W/m2 respectively was in Tir month (June 22–July 22 and the minimum average intensity of UVA and UVB rays with 10.36±0.83 W/m2 and 0.041±0.010 W/m2 respectively was in Dai month (December 22–January 20. Conclusion: With regards to the results, it is recommended that individuals were less exposed to exposure time with direct sunshine and use appropriate protective measures such as; wear appropriate clothing, sunglasses, and sunscreen.

Research and development of utilization technology of solar thermal energy system for industrial and other use. Research and development of solar system (investigation of popular type snow melting systems); Sangyoyo nado solar system jitsuyoka gijutsu kaihatsu. Solar system no chosa kenkyu (fukyugata yusetsu system no kenkyu chosa)

Energy Technology Data Exchange (ETDEWEB)

Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

1994-12-01

Described herein are the results of the FY1994 research program for investigation for popular type snow melting systems using solar energy. Two types of technologies are proposed to utilize solar energy for snow melting in winter and create comfortable environments. One is combined (active plus passive) type, which transfers solar heat it collects by the whole wall surfaces to an attic to heat it totally, and makes the whole roof as a radiator to melt snow. However, heat radiated from the roof is insufficient to melt all snow on the roof, allowing it to remain to an extent that it works as an insulator. The other is active type, which transfers heat it collects by the collector to the heat storage tank, from which heat is extracted in winter for various purposes, including snow melting. Such a system must store heat for an extended period, for which a highly insulating heat storage tank is proposed to balance capacity of heat storage between seasons and building size.

Solar building

OpenAIRE

Zhang, Luxin

2014-01-01

In my thesis I describe the utilization of solar energy and solar energy with building integration. In introduction it is also mentioned how the solar building works, trying to make more people understand and accept the solar building. The thesis introduces different types of solar heat collectors. I compared the difference two operation modes of solar water heating system and created examples of solar water system selection. I also introduced other solar building applications. It is conv...

Advantages of using Ti-mesh type electrodes for flexible dye-sensitized solar cells

International Nuclear Information System (INIS)

He Weizhen; Kim, Hyung-Kook; Hwang, Yoon-Hwae; Qiu Jijun; Zhuge Fuwei; Li Xiaomin; Lee, Jae-Ho; Kim, Yang-Do

2012-01-01

We used Ti meshes for both the photoanodes and counter electrodes of dye-sensitized solar cells (DSSCs) to improve the flexibility and conductivity of the electrodes. These mesh type electrodes showed good transparency and high bendability when subjected to an external force. We demonstrated the advantages of cells using such electrodes compared to traditional transparent conducting oxide based electrodes and back side illuminated DSSCs, such as low sheet resistance, elevated photo-induced current and enhanced sunlight utilization. Nanotube layers of different thicknesses were investigated to determine their effect on the photovoltaic parameters of the cell. The overall efficiency of the best cells was approximately 5.3% under standard air mass 1.5 global (AM 1.5 G) solar conditions. Furthermore, the DSSCs showed an efficiency of approximately 3.15% due to the all Ti-mesh type electrodes even after illumination from the back side. (paper)

Widely Applicable n-Type Molecular Doping for Enhanced Photovoltaic Performance of All-Polymer Solar Cells.

Science.gov (United States)

Xu, Yalong; Yuan, Jianyu; Sun, Jianxia; Zhang, Yannan; Ling, Xufeng; Wu, Haihua; Zhang, Guobing; Chen, Junmei; Wang, Yongjie; Ma, Wanli

2018-01-24

A widely applicable doping design for emerging nonfullerene solar cells would be an efficient strategy in order to further improve device photovoltaic performance. Herein, a family of compound TBAX (TBA= tetrabutylammonium, X = F, Cl, Br, or I, containing Lewis base anions are considered as efficient n-dopants for improving polymer-polymer solar cells (all-PSCs) performance. In all cases, significantly increased fill factor (FF) and slightly increased short-circuit current density (J sc ) are observed, leading to a best PCE of 7.0% for all-PSCs compared to that of 5.8% in undoped devices. The improvement may be attributed to interaction between different anions X - (X = F, Cl, Br, and I) in TBAX with the polymer acceptor. We reveal that adding TBAX at relatively low content does not have a significantly impact on blend morphology, while it can reduce the work function (WF) of the electron acceptor. We find this simple and solution processable n-type doping can efficiently restrain charge recombination in all-polymer solar cell devices, resulting in improved FF and J sc. More importantly, our findings may provide new protocles and insights using n-type molecular dopants in improving the performance of current polymer-polymer solar cells.

Design and testing of a separate-type lighting system using solar energy and cold-cathode fluorescent lamps

Energy Technology Data Exchange (ETDEWEB)

Yang, J.-P. [Department of Electrical Engineering, China Institute of Technology, Taipei, Taiwan 115, Taiwan (China)]. E-mail: april4120@tp.edu.tw; Hsiao, H.-C. [Department of Electrical Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 106, Taiwan (China)]. E-mail: hsiao@mouse.ee.ntust.edu.tw

2007-01-15

This paper presents a solar-powered lighting system, using cold-cathode fluorescent-lamps (CCFLs), with its battery-charging circuit and lamp-ignition circuit being separated so that its solar panels can be installed at any distance deemed necessary away from the lighting site in order to receive the maximum solar energy available. This system adopts the maximum-power point tracking (MPPT) method to control the power output of the solar panels and uses the zero-voltage switching (ZVS) DC-DC converter, as the charging circuit, to increase the panels' power generation efficiency and the charging circuit's conversion efficiency. The electronic ballast circuit for the CCFL is constructed with a half-bridge inverter, a resonant inductor, and a Rosen-type piezoelectric transformer, which forms a piezoelectric resonant-type inverter: to simplify the circuitry and to improve the power conversion efficiency, the ballast circuit is designed to directly step up the battery voltage in igniting the lamp. We also establish the transmission-parameter model for the piezoelectric resonant-type inverter to provide the base for the electric-power circuit design. Our experimental results indicate that the proposed system possesses some advantages, such as greater energy efficiency, circuitry simplicity, and so on, and is suitable for night lighting in house yards, parks and advertising panels.

Design and testing of a separate-type lighting system using solar energy and cold-cathode fluorescent lamps

International Nuclear Information System (INIS)

Yang, J.-P.; Hsiao, H.-C.

2007-01-01

This paper presents a solar-powered lighting system, using cold-cathode fluorescent-lamps (CCFLs), with its battery-charging circuit and lamp-ignition circuit being separated so that its solar panels can be installed at any distance deemed necessary away from the lighting site in order to receive the maximum solar energy available. This system adopts the maximum-power point tracking (MPPT) method to control the power output of the solar panels and uses the zero-voltage switching (ZVS) DC-DC converter, as the charging circuit, to increase the panels' power generation efficiency and the charging circuit's conversion efficiency. The electronic ballast circuit for the CCFL is constructed with a half-bridge inverter, a resonant inductor, and a Rosen-type piezoelectric transformer, which forms a piezoelectric resonant-type inverter: to simplify the circuitry and to improve the power conversion efficiency, the ballast circuit is designed to directly step up the battery voltage in igniting the lamp. We also establish the transmission-parameter model for the piezoelectric resonant-type inverter to provide the base for the electric-power circuit design. Our experimental results indicate that the proposed system possesses some advantages, such as greater energy efficiency, circuitry simplicity, and so on, and is suitable for night lighting in house yards, parks and advertising panels

Effect of openings collectors and solar irradiance on the thermal efficiency of flat plate-finned collector for indirect-type passive solar dryer

Science.gov (United States)

Batubara, Fatimah; Dina, Sari Farah; Klaudia Kathryn Y., M.; Turmuzi, M.; Siregar, Fitri; Panjaitan, Nora

2017-06-01

Research on the effect of openings solar collector and solar irradiance to thermal efficiency has been done. Solar collector by flat plate-finned type consists of 3 ply insulator namely wood, Styrofoam and Rockwool with thickness respectively are 10 mm, 25 mm and 50 mm. Absorber plate made of aluminum sheet with thickness of 0.30 mm, painted by black-doff. Installation of 19 units fins (length x height x thickness: 1000x20x10 mm) on the collector will increase surface area of absorber so it can receive much more solar energy. The solar collector cover is made of glass (thickness of 5 mm). During the research, the solar irradiance and temperature of collector are measured and recorded every five minutes. Temperature measurement performed on the surface of the absorber plate, inside of collector, surface cover and the outer side insulator (plywood). This data is used to calculate the heat loss due to conduction, convection and radiation on the collector. Openings of collectors vary as follows: 100%, 75%, 15% and 0% (total enclosed). The data collecting was conducted from 09.00 am to 17.00 pm and triplicates. The collector thermal efficiency calculated based on the ratio of the amount of heat received to the solar irradiance absorbed. The results show that each of openings solar collector has different solar irradiance (because it was done on a different day) which is in units of W/m2: 390 (100% open), 376 (75% open), 429 (15% open), and 359 (totally enclosed). The highest thermal efficiency is in openings variation of 15% opened. These results indicate that the efficiency of the collector is influenced by the solar irradiance received by the collector and the temperature on the collector plate. The highest thermal efficiency is in variation of openings 15%. These indicate that the efficiency of the collector was influenced by solar irradiance received by the collector and openings of the collector plate.

Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review.

Science.gov (United States)

Chamsa-Ard, Wisut; Brundavanam, Sridevi; Fung, Chun Che; Fawcett, Derek; Poinern, Gerrard

2017-05-31

The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

Investigation of superflares frequency variability of solar-type stars

International Nuclear Information System (INIS)

Akopian, A.A.

2015-01-01

Statistical study of the variability of the superflares frequency of 46 solar-type stars detected by orbital observatory 'Kepler' is presented. Two possible scenarios for changes in frequency are considered. In the first, the temporal sequence of superflares is regarded as a piecewise stationary Poissonian process. Statistically significant change in the frequency of superflares by several times is revealed at five stars. Moments of change of frequency are accompanied by sudden changes in the behavior of the star's brightness. Brightness of a star for a short time becomes irregular, with a significant decrease in the amplitude

Mass-loss Rates from Coronal Mass Ejections: A Predictive Theoretical Model for Solar-type Stars

Energy Technology Data Exchange (ETDEWEB)

Cranmer, Steven R. [Department of Astrophysical and Planetary Sciences, Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO 80309 (United States)

2017-05-10

Coronal mass ejections (CMEs) are eruptive events that cause a solar-type star to shed mass and magnetic flux. CMEs tend to occur together with flares, radio storms, and bursts of energetic particles. On the Sun, CME-related mass loss is roughly an order of magnitude less intense than that of the background solar wind. However, on other types of stars, CMEs have been proposed to carry away much more mass and energy than the time-steady wind. Earlier papers have used observed correlations between solar CMEs and flare energies, in combination with stellar flare observations, to estimate stellar CME rates. This paper sidesteps flares and attempts to calibrate a more fundamental correlation between surface-averaged magnetic fluxes and CME properties. For the Sun, there exists a power-law relationship between the magnetic filling factor and the CME kinetic energy flux, and it is generalized for use on other stars. An example prediction of the time evolution of wind/CME mass-loss rates for a solar-mass star is given. A key result is that for ages younger than about 1 Gyr (i.e., activity levels only slightly higher than the present-day Sun), the CME mass loss exceeds that of the time-steady wind. At younger ages, CMEs carry 10–100 times more mass than the wind, and such high rates may be powerful enough to dispel circumstellar disks and affect the habitability of nearby planets. The cumulative CME mass lost by the young Sun may have been as much as 1% of a solar mass.

Performance Evaluation of a Solar Adsorption Refrigeration System with a Wing Type Compound Parabolic Concentrator

Directory of Open Access Journals (Sweden)

Muhammad Umair

2014-03-01

Full Text Available Simulation study of a solar adsorption refrigeration system using a wing type compound parabolic concentrator (CPC is presented. The system consists of the wing type collector set at optimum angles, adsorption bed, a condenser and a refrigerator. The wing type collector captures the solar energy efficiently in the morning and afternoon and provides the effective temperature for a longer period of time compared to that achieved by a linear collector. The objectives of the study were to evaluate the system behavior, the effect of wing length, and to compare the performance of the systems with wing type and linear CPCs. A detailed dynamic simulation model was developed based on mass and energy balance equations. The simulation results show that the system performance with wing type CPC increases by up to 6% in the summer and up to 2% in the winter, compared to the performance with a linear CPC having same collector length. The ice production also increases up to 13% in the summer with the wing type CPC. This shows that the wing type CPC is helpful to increase the performance of the system compared to the linear CPC with the same collector length and without the need for tracking.

Detection of glycolaldehyde toward the solar-type protostar NGC 1333 IRAS2A

DEFF Research Database (Denmark)

Coutens, Audrey; Persson, M. V.; Jørgensen, J. K.

2015-01-01

Glycolaldehyde is a key molecule in the formation of biologically relevant molecules such as ribose. We report its detection with the Plateau de Bure interferometer toward the Class 0 young stellar object NGC 1333 IRAS2A, which is only the second solar-type protostar for which this prebiotic mole...

Automated Asteroseismic Analysis of Solar-type Stars

DEFF Research Database (Denmark)

Karoff, Christoffer; Campante, T.L.; Chaplin, W.J.

2010-01-01

The rapidly increasing volume of asteroseismic observations on solar-type stars has revealed a need for automated analysis tools. The reason for this is not only that individual analyses of single stars are rather time consuming, but more importantly that these large volumes of observations open...... are calculated in a consistent way. Here we present a set of automated asterosesimic analysis tools. The main engine of these set of tools is an algorithm for modelling the autocovariance spectra of the stellar acoustic spectra allowing us to measure not only the frequency of maximum power and the large......, radius, luminosity, effective temperature, surface gravity and age based on grid modeling. All the tools take into account the window function of the observations which means that they work equally well for space-based photometry observations from e.g. the NASA Kepler satellite and ground-based velocity...

Exergetic analysis of basin type solar still

Directory of Open Access Journals (Sweden)

Apurba Layek

2018-02-01

Full Text Available Simplicity of solar distillation system makes it very attractive, but the yield as well as the overall efficiency is very low. Different types of absorng materials e.g. black ink, black dye solution in brackish water and black toner on water surface were used to evaluate their effect on the yield. As the absorng material absorbs more insolation to increase brackish water temperature, increases yield as well as overall energy efficiency. To enhance the thermal performance, and to have the insight of thermal losses; exergetic analysis of all the components is done. The maximum overall energy efficiency obtained for brackish water having these absorber on brackish water are about 41.3%, 43.42% and 45.79%, while exergetic efficiency values are 5.91%, 6.34% and 7.10% respectively. Exergy destruction from basin liner is the highest compared to that from brackish water and glazing.

Three-dimensional Langmuir wave instabilities in type III solar radio bursts

International Nuclear Information System (INIS)

Bardwell, S.; Goldman, M.V.

1976-01-01

Assuming that type III solar radio bursts are associated with electron streams moving at about c/3, Langmuir waves should be strongly excited. We have studied all of the Langmuir-wave linear parametric instabilities excited in cylindrical symmetry by an electron-stream--driven Langmuir wave-pump propagating along the stream axis. Included in this unified homogeneous treatment are induced backscattering off ions, the oscillating two-stream instability, and a new ''stimulated modulational instability,'' previously unconsidered in this context. Near a few solar radii, the latter two deposit Langmuir wave energy into a forward-scattering cone about the stream axis. It is concluded that the linear stage of the forward-scattering instabilities involves transfer of energy to Langmuir waves which remain in resonance with the stream, and therefore probably do not prevent rapid depletion of the electron stream due to quasilinear plateau formation at these distances from the Sun

Nanofluid Types, Their Synthesis, Properties and Incorporation in Direct Solar Thermal Collectors: A Review

Directory of Open Access Journals (Sweden)

Wisut Chamsa-ard

2017-05-01

Full Text Available The global demand for energy is increasing and the detrimental consequences of rising greenhouse gas emissions, global warming and environmental degradation present major challenges. Solar energy offers a clean and viable renewable energy source with the potential to alleviate the detrimental consequences normally associated with fossil fuel-based energy generation. However, there are two inherent problems associated with conventional solar thermal energy conversion systems. The first involves low thermal conductivity values of heat transfer fluids, and the second involves the poor optical properties of many absorbers and their coating. Hence, there is an imperative need to improve both thermal and optical properties of current solar conversion systems. Direct solar thermal absorption collectors incorporating a nanofluid offers the opportunity to achieve significant improvements in both optical and thermal performance. Since nanofluids offer much greater heat absorbing and heat transfer properties compared to traditional working fluids. The review summarizes current research in this innovative field. It discusses direct solar absorber collectors and methods for improving their performance. This is followed by a discussion of the various types of nanofluids available and the synthesis techniques used to manufacture them. In closing, a brief discussion of nanofluid property modelling is also presented.

Passive-solar construction handbook

Energy Technology Data Exchange (ETDEWEB)

Levy, E.; Evans, D.; Gardstein, C.

1981-02-01

Many of the basic elements of passive solar design are reviewed. Passive solar construction is covered according to system type, each system type discussion including a general discussion of the important design and construction issues which apply to the particular system and case studies illustrating designed and built examples of the system type. The three basic types of passive solar systems discussed are direct gain, thermal storage wall, and attached sunspace. Thermal performance and construction information is presented for typical materials used in passive solar collector components, storage components, and control components. Appended are an overview of analysis methods and a technique for estimating performance. (LEW)

Diurnal, seasonal, and interannual differences in the links of probabilities of derivation of different types Es with solar activity

Science.gov (United States)

Petrukhin, Venedict F.; Poddubnaya, I. V.; Ponomarev, Evgenij A.; Sutyrin, Nicolaj A.

2004-12-01

The analysis of the ionospheric data on Irkutsk obtained from 1960 to 1996 was made. Was shown, that the link of probabilities of observation of the sporadic derivations in E-region of ionosphere with solar activity (SA) essentially depends on time of day, season and correlation between solar and geophysical parameters. For different types of sporadic derivations this link has different character and with a different image varies with current of time. It is necessary to mark, that the link of night sporadic derivations (Es such as "f") with solar activity in the summer very high and practically does not vary in time (r=-0.897-/+0.04). The temporary course of coefficients of correlation between solar activity and probability of observation of sporadic stratums (r) of a different type varies depending on the season. Further, for stratums of a type "cl" and "l" the change r happens within increase of SA. At the same time, there is an abnormal behavior of height so f sporadic stratums such as "cl". There is an impression that in a considered time frame there is competition of two factors. One of them - solar activity, which in the norm supports the negative correlation link with frequency of observation and second - a factor of an unknown nature, which has caused evocative anomaly of altitude, becomes dominant above natural negative link.

Performance analysis of nanodisk and core/shell/shell-nanowire type III-Nitride heterojunction solar cell for efficient energy harvesting

Science.gov (United States)

Routray, S. R.; Lenka, T. R.

2017-11-01

Now-a-days III-Nitride nanowires with axial (nanodisk) and radial (core/shell/shell-nanowire) junctions are two unique and potential methods for solar energy harvesting adopted by worldwide researchers. In this paper, polarization behavior of GaN/InGaN/GaN junction and its effect on carrier dynamics of nanodisk and CSS-nanowire type solar cells are intensively studied and compared with its planar counterpart by numerical simulations using commercially available Victory TCAD. It is observed that CSS-NW with hexagonal geometrical shapes are robust to detrimental impact of polarization charges and could be good enough to accelerate carrier collection efficiency as compared to nanodisk and planar solar cells. This numerical study provides an innovative aspect of fundamental device physics with respect to polarization charges in CSS-NW and nanodisk type junction towards photovoltaic applications. The internal quantum efficiencies (IQE) are also discussed to evaluate carrier collection mechanisms and recombination losses in each type of junctions of solar cell. Finally, it is interesting to observe a maximum conversion efficiency of 6.46% with 91.6% fill factor from n-GaN/i-In0.1Ga0.9N/p-GaN CSS-nanowire solar cell with an optimized thickness of 180 nm InGaN layer under one Sun AM1.5 illumination.

Interplanetary scattering of fast solar electrons deduced from type III bursts observed at low frequencies

International Nuclear Information System (INIS)

Alvarez, H.; Lin, R.P.

1976-01-01

Observations of low frequency solar type III radio bursts and the associated fast solar electrons show that the total path length travelled by the particles between the Sun and the Earth is significantly greater than the length of the smooth Archimedean spiral trajectory followed by the centroid of the type III exciter (Alvarez et al., 1975). Here it is assumed that the ratio of electron path length and the spiral length increases approximately as rsup(n), where r is heliocentric distance, and then compute the radio bursts arrival time at 1 AU for different values of n. A comparison with the radio observations indicates that the best fit occurs for n=1.5+-1.0. These results are interpreted in terms of the variation of electron scattering with heliocentric distance. (Auth.)

Comparison of Nanohole-Type and Nanopillar-Type Patterned Metallic Electrodes Incorporated in Organic Solar Cells

Science.gov (United States)

Wang, Wenyan; Cui, Yanxia; Fung, Kin Hung; Zhang, Ye; Ji, Ting; Hao, Yuying

2017-09-01

Both the nanohole- and nanopillar-type patterned metallic electrodes (PMEs) have been introduced in organic solar cells (OSCs) for improving device performances experimentally, but there is few work addressing the similarities and differences between them. In this theoretical work, we systematically compare the impact of the nanohole- and nanopillar-type PMEs on the performance of an OSC based on hybridized cavity resonances. By optimizing the geometrical parameters of each PME, we obtained an interesting result that the integrated absorption efficiencies in the active layer with different optimized PMEs are almost the same (both are equal to 82.4%), outperforming that of the planar control by 9.9%. Though the absorption enhancement spectra of the two different optimal devices are similar as well, the mechanisms of light trapping at the corresponding enhancement peaks are distinct from each other. In a comprehensive view, the nanopillar-type PME is suggested to be applied in the present system, since its optimal design has a moderate filling ratio, which is much easier to fabricate than its counterpart. This work could contribute to the development of high-efficiency OSCs.

Naphthalene Diimide Based n-Type Conjugated Polymers as Efficient Cathode Interfacial Materials for Polymer and Perovskite Solar Cells.

Science.gov (United States)

Jia, Tao; Sun, Chen; Xu, Rongguo; Chen, Zhiming; Yin, Qingwu; Jin, Yaocheng; Yip, Hin-Lap; Huang, Fei; Cao, Yong

2017-10-18

A series of naphthalene diimide (NDI) based n-type conjugated polymers with amino-functionalized side groups and backbones were synthesized and used as cathode interlayers (CILs) in polymer and perovskite solar cells. Because of controllable amine side groups, all the resulting polymers exhibited distinct electronic properties such as oxidation potential of side chains, charge carrier mobilities, self-doping behaviors, and interfacial dipoles. The influences of the chemical variation of amine groups on the cathode interfacial effects were further investigated in both polymer and perovskite solar cells. We found that the decreased electron-donating property and enhanced steric hindrance of amine side groups substantially weaken the capacities of altering the work function of the cathode and trap passivation of the perovskite film, which induced ineffective interfacial modifications and declining device performance. Moreover, with further improvement of the backbone design through the incorporation of a rigid acetylene spacer, the resulting polymers substantially exhibited an enhanced electron-transporting property. Upon use as CILs, high power conversion efficiencies (PCEs) of 10.1% and 15.2% were, respectively, achieved in polymer and perovskite solar cells. Importantly, these newly developed n-type polymers were allowed to be processed over a broad thickness range of CILs in photovoltaic devices, and a prominent PCE of over 8% for polymer solar cells and 13.5% for perovskite solar cells can be achieved with the thick interlayers over 100 nm, which is beneficial for roll-to-roll coating processes. Our findings contribute toward a better understanding of the structure-performance relationship between CIL material design and solar cell performance, and provide important insights and guidelines for the design of high-performance n-type CIL materials for organic and perovskite optoelectronic devices.

First detection of cyanamide (NH2CN) towards solar-type protostars

Science.gov (United States)

Coutens, A.; Willis, E. R.; Garrod, R. T.; Müller, H. S. P.; Bourke, T. L.; Calcutt, H.; Drozdovskaya, M. N.; Jørgensen, J. K.; Ligterink, N. F. W.; Persson, M. V.; Stéphan, G.; van der Wiel, M. H. D.; van Dishoeck, E. F.; Wampfler, S. F.

2018-05-01

Searches for the prebiotically relevant cyanamide (NH2CN) towards solar-type protostars have not been reported in the literature. We present here the first detection of this species in the warm gas surrounding two solar-type protostars, using data from the Atacama Large Millimeter/Submillimeter Array Protostellar Interferometric Line Survey (PILS) of IRAS 16293-2422 B and observations from the IRAM Plateau de Bure Interferometer of NGC 1333 IRAS2A. We also detected the deuterated and 13C isotopologs of NH2CN towards IRAS 16293-2422 B. This is the first detection of NHDCN in the interstellar medium. Based on a local thermodynamic equilibrium analysis, we find that the deuteration of cyanamide ( 1.7%) is similar to that of formamide (NH2CHO), which may suggest that these two molecules share NH2 as a common precursor. The NH2CN/NH2CHO abundance ratio is about 0.2 for IRAS 16293-2422 B and 0.02 for IRAS2A, which is comparable to the range of values found for Sgr B2. We explored the possible formation of NH2CN on grains through the NH2 + CN reaction using the chemical model MAGICKAL. Grain-surface chemistry appears capable of reproducing the gas-phase abundance of NH2CN with the correct choice of physical parameters.

Preparation of p-type NiO films by reactive sputtering and their application to CdTe solar cells

Science.gov (United States)

Ishikawa, Ryousuke; Furuya, Yasuaki; Araki, Ryouichi; Nomoto, Takahiro; Ogawa, Yohei; Hosono, Aikyo; Okamoto, Tamotsu; Tsuboi, Nozomu

2016-02-01

Transparent p-type NiO films were prepared by reactive sputtering using the facing-target system under Ar-diluted O2 gas at Tsub of 30 and 200 °C. The increasing intensity of dominant X-ray diffraction (XRD) peaks indicates improvements in the crystallinity of NiO films upon Cu doping. In spite of the crystallographic and optical changes after Cu-doping, the electrical properties of Cu-doped NiO films were slightly improved. Upon Ag-doping at 30 °C under low O2 concentration, on the other hand, the intensity of the dominant (111) XRD peaks was suppressed and p-type conductivity increased from ˜10-3 to ˜10-1 S cm-1. Finally, our Ag-doped NiO films were applied as the back contact of CdTe solar cells. CdTe solar cells with a glass/ITO/CdS/CdTe/NiO structure exhibited an efficiency of 6.4%, suggesting the high potential of using p-type NiO for the back-contact film in thin-film solar cells.

Novel low fluence combination laser treatment of solar lentigines in type III Asian skin

Directory of Open Access Journals (Sweden)

Brian Wei Cheng Anthony Tian

2015-01-01

Full Text Available Objective: To demonstrate a novel low fluence combination laser technique [Erbium-doped yttrium aluminum garnet (Erb:YAG and neodymium-doped yttrium aluminum garnet (Nd:YAG] to effectively treat solar lentigines in type III Asian skin in a single session. Design: A prospective study. Setting: A Singapore-based clinic. Participants: Five patients (all females were enrolled into the study. The ages ranged 35-60 years; all patients had Fitzpatrick skin type III. Measurements: Photographs were taken at baseline and at 1-month follow-up. These were reviewed by two independent physicians who were blinded to the study. Changes in pigment severity were assessed by a 5-point scale (1: Aggravation of pigment, 2: No change, 3: 25-50% improvement, 4: 51-75% improvement, and 5: 76-100% improvement. Results: All patients received a single treatment session. At 1-month follow-up, a reduction in pigment was observed in all patients. Both physicians′ reports were independently agreeable. All patients scored 5, having >90% improvement in pigment severity. No hypopigmentation, postinflammatory hyperpigmentation (PIH, or recurrence was seen. Conclusion: Low fluence combination laser is effective and safe for clearance of solar lentigines in type III Asian skin.

Enhanced power conversion efficiency of p-i-n type organic solar cells by employing a p-layer of palladium phthalocyanine

KAUST Repository

Kim, Inho; Haverinen, Hanna M.; Li, Jian; Jabbour, Ghassan E.

2010-01-01

We demonstrate an enhancement in the power conversion efficiency (PCE) of p-i-n type organic solar cells consisting of zinc phthalocyanine (ZnPc) and fullerene (C60) using a p-layer of palladium phthalocyanine (PdPc). Solar cells employing three

Influence of encapsulated electron active molecules of single walled-carbon nanotubes on superstrate-type Cu(In,Ga)Se{sub 2} solar cells

Energy Technology Data Exchange (ETDEWEB)

Lee, Jungwoo [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); CRD Laboratory, LG Chem. Research Park, Daejeon 305-738 (Korea, Republic of); Lee, Wonjoo [Department of Defense Ammunitions, Daeduk College, Daejeon 305-715 (Korea, Republic of); Shrestha, Nabeen K.; Lee, Deok Yeon; Lim, Iseul [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Kang, Soon Hyung [Department of Chemistry Education, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Nah, Yoon-Chae [School of Energy, Materials, and Chemical Engineering, Korea University of Technology and Education, Cheonan 330-708 (Korea, Republic of); Lee, Soo-Hyoung, E-mail: shlee66@jbnu.ac.kr [School of Semiconductor and Chemical Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Yi, Whikun, E-mail: wkyi@hanyang.ac.kr [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of); Han, Sung-Hwan, E-mail: shhan@hanyang.ac.kr [Department of Chemistry, Hanyang University, Seoul 133-791 (Korea, Republic of)

2014-03-01

Chemical functionalization of carbon nanotubes (CNTs) can strongly affect the efficiency of solar cells due to change of three factors viz. electronic energy structures, interfacial resistance, and electrical field. Therefore, it is worthwhile to investigate the influence of these three factors on the solar cells based on the functionalization of various active molecules in CNTs. In the present study, we investigate the influence of the three factors in the efficiency of superstrate-type Cu(In,Ga)Se{sub 2} (CIGS) solar cells [i.e. F-doped SnO{sub 2}/CNTs/CdS/CIGS/Au] by encapsulation of electron withdrawing and donating organic molecules inside CNTs. The CIGS solar cell was characterized using the electronic diagram, electrochemical impendence spectroscopy, reverse field emission currents, and currents–voltages curves. - Highlights: • We investigated the three effects of CNTs in superstrate-type CIGS solar cells. • Chemical functionalization of CNTs strongly affect the efficiency of solar cells. • The electrical field of solar cell was characterized using the reverse FE-currents.

Planet Occurrence within 0.25 AU of Solar-type Stars from Kepler

DEFF Research Database (Denmark)

Howard, A.W.; Geoffrey, G.W.; Bryson, S.T.

2012-01-01

We report the distribution of planets as a function of planet radius, orbital period, and stellar effective temperature for orbital periods less than 50 days around solar-type (GK) stars. These results are based on the 1235 planets (formally "planet candidates") from the Kepler mission that include...... a nearly complete set of detected planets as small as 2 R ⊕. For each of the 156,000 target stars, we assess the detectability of planets as a function of planet radius, R p, and orbital period, P, using a measure of the detection efficiency for each star. We also correct for the geometric probability...... of transit, R /a. We consider first Kepler target stars within the "solar subset" having T eff = 4100-6100 K, log g = 4.0-4.9, and Kepler magnitude Kp planets down to 2 R...

Solar radiophysics

International Nuclear Information System (INIS)

McLean, D.J.; Labrum, N.R.

1985-01-01

This book treats all aspects of solar radioastronomy at metre wavelengths, particularly work carried out on the Australian radioheliograph at Culgoora, with which most of the authors have been associated in one way or another. After an introductory section on historical aspects, the solar atmosphere, solar flares, and coronal radio emission, the book deals with instrumentation, theory, and details of observations and interpretations of the various aspects of metrewave solar radioastronomy, including burst types, solar storms, and the quiet sun. (U.K.)

Numerical and experimental investigation on a new type of compound parabolic concentrator solar collector

International Nuclear Information System (INIS)

Zheng, Wandong; Yang, Lin; Zhang, Huan; You, Shijun; Zhu, Chunguang

2016-01-01

Highlights: • A serpentine compound parabolic concentrator solar collector is proposed. • A mathematical model for the new collector is developed and verified by experiments. • The thermal efficiency of the collector can be up to 60.5% during the experiments. • The effects of key parameters on the thermal performance are mathematically studied. - Abstract: In order to improve the thermal efficiency, reduce the heat losses and achieve high freezing resistance of the solar device for space heating in cold regions, a new type of serpentine compound parabolic concentrator solar collector is presented in this paper, which is a combination of a compound parabolic concentrator solar collector and a flat plate solar collector. A detailed mathematical model for the new collector based on the analysis of heat transfer is developed and then solved by the software tool Matlab. The numerical results are compared with the experimental data and the maximum deviation is 8.07%, which shows a good agreement with each other. The experimental results show that the thermal efficiency of the collector can be as high as 60.5%. The model is used to predict the thermal performance of the new collector. The effects of structure and operating parameters on the thermal performance are mathematically discussed. The numerical and experimental results show that the new collector is more suitable to provide low temperature hot water for space heating in cold regions and the mathematical model will be much helpful in the designing and optimizing of the solar collectors.

Efficiency improvements by Metal Wrap Through technology for n-type Si solar cells and modules

Energy Technology Data Exchange (ETDEWEB)

Wenchao, Zhao; Jianming, Wang; Yanlong, Shen; Ziqian, Wang; Yingle, Chen; Shuquan, Tian; Zhiliang, Wan; Bo, Yu; Gaofei, Li; Zhiyan, Hu; Jingfeng, Xiong [Yingli Green Energy Holding Co., Ltd, 3399 North Chaoyang Avenue, Baoding (China); Guillevin, N.; Heurtault, B.; Aken, B.B. van; Bennett, I.J.; Geerligs, L.J.; Weeber, A.W.; Bultman, J.H. [ECN Solar Energy, Petten (Netherlands)

2012-09-15

N-type Metal Wrap Through (n-MWT) is presented as an industrially promising back-contact technology to reach high performance of silicon solar cells and modules. It can combine benefits from both n-type base and MWT metallization. In this paper, the efficiency improvements of commercial industrial n-type bifacial Si solar cells (239 cm{sup 2}) and modules (60 cells) by the integration of the MWT technique are described. For the cell, after the optimization of integration, over 0.3% absolute efficiency gain was achieved over the similar non-MWT technology, and Voc gain and Isc gain up to 0.9% and 3.5%, respectively. These gains are mainly attributed to reduced shading loss and surface recombination. Besides the front pattern optimization, a 0.1m{Omega} reduction of Rs in via part will induce further 0.06% absolute efficiency improvement. For the module part, a power output of n-MWT module up to 279W was achieved, corresponding to a module efficiency of about 17.7%.

DEBRIS DISKS AROUND SOLAR-TYPE STARS: OBSERVATIONS OF THE PLEIADES WITH THE SPITZER SPACE TELESCOPE

International Nuclear Information System (INIS)

Sierchio, J. M.; Rieke, G. H.; Su, K. Y. L.; Plavchan, P.; Stauffer, J. R.; Gorlova, N. I.

2010-01-01

We present Spitzer MIPS observations at 24 μm of 37 solar-type stars in the Pleiades and combine them with previous observations to obtain a sample of 71 stars. We report that 23 stars, or 32% ± 6.8%, have excesses at 24 μm at least 10% above their photospheric emission. We compare our results with studies of debris disks in other open clusters and with a study of A stars to show that debris disks around solar-type stars at 115 Myr occur at nearly the same rate as around A-type stars. We analyze the effects of binarity and X-ray activity on the excess flux. Stars with warm excesses tend not to be in equal-mass binary systems, possibly due to clearing of planetesimals by binary companions in similar orbits. We find that the apparent anti-correlations in the incidence of excess and both the rate of stellar rotation and also the level of activity as judged by X-ray emission are statistically weak.

Study on the Operating Characteristics and System Modelling of Loop type Thermosyphon for Using Solar Thermal Energy

International Nuclear Information System (INIS)

Kang, Myeong Cheol

1999-02-01

Solar energy is one of the promising resources of renewable energy. It is of particular interest due to the energy shortage and environment pollution problems. Water heating by solar energy for domestic use is one of the most successful and feasible applications of solar energy. The thermosyphon SDHWS and the loop type thermosyphon systems are widely used for domestic hot water system. The loop type thermosyphon is a circulation device for transferring the heat produced at the evaporator area to the condenser area in the loop by a working fluid. The system has the advantage of high heat transfer rate. A phase change of the working fluid occurs at the evaporator section and the vapor is transported to the condenser by the density gradient. The loop type thermosyphon collector can be made of smaller area and has higher efficiency than the present thermosyphon SDHWS. In this study, the operating characteristics of various working fluids being used have been identified. The working fluids employed in the study were ethanol, water and a binary mixture of ethanol and water. The volume of working fluid used in this study were 30%, 40%, 50%, 60% and 70% of evaporator volume. An increased heat was applied with the increased volume of working fluid. It is observed that, in the thermosyphon with low volume of working fluid, such as 30% or 40%, the fluid was dried out. The average efficiency of the loop type thermosyphon was 46% with high solar irradiation and 43% with low irradiation. The flow pattern and mechanism of the heat transfer were identified through this study. Flow patterns of the binary mixture working fluid were also investigated, and the patterns were recorded in the camera. The system parameters were calculated using the thermal performance data. Modelling of the system was carried out using PSTAR method and TRNSYS program

A novel solar hot plate for cooking

Energy Technology Data Exchange (ETDEWEB)

Rincon Mejia, Eduardo A; Osorio Jaramillo, Fidel A [Facultad de Ingenieria, UAEMex, Toluca, Edo. (Mexico)

2000-07-01

In Mexico and other developing countries, the use of firewood as combustible for cooking has contributed to deforestation and desertification of large zones. This is due to the lack of alternative combustibles for the poor inhabitants of the countryside and remote areas. In this paper, a new solar hot plate, intended for contributing to solve this problem, is presented. It can be used for cooking not only a great variety of prehispanic and traditional meals, like tortillas, fried meat and vegetables, but also hot cakes, bacon, eggs, steaks and fries. The hot plate solar cooker, called Tolocatzin, consists of a horizontal metallic plate, which is heated from both of its top and bottom surfaces by concentrated sun light from multicompound concentrator based on nonimaging optics, and built with nine ordinary plane glass-silvered, and two curved aluminum mirrors, so it can be manufactured easily in a small factory or at home. For an acceptance angle of 15 Celsius degrees, which allows the concentration of sun light without sun-tracking for about one hour, it can reach temperatures up to 240 Celsius degrees in a few minutes. This temperature is high enough for cooking almost all fried or grilled meals. The design was optimized using ray-trace procedures. The operational experience with early prototypes has shown that the Tolocatzin solar hot plate does an excellent cooking job and could really be massively used in sunny countries. [Spanish] En Mexico y otros paises en desarrollo, el uso de la madera como combustible para cocinar ha contribuido a la deforestacion y desertificacion de grandes zonas. Esto es debido a la falta de combustibles alternativos por parte de los habitantes pobres del campo y de areas remotas. En este articulo se presenta una nueva placa solar que tiene el proposito de contribuir a resolver este problema. Puede ser usada para cocinar no solamente una gran variedad de comidas prehispanicas y tradicionales, como tortillas, carne frita y verduras sino

Harnessing light energy with a planar transparent hybrid of graphene/single wall carbon nanotube/n-type silicon heterojunction solar cell

DEFF Research Database (Denmark)

Chen, Leifeng; Yu, Hua; Zhong, Jiasong

2015-01-01

The photovoltaic conversion efficiency of a solar cell fabricated by a simple electrophoretic method with a planar transparent hybrid of graphenes (GPs) and single wall carbon nanotubes (SCNTs)/n-type silicon heterojunction was significantly increased compared to GPs/n-Si and SCNTs/n-Si solar cells...

Core–shell-typed Ag-SiO2 nanoparticles as solar selective coating materials

International Nuclear Information System (INIS)

Gao, Tao; Jelle, Bjørn Petter; Gustavsen, Arild

2013-01-01

Silver (Ag) nanoparticles with typical diameter of about 50 nm have been prepared via a polyol process. The as-prepared Ag nanoparticles are well crystallized and exhibit a characteristic surface plasmon resonance (SPR) band centered at ∼423 nm. The SPR band shows a strong dependence on the sizes of Ag nanoparticles and the types of the dielectric medium. Core–shell-typed Ag-SiO 2 nanoparticles have also been prepared by depositing a thin layer (∼25 nm) of silica on Ag nanoparticles. The core–shell-typed Ag-SiO 2 nanoparticles show similar optical behaviors (absorption, transmission, and reflection) but enhanced stability compared to those of the Ag nanoparticles, indicating that the core–shell-typed Ag-SiO 2 nanoparticles may be used as solar selective coating materials for architectural window applications.

Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment

Directory of Open Access Journals (Sweden)

A. G. Gutierrez-Mata

2017-01-01

Full Text Available This literature research, although not exhaustive, gives perspective to solar-driven photocatalysis, such as solar photo-Fenton and TiO2 solar photocatalysis, reported in the literature for the degradation of aqueous organic pollutants. Parameters that influence the degradation and mineralization of organics like catalyst preparation, type and load of catalyst, catalyst phase, pH, applied potential, and type of organic pollutant are addressed. Such parameters may also affect the photoactivity of the catalysts used in the studied solar processes. Solar irradiation is a renewable, abundant, and pollution-free energy source for low-cost commercial applications. Therefore, these solar processes represent an environmentally friendly alternative mainly because the use of electricity can be decreased/avoided.

Two Types of Long-duration Quasi-static Evolution of Solar Filaments

Science.gov (United States)

Xing, C.; Li, H. C.; Jiang, B.; Cheng, X.; Ding, M. D.

2018-04-01

In this Letter, we investigate the long-duration quasi-static evolution of 12 pre-eruptive filaments (four active region (AR) and eight quiescent filaments), mainly focusing on the evolution of the filament height in 3D and the decay index of the background magnetic field. The filament height in 3D is derived through two-perspective observations of Solar Dynamics Observatory (SDO) and Solar TErrestrial RElations Observatory (STEREO). The coronal magnetic field is reconstructed using the potential field source surface model. A new finding is that the filaments we studied show two types of long-duration evolution: one type comprises a long-duration static phase and a short, slow rise phase with a duration of less than 12 hr and a speed of 0.1–0.7 km s‑1, while the other one only presents a slow rise phase but with an extremely long duration of more than 60 hr and a smaller speed of 0.01–0.2 km s‑1. At the moment approaching the eruption, the decay index of the background magnetic field at the filament height is similar for both AR and quiescent filaments. The average value and upper limit are ∼0.9 and ∼1.4, close to the critical index of torus instability. Moreover, the filament height and background magnetic field strength are also found to be linearly and exponentially related with the filament length, respectively.

Comparative study of two weir type cascade solar stills with and without PCM storage using energy and exergy analysis

International Nuclear Information System (INIS)

Sarhaddi, Faramarz; Farshchi Tabrizi, Farshad; Aghaei Zoori, Halimeh; Mousavi, Seyed Amir Hossein Seyed

2017-01-01

Highlights: • Performance evaluation of cascade solar stills with PCM storage is carried out. • Model of cascade solar still is weir type. • Present study is based on numerical simulation. • Effect of operating parameters is studies on yield, energy and exergy efficiencies. - Abstract: In this paper, the comparative study of energy and exergy performance of two weir type cascade solar stills with and without PCM storage in sunny and semi-cloudy days is carried out. The governing equations of energy analysis include a set of nonlinear equations which is obtained by writing energy balance for the various components of a solar still (i.e. glass cover, brackish water, absorber plate, phase change materials). A detailed exergy analysis is carried out and various irreversibility rates in the solar still system and its exergy efficiency are introduced. In order to solve the governing equations a computer simulation program is developed. The results of a numerical simulation of the present study are in good agreement with the experimental data of previous literatures. The numerical results of the present study show that the energy and exergy performance of solar still without PCM storage is better than the solar still with PCM storage in sunny days. On the other hand, the solar still with PCM storage is preferred for semi-cloudy days due to its better energy and exergy performance. The maximum value of the energy and exergy efficiencies of the solar still without PCM for a typical sunny day are 76.69% and 6.53%, respectively. While, the maximum energy and exergy efficiencies of the solar still with PCM for a sample semi-cloudy day are 74.35% and 8.59%, respectively. Furthermore, it is observed that the highest irreversibility rate belongs to the absorber plate and its value for the solar still without PCM on typical sunny day and the solar still with PCM on semi-cloudy days is 83.1% and 78.8% of the whole of system irreversibility rates, respectively. Whereas, the

Laser synthesized super-hydrophobic conducting carbon with broccoli-type morphology as a counter-electrode for dye sensitized solar cells

Science.gov (United States)

Gokhale, Rohan; Agarkar, Shruti; Debgupta, Joyashish; Shinde, Deodatta; Lefez, Benoit; Banerjee, Abhik; Jog, Jyoti; More, Mahendra; Hannoyer, Beatrice; Ogale, Satishchandra

2012-10-01

A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode.A laser photochemical process is introduced to realize superhydrophobic conducting carbon coatings with broccoli-type hierarchical morphology for use as a metal-free counter electrode in a dye sensitized solar cell. The process involves pulsed excimer laser irradiation of a thin layer of liquid haloaromatic organic solvent o-dichlorobenzene (DCB). The coating reflects a carbon nanoparticle-self assembled and process-controlled morphology that yields solar to electric power conversion efficiency of 5.1% as opposed to 6.2% obtained with the conventional Pt-based electrode. Electronic supplementary information (ESI) available: Materials and equipment details, solar cell fabrication protocol, electrolyte spreading time measurement details, XPS spectra, electronic study, film adhesion test detailed analysis and field emission results. See DOI: 10.1039/c2nr32082g

Influence of Axisymmetrically Deformed Explosions in Type II Supernovae on the Reproduction of the Solar System Abundances

Science.gov (United States)

Nagataki, Shigehiro

1999-01-01

We have tried to reproduce the solar system abundances using the nucleosynthesis products of Type Ia and Type II supernovae. In particular, we examined the effects of axisymmetrically deformed explosions in Type II supernovae. 44Ca and 47,48Ti are enhanced considerably in axisymmetrically deformed explosion models because of the active alpha-rich freezeout. The enhancement of nuclei around A=45 is a welcome result since it solves the problem of the nuclei shortage. Moreover, 59Co, 63,65Cu, and 66Zn are enhanced enough to reproduce the solar system abundances. The enhancement of Cu and Zn means the possibility that these nuclei, which have been said to be produced by the slow process, can be synthesized fairly well during the explosive nucleosynthesis. To discuss their origin quantitatively, the position of the mass cut is a very important parameter that is very difficult to determine numerically at present. We also stress that an axisymmetrically deformed explosion of Type II supernovae of the degree that is considered in this analysis is not excluded by the results of calculations of explosive nucleosynthesis, that is, the nucleosynthesis products are not extremely disturbed and the solar system abundances can be reproduced fairly well by the axisymmetrically deformed explosion models. This conclusion will be good for the theory of core collapse including the rotation of an iron core, magnetic field, and axisymmetrically modified neutrino radiation from a rotating protoneutron star, which possibly can cause an axisymmetrically deformed explosion.

The study of the application of crystalline silicone solar cell type for a temporary flood camp

Science.gov (United States)

Hendarti, R.; Katarina, W.; Wangidjaja, W.

2017-12-01

During flood period, most of temporary evacuation shelters in Jakarta are lack in electricity because the local electricity company turned the electricity off to avoid any electrical problem because of the high water level over the flooded area. Whereas, the local electricity or the grid is the main energy source for the lighting and water pump machine, therefore the energy source becomes a significant issue during this period. Currently, the local government has already provided diesel generators to substitute the local grid when it is off, however, the amount of the generators is still limited. This study, therefore, investigated an alternative energy for the electricity, particularly solar energy and this paper presents an analysis of the Jakarta duration of sunshine during rainy seasons in order to investigate which Crystalline Silicone solar cell type that can be implemented optimally for energy supply in the period of flood evacuation as well as for the shelter. A deep analysis on literature review was conducted on the three types of Crystalline Silicone solar cell, Jakarta local weather. Furthermore, the standard of International Federation of Red Cross and Red Crescent Societies (IFRC) was also studied for the shelter design. The results of this study could be used as a reference for the local authority in providing the substitute energy supply in the temporary evacuation area during flood period in which the solar energy source could be also attached on the shelter.

Asteroseismology of solar-type stars: particular physical effects

Energy Technology Data Exchange (ETDEWEB)

Carrier, F [Instituut voor Sterrenkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven (Belgium); Eggenberger, P; Leyder, J-C [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 aout, 4000 Liege (Belgium)], E-mail: fabien@ster.kuleuven.be

2008-10-15

Since the success of helioseismology, numerous efforts have been made to detect solar-like oscillations on other stars. The measurement of the frequencies of p-mode oscillations provides an insight into the internal structure and is nowadays the most powerful constraint on the theory of stellar evolution. The existing asteroseismic observations were mainly motivated by the need to explore the seismological properties of stars with various global parameters, i.e. various locations in the HR diagram. With the aim of testing different physical effects on solar-like oscillations, we report here detection of acoustic modes on solar-like targets achieved with the spectrograph HARPS installed on the 3.6-m telescope at ESO La Silla Observatory.

Production of fine structures in type III solar radio bursts due to turbulent density profiles

International Nuclear Information System (INIS)

Loi, Shyeh Tjing; Cairns, Iver H.; Li, Bo

2014-01-01

Magnetic reconnection events in the corona release energetic electron beams along open field lines, and the beams generate radio emission at multiples of the electron plasma frequency f p to produce type III solar radio bursts. Type III bursts often exhibit irregularities in the form of flux modulations with frequency and/or local temporal advances and delays, and a type IIIb burst represents the extreme case where a type III burst is fragmented into a chain of narrowband features called striae. Remote and in situ spacecraft measurements have shown that density turbulence is ubiquitous in the corona and solar wind, and often exhibits a Kolmogorov power spectrum. In this work, we numerically investigate the effects of one-dimensional macroscopic density turbulence (along the beam direction) on the behavior of type III bursts, and find that this turbulence produces stria-like fine structures in the dynamic spectra of both f p and 2 f p radiation. Spectral and temporal fine structures in the predicted type III emission are produced by variations in the scattering path lengths and group speeds of radio emission, and in the locations and sizes of emitting volumes. Moderate turbulence levels yield flux enhancements with much broader half-power bandwidths in f p than 2 f p emission, possibly explaining the often observed type IIIb-III harmonic pairs as being where intensifications in 2 f p radiation are not resolved observationally. Larger turbulence levels producing trough-peak regions in the plasma density profile may lead to broader, resolvable intensifications in 2 f p radiation, which may account for the type IIIb-IIIb pairs that are sometimes observed.

PROPERTIES OF 42 SOLAR-TYPE KEPLER TARGETS FROM THE ASTEROSEISMIC MODELING PORTAL

Energy Technology Data Exchange (ETDEWEB)

Metcalfe, T. S.; Mathur, S. [Space Science Institute, 4750 Walnut Street Suite 205, Boulder, CO 80301 (United States); Creevey, O. L. [Institut d' Astrophysique Spatiale, Université Paris XI, UMR 8617, CNRS, Batiment 121, F-91405 Orsay Cedex (France); Doğan, G.; Christensen-Dalsgaard, J.; Karoff, C.; Trampedach, R. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Xu, H. [Computational and Information Systems Laboratory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); Bedding, T. R.; Benomar, O. [Sydney Institute for Astronomy (SIfA), School of Physics, University of Sydney, NSW 2006 (Australia); Chaplin, W. J.; Campante, T. L.; Davies, G. R. [School of Physics and Astronomy, University of Birmingham, Birmingham B15 2TT (United Kingdom); Brown, B. P. [Department of Astronomy and Center for Magnetic Self Organization in Laboratory and Astrophysical Plasmas, University of Wisconsin, Madison, WI 53706 (United States); Buzasi, D. L. [Department of Chemistry and Physics, Florida Gulf Coast University, Fort Myers, FL 33965 (United States); Çelik, Z. [Ege University, Department of Astronomy and Space Sciences, Bornova, 35100, Izmir (Turkey); Cunha, M. S. [Centro de Astrofísica e Faculdade de Ciências, Universidade do Porto, Rua das Estrelas, 4150-762, Porto (Portugal); Deheuvels, S. [Université de Toulouse, UPS-OMP, IRAP, Toulouse (France); Derekas, A. [Konkoly Observatory, MTA CSFK, H-1121 Budapest, Konkoly Thege M. út 15-17 (Hungary); Mauro, M. P. Di [INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy); and others

2014-10-01

Recently the number of main-sequence and subgiant stars exhibiting solar-like oscillations that are resolved into individual mode frequencies has increased dramatically. While only a few such data sets were available for detailed modeling just a decade ago, the Kepler mission has produced suitable observations for hundreds of new targets. This rapid expansion in observational capacity has been accompanied by a shift in analysis and modeling strategies to yield uniform sets of derived stellar properties more quickly and easily. We use previously published asteroseismic and spectroscopic data sets to provide a uniform analysis of 42 solar-type Kepler targets from the Asteroseismic Modeling Portal. We find that fitting the individual frequencies typically doubles the precision of the asteroseismic radius, mass, and age compared to grid-based modeling of the global oscillation properties, and improves the precision of the radius and mass by about a factor of three over empirical scaling relations. We demonstrate the utility of the derived properties with several applications.

Study of an Amorphous Silicon Oxide Buffer Layer for p-Type Microcrystalline Silicon Oxide/n-Type Crystalline Silicon Heterojunction Solar Cells and Their Temperature Dependence

Directory of Open Access Journals (Sweden)

Taweewat Krajangsang

2014-01-01

Full Text Available Intrinsic hydrogenated amorphous silicon oxide (i-a-SiO:H films were used as front and rear buffer layers in crystalline silicon heterojunction (c-Si-HJ solar cells. The surface passivity and effective lifetime of these i-a-SiO:H films on an n-type silicon wafer were improved by increasing the CO2/SiH4 ratios in the films. Using i-a-SiO:H as the front and rear buffer layers in c-Si-HJ solar cells was investigated. The front i-a-SiO:H buffer layer thickness and the CO2/SiH4 ratio influenced the open-circuit voltage (Voc, fill factor (FF, and temperature coefficient (TC of the c-Si-HJ solar cells. The highest total area efficiency obtained was 18.5% (Voc=700 mV, Jsc=33.5 mA/cm2, and FF=0.79. The TC normalized for this c-Si-HJ solar cell efficiency was −0.301%/°C.

TIME-DEPENDENT NONEXTENSIVITY ARISING FROM THE ROTATIONAL EVOLUTION OF SOLAR-TYPE STARS

Energy Technology Data Exchange (ETDEWEB)

Silva, J. R. P.; Nepomuceno, M. M. F.; Soares, B. B.; De Freitas, D. B., E-mail: joseronaldo@uern.br [Departamento de Física, Universidade do Estado do Rio Grande do Norte, Mossoró-RN (Brazil)

2013-11-01

Nonextensive formalism is a generalization of the Boltzmann-Gibbs statistics. In this formalism, the entropic index q is a quantity characterizing the degree of nonextensivity and is interpreted as a parameter of long-memory or long-range interactions between the components of the system. Since its proposition in 1988, this formalism has been applied to investigate a wide variety of natural phenomena. In stellar astrophysics, a theoretical distribution function based on nonextensive formalism (q distributions) has been successfully applied to reproduce the distribution of stellar radial and rotational velocity data. In this paper, we investigate the time variation of the entropic index q obtained from the distribution of rotation, Vsin i, for a sample of 254 rotational data for solar-type stars from 11 open clusters aged between 35.5 Myr and 2.6 Gyr. As a result, we have found an anti-correlation between the entropic index q and the age of clusters, and that the distribution of rotation Vsin i for these stars becomes extensive for an age greater than about 170 Myr. Assuming that the parameter q is associated with long-memory effects, we suggest that the memory of the initial angular momentum of solar-type stars can be scaled by the entropic index q. We also propose a physical link between the parameter q and the magnetic braking of stellar rotation.

Carrier extraction behaviour in type II GaSb/GaAs quantum ring solar cells

International Nuclear Information System (INIS)

Fujita, Hiromi; James, Juanita; Carrington, Peter J; Marshall, Andrew R J; Krier, Anthony; Wagener, Magnus C; Botha, Johannes R

2014-01-01

The introduction of quantum dot (QD) or quantum ring (QR) nanostructures into GaAs single-junction solar cells has shown enhanced photo-response above the GaAs absorption edge, because of sub-bandgap photon absorption. However, to further improve solar cell performance a better understanding of the mechanisms of photogenerated carrier extraction from QDs and QRs is needed. In this work we have used a direct excitation technique to study type II GaSb/GaAs quantum ring solar cells using a 1064 nm infrared laser, which enables us to excite electron–hole pairs directly within the GaSb QRs without exciting the GaAs host material. Temperature and laser intensity dependence of the current–voltage characteristics revealed that the thermionic emission process produced the dominant contribution to the photocurrent and accounts for 98.9% of total photocurrent at 0 V and 300 K. Although the tunnelling process gives only a low contribution to the photocurrent, an enhancement of the tunnelling current was clearly observed when an external electric field was applied. (paper)

Solar Simulator

Science.gov (United States)

1981-01-01

Oriel Corporation's simulators have a high pressure xenon lamp whose reflected light is processed by an optical system to produce a uniform solar beam. Because of many different types of applications, the simulators must be adjustable to replicate many different areas of the solar radiation spectrum. Simulators are laboratory tools for such purposes as testing and calibrating solar cells, or other solar energy systems, testing dyes, paints and pigments, pharmaceuticals and cosmetic preparations, plant and animal studies, food and agriculture studies and oceanographic research.

NUMERICAL SIMULATION OF SOLAR MICROFLARES IN A CANOPY-TYPE MAGNETIC CONFIGURATION

International Nuclear Information System (INIS)

Jiang, R.-L.; Fang, C.; Chen, P.-F.

2012-01-01

Microflares are small activities in the solar low atmosphere; some are in the low corona while others are in the chromosphere. Observations show that some of the microflares are triggered by magnetic reconnection between the emerging flux and a pre-existing background magnetic field. We perform 2.5-dimensional, compressible, resistive magnetohydrodynamic simulations of the magnetic reconnection with gravity considered. The background magnetic field is a canopy-type configuration that is rooted at the boundary of the solar supergranule. By changing the bottom boundary conditions in the simulation, a new magnetic flux emerges at the center of the supergranule and reconnects with the canopy-type magnetic field. We successfully simulate the coronal and chromospheric microflares whose current sheets are located at the corona and the chromosphere, respectively. The microflare with a coronal origin has a larger size and a higher temperature enhancement than the microflare with a chromospheric origin. In the microflares with coronal origins, we also found a hot jet (∼1.8 × 10 6 K), which is probably related to the observational extreme ultraviolet or soft X-ray jets, and a cold jet (∼10 4 K), which is similar to the observational Hα/Ca surges. However, there is only a Hα/Ca bright point in the microflares that have chromospheric origins. The study of parameter dependence shows that the size and strength of the emerging magnetic flux are the key parameters that determine the height of the reconnection location, and they further determine the different observational features of the microflares.

Prediction and experimental verification of performance of box type solar cooker. Part II: Cooking vessel with depressed lid

International Nuclear Information System (INIS)

Reddy, Avala Raji; Rao, A.V. Narasimha

2008-01-01

Our previous article (Part I) discussed the theoretical and experimental study of the performance boost obtained by a cooking vessel with central cylindrical cavity on lugs when compared to that of a conventional cylindrical vessel on floor/lugs. This article compares the performance of the cooking vessel with depressed lid on lugs with that of the conventional vessel on lugs. A mathematical model is presented to understand the heat flow process to the cooking vessel and, thereby, to the food material. It is found from the experiments that the cooking vessel with depressed lid results in higher temperature of the thermic fluid loaded in the cooking vessel compared to that of the thermic fluid kept in the conventional vessel when both are placed on lugs. Similar results were obtained by modeling the process mathematically. The average improvement of performance of the vessel with depressed lid is found to be 8.4% better than the conventional cylindrical vessel

Photovoltaic solar cell

Science.gov (United States)

Nielson, Gregory N; Okandan, Murat; Cruz-Campa, Jose Luis; Resnick, Paul J

2013-11-26

A photovoltaic solar cell for generating electricity from sunlight is disclosed. The photovoltaic solar cell comprises a plurality of spaced-apart point contact junctions formed in a semiconductor body to receive the sunlight and generate the electicity therefrom, the plurality of spaced-apart point contact junctions having a first plurality of regions having a first doping type and a second plurality of regions having a second doping type. In addition, the photovoltaic solar cell comprises a first electrical contact electrically connected to each of the first plurality of regions and a second electrical contact electrically connected to each of the second plurality of regions, as well as a passivation layer covering major surfaces and sidewalls of the photovoltaic solar cell.

Asteroseismic modelling of solar-type stars: internal systematics from input physics and surface correction methods

Science.gov (United States)

Nsamba, B.; Campante, T. L.; Monteiro, M. J. P. F. G.; Cunha, M. S.; Rendle, B. M.; Reese, D. R.; Verma, K.

2018-04-01

Asteroseismic forward modelling techniques are being used to determine fundamental properties (e.g. mass, radius, and age) of solar-type stars. The need to take into account all possible sources of error is of paramount importance towards a robust determination of stellar properties. We present a study of 34 solar-type stars for which high signal-to-noise asteroseismic data is available from multi-year Kepler photometry. We explore the internal systematics on the stellar properties, that is, associated with the uncertainty in the input physics used to construct the stellar models. In particular, we explore the systematics arising from: (i) the inclusion of the diffusion of helium and heavy elements; and (ii) the uncertainty in solar metallicity mixture. We also assess the systematics arising from (iii) different surface correction methods used in optimisation/fitting procedures. The systematics arising from comparing results of models with and without diffusion are found to be 0.5%, 0.8%, 2.1%, and 16% in mean density, radius, mass, and age, respectively. The internal systematics in age are significantly larger than the statistical uncertainties. We find the internal systematics resulting from the uncertainty in solar metallicity mixture to be 0.7% in mean density, 0.5% in radius, 1.4% in mass, and 6.7% in age. The surface correction method by Sonoi et al. and Ball & Gizon's two-term correction produce the lowest internal systematics among the different correction methods, namely, ˜1%, ˜1%, ˜2%, and ˜8% in mean density, radius, mass, and age, respectively. Stellar masses obtained using the surface correction methods by Kjeldsen et al. and Ball & Gizon's one-term correction are systematically higher than those obtained using frequency ratios.

EXPERIMENTAL RESEARCH OF THE INFLUENCE OF VARIOUS TYPES OF SOLAR COLLECTORS FOR PERFORMANCE SOLAR DESALINATION PLANT

Directory of Open Access Journals (Sweden)

Rakhmatulin I.R.

2014-04-01

Full Text Available The article discusses the possibility of using renewable energy for water purification. Results of analysis of a preferred energy source for a water purification using installed in places where fresh water shortages and a lack of electrical energy. The possibility of desalination of salt water using solar energy for regions with temperate climate. Presented desalination plant working on energy vacuum solar collectors, principles of action developed by the desalination plant. The experimental results of a constructed distiller when working with vacuum glass tubes and vacuum tubes with copper core inside. Conclusions about the possibility of using solar collectors for water desalination, are tips and tricks to improve the performance of solar desalination plant.

Characterization of HIT type solar cells

NARCIS (Netherlands)

Rath, J.K.

2011-01-01

The silicon heterojunction solar cell (SHJ) has made rapid progress in reaching high efficiency and it is already developed as an industrially viable product. However, much of its progress has come through process development while there is scarce knowledge on the microscopic nature of the

Solar weather monitoring

Directory of Open Access Journals (Sweden)

J.-F. Hochedez

2005-11-01

Full Text Available Space Weather nowcasting and forecasting require solar observations because geoeffective disturbances can arise from three types of solar phenomena: coronal mass ejections (CMEs, flares and coronal holes. For each, we discuss their definition and review their precursors in terms of remote sensing and in-situ observations. The objectives of Space Weather require some specific instrumental features, which we list using the experience gained from the daily operations of the Solar Influences Data analysis Centre (SIDC at the Royal Observatory of Belgium. Nowcasting requires real-time monitoring to assess quickly and reliably the severity of any potentially geoeffective solar event. Both research and forecasting could incorporate more observations in order to feed case studies and data assimilation respectively. Numerical models will result in better predictions of geomagnetic storms and solar energetic particle (SEP events. We review the data types available to monitor solar activity and interplanetary conditions. They come from space missions and ground observatories and range from sequences of dopplergrams, magnetograms, white-light, chromospheric, coronal, coronagraphic and radio images, to irradiance and in-situ time-series. Their role is summarized together with indications about current and future solar monitoring instruments.

N-type polymers as electron extraction layers in hybrid perovskite solar cells with improved ambient stability

NARCIS (Netherlands)

Shao, S.; Chen, Z.; Fang, H. -H.; ten Brink, G. H.; Bartesaghi, D.; Adjokatse, S.; Koster, L. J. A.; Kooi, B. J.; Facchetti, A.; Loi, M. A.

2016-01-01

We studied three n-type polymers of the naphthalenediimide-bithiophene family as electron extraction layers (EELs) in hybrid perovskite solar cells. The recombination mechanism in these devices is found to be heavily influenced by the EEL transport properties. The maximum efficiency of the devices

Rotational studies of late-type stars. II. Ages of solar-type stars and the rotational history of the sun

International Nuclear Information System (INIS)

Soderblom, D.R.

1983-01-01

In the first part of this investigation, age indicators for solar-type stars are discussed. A Li abundance-age calibration is derived; it indicates that 1 M/sub sun/ stars have lost as much as 80% of their initial Li before reaching the main sequence. The e-folding time for Li depletion on the main sequence is 1 1/4 Gyr. The distribution of Li abundances for 1 M/sub sun/ stars is consistent with a uniform initial Li abundance for all stars

Are coronae of late type stars made of solar-like structures? The Fx-HR diagram and the pressure-temperature correlation

OpenAIRE

Peres, G.; Orlando, S.; Reale, F.

2004-01-01

We show that stellar coronae can be composed of X-ray emitting structures like those in the solar corona, using a large set of ROSAT/PSPC observations of late-type-stars, and a large set of solar X-ray data collected with Yohkoh/SXT. We have considered data on the solar corona at various phases of the cycle and various kinds of X-ray coronal structures, from flares to the background corona. The surface flux (F_x) vs. spectral hardness ratio (HR) diagram is a fundamental tool for our study. We...

Imaging spectroscopy of type U and J solar radio bursts with LOFAR

Science.gov (United States)

Reid, Hamish A. S.; Kontar, Eduard P.

2017-10-01

Context. Radio U-bursts and J-bursts are signatures of electron beams propagating along magnetic loops confined to the corona. The more commonly observed type III radio bursts are signatures of electron beams propagating along magnetic loops that extend into interplanetary space. Given the prevalence of solar magnetic flux to be closed in the corona, why type III bursts are more frequently observed than U-bursts or J-bursts is an outstanding question. Aims: We use Low-Frequency Array (LOFAR) imaging spectroscopy between 30-80 MHz of low-frequency U-bursts and J-bursts, for the first time, to understand why electron beams travelling along coronal loops produce radio emission less often. Radio burst observations provide information not only about the exciting electron beams but also about the structure of large coronal loops with densities that are too low for standard extreme ultraviolet (EUV) or X-ray analysis. Methods: We analysed LOFAR images of a sequence of two J-bursts and one U-burst. The different radio source positions were used to model the spatial structure of the guiding magnetic flux tube and then deduce the energy range of the exciting electron beams without the assumption of a standard density model. We also estimated the electron density along the magnetic flux rope and compared it to coronal models. Results: The radio sources infer a magnetic loop that is 1 solar radius in altitude with the highest frequency sources starting around 0.6 solar radii. Electron velocities were found between 0.13 c and 0.24 c with the front of the electron beam travelling faster than the back of the electron beam. The velocities correspond to energy ranges within the beam from 0.7-11 keV to 0.7-43 keV. The density along the loop is higher than typical coronal density models and the density gradient is smaller. Conclusions: We found that a more restrictive range of accelerated beam and background plasma parameters can result in U-bursts or J-bursts, causing type III

Photovoltaic solar concentrator

Science.gov (United States)

Nielson, Gregory N.; Cruz-Campa, Jose Luis; Okandan, Murat; Resnick, Paul J.; Sanchez, Carlos Anthony; Clews, Peggy J.; Gupta, Vipin P.

2015-09-08

A process including forming a photovoltaic solar cell on a substrate, the photovoltaic solar cell comprising an anchor positioned between the photovoltaic solar cell and the substrate to suspend the photovoltaic solar cell from the substrate. A surface of the photovoltaic solar cell opposite the substrate is attached to a receiving substrate. The receiving substrate may be bonded to the photovoltaic solar cell using an adhesive force or a metal connecting member. The photovoltaic solar cell is then detached from the substrate by lifting the receiving substrate having the photovoltaic solar cell attached thereto and severing the anchor connecting the photovoltaic solar cell to the substrate. Depending upon the type of receiving substrate used, the photovoltaic solar cell may be removed from the receiving substrate or remain on the receiving substrate for use in the final product.

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

Energy Technology Data Exchange (ETDEWEB)

Suzuki, Atsushi, E-mail: suzuki@mat.usp.ac.jp; Furukawa, Ryo, E-mail: suzuki@mat.usp.ac.jp; Akiyama, Tsuyoshi, E-mail: suzuki@mat.usp.ac.jp; Oku, Takeo, E-mail: suzuki@mat.usp.ac.jp [Department of Materials Science, The University of Shiga Prefecture 2500 Hassaka, Hikone, Shiga 522-8533 (Japan)

2015-02-27

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C{sub 61}-butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance.

Fabrication and characterization of inverted organic solar cells using shuttle cock-type metal phthalocyanine and PCBM:P3HT

International Nuclear Information System (INIS)

Suzuki, Atsushi; Furukawa, Ryo; Akiyama, Tsuyoshi; Oku, Takeo

2015-01-01

Inverted organic solar cells using shuttle cock-type phthalocyanine, semiconducting polymer and fullerenes were fabricated and characterized. Photovoltaic and optical properties of the solar cells with inverted structures were investigated by optical absorption, current density-voltage characteristics. The photovoltaic properties of the tandem organic solar cell using titanyl phthalocyanine, vanadyl phthalocyanine, poly(3-hexylthiophene) (P3HT) and [6, 6]-phenyl C 61 -butyric acid methyl ester (PCBM) were improved. Effect of annealing and solvent treatment on surface morphologies of the active layer was investigated. The photovoltaic mechanisms, energy levels and band gap of active layers were discussed for improvement of the photovoltaic performance

MAGNETIC ROSSBY WAVES IN THE SOLAR TACHOCLINE AND RIEGER-TYPE PERIODICITIES

International Nuclear Information System (INIS)

Zaqarashvili, Teimuraz V.; Carbonell, Marc; Oliver, Ramon; Ballester, Jose Luis

2010-01-01

Apart from the eleven-year solar cycle, another periodicity around 155-160 days was discovered during solar cycle 21 in high-energy solar flares, and its presence in sunspot areas and strong magnetic flux has been also reported. This periodicity has an elusive and enigmatic character, since it usually appears only near the maxima of solar cycles, and seems to be related with a periodic emergence of strong magnetic flux at the solar surface. Therefore, it is probably connected with the tachocline, a thin layer located near the base of the solar convection zone, where a strong dynamo magnetic field is stored. We study the dynamics of Rossby waves in the tachocline in the presence of a toroidal magnetic field and latitudinal differential rotation. Our analysis shows that the magnetic Rossby waves are generally unstable and that the growth rates are sensitive to the magnetic field strength and to the latitudinal differential rotation parameters. Variation of the differential rotation and the magnetic field strength throughout the solar cycle enhance the growth rate of a particular harmonic in the upper part of the tachocline around the maximum of the solar cycle. This harmonic is symmetric with respect to the equator and has a period of 155-160 days. A rapid increase of the wave amplitude could give rise to a magnetic flux emergence leading to observed periodicities in solar activity indicators related to magnetic flux.

Deuterated water in the solar-type protostars NGC 1333 IRAS 4A and IRAS 4B

NARCIS (Netherlands)

Coutens, A.; Vastel, C.; Cabrit, S.; Codella, C.; Kristensen, L. E.; Ceccarelli, C.; van Dishoeck, E. F.; Boogert, A. C. A.; Bottinelli, S.; Castets, A.; Caux, E.; Comito, C.; Demyk, K.; Herpin, F.; Lefloch, B.; McCoey, C.; Mottram, J. C.; Parise, B.; Taquet, V.; van der Tak, F. F. S.; Visser, R.; Yıldız, U. A.

2013-01-01

Context. The measure of the water deuterium fractionation is a relevant tool for understanding mechanisms of water formation and evolution from the prestellar phase to the formation of planets and comets. Aims: The aim of this paper is to study deuterated water in the solar-type protostars NGC 1333

Principles of solar engineering

CERN Document Server

Goswami, D Yogi

2015-01-01

Introduction to Solar Energy ConversionGlobal Energy Needs and ResourcesSolar EnergyEnergy StorageEconomics of Solar SystemsSummary of RE ResourcesForecast of Future Energy MixReferencesFundamentals of Solar RadiationThe Physics of the Sun and Its Energy TransportThermal Radiation FundamentalsSun-Earth Geometric RelationshipSolar RadiationEstimation of Terrestrial Solar RadiationModels Based on Long-Term Measured Horizontal Solar RadiationMeasurement of Solar RadiationSolar Radiation Mapping Using Satellite DataReferencesSuggested ReadingsSolar Thermal CollectorsRadiative Properties and Characteristics of MaterialsFlat-Plate CollectorsTubular Solar Energy CollectorsExperimental Testing of CollectorsConcentrating Solar CollectorsParabolic Trough ConcentratorCompound-Curvature Solar ConcentratorsCentral Receiver CollectorFresnel Reflectors and LensesSolar Concentrator SummaryReferencesSuggested ReadingThermal Energy Storage and TransportThermal Energy StorageTypes of TESDesign of Storage SystemEnergy Transport ...

Effect of insulation thickness on the productivity of basin type solar stills: An experimental verification under local climate

International Nuclear Information System (INIS)

Khalifa, Abdul Jabbar N.; Hamood, Ahmad M.

2009-01-01

To achieve a high efficiency of a solar still, heat losses from the sides and base should be minimized by adequate insulation to insure the storage of the absorbed thermal energy. The effect of insulation on the productivity of a basin type solar still is verified in this study. Solar stills with insulation thickness of 30, 60 and 100 mm are investigated and the results are compared with those obtained for a still without insulation. It was found that the insulation thickness has a significant impact on the productivity of the still up to a thickness of 60 mm. The insulation thickness could influence the productivity of the still by over 80%. A performance correlation for the effect of insulation on productivity is also developed.

Solar Energy Technologies and the Utilization on Native American Tribal Lands

Energy Technology Data Exchange (ETDEWEB)

Hall, Kathryn [Univ. of North Dakota, Grand Forks, ND (United States)

2017-08-31

As an undergraduate researcher, I worked on a new technology called nanofluid-based direct absorption solar collectors (DASC) which is a type of solar water heater that has the potential to be more efficient than traditional solar water heaters. Because of my experience with this type of technology, I decided to look into other types of solar energy technologies which could be used on Native American tribal lands. Some types of solar energy technologies that I wanted to focus on are photovoltaic solar energy systems, passive solar design, and solar water heaters.

Laboratory Experiment and Numerical Analysis of a New Type of Solar Tower Efficiently Generating a Thermal Updraft

Directory of Open Access Journals (Sweden)

Yuji Ohya

2016-12-01

Full Text Available A new type of solar tower was developed through laboratory experiments and numerical analyses. The solar tower mainly consists of three components. The transparent collector area is an aboveground glass roof, with increasing height toward the center. Attached to the center of the inside of the collector is a vertical tower within which a wind turbine is mounted at the lower entry to the tower. When solar radiation heats the ground through the glass roof, ascending warm air is guided to the center and into the tower. A solar tower that can generate electricity using a simple structure that enables easy and less costly maintenance has considerable advantages. However, conversion efficiency from sunshine energy to mechanical turbine energy is very low. Aiming to improve this efficiency, the research project developed a diffuser-type tower instead of a cylindrical tower, and investigated a suitable diffuser shape for practical use. After changing the tower height and diffuser open angle, with a temperature difference between the ambient air aloft and within the collector, various diffuser tower shapes were tested by laboratory experiments and numerical analyses. As a result, it was found that a diffuser tower with a semi-open angle of 4° is an optimal shape, producing the fastest updraft at each temperature difference in both the laboratory experiments and numerical analyses. The relationships between thermal updraft speed and temperature difference and/or tower height were confirmed. It was found that the thermal updraft velocity is proportional to the square root of the tower height and/or temperature difference.

HIT Solar Cells with N-Type Low-Cost Metallurgical Si

Directory of Open Access Journals (Sweden)

Xing Yang

2018-01-01

Full Text Available A conversion efficiency of 20.23% of heterojunction with intrinsic thin layer (HIT solar cell on 156 mm × 156 mm metallurgical Si wafer has been obtained. Applying AFORS-HET software simulation, HIT solar cell with metallurgical Si was investigated with regard to impurity concentration, compensation level, and their impacts on cell performance. It is known that a small amount of impurity in metallurgical Si materials is not harmful to solar cell properties.

Trial manufacture of simple integrated tube-type pyranometer by phycoerythrin and measurements of transmittance of solar radiation in crop canopies

International Nuclear Information System (INIS)

Yamamoto, H.; Honjo, H.; Kamota, F.; Suzuki, Y.; Hayakawa, S.

1998-01-01

We tried to construct a simple integrated tube-type pyranometer using phycoerythrin from seaweed pigment. The maximum sensitive wavehand of phycoerythrin was 550 nm - 560 nm, and this waveband was in the photosynthetically active radiation range. The acrylic tubes (outside diameter, 22 mm, length, 100 cm) were spread with white paints except for a strip 15 mm in width, and phycoerythrin was put into the acrylic tube. In the results from the outdoor measurements, the tube-type pyranometer showed a positive correlation between the transmittance of phycoerythrin (%) and the measured accumulated solar radiation (MJ n(-2)), but the slope of the linear equation was different in summer and winter. In an artificial climate room, the relationship between the transmissions of phycoerythrin and the accumulated solar radiation could be approximated by a quadratic equation at every temperature. In the measurements made outdoors, the accumulated solar radiation could be estimated using the transmittance of phycoerythrin and the mean air temperature during measurements

Dye Sensitized Solar Cell, DSSC

Directory of Open Access Journals (Sweden)

Pongsatorn Amornpitoksuk

2003-07-01

Full Text Available A dye sensitized solar cell is a new type of solar cell. The operating system of this solar cell type is similar to plant’s photosynthesis process. The sensitizer is available for absorption light and transfer electrons to nanocrystalline metal oxide semiconductor. The ruthenium(II complexes with polypyridyl ligands are usually used as the sensitizers in solar cell. At the present time, the complex of [Ru(2,2',2'’-(COOH3- terpy(NCS3] is the most efficient sensitizer. The total photon to current conversion efficiency was approximately 10% at AM = 1.5.

Modifikasi dan Uji Kinerja Kompos Spiral dengan Bahan Bakar Minyak Jarak Pagar

Directory of Open Access Journals (Sweden)

Gatot S.A Fatah

2013-01-01

Full Text Available Energy crisis in Indonesia is still a problem that has not been fully resolved. Kerosene as the primary fuel for cooking, the price is very expensive (at Rp 8000.-/liter. Until now, the pressure cooker kerosene is still used by cake makers, bread, and noodle. By modifying the part of the cup rubbing alcohol and add a protective piping hot, the stove can be used with pressurized fuel Jatropha oil. Tobacco industry, ceramic and asphalt still use the stove. The purpose of this study is to obtain a prototype pressure cooker spiral type, fueled with jatropha oil by modifying the part of the reservoir cup rubbing alcohol, pipe and nozzle heat shield oil expenses. Modified pressure cooker and test performance using Jatropha oil is obtained as follows: the fuel consumption of 935 ml / hour; pre-heating 17 minutes; time required to boil 2 liters of water was 5 minutes; noise level of 83.3 dB and the reddish color of blue flame.

Fabrication and characterization of a slanting-type solar water ...

African Journals Online (AJOL)

The system includes four major components; a wooden basin of surface area 0.16 m2, an absorber surface, a slanting glass roof and a condensate channel. Very cheap locally available materials were used to fabricate the solar still. The solar still produced an average of 0.09 m3 of distilled water per day, and this study was ...

Measurement of acoustic glitches in solar-type stars from oscillation frequencies observed by Kepler

Energy Technology Data Exchange (ETDEWEB)

Mazumdar, A. [Homi Bhabha Centre for Science Education, TIFR, V. N. Purav Marg, Mankhurd, Mumbai 400088 (India); Monteiro, M. J. P. F. G.; Cunha, M. S. [Centro de Astrofísica da Universidade do Porto, Rua das Estrelas, 4150-762 Porto (Portugal); Ballot, J. [CNRS, Institut de Recherche en Astrophysique et Planétologie, 14 avenue Edouard Belin, F-31400 Toulouse (France); Antia, H. M. [Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005 (India); Basu, S. [Astronomy Department, Yale University, P.O. Box 208101, New Haven, CT 065208101 (United States); Houdek, G.; Silva Aguirre, V.; Christensen-Dalsgaard, J.; Metcalfe, T. S. [Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C (Denmark); Mathur, S. [High Altitude Observatory, NCAR, P.O. Box 3000, Boulder, CO 80307 (United States); García, R. A. [Laboratoire AIM, CEA/DSM, CNRS, Université Paris Diderot, IRFU/SAp, Centre de Saclay, F-91191 Gif-sur-Yvette Cedex (France); Salabert, D. [Laboratoire Lagrange, UMR7293, Université de Nice Sophia-Antipolis, CNRS, Observatoire de la Côte d' Azur, F-06304 Nice (France); Verner, G. A.; Chaplin, W. J. [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Sanderfer, D. T. [NASA Ames Research Center, Moffett Field, CA 94035 (United States); Seader, S. E.; Smith, J. C. [SETI Institute/NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2014-02-10

For the very best and brightest asteroseismic solar-type targets observed by Kepler, the frequency precision is sufficient to determine the acoustic depths of the surface convective layer and the helium ionization zone. Such sharp features inside the acoustic cavity of the star, which we call acoustic glitches, create small oscillatory deviations from the uniform spacing of frequencies in a sequence of oscillation modes with the same spherical harmonic degree. We use these oscillatory signals to determine the acoustic locations of such features in 19 solar-type stars observed by the Kepler mission. Four independent groups of researchers utilized the oscillation frequencies themselves, the second differences of the frequencies and the ratio of the small and large separation to locate the base of the convection zone and the second helium ionization zone. Despite the significantly different methods of analysis, good agreement was found between the results of these four groups, barring a few cases. These results also agree reasonably well with the locations of these layers in representative models of the stars. These results firmly establish the presence of the oscillatory signals in the asteroseismic data and the viability of several techniques to determine the location of acoustic glitches inside stars.

The contribution of renewable energy resources on the electrification and development at the Guantanamo Province

Energy Technology Data Exchange (ETDEWEB)

Perez, S.; Angel, J. [CUBASOLAR, Guantanamo (Cuba); Moreno Figueredo, C. [Centro de Estudio de Tecnologias Energeticas Renovables (Cuba); Montesinos Larrosa, A. [Sociedad Cubana para la Promocion de las Energias Renovables (Cuba)

2008-07-01

Cuba's Guantanamo province is a leader in the application of renewable energy technologies. This paper discussed the socio-economic impact of renewable energy projects that are underway in the Guantanamo province to improve the standard of living in rural areas. More than 400 rural schools and 70 rural medical offices get their electricity from photovoltaic systems. Hydropower provides the energy needs to 3000 rural houses with 11,000 inhabitants. Other applications include remote community solar systems, improved woodstoves for community kitchens, solar cookers and solar dryers. This paper demonstrated how the high penetration of these renewable energy technologies has contributed to the sustainable development of the province. The lessons learned in energy management by the local governments and research institutions were also outlined. 1 tab.

A survey of TiOλ567 nm absorption in solar-type stars

Science.gov (United States)

Azizi, Fatemeh; Mirtorabi, Mohammad Taghi

2018-04-01

Molecular absorption bands are estimators of stellar activity and spot cycles on magnetically active stars. We have previously introduced a new colour index that compares absorption strength of the titanium oxide (TiO) at 567 nm with nearby continuum. In this paper, we implement this index to measure long-term activity variations and the statistical properties of the index in a sample of 302 solar-type stars from the High Accuracy Radial Velocity Planet search Spectrograph planet search programme. The results indicate a pattern of change in star's activity, covers a range of periods from 2 yr up to 17 yr.

Adapting to an innovation: Solar cooking in the urban households of Ouagadougou (Burkina Faso)

Science.gov (United States)

Toonen, Hilde M.

Most households in Sub-Saharan Africa rely on wood as primary energy source. The availability of wood is decreasing and deforestation is a major ecological problem in Sub-Saharan Africa. The scarcity of wood is demanding for a sustainable solution. The sun seems to provide a good alternative. Solar energy is free, without unhealthy smoke or chances to burns. The idea of using solar energy for cooking is not new: many different techniques have already been tested. Most variants are expensive, and therefore not available for most families in Sub-Saharan Africa. A cheap solar cooking device is the CooKit, a cardboard panel cooker covered with aluminium foil. In the adaptation to the CooKit, as to all innovations, it is important that the users are convinced of the advantages. An important step in the adaptation process is learning how to use the cooking device; the best way to do this is by home practice. Monitoring and evaluating the real use is needed, for it is interesting to know if the CooKit is actually used, and also to find out how women have implemented the new technique in their kitchens. In 2005, the SUPO foundation started a project in Burkina Faso: Programme Energie Solaire Grand-Ouaga (PESGO). The aim of PESGO is to introduce the CooKit in the urban households in Ouagadougou by providing training sessions and home assistance. In this paper, a mid-term review on this small-scale cooking project is presented. The possibilities and challenges of solar cooking are outlined, taking the urban context of Ouagadougou in account. In PESGO, dependence on weather conditions is found to be one of the challenges: if sunrays are blocked by clouds or dust in the air, the cooking will be slowed down. The CooKit cannot replace firewood entirely, and a complementary element has to be found. SUPO is exploring the use of Jatropha oil as a complement to the CooKit. The Jatropha plant is drought tolerant and its fruits contain oil which can be used as fuel substitute. Further

A novel design for a cheap high temperature solar collector: The rotating solar boiler

NARCIS (Netherlands)

Luijtelaer, van J.P.H.; Kroon, M.C.

2009-01-01

In this work a novel type of high temperature solar collector is designed: the rotating solar boiler. This rotating solar boiler consists of two concentric tubes. The inner tube, called absorber, absorbs sunlight and boils water. The outer transparent tube, called cover, is filled with air. The

Coronal mass ejections, type II radio bursts, and solar energetic particle events in the SOHO era

Directory of Open Access Journals (Sweden)

N. Gopalswamy

2008-10-01

Full Text Available Using the extensive and uniform data on coronal mass ejections (CMEs, solar energetic particle (SEP events, and type II radio bursts during the SOHO era, we discuss how the CME properties such as speed, width and solar-source longitude decide whether CMEs are associated with type II radio bursts and SEP events. We discuss why some radio-quiet CMEs are associated with small SEP events while some radio-loud CMEs are not associated with SEP events. We conclude that either some fast and wide CMEs do not drive shocks or they drive weak shocks that do not produce significant levels of particle acceleration. We also infer that the Alfvén speed in the corona and near-Sun interplanetary medium ranges from <200 km/s to ~1600 km/s. Radio-quiet fast and wide CMEs are also poor SEP producers and the association rate of type II bursts and SEP events steadily increases with CME speed and width (i.e. energy. If we consider western hemispheric CMEs, the SEP association rate increases linearly from ~30% for 800 km/s CMEs to 100% for ≥1800 km/s. Essentially all type II bursts in the decametre-hectometric (DH wavelength range are associated with SEP events once the source location on the Sun is taken into account. This is a significant result for space weather applications, because if a CME originating from the western hemisphere is accompanied by a DH type II burst, there is a high probability that it will produce an SEP event.

Origin of solar radio waves

International Nuclear Information System (INIS)

Olmr, J.

1977-01-01

Solar radiowave radiation amounts to about 10 -7 of the total solar radiation. The solar atmosphere emits radiation of different wavelengths from a fraction of nanometer to kilometer waves. The solar radiowaves are of thermal origin and except for neutral hydrogen emission and solid body radio emission their emission always results from free electrons. The radiowave radiation active components were classified in several types, such as noise storms, flashes, flares, continuum, and flashes lasting for several minutes. The respective types are discussed and their origins shown. The mechanisms are described permitting the formation of radio waves of nonthermal origin, i.e., plasma oscillations, gyromagnetic emission, synchrotron and Cherenkov radiations. (J.P.)

Type II GaSb/GaAs quantum dot/ring stacks with extended photoresponse for efficient solar cells

Energy Technology Data Exchange (ETDEWEB)

Carrington, Peter James, E-mail: p.carrington@lancaster.ac.uk [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom); Mahajumi, Abu Syed [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom); Wagener, Magnus C.; Botha, Johannes Reinhardt [Department of Physics, Nelson Mandela Metropolitan University, Port Elizabeth (South Africa); Zhuang Qian; Krier, Anthony [Physics Department, Lancaster University, Lancaster LA1 4YB (United Kingdom)

2012-05-15

We report on the fabrication of GaAs based p-i-n solar cells containing 5 and 10 layers of type II GaSb quantum rings grown by molecular beam epitaxy. Solar cells containing quantum rings show improved efficiency at longer wavelengths into the near-IR extending up to 1500 nm and show enhanced short-circuit current under 1 sun illumination compared to a GaAs control cell. A reduction in the open-circuit voltage is observed due to the build-up of internal strain. The MBE growth, formation and photoluminescence of single and stacked layers of GaSb/GaAs quantum rings are also presented.

Type II GaSb/GaAs quantum dot/ring stacks with extended photoresponse for efficient solar cells

International Nuclear Information System (INIS)

Carrington, Peter James; Mahajumi, Abu Syed; Wagener, Magnus C.; Botha, Johannes Reinhardt; Zhuang Qian; Krier, Anthony

2012-01-01

We report on the fabrication of GaAs based p–i–n solar cells containing 5 and 10 layers of type II GaSb quantum rings grown by molecular beam epitaxy. Solar cells containing quantum rings show improved efficiency at longer wavelengths into the near-IR extending up to 1500 nm and show enhanced short-circuit current under 1 sun illumination compared to a GaAs control cell. A reduction in the open-circuit voltage is observed due to the build-up of internal strain. The MBE growth, formation and photoluminescence of single and stacked layers of GaSb/GaAs quantum rings are also presented.

Fabrication of selenization-free superstrate-type CuInS{sub 2} solar cells based on all-spin-coated layers

Energy Technology Data Exchange (ETDEWEB)

Cheshme khavar, Amir Hossein [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Mahjoub, Alireza, E-mail: mahjouba@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box. 14155-4383, Gisha Bridge, Tehran (Iran, Islamic Republic of); Samghabadi, Farnaz Safi [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Taghavinia, Nima, E-mail: taghavinia@sharif.edu [Physics Department, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of); Institute for Nanoscience and Nanotechnology, Sharif University of Technology, Tehran, 14588 (Iran, Islamic Republic of)

2017-01-15

Today manufacturing of high efficiency chalcogenide thin film solar cells is based on high cost vacuum-based deposition processes at high temperature (>500 °C) and in chalcogen -containing atmosphere. In this paper, we introduce a simple vacuum-free and selenization-free, solution processing for fabricating a superstrate-type CuInS{sub 2} (CIS) solar cell. The absorber, buffer and blocking layers were all deposited by spin coating of molecular precursor inks. We demonstrate the deposition of In{sub 2}S{sub 3} buffer layer by sol-gel spin casting for the first time. The rapid sintering process of CIS layer was carried out at 250 °C that is considered a very low temperature in CIGS thin-film technologies. A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. For the back contact we employed carbon, deposited by simple knife coating method. Different parameters including type of buffer, thickness of absorber layer, CIS and In{sub 2}S{sub 3} annealing temperature and morphology were optimized. Our air stable simple device structure consisting of showed promising power conversion efficiency (PCE) of 2.67%. - Highlights: • This work is an effort on the fabrication of all spin-coated CIS solar cells. • A novel molecular-ink route to deposit In{sub 2}S{sub 3} type buffer layer is presented. • The best devices showed power conversion efficiency (PCE) of 2.67%.

P-type sp3-bonded BN/n-type Si heterodiode solar cell fabricated by laser-plasma synchronous CVD method

International Nuclear Information System (INIS)

Komatsu, Shojiro; Nagata, Takahiro; Chikyo, Toyohiro; Sato, Yuhei; Watanabe, Takayuki; Hirano, Daisuke; Takizawa, Takeo; Nakamura, Katsumitsu; Hashimoto, Takuya; Nakamura, Takuya; Koga, Kazunori; Shiratani, Masaharu; Yamamoto, Atsushi

2009-01-01

A heterojunction of p-type sp 3 -bonded boron nitride (BN) and n-type Si fabricated by laser-plasma synchronous chemical vapour deposition (CVD) showed excellent rectifying properties and proved to work as a solar cell with photovoltaic conversion efficiency of 1.76%. The BN film was deposited on an n-type Si (1 0 0) substrate by plasma CVD from B 2 H 6 + NH 3 + Ar while doping of Si into the BN film was induced by the simultaneous irradiation of an intense excimer laser with a pulse power of 490 mJ cm -2 , at a wavelength of 193 nm and at a repetition rate of 20 Hz. The source of dopant Si was supposed to be the Si substrate ablated at the initial stage of the film growth. The laser enhanced the doping (and/or diffusion) of Si into BN as well as the growth of sp 3 -bonded BN simultaneously in this method. P-type conduction of BN films was determined by the hot (thermoelectric) probe method. The BN/Si heterodiode with an essentially transparent p-type BN as a front layer is supposed to efficiently absorb light reaching the active region so as to potentially result in high efficiency.

Pumps for medium sized solar systems

DEFF Research Database (Denmark)

Furbo, Simon

1996-01-01

The suitability of the electronically controlled circulation pump type UPE 2000 from Grundfos for large solar heating systems was elucidated.......The suitability of the electronically controlled circulation pump type UPE 2000 from Grundfos for large solar heating systems was elucidated....

Fast solar electrons, interplanetary plasma and km-wave type-III radio bursts observed from the IMP-6 spacecraft

International Nuclear Information System (INIS)

Alvarez, H.; Lin, R.P.

1975-01-01

IMP-6 spacecraft observations of low frequency radio emission, fast electrons, and solar wind plasma are used to examine the dynamics of the fast electron streams which generate solar type-III radio bursts. Of twenty solar electron events observed between April 1971 and August 1972, four were found to be amenable to detailed analysis. Observations of the direction of arrival of the radio emission at different frequencies were combined with the solar wind density and velocity measurements at 1 AU to define an Archimedean spiral trajectory for the radio burst exciter. The propagation characteristics of the exciter and of the fast electrons observed at 1 AU were then compared. It is found that: (1) the fast electrons excite the radio emission at the second harmonic; (2) the total distance travelled by the electrons was between 30 and 70% longer than the length of the smooth spiral defined by the radio observations; (3) this additional distance travelled is the result of scattering of the electrons in the interplanetary medium; (4) the observations are consistent with negligible true energy loss by the fast electrons.(Auth.)

SOLAR SOURCES OF 3He-RICH SOLAR ENERGETIC PARTICLE EVENTS IN SOLAR CYCLE 24

International Nuclear Information System (INIS)

Nitta, Nariaki V.; Mason, Glenn M.; Wang, Linghua; Cohen, Christina M. S.; Wiedenbeck, Mark E.

2015-01-01

Using high-cadence EUV images obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory, we investigate the solar sources of 26 3 He-rich solar energetic particle events at ≲1 MeV nucleon −1 that were well-observed by the Advanced Composition Explorer during solar cycle 24. Identification of the solar sources is based on the association of 3 He-rich events with type III radio bursts and electron events as observed by Wind. The source locations are further verified in EUV images from the Solar and Terrestrial Relations Observatory, which provides information on solar activities in the regions not visible from the Earth. Based on AIA observations, 3 He-rich events are not only associated with coronal jets as emphasized in solar cycle 23 studies, but also with more spatially extended eruptions. The properties of the 3 He-rich events do not appear to be strongly correlated with those of the source regions. As in the previous studies, the magnetic connection between the source region and the observer is not always reproduced adequately by the simple potential field source surface model combined with the Parker spiral. Instead, we find a broad longitudinal distribution of the source regions extending well beyond the west limb, with the longitude deviating significantly from that expected from the observed solar wind speed

Development of a tube-type solar still equipped with heat accumulation for irrigation

International Nuclear Information System (INIS)

Murase, Kazuo; Yamagishi, Yusuke; Iwashita, Yusuke; Sugino, Keita

2008-01-01

A tube-type solar still is found to be suitable for use in desert irrigation. The effectiveness of a heat accumulator with regard to distillate productivity is experimentally and numerically verified. The heat accumulator consists of tube bundles immersed in wax in order to utilize the latent heat of wax. The dynamic response to stepwise variation of irradiative intensity verified the contribution of wax to an increase of productivity only when the phase change of wax occurred. The effective distillate productivity was found to be 294.3 g/m 2 during the cyclic stepwise change of irradiative intensity, from 200 to 600 W/m 2 and back. Velocity vectors driven by natural convection and temperature contours estimated by numerical simulation verified the effectiveness of the heat accumulator especially after peak solar intensity. The latent heat of wax effectively contributed to a 15% increase in total distillate productivity per day. The still can feasibly meet irrigation water supply demands above an irrigative threshold of 17 MJ/m 2 d

Residential Solar Design Review: A Manual on Community Architectural Controls and Solar Energy Use.

Science.gov (United States)

Jaffe, Martin; Erley, Duncan

Presented are architectural design issues associated with solar energy use, and procedures for design review committees to consider in examining residential solar installation in light of existing aesthetic goals for their communities. Recommended design review criteria include the type of solar system being used and the ways in which the system…

Generation of type III solar radio bursts: the role of induced scattering of plasma waves by ions

International Nuclear Information System (INIS)

Levin, B.N.; Lerner, A.M.; Rapoport, V.O.

1984-01-01

The plasma waves in type III solar radio-burst sources might have a spectrum which can explain why, in the quasilinear burst generation model, nonlinear scattering of the waves by ions is so weak. The agent exciting a burst would travel through the corona at velocities limited to a definite range

Electrical Characterization of HIT type solar cells

NARCIS (Netherlands)

Rath, J.K.

2012-01-01

The silicon heterojunction solar cell (SHJ) has made rapid progress in reaching high efficiency and it is already developed as an industrially viable product. However, much of its progress has come through process development while there is scarce knowledge on the microscopic nature of the

Solar Thermal AIR Collector Based on New Type Selective Coating

Directory of Open Access Journals (Sweden)

Musiy, R.Y.

2014-01-01

Full Text Available Based on the best for optical performance and selective coating solar thermal air collector, which operates by solar power on the principle of simultaneous ventilation and heating facilities, is designed. It can be used for vacation homes, museums, wooden churches, warehouses, garages, houses, greenhouses etc.

Formation of a hybrid-type proto-atmosphere on Mars accreting in the solar nebula

Science.gov (United States)

Saito, Hiroaki; Kuramoto, Kiyoshi

2018-03-01

Recent studies of the chronology of Martian meteorites suggest that the growth of Mars was almost complete within a few Myr after the birth of the Solar system. During such rapid accretion, proto-Mars likely gravitationally maintained both the solar nebula component and the impact degassing component, containing H2O vapour and reduced gas species, as a proto-atmosphere to be called a hybrid-type proto-atmosphere. Here we numerically analyse the mass and composition of the degassed component and the atmospheric thermal structure sustained by accretional heating. Our results predict that a growing Mars possibly acquired a massive and hot hybrid-type proto-atmosphere with surface pressure and temperature greater than several kbar and 2000 K, respectively, which is sufficient to produce a deep magma ocean. In such a high-temperature and high-pressure environment, a significant amount of H2O, CH4, CO, and H2 is expected to be partitioned into the planetary interior, although this would strongly depend on the dynamics of the magma ocean and mantle solidification. The dissolved H2O may explain the wet Martian mantle implied from basaltic Martian meteorites. Along with the remnant reduced atmosphere after the hydrodynamic atmospheric escape, dissolved reduced gas species may have maintained an earliest Martian surface environment that allowed prebiotic chemical evolution and liquid H2O activities.

The research on a novel type of the solar-blind UV head-mounted displays

Science.gov (United States)

Zhao, Shun-long

2011-08-01

Ultraviolet technology of detecting is playing a more and more important role in the field of civil application, especially in the corona discharge detection, in modern society. Now the UV imaging detector is one of the most important equipments in power equipment flaws detection. And the modern head-mounted displays (HMDs) have shown the applications in the fields of military, industry production, medical treatment, entertainment, 3D visualization, education and training. We applied the system of head-mounted displays to the UV image detection, and a novel type of head-mounted displays is presented: the solar-blind UV head-mounted displays. And the structure is given. By the solar-blind UV head-mounted displays, a real-time, isometric and visible image of the corona discharge is correctly displayed upon the background scene where it exists. The user will see the visible image of the corona discharge on the real scene rather than on a small screen. Then the user can easily find out the power equipment flaws and repair them. Compared with the traditional UV imaging detector, the introducing of the HMDs simplifies the structure of the whole system. The original visible spectrum optical system is replaced by the eye in the solar-blind UV head-mounted displays. And the optical image fusion technology would be used rather than the digital image fusion system which is necessary in traditional UV imaging detector. That means the visible spectrum optical system and digital image fusion system are not necessary. This makes the whole system cheaper than the traditional UV imaging detector. Another advantage of the solar-blind UV head-mounted displays is that the two hands of user will be free. So while observing the corona discharge the user can do some things about it. Therefore the solar-blind UV head-mounted displays can make the corona discharge expose itself to the user in a better way, and it will play an important role in corona detection in the future.

Fibrous flexible solid-type dye-sensitized solar cells without transparent conducting oxide

International Nuclear Information System (INIS)

Fan Xing; Chu Zengze; Chen Lin; Zhang Chao; Wang Fuzhi; Tang Yanwei; Sun Jianliang; Zou Dechun

2008-01-01

We have explored a type of all-solid fibrous flexible dye-sensitized solar cells without transparent conducting oxide based on a CuI electrolyte. The working electrode's substrate is a metal wire. Cu wire counterelectrode is twisted with the dye-sensitized and CuI-coated working electrode. The cell's apparent diameter is about 150 μm. The cell's current-voltage output depends little on the incident angle of light. A 4-cm-long fibrous cell's open-circuit voltage and short-circuit current generate 304 mV and 0.032 mA, respectively. The interfacial interaction between the two electrodes has a significant influence on the inner charge transfer of the cell

Constraints on Nonlinear and Stochastic Growth Theories for Type 3 Solar Radio Bursts from the Corona to 1 AU

Science.gov (United States)

Cairns, Iver H.; Robinson, P. A.

1998-01-01

Existing, competing theories for coronal and interplanetary type III solar radio bursts appeal to one or more of modulational instability, electrostatic (ES) decay processes, or stochastic growth physics to preserve the electron beam, limit the levels of Langmuir-like waves driven by the beam, and produce wave spectra capable of coupling nonlinearly to generate the observed radio emission. Theoretical constraints exist on the wavenumbers and relative sizes of the wave bandwidth and nonlinear growth rate for which Langmuir waves are subject to modulational instability and the parametric and random phase versions of ES decay. A constraint also exists on whether stochastic growth theory (SGT) is appropriate. These constraints are evaluated here using the beam, plasma, and wave properties (1) observed in specific interplanetary type III sources, (2) predicted nominally for the corona, and (3) predicted at heliocentric distances greater than a few solar radii by power-law models based on interplanetary observations. It is found that the Langmuir waves driven directly by the beam have wavenumbers that are almost always too large for modulational instability but are appropriate to ES decay. Even for waves scattered to lower wavenumbers (by ES decay, for instance), the wave bandwidths are predicted to be too large and the nonlinear growth rates too small for modulational instability to occur for the specific interplanetary events studied or the great majority of Langmuir wave packets in type III sources at arbitrary heliocentric distances. Possible exceptions are for very rare, unusually intense, narrowband wave packets, predominantly close to the Sun, and for the front portion of very fast beams traveling through unusually dilute, cold solar wind plasmas. Similar arguments demonstrate that the ES decay should proceed almost always as a random phase process rather than a parametric process, with similar exceptions. These results imply that it is extremely rare for

Solar wind classification from a machine learning perspective

Science.gov (United States)

Heidrich-Meisner, V.; Wimmer-Schweingruber, R. F.

2017-12-01

It is a very well known fact that the ubiquitous solar wind comes in at least two varieties, the slow solar wind and the coronal hole wind. The simplified view of two solar wind types has been frequently challenged. Existing solar wind categorization schemes rely mainly on different combinations of the solar wind proton speed, the O and C charge state ratios, the Alfvén speed, the expected proton temperature and the specific proton entropy. In available solar wind classification schemes, solar wind from stream interaction regimes is often considered either as coronal hole wind or slow solar wind, although their plasma properties are different compared to "pure" coronal hole or slow solar wind. As shown in Neugebauer et al. (2016), even if only two solar wind types are assumed, available solar wind categorization schemes differ considerably for intermediate solar wind speeds. Thus, the decision boundary between the coronal hole and the slow solar wind is so far not well defined.In this situation, a machine learning approach to solar wind classification can provide an additional perspective.We apply a well-known machine learning method, k-means, to the task of solar wind classification in order to answer the following questions: (1) How many solar wind types can reliably be identified in our data set comprised of ten years of solar wind observations from the Advanced Composition Explorer (ACE)? (2) Which combinations of solar wind parameters are particularly useful for solar wind classification?Potential subtypes of slow solar wind are of particular interest because they can provide hints of respective different source regions or release mechanisms of slow solar wind.

Solar thermal repowering systems integration. Final report

Energy Technology Data Exchange (ETDEWEB)

Dubberly, L. J.; Gormely, J. E.; McKenzie, A. W.

1979-08-01

This report is a solar repowering integration analysis which defines the balance-of-plant characteristics and costs associated with the solar thermal repowering of existing gas/oil-fired electric generating plants. Solar repowering interface requirements for water/steam and salt or sodium-cooled central receivers are defined for unit sizes ranging from 50 MWe non-reheat to 350 MWe reheat. Finally balance-of-plant cost estimates are presented for each of six combinations of plant type, receiver type and percent solar repowering.

Development of practical solar-electric vehicle; Jitsuyo fukyugata solar denki jidosha no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Saito, S; Fujinaka, M [Tokyo Denki University, Tokyo (Japan)

1997-11-25

The paper reported on a Tokyo-Nagoya travel test on a practical spread type solar-electric vehicle, Solar-EV. A comparative study was made running the same type gasoline vehicle, GV. The measured power consumption amount of Solar-EV is 57.6 kWh. By converting it into Mcal unit, an energy consumption amount of 49.5 Mcal was obtained. Further, as to GV, the energy consumption amount of 316 Mcal was obtained using the amount of supply of gasoline (mean heating value: 8.4 Mcal/h) of 37.6 l and the fuel consumption of 16.2 km/l. Accordingly, the energy consumption amount of Solar-EV became a sixth of that of GV. In the cost comparison, the cost of Solar-EV was 1,440 yen (power source price: 25 yen/kWh), which is about a third of that of GV, 3760 yen (gasoline unit price: 100 yen/l). Monocrystal Si solar cells, 270W, installed on hood/roof are connected to the main 288V system (the auxiliary 12V system is amorphous Si), and generate power 4.4 kWh during travel. A total power consumption amount of Solar-EV in the total travel (Tokyo-Nagoya) is 79.9 kWh including the auxiliary system, approximately 6% of which was to be supplied from solar cells. 1 ref., 6 figs., 3 tabs.

IUE observations of the chromospheric activity-age relation in young solar-type stars

International Nuclear Information System (INIS)

Simon, T.; Boesgaard, A.M.

1983-01-01

Except for the synoptic observations of the chromospheric Ca II H-K lines by Wilson (1978), in which he sought evidence for magnetic activity cycles, there is still scant data on stellar activity, especially at UV and X-ray wavelengths where 10 5 K TRs and 10 6 - 10 7 K coronae are expected to radiate. This paper presents new UV data, obtained with the IUE spacecraft, for a dozen solar-type stars in the field. The stars are of spectral type F6 V - G1 V; on the basis of their high Li content, they range in age from 0.1 to 2.8 Gyr. The purpose is to study the evolution of TR and chromospheric emission with stellar age, and also the surface distribution of magnetically active regions as revealed by rotational modulation of UV emission line fluxes. (Auth.)

Asteroseismic modelling of the solar-type subgiant star β Hydri

Science.gov (United States)

Brandão, I. M.; Doğan, G.; Christensen-Dalsgaard, J.; Cunha, M. S.; Bedding, T. R.; Metcalfe, T. S.; Kjeldsen, H.; Bruntt, H.; Arentoft, T.

2011-03-01

Context. Comparing models and data of pulsating stars is a powerful way to understand the stellar structure better. Moreover, such comparisons are necessary to make improvements to the physics of the stellar models, since they do not yet perfectly represent either the interior or especially the surface layers of stars. Because β Hydri is an evolved solar-type pulsator with mixed modes in its frequency spectrum, it is very interesting for asteroseismic studies. Aims: The goal of the present work is to search for a representative model of the solar-type star β Hydri, based on up-to-date non-seismic and seismic data. Methods: We present a revised list of frequencies for 33 modes, which we produced by analysing the power spectrum of the published observations again using a new weighting scheme that minimises the daily sidelobes. We ran several grids of evolutionary models with different input parameters and different physics, using the stellar evolutionary code ASTEC. For the models that are inside the observed error box of β Hydri, we computed their frequencies with the pulsation code ADIPLS. We used two approaches to find the model that oscillates with the frequencies that are closest to the observed frequencies of β Hydri: (i) we assume that the best model is the one that reproduces the star's interior based on the radial oscillation frequencies alone, to which we have applied the correction for the near-surface effects; (ii) we assume that the best model is the one that produces the lowest value of the chi-square (χ2), i.e. that minimises the difference between the observed frequencies of all available modes and the model predictions, after all model frequencies are corrected for near-surface effects. Results: We show that after applying a correction for near-surface effects to the frequencies of the best models, we can reproduce the observed modes well, including those that have mixed mode character. The model that gives the lowest value of the χ2 is a post

Convection and magnetism of solar-type stars (G and K)

International Nuclear Information System (INIS)

Do-Cao, Olivier Long

2013-01-01

This thesis aims at understanding the internal dynamics of solar-type stars and the origin of their magnetism. We will explore the complex nonlinear interactions between convection, rotation and magnetism conducting both 2D (STELEM code) and 3D (ASH code) numerical simulations. This dual approach will unveil the mechanisms and key parameters behind those physical processes. While the Sun has played a central role in previous studies, this work extends our knowledge to G and K stars. This manuscript is divided into 4 parts. The first one introduces the concepts behind internal stellar dynamics, and emphasizes the dynamo effect. Accurate observations of the Sun will be compared to stellar data, allowing us to determine what is specific to the Sun and what is generic for all stars. The second part reports the results obtained with the 2D STELEM code. This code allows us to study the generation and evolution of the large scale magnetic fields on a timescale comparable to the solar cycle period (11 years), giving us insight into the underlying dynamo processes at work. We show that the current solar models cannot reproduce the observations, when applied to rapidly rotating stars, unless we consider a turbulent pumping mechanism under specific conditions. Then, we have improved these kinematic models by taking into account the large scale magnetic field feedback on the longitudinal velocity component, called the Malkus Proctor effect. The models are now able to reproduce the solar torsional oscillations and can predict how their properties evolve with rotation rate. The third part focuses on 3D numerical simulations running on massively parallel supercomputers, using the ASH code. In contrast with the previously described code, ASH explicitly resolves the full MHD equations. We have studied (hydrodynamically) how the convective properties of G and K stars change as function of mass and rotation rate, first by considering the convective envelope alone, then by taking into

A HIGH-FREQUENCY TYPE II SOLAR RADIO BURST ASSOCIATED WITH THE 2011 FEBRUARY 13 CORONAL MASS EJECTION

Energy Technology Data Exchange (ETDEWEB)

Cho, K.-S.; Kim, R.-S. [Korea Astronomy and Space Science Institute, Whaamdong, Yooseong-ku, Daejeon, 305-348 (Korea, Republic of); Gopalswamy, N.; Kwon, R.-Y.; Yashiro, S., E-mail: kscho@kasi.re.kr [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

2013-03-10

We examine the relationship between the high-frequency (425 MHz) type II radio burst and the associated white-light coronal mass ejection (CME) that occurred on 2011 February 13. The radio burst had a drift rate of 2.5 MHz s{sup -1}, indicating a relatively high shock speed. From SDO/AIA observations we find that a loop-like erupting front sweeps across high-density coronal loops near the start time of the burst (17:34:17 UT). The deduced distance of shock formation (0.06 Rs) from the flare center and speed of the shock (1100 km s{sup -1}) using the measured density from SDO/AIA observations are comparable to the height (0.05 Rs, from the solar surface) and speed (700 km s{sup -1}) of the CME leading edge observed by STEREO/EUVI. We conclude that the type II burst originates even in the low corona (<59 Mm or 0.08 Rs, above the solar surface) due to the fast CME shock passing through high-density loops.

Characteristics of coronal mass ejections associated with solar frontside and backside metric type II bursts

International Nuclear Information System (INIS)

Kahler, S.W.; Cliver, E.W.; Sheeley, N.R. Jr.; Howard, R.A.; Koomen, M.J.; Michels, D.J.

1985-01-01

We compare fast (v> or =500 km s -1 ) coronal mass ejections (CME's) with reported metric type II bursts to study the properties of CME's associated with coronal shocks. We confirm an earlier report of fast frontside CME's with no associated metric type II bursts and calculate that 33 +- 15% of all fast frontside CME's are not associated with such bursts. Faster CME's are more likely to be associated with type II bursts, as expected from the hypothesis of piston-driven shocks. However, CME brightness and associated peak 3-cm burst intensity are also important factors, as might be inferred from the Wagner and MacQueen (1983) view of type II shocks decoupled from associated CME's. We use the equal visibility of solar frontside and backside CME's to deduce the observability of backside type II bursts. We calculate that 23 +- 7% of all backside type II bursts associated with fast CME's can be observed at the earth and that 13 +- 4% of all type II bursts originate in backside flares. CME speed again is the most important factor in the observability of backside type II bursts

Proton irradiation effects of amorphous silicon solar cell for solar power satellite

Energy Technology Data Exchange (ETDEWEB)

Morita, Yousuke; Oshima, Takeshi [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Sasaki, Susumu; Kuroda, Hideo; Ushirokawa, Akio

1997-03-01

Flexible amorphous silicon(fa-Si) solar cell module, a thin film type, is regarded as a realistic power generator for solar power satellite. The radiation resistance of fa-Si cells was investigated by the irradiations of 3,4 and 10 MeV protons. The hydrogen gas treatment of the irradiated fa-Si cells was also studied. The fa-Si cell shows high radiation resistance for proton irradiations, compared with a crystalline silicon solar cell. (author)

A comparative study on three types of solar utilization technologies for buildings: Photovoltaic, solar thermal and hybrid photovoltaic/thermal systems

International Nuclear Information System (INIS)

Huide, Fu; Xuxin, Zhao; Lei, Ma; Tao, Zhang; Qixing, Wu; Hongyuan, Sun

2017-01-01

Highlights: • Models of Solar thermal, Photovoltaic and Photovoltaic/thermal systems are developed. • Experiments are performed to validate the simulation results. • Annual performances of the three solar systems used in china are predicted. • Energy comparison between the three solar systems is analyzed. - Abstract: Buildings need energy including heat and electricity, and both of them can be provided by the solar systems. Solar thermal and photovoltaic systems absorb the solar energy and can supply the heat and electricity for buildings, respectively. However, for the urban residential buildings, the limited available area makes installation of the solar thermal collectors and photovoltaic modules together impossible. A hybrid photovoltaic/thermal system can simultaneously generate heat and electricity, which is deemed to be quite suitable for the urban residential buildings application. And yet, for a rural house of China, the available area for installation of the solar collectors is large but daily domestic hot water demand of a rural family is generally not exceeded 300 L. If only the hybrid photovoltaic/thermal collectors are installed on the whole available area, this will lead to an overproduction of the thermal energy, especially in summer. Moreover, buildings requiring for the heat and electricity are different in different regions and different seasons. In this paper, simulation models of the solar thermal, photovoltaic and hybrid photovoltaic/thermal systems are presented, and experiments are also performed to validate the simulation results. Using the validated models, performances of the three solar systems for residential applications were predicted. And energy comparison between the three solar systems used in Hongkong, Lhasa, Shanghai and Beijing of China, respectively, were also studied. Results show that, for the urban residential building with limited available installation space, a hybrid photovoltaic/thermal system may have the

Solar neutrinos and solar accretion of interstellar matter

International Nuclear Information System (INIS)

Newman, M.J.; Talbot, R.J. Jr.

1976-01-01

It is argued that if the Hoyle-Lyttleton mass accretion rate applies (Proc. Camb. Phil. Soc., Math. Phys. Sci. 35: 405 (1939)) the accretion of interstellar matter by the Sun is sufficient to enhance the surface heavy element abundances. This will also apply to other solar-type stars. The enhancement may be sufficient to allow the construction of consistent solar models with an interior heavy element abundance significantly lower than the observed surface abundance. This state of affairs lowers the predicted solar neutrino flux. It has been suggested that a similar enhancement of surface abundances might occur due to accretion of 'planetesimals' left over after formation of the solar system, and both processes may occur, thereby increasing the effect. The simple accretion model of Hoyle and Lyttleton is discussed mathematically. A crucial question to be answered by future research, however, is whether or not accretion on to the solar surface actually occurs. One of the most obvious obstacles is the outward flowing solar wind, and this is discussed. It appears that the outward flow can be reversed to an inward flow for certain interstellar cloud densities. (U.K.)

Performance of 7-cells Dye Sensitized Solar Module in Z-type Series Interconnection

Science.gov (United States)

Nur Anggraini, Putri; Muliani, Lia; Maulani Nursam, Natalita; Hidayat, Jojo

2018-01-01

Dye sensitized solar cells (DSSC) is becoming attractive research topic as third generation solar cells technology since it provides clean energy and low cost fabrication. In this study, DSSC was fabricated into module scale, which is important for practical applications. The module was prepared in sandwich structure consisting of TiO2 working electrode and Pt counter electrode on conductive substrate with an area of 100 mm x 100 mm, which was distributed into seven active cells. TiO2 paste was deposited on FTO glass as working electrode with a size of 10 mm x 98 mm per unit cell by screen printing method. Each cell was connected in Z-type series that able to produce high voltage. I - V measurement was applied in two methods consisting of laboratory testing using sun simulator under 500 W/m2 of illumination and outdoor testing using a digital multimeter under direct sunlight. The result shows that DSSC module has photoconversion efficiency of 1.08% and 1.17% for laboratory and outdoor testing, respectively. The module was also tested in three different times to monitor its stability performance.

Observation of solar radio bursts of type II and III at kilometer wavelengths from Prognoz-8 during STIP Interval XII

International Nuclear Information System (INIS)

Pinter, S.; Kecskemety, K.; Kudela, K.

1982-04-01

Type II and type III radio events were observed at low frequencies (2.16 MHz to 114 kHz) by the Prognoz-8 satellite during the period of STIP Interval XII in April and May, 1981, respectively. This review covers briefly a chronology of the sub-megahertz radio events, and where possible their association with both groundbased radio observations and solar flare. (author)

Effects of the selection of heat transfer fluid and condenser type on the performance of a solar thermal power plant with technoeconomic approach

International Nuclear Information System (INIS)

Yilmazoglu, M. Zeki

2016-01-01

Highlights: • The effects of the selection of HTF and condenser type on STPs were examined. • Levelized cost of energy (LCOE) for STP was investigated. • LCOE for STP compared with gas turbine and combined cycle. • CSP with thermal storage can be competitive technology with carbon tax/credits. - Abstract: Renewable electricity generation systems have an increasing trend in terms of usage due to aiming to decrease greenhouse gas emissions and energy source diversification strategies of countries. Parabolic trough, Fresnel, and solar tower systems have been used to generate solar thermal electricity around the world. In this study, the effects of the selection of collector heat transfer fluid (HTF) and condenser type on a concentrated solar thermal power plant were analyzed. Net power, net electrical efficiency, and economic analysis were carried out for the selected HTFs for different collector outlet temperature cases. In the case of condenser type selection four different systems were considered; water cooled, air cooled (dry air) and air cooled with water spraying (spraying before fan and spraying before and after fan). Levelized cost of energy (LCOE) and specific investment cost were calculated. According to the results, specific investment cost and LCOE were found to be 4000 USD/kW_e_l and 0.207 USD/kW h, respectively. Carbon tax/credit was also included to the calculations of LCOE and a comparison study was carried out for gas turbine, combined cycle and solar thermal power plant with thermal storage. Including carbon tax/credit to the LCOE shows that solar thermal power plant with heat storage can be competitive when compared to gas turbines.

Better lumber drying process with a non-greenhouse type solar kiln

Energy Technology Data Exchange (ETDEWEB)

Yang, K C

1979-01-01

The preliminary study of using solar energy for lumber drying in NW Ontario is proven applicable and practical by the evidence of data collected. It was found that lumber seasoning using solar energy in the region is more favorable in the summer than in the winter. The most significant advantages of lumber drying with a solar kiln are: (1) low percentage of drying defect lumber produced; (2) higher strength properties of lumber produced; (3) unlimited sources of heat energy from the sun are available. The longer drying periods with a solar kiln as compared to a conventional steam kiln can be overcome by utilizing a supplemental heat system, e.g., wood residue burner to shorten the drying period. However, some improvements and modification of the existing kiln should be done in order to increase the efficiency of the lumber drying system.

Performance Study of a Cylindrical Parabolic Concentrating Solar Water Heater with Nail Type Twisted Tape Inserts in the Copper Absorber Tube

Directory of Open Access Journals (Sweden)

Amit K. Bhakta

2018-01-01

Full Text Available This paper reports the overall thermal performance of a cylindrical parabolic concentrating solar water heater (CPCSWH with inserting nail type twisted tape (NTT in the copper absorber tube for the nail twist pitch ratios, 4.787, 6.914 and 9.042, respectively. The experiments are conducted for a constant volumetric water flow rate and during the time period 9:00 a.m. to 15:00 p.m. The useful heat gain, hourly solar energy collected and hourly solar energy stored in this solar water heater were found to be higher for the nail twist pitch ratio 4.787. The above said parameters were found to be at a peak at noon and observed to follow the path of variation of solar intensity. At the start of the experiment, the value of charging efficiency was observed to be maximum, whereas the maximum values of instantaneous efficiency and overall thermal efficiency were observed at noon. The key finding is that the nail twist pitch ratio enhances the overall thermal performance of the CPCSWH.

Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

Energy Technology Data Exchange (ETDEWEB)

Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z. [Nano-Optoelectronics Research and Technology Laboratory, School of Physics, Universiti Sains Malaysia, Minden 11800 Penang (Malaysia)

2015-04-24

One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×10{sup 16} atoms/cm{sup 3}) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

Electrical properties and surface morphology of electron beam evaporated p-type silicon thin films on polyethylene terephthalate for solar cells applications

Science.gov (United States)

Ang, P. C.; Ibrahim, K.; Pakhuruddin, M. Z.

2015-04-01

One way to realize low-cost thin film silicon (Si) solar cells fabrication is by depositing the films with high-deposition rate and manufacturing-compatible electron beam (e-beam) evaporation onto inexpensive foreign substrates such as glass or plastic. Most of the ongoing research is reported on e-beam evaporation of Si films on glass substrates to make polycrystalline solar cells but works combining both e-beam evaporation and plastic substrates are still scarce in the literature. This paper studies electrical properties and surface morphology of 1 µm electron beam evaporated Al-doped p-type silicon thin films on textured polyethylene terephthalate (PET) substrate for application as an absorber layer in solar cells. In this work, Si thin films with different doping concentrations (including an undoped reference) are prepared by e-beam evaporation. Energy dispersion X-ray (EDX) showed that the Si films are uniformly doped by Al dopant atoms. With increased Al/Si ratio, doping concentration increased while both resistivity and carrier mobility of the films showed opposite relationships. Root mean square (RMS) surface roughness increased. Overall, the Al-doped Si film with Al/Si ratio of 2% (doping concentration = 1.57×1016 atoms/cm3) has been found to provide the optimum properties of a p-type absorber layer for fabrication of thin film Si solar cells on PET substrate.

Fibre structure of decametric type II radio bursts as a manifestation of emission propagation effects in a disturbed near-solar plasma

OpenAIRE

A. N. Afanasiev

2009-01-01

This paper addresses the fine structure of solar decametric type II radio bursts in the form of drifting narrowband fibres on the dynamic spectrum. Observations show that this structure appears in those events where there is a coronal mass ejection (CME) traveling in the near-solar space ahead of the shock wave responsible for the radio burst. The diversity in observed morphology of fibres and values of their parameters implies that the fibres may be caused by different formation mechanisms. ...

Structural studies of n-type nc-Si-QD thin films for nc-Si solar cells

Science.gov (United States)

Das, Debajyoti; Kar, Debjit

2017-12-01

A wide optical gap nanocrystalline silicon (nc-Si) dielectric material is a basic requirement at the n-type window layer of nc-Si solar cells in thin film n-i-p structure on glass substrates. Taking advantage of the high atomic-H density inherent to the planar inductively coupled low-pressure (SiH4 + CH4)-plasma, development of an analogous material in P-doped nc-Si-QD/a-SiC:H network has been tried. Incorporation of C in the Si-network extracted from the CH4 widens the optical band gap; however, at enhanced PH3-dilution of the plasma spontaneous miniaturization of the nc-Si-QDs below the dimension of Bohr radius (∼4.5 nm) further enhances the band gap by virtue of the quantum size effect. At increased flow rate of PH3, dopant induced continuous amorphization of the intrinsic crystalline network is counterbalanced by the further crystallization promoted by the supplementary atomic-H extracted from PH3 (1% in H2) in the plasma, eventually holding a moderately high degree of crystallinity. The n-type wide band gap (∼1.93 eV) window layer with nc-Si-QDs in adequate volume fraction (∼52%) could furthermore be instrumental as an effective seed layer for advancing sequential crystallization in the i-layer of nc-Si solar cells with n-i-p structure in superstrate configuration.

Forced-circulation solar water heater using a solar battery; Taiyo denchi wo mochiita kyosei junkanshiki taiyonetsu onsuiki

Energy Technology Data Exchange (ETDEWEB)

Asai, S; Mizuno, T [Yazaki Resources Co. Ltd., Shizuoka (Japan)

1996-10-27

For the purpose of satisfying demands for qualitative improvement on tapwater temperature and pressure, an indirect-type solar water heater using solar cells, in which a closed type hot water storage tank connected directly to the water supply is integrated with a solar collector, was examined for its characteristics and performance. The heat collecting medium is a water solution of polypropylene glycol, which circulates through the solar collector pump, cistern, solar collector, and heat exchanger (hot water storage tank). The results of the test are summarized below. When comparison is made between the two solar collector pump control methods, the solar cells direct connection method and the differential thermo method utilizing temperature difference between the solar collector and the hot water storage tank, they are alike in collecting heat on clear days, but on cloudy days the latter collects 5% more than the former. In winter, when the heat exchanger heat transfer area is 0.4m{sup 2} large, a further increase in the area improves but a little the heat collecting efficiency. An increase in the medium flow rate and temperature, or in the Reynolds number, enhances the heat collecting efficiency. 13 figs., 6 tabs.

Solar flares, coronal mass ejections and solar energetic particle event characteristics

Science.gov (United States)

Papaioannou, Athanasios; Sandberg, Ingmar; Anastasiadis, Anastasios; Kouloumvakos, Athanasios; Georgoulis, Manolis K.; Tziotziou, Kostas; Tsiropoula, Georgia; Jiggens, Piers; Hilgers, Alain

2016-12-01

A new catalogue of 314 solar energetic particle (SEP) events extending over a large time span from 1984 to 2013 has been compiled. The properties as well as the associations of these SEP events with their parent solar sources have been thoroughly examined. The properties of the events include the proton peak integral flux and the fluence for energies above 10, 30, 60 and 100 MeV. The associated solar events were parametrized by solar flare (SF) and coronal mass ejection (CME) characteristics, as well as related radio emissions. In particular, for SFs: the soft X-ray (SXR) peak flux, the SXR fluence, the heliographic location, the rise time and the duration were exploited; for CMEs the plane-of-sky velocity as well as the angular width were utilized. For radio emissions, type III, II and IV radio bursts were identified. Furthermore, we utilized element abundances of Fe and O. We found evidence that most of the SEP events in our catalogue do not conform to a simple two-class paradigm, with the 73% of them exhibiting both type III and type II radio bursts, and that a continuum of event properties is present. Although, the so-called hybrid or mixed events are found to be present in our catalogue, it was not possible to attribute each SEP event to a mixed/hybrid sub-category. Moreover, it appears that the start of the type III burst most often precedes the maximum of the SF and thus falls within the impulsive phase of the associated SF. At the same time, type III bursts take place within ≈5.22 min, on average, in advance from the time of maximum of the derivative of the SXR flux (Neupert effect). We further performed a statistical analysis and a mapping of the logarithm of the proton peak flux at E > 10 MeV, on different pairs of the parent solar source characteristics. This revealed correlations in 3-D space and demonstrated that the gradual SEP events that stem from the central part of the visible solar disk constitute a significant radiation risk. The velocity of

Site selective doping of Zn for the p-type Cu(In,Ga)Se{sub 2} thin film for solar cell application

Energy Technology Data Exchange (ETDEWEB)

Shirakata, Sho [Faculty of Engineering, Ehime University, Matsuyama 790-8577 (Japan); Tokyo University of Science, Research Institute for Science and Technology, Noda, Chiba 278-8510 (Japan)

2017-06-15

Selective doping of a Zn impurity at the group III site in a Cu(In, Ga)Se{sub 2} (CIGS) film was performed by the doping of Zn at the first stage of the three-stage method. The p-type CIGS:Zn film was obtained, which is in contrast to the n-type CIGS:Zn film obtained by the Zn impurity doping at the second and third-stages. Based on excitation intensity dependence of photoluminescence (PL) at low-temperature, the change in the acceptor level was observed. The enhancement of carrier concentration as a result of Zn-doping in the p-type CIGS:Zn film was observed. The CIGS:Zn solar cells exhibited η of 14.5% and V{sub oc} of 0.658 V, which are higher than that of the corresponding solar cells using the undoped CIGS films. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Low cost bare-plate solar air collector

Science.gov (United States)

Maag, W. L.; Wenzler, C. J.; Rom, F. E.; Vanarsdale, D. R.

1980-09-01

A low cost, bare plate solar collector for preheating ambient air was developed. This type of solar heating system would be applicable for preheating ventilation air for public buildings or other commercial and industrial ventilation requirements. Two prototype collectors were designed, fabricated and installed into an instrumented test system. Tests were conducted for a period of five months. Results of the tests showed consistent operating efficiencies of 60 percent or greater with air preheat temperature uses up to 20 degrees for one of the prototypes. The economic analyses indicated that this type of solar system was economically viable. For the materials of construction and the type of fabrication and installation perceived, costs for the bare plate solar collector are attainable. Applications for preheating ventilation air for schools were evaluated and judged to be economically viable.

Solar-energy drying systems. A review

Energy Technology Data Exchange (ETDEWEB)

Sharma, Atul; Chen, C.R.; Vu Lan, Nguyen [Department of Mechanical Engineering, Kun Shan University, 949, Da-Wan Road, Yung-Kang City, Tainan Hsien 71003 (China)

2009-08-15

In many countries of the world, the use of solar thermal systems in the agricultural area to conserve vegetables, fruits, coffee and other crops has shown to be practical, economical and the responsible approach environmentally. Solar heating systems to dry food and other crops can improve the quality of the product, while reducing wasted produce and traditional fuels - thus improving the quality of life, however the availability of good information is lacking in many of the countries where solar food processing systems are most needed. Solar food dryers are available in a range of size and design and are used for drying various food products. It is found that various types of driers are available to suit the needs of farmers. Therefore, selection of dryers for a particular application is largely a decision based on what is available and the types of dryers currently used widely. A comprehensive review of the various designs, details of construction and operational principles of the wide variety of practically realized designs of solar-energy drying systems reported previously is presented. A systematic approach for the classification of solar-energy dryers has been evolved. Two generic groups of solar-energy dryers can be identified, viz. passive or natural-circulation solar-energy dryers and active or forced-convection solar-energy dryers. Some very recent developments in solar drying technology are highlighted. (author)

Solar variability observed through changes in solar figure and mean diameter

International Nuclear Information System (INIS)

Hill, H.A.

1991-01-01

The work performed on solar variability during 1990 at SCLERA is reviewed. That portion of the SCLERA research program supported by the Department of Energy has been directed toward the detection and monitoring of climatically significant solar variability by accurate measurement of the variability in solar shape and diameter. Observations were obtained in 1990 and results from analysis of earlier observations obtained. The observational evidence of systematic long-term changes in the apparent solar diameter and/or radius has been detected, and these changes continue to strongly correlated with long-term changes in solar total irradiance. Additional evidence for internal gravity modes has been found which may be important to understanding the internal structure of the Sun. Each of these findings shows promise for anticipating future changes in the solar luminosity. Progress has been made in setting up an international network based on SCLERA-type instruments to improve the coverage and quality of the observations. A proposal is made for the continuation of support from the Department of Energy for further studies relevant to solar-variability forecasting

Indoor Light Performance of Coil Type Cylindrical Dye Sensitized Solar Cells.

Science.gov (United States)

Kapil, Gaurav; Ogomi, Yuhei; Pandey, Shyam S; Ma, Tingli; Hayase, Shuzi

2016-04-01

A very good performance under low/diffused light intensities is one of the application areas in which dye-sensitized solar cells (DSSCs) can be utilized effectively compared to their inorganic silicon solar cell counterparts. In this article, we have investigated the 1 SUN and low intensity fluorescent light performance of Titanium (Ti)-coil based cylindrical DSSC (C-DSSC) using ruthenium based N719 dye and organic dyes such as D205 and Y123. Electrochemical impedance spectroscopic results were analyzed for variable solar cell performances. Reflecting mirror with parabolic geometry as concentrator was also utilized to tap diffused light for indoor applications. Fluorescent light at relatively lower illumination intensities (0.2 mW/cm2 to 0.5 mW/cm2) were used for the investigation of TCO-less C-DSSC performance with and without reflector geometry. Furthermore, the DSSC performances were analyzed and compared with the commercially available amorphous silicon based solar cell for indoor applications.

Modelling solar-like oscillators

Energy Technology Data Exchange (ETDEWEB)

Eggenberger, P; Miglio, A [Institut d' Astrophysique et de Geophysique de l' Universite de Liege, 17 Allee du 6 Aout, B-4000 Liege (Belgium); Carrier, F [Institute of Astronomy, University of Leuven, Celestijnenlaan 200 D, B-3001 Leuven (Belgium); Mathis, S [CEA/DSM/DAPNIA/Service d' Astrophysique, CEA/Saclay, AIM-Unite Mixte de Recherche CEA-CNRS-Universite Paris VII, UMR 7158, 91191 Gif-sur-Yvette Cedex (France)], E-mail: eggenberger@Qastro.ulg.ac.be

2008-10-15

The computation of models of stars for which solar-like oscillations have been observed is discussed. After a brief intoduction on the observations of solar-like oscillations, the modelling of isolated stars and of stars belonging to a binary system is presented with specific examples of recent theoretical calibrations. Finally the input physics introduced in stellar evolution codes for the computation of solar-type stars is discussed with a peculiar emphasis on the modelling of rotation for these stars.

Solar Walls in tsbi3

DEFF Research Database (Denmark)

Wittchen, Kim Bjarne

tsbi3 is a user-friendly and flexible computer program, which provides support to the design team in the analysis of the indoor climate and the energy performance of buildings. The solar wall module gives tsbi3 the capability of simulating solar walls and their interaction with the building....... This version, C, of tsbi3 is capable of simulating five types of solar walls say: mass-walls, Trombe-walls, double Trombe-walls, internally ventilated walls and solar walls for preheating ventilation air. The user's guide gives a description of the capabilities and how to simulate solar walls in tsbi3....

First detection of thermal radio emission from solar-type stars with the Karl G. Jansky very large array

Energy Technology Data Exchange (ETDEWEB)

Villadsen, Jackie; Hallinan, Gregg; Bourke, Stephen [Department of Astronomy, California Institute of Technology, 1200 E. California Ave., Pasadena, CA 91125 (United States); Güdel, Manuel [Department of Astrophysics, University of Vienna, Türkenschanzstrasse 17, A-1180 Vienna (Austria); Rupen, Michael, E-mail: jrv@astro.caltech.edu [National Radio Astronomy Observatory, Socorro, NM 87801 (United States)

2014-06-20

We present the first detections of thermal radio emission from the atmospheres of solar-type stars τ Cet, η Cas A, and 40 Eri A. These stars all resemble the Sun in age and level of magnetic activity, as indicated by X-ray luminosity and chromospheric emission in Ca II H and K lines. We observed these stars with the Karl G. Jansky Very Large Array with sensitivities of a few μJy at combinations of 10.0, 15.0, and 34.5 GHz. τ Cet, η Cas A, and 40 Eri A are all detected at 34.5 GHz with signal-to-noise ratios of 6.5, 5.2, and 4.5, respectively. 15.0 GHz upper limits imply a rising spectral index greater than 1.0 for τ Cet and 1.6 for η Cas A, at the 95% confidence level. The measured 34.5 GHz flux densities correspond to stellar disk-averaged brightness temperatures of roughly 10,000 K, similar to the solar brightness temperature at the same frequency. We explain this emission as optically thick thermal free-free emission from the chromosphere, with possible contributions from coronal gyroresonance emission above active regions and coronal free-free emission. These and similar quality data on other nearby solar-type stars, when combined with Atacama Large Millimeter/Submillimeter Array observations, will enable the construction of temperature profiles of their chromospheres and lower transition regions.

First detection of thermal radio emission from solar-type stars with the Karl G. Jansky very large array

International Nuclear Information System (INIS)

Villadsen, Jackie; Hallinan, Gregg; Bourke, Stephen; Güdel, Manuel; Rupen, Michael

2014-01-01

We present the first detections of thermal radio emission from the atmospheres of solar-type stars τ Cet, η Cas A, and 40 Eri A. These stars all resemble the Sun in age and level of magnetic activity, as indicated by X-ray luminosity and chromospheric emission in Ca II H and K lines. We observed these stars with the Karl G. Jansky Very Large Array with sensitivities of a few μJy at combinations of 10.0, 15.0, and 34.5 GHz. τ Cet, η Cas A, and 40 Eri A are all detected at 34.5 GHz with signal-to-noise ratios of 6.5, 5.2, and 4.5, respectively. 15.0 GHz upper limits imply a rising spectral index greater than 1.0 for τ Cet and 1.6 for η Cas A, at the 95% confidence level. The measured 34.5 GHz flux densities correspond to stellar disk-averaged brightness temperatures of roughly 10,000 K, similar to the solar brightness temperature at the same frequency. We explain this emission as optically thick thermal free-free emission from the chromosphere, with possible contributions from coronal gyroresonance emission above active regions and coronal free-free emission. These and similar quality data on other nearby solar-type stars, when combined with Atacama Large Millimeter/Submillimeter Array observations, will enable the construction of temperature profiles of their chromospheres and lower transition regions.

A STATISTICAL STUDY OF SOLAR ELECTRON EVENTS OVER ONE SOLAR CYCLE

International Nuclear Information System (INIS)

Wang Linghua; Lin, R. P.; Krucker, Säm; Mason, Glenn M.

2012-01-01

We survey the statistical properties of 1191 solar electron events observed by the WIND 3DP instrument from 300 keV for a solar cycle (1995 through 2005). After taking into account times of high background, the corrected occurrence frequency of solar electron events versus peak flux exhibits a power-law distribution over three orders of magnitude with exponents between –1.0 and –1.6 for different years, comparable to the frequency distribution of solar proton events, microflares, and coronal mass ejections (CMEs), but significantly flatter than that of soft X-ray (SXR) flares. At 40 keV (2.8 keV), the integrated occurrence rate above ∼0.29 (∼330) cm –2 s –1 sr –1 keV –1 near 1 AU is ∼1000 year –1 (∼600 year –1 ) at solar maximum and ∼35 year –1 (∼25 year –1 ) at solar minimum, about an order of magnitude larger than the observed occurrence rate. We find these events typically extend over ∼45° in longitude, implying the occurrence rate over the whole Sun is ∼10 4 year –1 near solar maximum. The observed solar electron events have a 98.75% association with type III radio bursts, suggesting all type III bursts may be associated with a solar electron event. They have a close (∼76%) association with the presence of low-energy (∼0.02-2 MeV nucleon –1 ), 3 He-rich ( 3 He/ 4 He ≥ 0.01) ion emissions measured by the ACE ULEIS instrument. For these electron events, only ∼35% are associated with a reported GOES SXR flare, but ∼60% appear to be associated with a CME, with ∼50% of these CMEs being narrow. These electrons are often detected down to below 1 keV, indicating a source high in the corona.

Sandwich-cell-type bulk-heterojunction organic solar cells utilizing liquid crystalline phthalocyanine

Science.gov (United States)

Nakata, Yuya; Usui, Toshiki; Nishikawa, Yuki; Nekelson, Fabien; Shimizu, Yo; Fujii, Akihiko; Ozaki, Masanori

2018-03-01

Sandwich-cell-type bulk-heterojunction organic solar cells utilizing the liquid crystalline phthalocyanine, 1,4,8,11,15,18,22,25-octahexylphthalocyanine (C6PcH2), have been fabricated and their photovoltaic properties have been studied. The short-circuit current (J SC) and power conversion efficiency (PCE) depended on the blend ratio of donor and acceptor molecules, and the maximum performance, such as J SC of 3.4 mA/cm2 and PCE of 0.67%, was demonstrated, when the blend ratio of the acceptor was 10 mol %. The photovoltaic properties were discussed by taking the relationship between the column axis direction of C6PcH2 and the carrier mobility in the active layer into consideration.

Transferencia de Tecnologías a una Cooperativa en Argentina. Un Estudio de Caso

Directory of Open Access Journals (Sweden)

Maximiliano Facundo Vila Seoane

2013-04-01

Full Text Available This paper describes a pilot technology transfer process carried out in the province of Salta, northwestern Argentina, whose goal was to disseminate knowledge to produce solar cookers. The particularity of this experience is that the source of knowledge transfer has been made from a research and development center to a cooperative public work in the province. The paper describes in detail all the stages of the process, methods that have been used, and suggests a set of points to consider in future similar experiences.

Solar Storage Tank Insulation Influence on the Solar Systems Efficiency

Directory of Open Access Journals (Sweden)

Negoitescu Arina

2012-09-01

Full Text Available For the storage tank of a solar system for domestic hot water production was analyzed the insulation thickness and material influence. To this end, it was considered a private house, occupied by 3 persons, located in zone I of thermal radiation, for which has been simulated the domestic hot water production process. The tank outlet hot water temperature was considered of 45°C. For simulation purposes, as insulation materials for the storage tank were taking into account glass wool and polyurethane with various thicknesses. Finally, was carried out the comparative analysis of two types of tanks, in terms of the insulation thickness influence on the solar fraction, annual solar contribution and solar annual productivity. It resulted that polyurethane is the most advantageous from all points of view.

Novel configurations of solar distillation system for potable water production

Science.gov (United States)

Riahi, A.; Yusof, K. W.; Sapari, N.; Singh, B. S.; Hashim, A. M.

2013-06-01

More and more surface water are polluted with toxic chemicals. Alternatively brackish and saline water are used as feed water to water treatment plants. Expensive desalination process via reverse osmosis or distillation is used in the plants. Thus, this conventional desalination is not suitable for low and medium income countries. A cheaper method is by solar distillation. However the rate of water production by this method is generally considered low. This research attempts to enhance water production of solar distillation by optimizing solar capture, evaporation and condensation processes. Solar radiation data was captured in several days in Perak, Malaysia. Three kinds of experiments were done by fabricating triangular solar distillation systems. First type was conventional solar still, second type was combined with 50 Watt solar photovoltaic panel and 40 Watt Dc heater, while third type was integrated with 12 Volt Solar battery and 40 Watt Dc heater. The present investigation showed that the productivity of second and third systems were 150% and 480% of the conventional still type, respectively. The finding of this research can be expected to have wide application in water supply particularly in areas where fresh surface water is limited.

Novel configurations of solar distillation system for potable water production

International Nuclear Information System (INIS)

Riahi, A; Yusof, K W; Sapari, N; Hashim, A M; Singh, B S

2013-01-01

More and more surface water are polluted with toxic chemicals. Alternatively brackish and saline water are used as feed water to water treatment plants. Expensive desalination process via reverse osmosis or distillation is used in the plants. Thus, this conventional desalination is not suitable for low and medium income countries. A cheaper method is by solar distillation. However the rate of water production by this method is generally considered low. This research attempts to enhance water production of solar distillation by optimizing solar capture, evaporation and condensation processes. Solar radiation data was captured in several days in Perak, Malaysia. Three kinds of experiments were done by fabricating triangular solar distillation systems. First type was conventional solar still, second type was combined with 50 Watt solar photovoltaic panel and 40 Watt Dc heater, while third type was integrated with 12 Volt Solar battery and 40 Watt Dc heater. The present investigation showed that the productivity of second and third systems were 150% and 480% of the conventional still type, respectively. The finding of this research can be expected to have wide application in water supply particularly in areas where fresh surface water is limited.

Synthesis of an A-D-A type of molecule used as electron acceptor for improving charge transfer in organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Zhang, Chao-Zhi, E-mail: chzhzhang@sohu.com [Department of Chemistry, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Gu, Shu-Duo; Shen, Dan; Yuan, Yang [Department of Chemistry, Nanjing University of Information Science & Technology, Nanjing 210044 (China); Zhang, Mingdao, E-mail: matchlessjimmy@163.com [Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science & Technology, Nanjing 210044 (China)

2016-08-22

Electron-accepting molecules play an important role in developing organic solar cells. A new type of A-D-A molecule, 3,6-di([7-(5-bromothiophen-2-yl)-1,5,2,4,6,8-dithiotetrazocin-3-yl]thiophen -2-yl)-9-(2-ethylhexyl)carbazole, was synthesized. The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels are −3.55 and −5.85 eV, respectively. Therefore, the A-D-A type of compound could be used as electron acceptor for fabricating organic solar cell with a high open circuit voltage. Gibbs free energy (−49.2 kJ/mol) reveals that the process of A-D-A acceptor accepting an electron from poly(3-hexylthiophene) at excited state is spontaneous. The value of entropy (118 J/mol) in the process of an electron transferring from P3HT to the A-D-A acceptor at organic interface suggests that electrons generated from separation of electron-hole pairs at donor/acceptor interface would be delocalized efficiently. Therefore, the A-D-A molecule would be a potential acceptor for efficient organic BHJ solar cells.

Solar energy utilization in the USSR

International Nuclear Information System (INIS)

Shpil'rajn, Eh.Eh.

1993-01-01

The conditions for solar energy utilization in the USSR are not too favorable. Only in the country's southern regions is there sufficient insolation to make solar energy utilization economical. In higher latitudes only seasonable use of solar energy is reasonable. Up to now, the main application of solar energy was to produce low temperature heat for hot water production, drying of agricultural goods, space heating and thermal treating of concrete. A substantial part of the solar heating installations is flat plate solar collectors. The total installed area of solar collectors slightly exceeds 100,000 m 2 . The collectors are produced by industry, as well as by small enterprises. In some cases selective coatings are used over the absorber plates; black nickel or chromium is the main coating material. Recently, new projects were launched to develop and produce advanced collectors with enhanced efficiency and reliability. Substantial progress has been made in the USSR in developing and producing photovoltaic cells, mainly for space applications. Terrestrial applications of photovoltaic is only in the very early stage. About 100 Kw of photovoltaic cells are produced annually in the USSR, based on mono or polycrystalline silicon. Some experimental photovoltaic-arrays in the range of several tenth of Kw are installed in different places. Research and development work is carried out to produce thin film cells. Effort are in progress to construct automated production lines for 1 MW per year of crystalline and amorphous silicon. In the Crimea, a solar power plant SES-5 (5 MW peak power) was commissioned some years ago. The plant is of a tower type, with a circular helioscope field. The plants working fluid is steam. The experienced gained demonstrates that this design concept has several disadvantages. The cost of electricity produced by such type plants extremely high. Recently, alternative types of solar power plants have been under development, in particular, a project

Understanding Solar Cycle Variability

Energy Technology Data Exchange (ETDEWEB)

Cameron, R. H.; Schüssler, M., E-mail: cameron@mps.mpg.de [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany)

2017-07-10

The level of solar magnetic activity, as exemplified by the number of sunspots and by energetic events in the corona, varies on a wide range of timescales. Most prominent is the 11-year solar cycle, which is significantly modulated on longer timescales. Drawing from dynamo theory, together with the empirical results of past solar activity and similar phenomena for solar-like stars, we show that the variability of the solar cycle can be essentially understood in terms of a weakly nonlinear limit cycle affected by random noise. In contrast to ad hoc “toy models” for the solar cycle, this leads to a generic normal-form model, whose parameters are all constrained by observations. The model reproduces the characteristics of the variable solar activity on timescales between decades and millennia, including the occurrence and statistics of extended periods of very low activity (grand minima). Comparison with results obtained with a Babcock–Leighton-type dynamo model confirm the validity of the normal-mode approach.

The Use of Meteosat Second Generation Satellite Data Within A New Type of Solar Irradiance Calculation Scheme

Science.gov (United States)

Mueller, R. W.; Beyer, H. G.; Cros, S.; Dagestad, K. F.; Dumortier, D.; Ineichen, P.; Hammer, A.; Heinemann, D.; Kuhlemann, R.; Olseth, J. A.; Piernavieja, G.; Reise, C.; Schroedter, M.; Skartveit, A.; Wald, L.

presentation a new type of the solar irradiance calculation scheme is de- scribed. It is based on the integrated use of a radiative transfer model (RTM), whereas the information of the atmospheric parameters retrieved from satellites (MSG and GOME/ATSR-2) will be used as input for the RTM. First comparisons between calcu- lated and measured solar irradiance are presented. The improvements linked with the usage of the new calculation scheme are discussed, taking into account the benefits and limitations of the new method and the MSG satellite.

Enhancing Solar Cell Efficiency Using Photon Upconversion Materials.

Science.gov (United States)

Shang, Yunfei; Hao, Shuwei; Yang, Chunhui; Chen, Guanying

2015-10-27

Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous), gallium arsenide (GaAs) solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed.

Enhancing Solar Cell Efficiency Using Photon Upconversion Materials

Directory of Open Access Journals (Sweden)

Yunfei Shang

2015-10-01

Full Text Available Photovoltaic cells are able to convert sunlight into electricity, providing enough of the most abundant and cleanest energy to cover our energy needs. However, the efficiency of current photovoltaics is significantly impeded by the transmission loss of sub-band-gap photons. Photon upconversion is a promising route to circumvent this problem by converting these transmitted sub-band-gap photons into above-band-gap light, where solar cells typically have high quantum efficiency. Here, we summarize recent progress on varying types of efficient upconversion materials as well as their outstanding uses in a series of solar cells, including silicon solar cells (crystalline and amorphous, gallium arsenide (GaAs solar cells, dye-sensitized solar cells, and other types of solar cells. The challenge and prospect of upconversion materials for photovoltaic applications are also discussed

Photovoltaic solar energy: State of the art

International Nuclear Information System (INIS)

Van Sark, W.G.J.H.M.; Sinke, W.C.

1993-03-01

Attention is paid to developments in the Netherlands of all aspects of photovoltaic (PV) energy: solar cells, components, PV-systems and all kinds of applications. Efficiencies of the present solar cell types still increase, varying from more than 10% for organic/TiO 2 solar cells to 33% for GaAs/GaSb concentrator tandem solar cells. 3 figs., 2 ills., 1 tab

Fiscal 1998 achievement report on regional consortium research and development project. Venture business raising type regional consortium - small business creating base type (Development of mobile hybrid power source system using wind and solar energies); 1998 nendo kahanshiki furyoku taiyoko hybrid dengen system no kaihatsu seika hokokusho

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-12-01

Regarding new energy power sources such as solar cells and small wind power systems (1-3kW), research and development is conducted for a new hybrid system featuring 'mobile, package type, no construction cost.' In the research, 4-12m telescopic wind turbine supporting poles are manufactured for two types of wind turbines respectively generating 1.5kW and 2.5kW. A slide type mechanism is employed for solar cell deployment, which enables on-site deployment. Each solar panel accommodates 24 solar cells, and one is installed on top of a container to serve as control room. A control system is developed for this hybrid power source system, which receives power from a wind power turbine and solar cells and supplies power to three kinds of power sources. For the stable supply of power to the loads, 24V/1500Ah batteries are provided. Each power charging controller and protecting device are found to operate smoothly in a verification test, which means the goal of the development endeavors has been achieved. (NEDO)

A PROPOSED PARADIGM FOR SOLAR CYCLE DYNAMICS MEDIATED VIA TURBULENT PUMPING OF MAGNETIC FLUX IN BABCOCK–LEIGHTON-TYPE SOLAR DYNAMOS

Energy Technology Data Exchange (ETDEWEB)

Hazra, Soumitra; Nandy, Dibyendu [Department of Physical Sciences, Indian Institute of Science Education and Research, Kolkata (India)

2016-11-20

At present, the Babcock–Leighton flux transport solar dynamo models appear to be the most promising models for explaining diverse observational aspects of the sunspot cycle. The success of these flux transport dynamo models is largely dependent upon a single-cell meridional circulation with a deep equatorward component at the base of the Sun’s convection zone. However, recent observations suggest that the meridional flow may in fact be very shallow (confined to the top 10% of the Sun) and more complex than previously thought. Taken together, these observations raise serious concerns on the validity of the flux transport paradigm. By accounting for the turbulent pumping of magnetic flux, as evidenced in magnetohydrodynamic simulations of solar convection, we demonstrate that flux transport dynamo models can generate solar-like magnetic cycles even if the meridional flow is shallow. Solar-like periodic reversals are recovered even when meridional circulation is altogether absent. However, in this case, the solar surface magnetic field dynamics does not extend all the way to the polar regions. Very importantly, our results demonstrate that the Parker–Yoshimura sign rule for dynamo wave propagation can be circumvented in Babcock–Leighton dynamo models by the latitudinal component of turbulent pumping, which can generate equatorward propagating sunspot belts in the absence of a deep, equatorward meridional flow. We also show that variations in turbulent pumping coefficients can modulate the solar cycle amplitude and periodicity. Our results suggest the viability of an alternate magnetic flux transport paradigm—mediated via turbulent pumping—for sustaining solar-stellar dynamo action.

A PROPOSED PARADIGM FOR SOLAR CYCLE DYNAMICS MEDIATED VIA TURBULENT PUMPING OF MAGNETIC FLUX IN BABCOCK–LEIGHTON-TYPE SOLAR DYNAMOS

International Nuclear Information System (INIS)

Hazra, Soumitra; Nandy, Dibyendu

2016-01-01

At present, the Babcock–Leighton flux transport solar dynamo models appear to be the most promising models for explaining diverse observational aspects of the sunspot cycle. The success of these flux transport dynamo models is largely dependent upon a single-cell meridional circulation with a deep equatorward component at the base of the Sun’s convection zone. However, recent observations suggest that the meridional flow may in fact be very shallow (confined to the top 10% of the Sun) and more complex than previously thought. Taken together, these observations raise serious concerns on the validity of the flux transport paradigm. By accounting for the turbulent pumping of magnetic flux, as evidenced in magnetohydrodynamic simulations of solar convection, we demonstrate that flux transport dynamo models can generate solar-like magnetic cycles even if the meridional flow is shallow. Solar-like periodic reversals are recovered even when meridional circulation is altogether absent. However, in this case, the solar surface magnetic field dynamics does not extend all the way to the polar regions. Very importantly, our results demonstrate that the Parker–Yoshimura sign rule for dynamo wave propagation can be circumvented in Babcock–Leighton dynamo models by the latitudinal component of turbulent pumping, which can generate equatorward propagating sunspot belts in the absence of a deep, equatorward meridional flow. We also show that variations in turbulent pumping coefficients can modulate the solar cycle amplitude and periodicity. Our results suggest the viability of an alternate magnetic flux transport paradigm—mediated via turbulent pumping—for sustaining solar-stellar dynamo action.

Road to Grid Parity through Deployment of Low-Cost 21.5% N-Type Si Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Velundur, Vijay [Suniva, Norcross, GA (United States)

2017-04-19

This project seeks to develop and deploy differentiated 21.5% efficient n-type Si solar cells while reaching the SunShot module cost goal of ≤ $0.50/W. This objective hinges on development of enabling low cost technologies that simplify the manufacturing process and reduce overall processing costs. These comprise of (1) Boron emitter formation and passivation; (2) Simplified processing process for emitter and BSF layers; and (3) Advanced metallization for the front and back contacts.

Collector Efficiency in Downward-Type Internal-Recycle Solar Air Heaters with Attached Fins

Directory of Open Access Journals (Sweden)

Chii-Dong Ho

2013-10-01

Full Text Available The internal-recycle operation effect on collector efficiency in downward-type rectangular solar air heaters with attached fins is theoretically investigated. It is found that considerable collector efficiency is obtainable if the collector has attached fins and the operation is carried out with internal recycling. The recycling operation increases the fluid velocity to decrease the heat transfer resistance, compensating for the undesirable effect of decreasing the heat transfer driving force (temperature difference due to remixing. The attached fins provide an enlarged heat transfer area. The order of performance in a device of same size is: double pass with recycle and fins > double pass with recycle but without fins > single pass without recycle and fins.

Tracking Solar Type II Bursts with Space Based Radio Interferometers

Science.gov (United States)

Hegedus, Alexander M.; Kasper, Justin C.; Manchester, Ward B.

2018-06-01

The Earth’s Ionosphere limits radio measurements on its surface, blocking out any radiation below 10 MHz. Valuable insight into many astrophysical processes could be gained by having a radio interferometer in space to image the low frequency window for the first time. One application is observing type II bursts tracking solar energetic particle acceleration in Coronal Mass Ejections (CMEs). In this work we create a simulated data processing pipeline for several space based radio interferometer (SBRI) concepts and evaluate their performance in the task of localizing these type II bursts.Traditional radio astronomy software is hard coded to assume an Earth based array. To circumvent this, we manually calculate the antenna separations and insert them along with the simulated visibilities into a CASA MS file for analysis. To create the realest possible virtual input data, we take a 2-temperature MHD simulation of a CME event, superimpose realistic radio emission models from the CME-driven shock front, and propagate the signal through simulated SBRIs. We consider both probabilistic emission models derived from plasma parameters correlated with type II bursts, and analytical emission models using plasma emission wave interaction theory.One proposed SBRI is the pathfinder mission SunRISE, a 6 CubeSat interferometer to circle the Earth in a GEO graveyard orbit. We test simulated trajectories of SunRISE and image what the array recovers, comparing it to the virtual input. An interferometer on the lunar surface would be a stable alternative that avoids noise sources that affect orbiting arrays, namely the phase noise from positional uncertainty and atmospheric 10s-100s kHz noise. Using Digital Elevation Models from laser altimeter data, we test different sets of locations on the lunar surface to find near optimal configurations for tracking type II bursts far from the sun. Custom software is used to model the response of different array configurations over the lunar year

Lithium abundances, K line emission and ages of nearby solar type stars

International Nuclear Information System (INIS)

Duncan, D.K.

1981-01-01

Li abundances and chromospheric emission fluxes measured in the core of the Ca II K line have been determined in over 100 field F5--G5 dwarfs and subgiants. Although both quantities are known statistically to decrease in older stars, the correlation between them is not good. In particular, there are a number of anomalous solar type stars which show high Li abundances and very little chromospheric flux; the converse is rare. This might be understood if the intensity of chromospheric emission undergoes a sudden decrease when stars reach an age of 1 to 2 x 10 9 years, before much Li depletion occurs. Some of the anomalous stars appear to be older than this, however. Such stars must have preserved their Li from main sequence destruction

Modulated charge injection in p-type dye-sensitized solar cells using fluorene-based light absorbers.

Science.gov (United States)

Liu, Zonghao; Xiong, Dehua; Xu, Xiaobao; Arooj, Qudsia; Wang, Huan; Yin, Liyuan; Li, Wenhui; Wu, Huaizhi; Zhao, Zhixin; Chen, Wei; Wang, Mingkui; Wang, Feng; Cheng, Yi-Bing; He, Hongshan

2014-03-12

In this study, new pull-push arylamine-fluorene based organic dyes zzx-op1, zzx-op2, and zzx-op3 have been designed and synthesized for p-type dye-sensitized solar cells (p-DSCs). In zzx-op1, a di(p-carboxyphenyl)amine (DCPA) was used as an electron donor, a perylenemonoimide (PMID) as an electron acceptor, and a fluorene (FLU) unit with two aliphatic hexyl chains as a π-conjugated linker. In zzx-op2 and zzx-op3, a 3,4-ethylenedioxythiophene (EDOT) and a thiophene were inserted consecutively between PMID and FLU to tune the energy levels of the frontier molecular orbitals of the dyes. The structural modification broadened the spectral coverage from an onset of 700 nm for zzx-op1 to 750 nm for zzx-op3. The electron-rich EDOT and thiophene lifted up the HOMO (highest occupied molecular orbital) levels of zzx-op2 and zzx-op3, making their potential more negative than zzx-op1. When three dyes were employed in p-type DSCs with I(-)/I3(-) as a redox couple and NiO nanoparticles as hole materials, zzx-op1 exhibited impressive energy conversion efficiency of 0.184% with the open-circuit voltage (VOC) of 112 mV and the short-circuit current density (JSC) of 4.36 mA cm(-2) under AM 1.5G condition. Density functional theory calculations, transient photovoltage decay measurements, and electrochemical impedance spectroscopic studies revealed that zzx-op1 sensitized solar cell exhibited much higher charge injection efficiency (90.3%) than zzx-op2 (53.9%) and zzx-op3 (39.0%), indicating a trade-off between spectral broadening and electron injection driving force in p-type DSCs.

Solar Deployment System (SolarDS) Model: Documentation and Sample Results

Energy Technology Data Exchange (ETDEWEB)

Denholm, P.; Drury, E.; Margolis, R.

2009-09-01

The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

Surface Passivation for Silicon Heterojunction Solar Cells

NARCIS (Netherlands)

Deligiannis, D.

2017-01-01

Silicon heterojunction solar cells (SHJ) are currently one of the most promising solar cell technologies in the world. The SHJ solar cell is based on a crystalline silicon (c-Si) wafer, passivated on both sides with a thin intrinsic hydrogenated amorphous silicon (a-Si:H) layer. Subsequently, p-type

Solar neutrino problem accounting for self-consistent magnetohydrodynamics solution for solar magnetic fields

International Nuclear Information System (INIS)

Miranda, O.G.; Pena-Garay, C.; Valle, J.W.F.; Rashba, T.I.; Semikoz, V.B.

2001-01-01

The analysis of the resonant spin-flavour (RSF) solutions to the solar neutrino problem in the framework of the simplest analytical solutions to the solar magnetohydrodynamics (MHD) equations is presented. We performed the global fit of the recent solar neutrino data, including event rates as well as zenith angle distributions and recoil electron spectra induced by solar neutrino interactions in Superkamiokande. We compare quantitatively our simplest MHD-RSF fit with vacuum oscillation (VAC) and MSW-type (SMA, LMA and LOW) solutions to the solar neutrino problem using a common well-calibrated theoretical calculation and fit procedure and find MHD-RSF fit to be somewhat better than those obtained for the favored neutrino oscillation solutions. We made the predictions for future experiments (e.g., SNO) to disentangle the MHD-RSF scenario from other scenarios

Design, Construction and Effectiveness Analysis of Hybrid Automatic Solar Tracking System for Amorphous and Crystalline Solar Cells

OpenAIRE

Bhupendra Gupta

2013-01-01

- This paper concerns the design and construction of a Hybrid solar tracking system. The constructed device was implemented by integrating it with Amorphous & Crystalline Solar Panel, three dimensional freedom mechanism and microcontroller. The amount of power available from a photovoltaic panel is determined by three parameters, the type of solar tracker, materials of solar panel and the intensity of the sunlight. The objective of this paper is to present analysis on the use of two differ...

Purchase aspects playing a part in the broad selection of solar boiler types

International Nuclear Information System (INIS)

Van Amerongen, G.A.H.

1996-01-01

Because of the large variety of solar water heaters in the Netherlands and abroad the arguments to purchase such boilers have to be reconsidered. In this article a few practical guidelines are given, focusing on solar boilers equipped with thermosyphon collector circuits or enamel steel storage tanks, and some typical aspects of imported solar water heaters. 3 figs., 1 tab., 1 refs

Comparison of interplanetary CME arrival times and solar wind parameters based on the WSA-ENLIL model with three cone types and observations

Science.gov (United States)

Jang, Soojeong; Moon, Y.-J.; Lee, Jae-Ok; Na, Hyeonock

2014-09-01

We have made a comparison between coronal mass ejection (CME)-associated shock propagations based on the Wang-Sheeley-Arge (WSA)-ENLIL model using three cone types and in situ observations. For this we use 28 full-halo CMEs, whose cone parameters are determined and their corresponding interplanetary shocks were observed at the Earth, from 2001 to 2002. We consider three different cone types (an asymmetric cone model, an ice cream cone model, and an elliptical cone model) to determine 3-D CME cone parameters (radial velocity, angular width, and source location), which are the input values of the WSA-ENLIL model. The mean absolute error of the CME-associated shock travel times for the WSA-ENLIL model using the ice-cream cone model is 9.9 h, which is about 1 h smaller than those of the other models. We compare the peak values and profiles of solar wind parameters (speed and density) with in situ observations. We find that the root-mean-square errors of solar wind peak speed and density for the ice cream and asymmetric cone model are about 190 km/s and 24/cm3, respectively. We estimate the cross correlations between the models and observations within the time lag of ± 2 days from the shock travel time. The correlation coefficients between the solar wind speeds from the WSA-ENLIL model using three cone types and in situ observations are approximately 0.7, which is larger than those of solar wind density (cc ˜0.6). Our preliminary investigations show that the ice cream cone model seems to be better than the other cone models in terms of the input parameters of the WSA-ENLIL model.

Design of an Experimental PCM Solar Tank

Energy Technology Data Exchange (ETDEWEB)

Szabo, Istvan Peter

2010-09-15

The one of the most important part of a solar collector system is the solar tank. The relevant type and capacity of the solar tank is a requirement of the good operation of the system. According the current architectural tendencies the boiler rooms are smaller, so the putting of the currently available solar tanks is very difficult. It is necessary to store the energy in a little space. The solution of the problem is the solar tank particularly filled with phase change material.

Capacitance spectroscopy on n-type GaNAs/GaAs embedded quantum structure solar cells

Science.gov (United States)

Venter, Danielle; Bollmann, Joachim; Elborg, Martin; Botha, J. R.; Venter, André

2018-04-01

In this study, both deep level transient spectroscopy (DLTS) and admittance spectroscopy (AS) have been used to study the properties of electrically active deep level centers present in GaNAs/GaAs quantum wells (QWs) embedded in p-i-n solar cells. The structures were grown by molecular beam epitaxy (MBE). In particular, the electrical properties of samples with Si (n-type) doping of the QWs were investigated. DLTS revealed four deep level centers in the material, whereas only three were detected by AS. NextNano++ simulation software was used to model the sample band-diagrams to provide reasoning for the origin of the signals produced by both techniques.

Producer responsibility and recycling solar photovoltaic modules

International Nuclear Information System (INIS)

McDonald, N.C.; Pearce, J.M.

2010-01-01

Rapid expansion of the solar photovoltaic (PV) industry is quickly causing solar to play a growing importance in the energy mix of the world. Over the full life cycle, although to a smaller degree than traditional energy sources, PV also creates solid waste. This paper examines the potential need for PV recycling policies by analyzing existing recycling protocols for the five major types of commercialized PV materials. The amount of recoverable semiconductor material and glass in a 1 m 2 area solar module for the five types of cells is quantified both physically and the profit potential of recycling is determined. The cost of landfill disposal of the whole solar module, including the glass and semiconductor was also determined for each type of solar module. It was found that the economic motivation to recycle most PV modules is unfavorable without appropriate policies. Results are discussed on the need to regulate for appropriate energy and environmental policy in the PV manufacturing industry particularly for PV containing hazardous materials. The results demonstrate the need to encourage producer responsibility not only in the PV manufacturing sector but also in the entire energy industry.

Evaluation methods of solar contribution in solar aided coal-fired power generation system

International Nuclear Information System (INIS)

Zhu, Yong; Zhai, Rongrong; Zhao, Miaomiao; Yang, Yongping; Yan, Qin

2015-01-01

Highlights: • Five methods for evaluating solar contribution are analyzed. • Method based on the second law of thermodynamics and thermal economics is more suitable for SACPGS. • Providing reliable reference for the formulation of feed-in tariff policies in China. - Abstract: Solar aided coal-fired power plants utilize solar thermal energy to couple with coal-fired power plants of various types by adopting characteristics of different thermal needs of plants. In this way, the costly thermal storage system and power generating system will become unnecessary, meanwhile the intermittent and unsteady nature of power generation can be avoided. In addition, large-scale utilization of solar thermal power and energy saving can be achieved. With the ever-deepening analyses of solar aided coal-fired power plants, the contribution evaluating system of solar thermal power is worth further exploration. In this paper, five common evaluation methods of solar contribution are analyzed, and solar aided coal-fired power plants of 1000 MW, 600 MW and 330 MW are studied with these five methods in a comparative manner. Therefore, this study can serve as a theoretical reference for future research of evaluation methods and subsidies for new energy

Semi-transparent solar cells

International Nuclear Information System (INIS)

Sun, J; Jasieniak, J J

2017-01-01

Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies. (topical review)

Semi-transparent solar cells

Science.gov (United States)

Sun, J.; Jasieniak, J. J.

2017-03-01

Semi-transparent solar cells are a type of technology that combines the benefits of visible light transparency and light-to-electricity conversion. One of the biggest opportunities for such technologies is in their integration as windows and skylights within energy-sustainable buildings. Currently, such building integrated photovoltaics (BIPV) are dominated by crystalline silicon based modules; however, the opaque nature of silicon creates a unique opportunity for the adoption of emerging photovoltaic candidates that can be made truly semi-transparent. These include: amorphous silicon-, kesterite-, chalcopyrite-, CdTe-, dye-sensitized-, organic- and perovskite- based systems. For the most part, amorphous silicon has been the workhorse in the semi-transparent solar cell field owing to its established, low-temperature fabrication processes. Excitement around alternative classes, particularly perovskites and the inorganic candidates, has recently arisen because of the major efficiency gains exhibited by these technologies. Importantly, each of these presents unique opportunities and challenges within the context of BIPV. This topic review provides an overview into the broader benefits of semi-transparent solar cells as building-integrated features, as well as providing the current development status into all of the major types of semi-transparent solar cells technologies.

Solar system for domestic hot water and space heating

Energy Technology Data Exchange (ETDEWEB)

Weiss, W. [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

1997-12-31

The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

Solar system for domestic hot water and space heating

Energy Technology Data Exchange (ETDEWEB)

Weiss, W [Arbeitsgemeinschaf Erneubare Energie, Gleisdorf (Austria)

1998-12-31

The solar thermal markets, different types of solar systems for hot water and space heating, the dimensioning and the components of solar heating systems, the properties of the systems are reviewed in this presentation

Solar Radio Bursts and Space Weather

Science.gov (United States)

Gopalswamy, Natchimuthuk,

2012-01-01

Radio bursts from the Sun are produced by electron accelerated to relativistic energies by physical processes on the Sun such as solar flares and coronal mass ejections (CMEs). The radio bursts are thus good indicators of solar eruptions. Three types of nonthermal radio bursts are generally associated with CMEs. Type III bursts due to accelerated electrons propagating along open magnetic field lines. The electrons are thought to be accelerated at the reconnection region beneath the erupting CME, although there is another view that the electrons may be accelerated at the CME-driven shock. Type II bursts are due to electrons accelerated at the shock front. Type II bursts are also excellent indicators of solar energetic particle (SEP) events because the same shock is supposed accelerate electrons and ions. There is a hierarchical relationship between the wavelength range of type /I bursts and the CME kinetic energy. Finally, Type IV bursts are due to electrons trapped in moving or stationary structures. The low frequency stationary type IV bursts are observed occasionally in association with very fast CMEs. These bursts originate from flare loops behind the erupting CME and hence indicate tall loops. This paper presents a summary of radio bursts and their relation to CMEs and how they can be useful for space weather predictions.

Industrial Silicon Wafer Solar Cells

OpenAIRE

Neuhaus, Dirk-Holger; Münzer, Adolf

2007-01-01

In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future e...

A STATISTICAL RECONSTRUCTION OF THE PLANET POPULATION AROUND KEPLER SOLAR-TYPE STARS

International Nuclear Information System (INIS)

Silburt, Ari; Wu, Yanqin; Gaidos, Eric

2015-01-01

Using the cumulative catalog of planets detected by the NASA Kepler mission, we reconstruct the intrinsic occurrence of Earth- to Neptune-size (1-4 R ⊕ ) planets and their distributions with radius and orbital period. We analyze 76,711 solar-type (0.8 < R * /R ☉ < 1.2) stars with 430 planets on 20-200 day orbits, excluding close-in planets that may have been affected by the proximity to the host star. Our analysis considers errors in planet radii and includes an ''iterative simulation'' technique that does not bin the data. We find a radius distribution that peaks at 2-2.8 Earth radii, with lower numbers of smaller and larger planets. These planets are uniformly distributed with logarithmic period, and the mean number of such planets per star is 0.46 ± 0.03. The occurrence is ∼0.66 if planets interior to 20 days are included. We estimate the occurrence of Earth-size planets in the ''habitable zone'' (defined as 1-2 R ⊕ , 0.99-1.7 AU for solar-twin stars) as 6.4 −1.1 +3.4 %. Our results largely agree with those of Petigura et al., although we find a higher occurrence of 2.8-4 Earth-radii planets. The reasons for this excess are the inclusion of errors in planet radius, updated Huber et al. stellar parameters, and also the exclusion of planets that may have been affected by proximity to the host star

Power Generator with Thermo-Differential Modules

Science.gov (United States)

Saiz, John R.; Nguyen, James

2010-01-01

A thermoelectric power generator consists of an oven box and a solar cooker/solar reflector unit. The solar reflector concentrates sunlight into heat and transfers the heat into the oven box via a heat pipe. The oven box unit is surrounded by five thermoelectric modules and is located at the bottom end of the solar reflector. When the heat is pumped into one side of the thermoelectric module and ejected from the opposite side at ambient temperatures, an electrical current is produced. Typical temperature accumulation in the solar reflector is approximately 200 C (392 F). The heat pipe then transfers heat into the oven box with a loss of about 40 percent. At the ambient temperature of about 20 C (68 F), the temperature differential is about 100 C (180 F) apart. Each thermoelectric module, generates about 6 watts of power. One oven box with five thermoelectric modules produces about 30 watts. The system provides power for unattended instruments in remote areas, such as space colonies and space vehicles, and in polar and other remote regions on Earth.

Solar flare irradiation records in Antarctic meteorites

International Nuclear Information System (INIS)

Goswami, J.N.

1981-01-01

Observations of solar flare heavy nuclei tracks in eight Antartic meteorite samples are reported. Two of these were interior specimens from an L-3 chondrite which contained track-rich grains (olivine) indicating their exposure to solar flare irradiation before compaction of the meteorite. Preliminary noble gas data also indicate the presence of solar-type gases. (U.K.)

Efficiency enhancement using a Zn1- x Ge x -O thin film as an n-type window layer in Cu2O-based heterojunction solar cells

Science.gov (United States)

Minami, Tadatsugu; Nishi, Yuki; Miyata, Toshihiro

2016-05-01

Efficiency enhancement was achieved in Cu2O-based heterojunction solar cells fabricated with a zinc-germanium-oxide (Zn1- x Ge x -O) thin film as the n-type window layer and a p-type Na-doped Cu2O (Cu2O:Na) sheet prepared by thermally oxidizing Cu sheets. The Ge content (x) dependence of the obtained photovoltaic properties of the heterojunction solar cells is mainly explained by the conduction band discontinuity that results from the electron affinity difference between Zn1- x Ge x -O and Cu2O:Na. The optimal value of x in Zn1- x Ge x -O thin films prepared by pulsed laser deposition was observed to be 0.62. An efficiency of 8.1% was obtained in a MgF2/Al-doped ZnO/Zn0.38Ge0.62-O/Cu2O:Na heterojunction solar cell.

Solar flares

International Nuclear Information System (INIS)

Kaastra, J.S.

1985-01-01

In this thesis an electrodynamic model for solar flares is developed. The main theoretical achievements underlying the present study are treated briefly and the observable flare parameters are described within the framework of the flare model of this thesis. The flare model predicts large induced electric fields. Therefore, acceleration processes of charged particles by direct electric fields are treated. The spectrum of the accelerated particles in strong electric fields is calculated, 3 with the electric field and the magnetic field perpendicular and in the vicinity of an X-type magnetic neutral line. An electromagnetic field configuration arises in the case of a solar flare. A rising current filament in a quiescent background bipolar magnetic field causes naturally an X-type magnetic field configuration below the filament with a strong induced electric field perpendicular to the ambient magnetic field. This field configuration drives particles and magnetic energy towards the neutral line, where a current sheet is generated. The global evolution of the fields in the flare is determined by force balance of the Lorentz forces on the filament and the force balance on the current sheet. The X-ray, optical and radio observations of a large solar flare on May 16, 1981 are analyzed. It is found that these data fit the model very well. (Auth.)

First ultraviolet observations of the transition regions of X-ray bright solar-type stars in the Pleiades

Science.gov (United States)

Caillault, J.-P.; Vilhu, O.; Linsky, J. L.

1990-01-01

Results are reported from A UV study of the transition regions of two X-ray-bright solar-type stars from the Pleiades, in an attempt to extend the main sequence age baseline for the transition-region activity-age relation over more than two orders of magnitude. However, no emission lines were detected from either star; the upper limits to the fluxes are consistent with previously determined saturation levels, but do not help to further constrain evolutionary models.

BM Solar Cells

KAUST Repository

Firdaus, Yuliar

2018-05-02

Fullerene‐based materials are widely used as electron acceptors in organic bulk‐heterojunction solar cells; yet, they have rarely been used as the only photoactive component due to their low absorbance and limited charge generation efficiency. However, blending the wide‐bandgap p‐type material copper (I) thiocyanate (CuSCN) with [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM) leads to the formation of a unique mesostructured p‐n like heterointerface between CuSCN and PC70BM and solar cells with a power conversion efficiency (PCE) of up to 5.4%. Here, we examine in detail the reasons for the surprisingly good device performance and elucidate the charge photogeneration and recombination mechanisms in CuSCN‐based devices with PC70BM as the exclusive light‐absorbing material. Our studies clearly demonstrate that a substantial fraction of the photocurrent in the CuSCN‐based devices results from improved dissociation of fullerene excitons and efficient charge transfer at the CuSCN:PC70BM interface combined with reduced geminate and nongeminate charge recombination losses. Our results have implications beyond the fullerene‐based devices studied here, as they demonstrate that careful selection of a mesostructured p‐type transparent semiconductor paves the path to a new type of efficient single photoactive material solar cells.

BM Solar Cells

KAUST Repository

Firdaus, Yuliar; Seitkhan, Akmaral; Eisner, Flurin; Sit, Wai-Yu; Kan, Zhipeng; Wehbe, Nimer; Balawi, Ahmed H.; Yengel, Emre; Karuthedath, Safakath; Laquai, Fré dé ric; Anthopoulos, Thomas D.

2018-01-01

Fullerene‐based materials are widely used as electron acceptors in organic bulk‐heterojunction solar cells; yet, they have rarely been used as the only photoactive component due to their low absorbance and limited charge generation efficiency. However, blending the wide‐bandgap p‐type material copper (I) thiocyanate (CuSCN) with [6,6]‐phenyl‐C71‐butyric acid methyl ester (PC70BM) leads to the formation of a unique mesostructured p‐n like heterointerface between CuSCN and PC70BM and solar cells with a power conversion efficiency (PCE) of up to 5.4%. Here, we examine in detail the reasons for the surprisingly good device performance and elucidate the charge photogeneration and recombination mechanisms in CuSCN‐based devices with PC70BM as the exclusive light‐absorbing material. Our studies clearly demonstrate that a substantial fraction of the photocurrent in the CuSCN‐based devices results from improved dissociation of fullerene excitons and efficient charge transfer at the CuSCN:PC70BM interface combined with reduced geminate and nongeminate charge recombination losses. Our results have implications beyond the fullerene‐based devices studied here, as they demonstrate that careful selection of a mesostructured p‐type transparent semiconductor paves the path to a new type of efficient single photoactive material solar cells.

Cleaning Robot for Solar Panels in Solar Power Station

Science.gov (United States)

Hang, Lu-Bin; Shen, Cheng-Wei; Bian, Huai-Qiang; Wang, Yan

2016-05-01

The dust particles on solar panel surface have been a serious problem for the photovoltaic industry, a new monorail-tracked robot used for automatic cleaning of solar panel is presented in this paper. To meet the requirement of comprehensive and stable cleaning of PV array, the monorail-tracked pattern of robot is introduced based on the monorail structure technique. The running and striding mechanism are designed for mobility of robot on the solar panels. According to the carrying capacity and water circulation mechanism, a type of self-cleaning device with filtering system is developed. Combined with the computer software and communications technology, the control system is built in this robot, which can realize the functions of autonomous operation, positioning and monitoring. The application of this developed cleaning robot can actualize the Industrialization of automatic cleaning for PV components and have wide market prospect.

Solar effects on communications

International Nuclear Information System (INIS)

Cleveland, F.; Malcolm, W.; Nordell, D.E.; Zirker, J.

1991-01-01

When people involved in the power industry think of Solar Magnetic Disturbances (SMD), they normally consider the potential for disrupting power transmission which results form solar-induced disturbances to the earth's magnetic field known as geomagnetic storms. However, in addition to the disruption of power transmission, solar phenomena can interfere with utility communication systems. Utilities use many different types of communication media, some of which can be affected by various solar phenomena. These include wire-based facilities (metallic cables and power line carrier), radio systems (HF, VHF, UHF mobile radio, microwave networks, and satellite transmissions), and fiber optic systems. This paper reports that the solar flares and other solar phenomena can affect these media through different mechanisms: Radio communications can be disturbed by flare-induced changes in the ionispheric layer of the atmosphere; Cable communications can be disrupted by the flare-induced changes in the magnetosphere which surrounds the earth. These changes, in turn, induce currents in the power equipment that energizes long communications cables; Satellite communications can be disrupted by the flare-induced perturbations of satellite orbits and equipment

Solar wind radiation damage in lunar dust grains and the characteristics of the ancient solar wind

International Nuclear Information System (INIS)

Borg, J.; Chaumont, J.

1980-01-01

Current understanding of the exposure history of lunar dust grains to the ancient solar wind is reviewed, the work being based mostly on a Monte Carlo statistical code, describing the 'gardening' effects of the meteorite bombardment in the lunar regolith, and on analytical models, yielding the lifetimes of the grains against various types of destruction processes. Families of lunar dust grains are identified, and evidence is presented showing that lunar dust grains were not partially shielded from solar wind ions. Results of solar wind simulation experiments are used to interpret the thickness distribution of the amorphous coatings of solar wind radiation-damaged material observed on 1-micron lunar dust grains. It is argued that such distributions reflect the speed distribution of the ancient solar wind as averaged over periods of approximately 5000 years in duration, and that the ancient solar wind is less energetic than the present day solar wind

Comparative study of solar cooling systems with building-integrated solar collectors for use in sub-tropical regions like Hong Kong

International Nuclear Information System (INIS)

Fong, K.F.; Lee, C.K.; Chow, T.T.

2012-01-01

Highlights: ► Performance of building-integrated solar collectors analyzed. ► Comparisons made with solar collectors installed on roof. ► Use of building-integrated solar collectors increased the total primary consumption. ► Reduction in the building load could not compensate drop in solar collector output. ► Building-integrated solar collectors only used when roof space insufficient. -- Abstract: The performance of solar cooling systems with building-integrated (BI) solar collectors was simulated and the results compared with those having the solar collectors installed conventionally on the roof based on the weather data in Hong Kong. Two types of solar collectors and the corresponding cooling systems, namely the flat-plate collectors for absorption refrigeration and the PV panels for DC-driven vapour compression refrigeration, were used in the analysis. It was found that in both cases, the adoption of BI solar collectors resulted in a lower solar fraction (SF) and consequently a higher primary energy consumption even though the zone loads were reduced. The reduction in SF was more pronounced in the peak load season when the solar radiation was nearly parallel to the solar collector surfaces during the daytimes, especially for those facing the south direction. Indeed, there were no outputs from the BI flat-plate collectors facing the south direction between May and July. The more severe deterioration in the system performance with the BI flat-plate type collectors made them technically infeasible in terms of the energy-saving potential. It was concluded that the use of BI solar collectors in solar cooling systems should be restricted only to situations where the availability of the roof was limited or insufficient when applied in sub-tropical regions like Hong Kong.

Development of a compact solar combisystem

DEFF Research Database (Denmark)

Thür, Alexander; Furbo, Simon

2006-01-01

Within the frame of the project REBUS, “Competitive solar heating systems for residential buildings”, which is financed by Nordic Energy Research, a new type of compact solar combisystem with high degree of prefabrication was developed. A hydraulic and control concept was designed with the goal...

Solar Grants Spot Training and Jobs.

Science.gov (United States)

Owen, Walter

1979-01-01

Employment and training in solar installation work is provided by fifteen Solar Utilization/Economic Development and Employment (SUEDE) demonstration projects funded by the United States Departments of Labor and Energy and the Community Services Administration. The article describes the projects and the types of work. (MF)

The influence of solar system oscillation on the variability of the total solar irradiance

Science.gov (United States)

Yndestad, Harald; Solheim, Jan-Erik

2017-02-01

Total solar irradiance (TSI) is the primary quantity of energy that is provided to the Earth. The properties of the TSI variability are critical for understanding the cause of the irradiation variability and its expected influence on climate variations. A deterministic property of TSI variability can provide information about future irradiation variability and expected long-term climate variation, whereas a non-deterministic variability can only explain the past. This study of solar variability is based on an analysis of two TSI data series, one since 1700 A.D. and one since 1000 A.D.; a sunspot data series since 1610 A.D.; and a solar orbit data series from 1000 A.D. The study is based on a wavelet spectrum analysis. First, the TSI data series are transformed into a wavelet spectrum. Then, the wavelet spectrum is transformed into an autocorrelation spectrum to identify stationary, subharmonic and coincidence periods in the TSI variability. The results indicate that the TSI and sunspot data series have periodic cycles that are correlated with the oscillations of the solar position relative to the barycenter of the solar system, which is controlled by gravity force variations from the large planets Jupiter, Saturn, Uranus and Neptune. A possible explanation for solar activity variations is forced oscillations between the large planets and the solar dynamo. We find that a stationary component of the solar variability is controlled by the 12-year Jupiter period and the 84-year Uranus period with subharmonics. For TSI and sunspot variations, we find stationary periods related to the 84-year Uranus period. Deterministic models based on the stationary periods confirm the results through a close relation to known long solar minima since 1000 A.D. and suggest a modern maximum period from 1940 to 2015. The model computes a new Dalton-type sunspot minimum from approximately 2025 to 2050 and a new Dalton-type period TSI minimum from approximately 2040 to 2065.

Spectral mismatch and solar simulator quality factor in advanced LED solar simulators

Science.gov (United States)

Scherff, Maximilian L. D.; Nutter, Jason; Fuss-Kailuweit, Peter; Suthues, Jörn; Brammer, Torsten

2017-08-01

Solar cell simulators based on light emitting diodes (LED) have the potential to achieve a large potential market share in the next years. As advantages they can provide a short and long time stable spectrum, which fits very well to the global AM1.5g reference spectrum. This guarantees correct measurements during the flashes and throughout the light engines’ life span, respectively. Furthermore, a calibration with a solar cell type of different spectral response (SR) as well as the production of solar cells with varying SR in between two calibrations does not affect the correctness of the measurement result. A high quality 21 channel LED solar cell spectrum is compared to former study comprising a standard modified xenon spectrum light source. It is shown, that the spectrum of the 21-channel-LED light source performs best for all examined cases.

Seguidor Solar, optimizando el aprovechamiento de la energía solar ; Solar tracker, optimizing ofimprovementof the solar energy

Directory of Open Access Journals (Sweden)

Noel Machado Toranzo

2015-06-01

Full Text Available En este trabajo se realizó el diseño e implementación de un dispositivo encargado de obtener las coordenadas del Sol en cualquier momento del día, es decir, un seguidor solar a dos ejes por punto luminoso. Este seguidor consta de dos bloques principales: la tarjeta controladora y la parte mecánica. Su diseño se basó en el uso de fotorresistencias, microcontroladores y motores de pasos, el mismo posee altas prestaciones y bajo costo. El prototipo construido es utilizado en las investigaciones de aprovechamiento de la energía solar que se realizan en el Grupo de Energía Renovable Aplicadas (GERA de la Universidad de Oriente, particularmente en los paneles fotovoltaicos y los calentadores de agua. Se realizó una prueba experimental en los laboratorios y en el polígono de dicho grupo y se comprobó que el seguidor solar funciona adecuadamente, cumpliendo con las expectativas deseadas.The design and implementation of a device for obtaining the coordinates of the sun at any time during the day, it means, a solar tracker of type two axis by luminous point is developed in this paper. This tracker consists of two main blocks: the controller board and the mechanical part. The design is based on the use of photoresistences, microcontrollers and stepper motors. The prototype is used on investigations about solar energy developed at the GERA (Grupo de Energía Renovable Aplicada of Universidad de Oriente, particularly in photovoltaic panels and water heaters. An experimental test was conducted in the laboratories and at the site of the group and it was found that the solar tracker is functioning properly, meeting the desired expectations.

DETECTION OF FORMAMIDE, THE SIMPLEST BUT CRUCIAL AMIDE, IN A SOLAR-TYPE PROTOSTAR

International Nuclear Information System (INIS)

Kahane, C.; Ceccarelli, C.; Faure, A.; Caux, E.

2013-01-01

Formamide (NH 2 CHO), the simplest possible amide, has recently been suggested to be a central species in the synthesis of metabolic and genetic molecules, the chemical basis of life. In this Letter, we report the first detection of formamide in a protostar, IRAS 16293–2422, which may be similar to the Sun and solar system progenitor. The data combine spectra from the millimeter and submillimeter TIMASSS survey with recent, more sensitive observations at the IRAM 30 m telescope. With an abundance relative to H 2 of ∼10 –10 , formamide appears as abundant in this solar-type protostar as in the two high-mass star-forming regions, Orion-KL and SgrB2, where this species has previously been detected. Given the largely different UV-illuminated environments of the three sources, the relevance of UV photolysis of interstellar ices in the synthesis of formamide is therefore questionable. Assuming that this species is formed in the gas phase via the neutral-neutral reaction between the radical NH 2 and H 2 CO, we predict an abundance in good agreement with the value derived from our observations. The comparison of the relative abundance [NH 2 CHO]/[H 2 O] in IRAS 16293–2422 and in the coma of the comet Hale-Bopp supports the similarity between interstellar and cometary chemistry. Our results thus suggest that the abundance of some cometary organic volatiles could reflect gas phase rather than grain-surface interstellar chemistry.

Passive solar construction handbook

Energy Technology Data Exchange (ETDEWEB)

Levy, E.; Evans, D.; Gardstein, C.

1981-08-01

Many of the basic elements of passive solar design are reviewed. The unique design constraints presented in passive homes are introduced and many of the salient issues influencing design decisions are described briefly. Passive solar construction is described for each passive system type: direct gain, thermal storage wall, attached sunspace, thermal storage roof, and convective loop. For each system type, important design and construction issues are discussed and case studies illustrating designed and built examples of the system type are presented. Construction details are given and construction and thermal performance information is given for the materials used in collector components, storage components, and control components. Included are glazing materials, framing systems, caulking and sealants, concrete masonry, concrete, brick, shading, reflectors, and insulators. The Load Collector Ratio method for estimating passive system performance is appended, and other analysis methods are briefly summarized. (LEW)

Economical analysis of a solar desalination system

DEFF Research Database (Denmark)

Chen, Ziqian; Wang, Tie-Zhu; He, Xiao-Rong

2012-01-01

Based on the calculation of the single-factor impact values of the parameters of a triple stage tower-type of solar desalination unit by utilizing a single-factor analyzing method, the influences of the cost of solar heating system, the cost of hot water tank, the costs of desalination unit...... and yearly electrical power, the life time of solar desalination unit and the yearly yield of fresh water, on the cost of the fresh water production of the solar desalination unit are studied. It is helpful to do the further investigation on solar desalination systems for reducing the cost of fresh water...

SolarProTeam - Final report; Solar production technology melts architects

Energy Technology Data Exchange (ETDEWEB)

2010-07-01

To this date, no module manufacturing line has been able to produce special designed multiple function modules or Custom Design Solution (hereafter CDS) modules at costs that are anywhere near the costs of standard modules. The goal of this R and D project was to provide the basis for eliminating the multiplication of costs for specialised modules. The purpose of the SolarProTeam R and D project is to form the foundation of special production equipment and production lay-out in order to realise a cost-effective CDS module production line. The main results derive from research and development of: (1) A number of new module designs corresponding to the special demands of end-users. For instance, black shiny modules with high efficiency; long large black modules with in-built thermal absorbers; flexible high voltage lightweight modules for ground water pumping; large area curved colorful modules with for architecturally advanced buildings; a solar tree for power supply placed along roads and in public places. Module designs are reported. (2) A new general concept 'Q-keys' based on a master plan and specially designed modules integrating both very large and medium sized individual solar plants in the environment of the end-user. I.e., in addition to integration with regard to architectural and environment demands, integration with respect to technical demands are met, such as storage, desalination plants, cooling, mini-grids, the general grid, etc. The Q-keys concept emphasizes the financial issue in that the solar plants are competitive with coal generated electricity and stand-alone diesel generation of electricity. (3) Fully automated production equipment and a semi-automatic module production line, which can mass produce advanced multifunctional and/or architecturally integrated modules at a cost effective price. The equipment and production line were inspired by the functional and technological demands of different types of costumer designed modules. Due

Exploring Demand Charge Savings from Commercial Solar

Energy Technology Data Exchange (ETDEWEB)

Darghouth, Naim [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Barbose, Galen [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mills, Andrew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Gagnon, Pieter [National Renewable Energy Lab. (NREL), Golden, CO (United States); Bird, Lori [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-07-31

Commercial retail electricity rates commonly include a demand charge component, based on some measure of the customer’s peak demand. Customer-sited solar PV can potentially reduce demand charges, but the magnitude of these savings can be difficult to predict, given variations in demand charge designs, customer loads, and PV generation profiles. Moreover, depending on the circumstances, demand charges from solar may or may not align well with associated utility cost savings. Lawrence Berkeley National Laboratory (Berkeley Lab) and the National Renewable Energy Laboratory (NREL) are collaborating in a series of studies to understand how solar PV can reduce demand charge levels for a variety of customer types and demand charges designs. Previous work focused on residential customs with solar. This study, instead, focuses on commercial customers and seeks to understand the extent and conditions under which rooftop can solar reduce commercial demand charges. To answer these questions, we simulate demand charge savings for a broad range of commercial customer types, demand charge designs, locations, and PV system characteristics. This particular analysis does not include storage, but a subsequent analysis in this series will evaluate demand charge savings for commercial customers with solar and storage.

Solar Radiation on Mars: Tracking Photovoltaic Array

Science.gov (United States)

Appelbaum, Joseph; Flood, Dennis J.; Crutchik, Marcos

1994-01-01

A photovoltaic power source for surface-based operation on Mars can offer many advantages. Detailed information on solar radiation characteristics on Mars and the insolation on various types of collector surfaces are necessary for effective design of future planned photovoltaic systems. In this article we have presented analytical expressions for solar radiation calculation and solar radiation data for single axis (of various types) and two axis tracking surfaces and compared the insulation to horizontal and inclined surfaces. For clear skies (low atmospheric dust load) tracking surfaces resulted in higher insolation than stationary surfaces, whereas for highly dusty atmospheres, the difference is small. The insolation on the different types of stationary and tracking surfaces depend on latitude, season and optical depth of the atmosphere, and the duration of system operation. These insolations have to be compared for each mission.

Making solar laws work: a study of state solar energy incentives

Energy Technology Data Exchange (ETDEWEB)

Roessner, J.D.

1980-11-01

The results of a research investigation of solar financial and research, demonstration, and development (RD and D) incentive programs in 18 states are summarized. The investigation focuses upon implementation - the organization and administrative processes required to convert a law into a viable program. Eleven financial and 12 RD and D programs were investigated. Results indicate that four conditions are common to successful implementation of both types of incentive programs: the opportunity to use solar energy as a heating source; characteristics of the agency selected to complement the law; involvement of outside groups in program implementation; and the specificity of guidance given to those responsible for implementation. Other conditions specific to the implementation of each type of program are discussed as well as the implications of these findings for state and federal policy makers.

Theoretical studies of solar-pumped lasers

Science.gov (United States)

Harries, W. L.

1983-01-01

Possible types of lasers were surveyed for solar power conversion. The types considered were (1) liquid dye lasers, (2) vapor dye lasers, and (3) nondissociative molecular lasers. These are discussed.

Industrial Silicon Wafer Solar Cells

Directory of Open Access Journals (Sweden)

Dirk-Holger Neuhaus

2007-01-01

Full Text Available In 2006, around 86% of all wafer-based silicon solar cells were produced using screen printing to form the silver front and aluminium rear contacts and chemical vapour deposition to grow silicon nitride as the antireflection coating onto the front surface. This paper reviews this dominant solar cell technology looking into state-of-the-art equipment and corresponding processes for each process step. The main efficiency losses of this type of solar cell are analyzed to demonstrate the future efficiency potential of this technology. In research and development, more various advanced solar cell concepts have demonstrated higher efficiencies. The question which arises is “why are new solar cell concepts not transferred into industrial production more frequently?”. We look into the requirements a new solar cell technology has to fulfill to have an advantage over the current approach. Finally, we give an overview of high-efficiency concepts which have already been transferred into industrial production.

Enhancing the solar still using immersion type water heater productivity and the effect of external cooling fan in winter

International Nuclear Information System (INIS)

Al-Garni, Ahmed Z.

2012-01-01

In the present work an attempt is made to enhance the of double slope solar still productivity by an immersion type water heater using. The effect of using an external fan to cool the glass surface is also examined. Experiments were carried out for winter season in Saudi Arabian climatic conditions at latitude 26 degree N. A solar still with 35 degree glass slope angle is chosen in our study. Since the yield of a solar still is more for low water depths, the water level in the base tank was maintained at 1 cm. The experimental results showed that the productivity increased by a significant 370% when two water heaters each having 500 W capacities was used. When external cooling fan was used the productivity was found to decrease by 4 % and 8% for wind speeds of 7 m/s and 9 m/s respectively. Thermal modeling was also done by the heat and mass transfer relations using, and then numerical simulations were carried out to validate with the experimental results. A good agreement between experimental and numerical results was found. The present study is partial implementation of two patents submitted in this field. (authors)

Asteroseismology of solar-type stars with Kepler: III. Ground-based data

DEFF Research Database (Denmark)

Karoff, Christoffer; Molenda-Żakowicz , J.

2010-01-01

We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler Asteroseis......We report on the ground-based follow-up program of spectroscopic and photometric observations of solar-like asteroseismic targets for the Kepler space mission. These stars constitute a large group of more than a thousand objects which are the subject of an intensive study by the Kepler...

Calibration of solar radiation measuring instruments. Final report

Energy Technology Data Exchange (ETDEWEB)

Bahm, R J; Nakos, J C

1979-11-01

A review of solar radiation measurement of instruments and some types of errors is given; and procedures for calibrating solar radiation measuring instruments are detailed. An appendix contains a description of various agencies who perform calibration of solar instruments and a description of the methods they used at the time this report was prepared. (WHK)

An Economic Analysis of Solar Water & Space Heating.

Science.gov (United States)

Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

Solar system designs for 13 cities were optimized so as to minimize the life cycle cost over the assumed 20-year lifetime of the solar energy systems. A number of major assumptions were made regarding the solar system, type and use of building, financial considerations, and economic environment used in the design optimization. Seven optimum…

Activity pattern and personal exposure to nitrogen dioxide in indoor and outdoor microenvironments.

Science.gov (United States)

Kornartit, C; Sokhi, R S; Burton, M A; Ravindra, Khaiwal

2010-01-01

People are exposed to air pollution from a range of indoor and outdoor sources. Concentrations of nitrogen dioxide (NO(2)), which is hazardous to health, can be significant in both types of environments. This paper reports on the measurement and analysis of indoor and outdoor NO(2) concentrations and their comparison with measured personal exposure in various microenvironments during winter and summer seasons. Furthermore, the relationship between NO(2) personal exposure in various microenvironments and including activities patterns were also studied. Personal, indoor microenvironments and outdoor measurements of NO(2) levels were conducted using Palmes tubes for 60 subjects. The results showed significant differences in indoor and outdoor NO(2) concentrations in winter but not for summer. In winter, indoor NO(2) concentrations were found to be strongly correlated with personal exposure levels. NO(2) concentration in houses using a gas cooker was higher in all rooms than those with an electric cooker during the winter campaign, whereas there was no significant difference noticed in summer. The average NO(2) levels in kitchens with a gas cooker were twice as high as those with an electric cooker, with no significant difference in the summer period. A time-weighted average personal exposure was calculated and compared with measured personal exposures in various indoor microenvironments (e.g. front doors, bedroom, living room and kitchen); including non-smokers, passive smokers and smoker. The estimated results were closely correlated, but showed some underestimation of the measured personal exposures to NO(2) concentrations. Interestingly, for our particular study higher NO(2) personal exposure levels were found during summer (14.0+/-1.5) than winter (9.5+/-2.4).

The Solar Wind from Pseudostreamers and their Environs: Opportunities for Observations with Parker Solar Probe and Solar Orbiter

Science.gov (United States)

Panasenco, O.; Velli, M.; Panasenco, A.; Lionello, R.

2017-12-01

The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona - active regions, solar filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Mid-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on solar wind properties. 1D numerical analysis of pseudostreamers shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at thepseudostreamer base low in the corona. We review and model possible coronal magnetic configurations and solar wind plasma properties at different distances from the solar surface that

Solar Hot Water Heater

Science.gov (United States)

1978-01-01

The solar panels pictured below, mounted on a Moscow, Idaho home, are part of a domestic hot water heating system capable of providing up to 100 percent of home or small business hot water needs. Produced by Lennox Industries Inc., Marshalltown, Iowa, the panels are commercial versions of a collector co-developed by NASA. In an effort to conserve energy, NASA has installed solar collectors at a number of its own facilities and is conducting research to develop the most efficient systems. Lewis Research Center teamed with Honeywell Inc., Minneapolis, Minnesota to develop the flat plate collector shown. Key to the collector's efficiency is black chrome coating on the plate developed for use on spacecraft solar cells, the coating prevents sun heat from "reradiating," or escaping outward. The design proved the most effective heat absorber among 23 different types of collectors evaluated in a Lewis test program. The Lennox solar domestic hot water heating system has three main components: the array of collectors, a "solar module" (blue unit pictured) and a conventional water heater. A fluid-ethylene glycol and water-is circulated through the collectors to absorb solar heat. The fluid is then piped to a double-walled jacket around a water tank within the solar module.

Large Scale Solar Heating

DEFF Research Database (Denmark)

Heller, Alfred

2001-01-01

The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

RIEGER-TYPE PERIODICITY DURING SOLAR CYCLES 14–24: ESTIMATION OF DYNAMO MAGNETIC FIELD STRENGTH IN THE SOLAR INTERIOR

Energy Technology Data Exchange (ETDEWEB)

Gurgenashvili, Eka; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil; Ramishvili, Giorgi; Shergelashvili, Bidzina [Abastumani Astrophysical Observatory at Ilia State University, Tbilisi, Georgia (United States); Oliver, Ramon; Ballester, Jose Luis [Departament de Física, Universitat de les Illes Balears, E-07122, Palma de Mallorca (Spain); Hanslmeier, Arnold [IGAM, Institute of Physics, University of Graz, Universitätsplatz 5, A-8010 Graz (Austria); Poedts, Stefaan, E-mail: teimuraz.zaqarashvili@uni-graz.at [Centre for Mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, Celestijnenlaan 200B, B-3001, Leuven (Belgium)

2016-07-20

Solar activity undergoes a variation over timescales of several months known as Rieger-type periodicity, which usually occurs near maxima of sunspot cycles. An early analysis showed that the periodicity appears only in some cycles and is absent in other cycles. But the appearance/absence during different cycles has not been explained. We performed a wavelet analysis of sunspot data from the Greenwich Royal Observatory and the Royal Observatory of Belgium during cycles 14–24. We found that the Rieger-type periods occur in all cycles, but they are cycle dependent: shorter periods occur during stronger cycles. Our analysis revealed a periodicity of 185–195 days during the weak cycles 14–15 and 24 and a periodicity of 155–165 days during the stronger cycles 16–23. We derived the dispersion relation of the spherical harmonics of the magnetic Rossby waves in the presence of differential rotation and a toroidal magnetic field in the dynamo layer near the base of the convection zone. This showed that the harmonics of fast Rossby waves with m = 1 and n = 4, where m ( n ) indicates the toroidal (poloidal) wavenumbers, perfectly fit with the observed periodicity. The variation of the toroidal field strength from weaker to stronger cycles may lead to the different periods found in those cycles, which explains the observed enigmatic feature of the Rieger-type periodicity. Finally, we used the observed periodicity to estimate the dynamo field strength during cycles 14–24. Our estimations suggest a field strength of ∼40 kG for the stronger cycles and ∼20 kG for the weaker cycles.

Influence of the transition region between p- and n-type polycrystalline silicon passivating contacts on the performance of interdigitated back contact silicon solar cells

Science.gov (United States)

Reichel, Christian; Müller, Ralph; Feldmann, Frank; Richter, Armin; Hermle, Martin; Glunz, Stefan W.

2017-11-01

Passivating contacts based on thin tunneling oxides (SiOx) and n- and p-type semi-crystalline or polycrystalline silicon (poly-Si) enable high passivation quality and low contact resistivity, but the integration of these p+/n emitter and n+/n back surface field junctions into interdigitated back contact silicon solar cells poses a challenge due to high recombination at the transition region from p-type to n-type poly-Si. Here, the transition region was created in different configurations—(a) p+ and n+ poly-Si regions are in direct contact with each other ("pn-junction"), using a local overcompensation (counterdoping) as a self-aligning process, (b) undoped (intrinsic) poly-Si remains between the p+ and n+ poly-Si regions ("pin-junction"), and (c) etched trenches separate the p+ and n+ poly-Si regions ("trench")—in order to investigate the recombination characteristics and the reverse breakdown behavior of these solar cells. Illumination- and injection-dependent quasi-steady state photoluminescence (suns-PL) and open-circuit voltage (suns-Voc) measurements revealed that non-ideal recombination in the space charge regions with high local ideality factors as well as recombination in shunted regions strongly limited the performance of solar cells without a trench. In contrast, solar cells with a trench allowed for open-circuit voltage (Voc) of 720 mV, fill factor of 79.6%, short-circuit current (Jsc) of 41.3 mA/cm2, and a conversion efficiencies (η) of 23.7%, showing that a lowly conducting and highly passivating intermediate layer between the p+ and n+ poly-Si regions is mandatory. Independent of the configuration, no hysteresis was observed upon multiple stresses in reverse direction, indicating a controlled and homogeneously distributed breakdown, but with different breakdown characteristics.

Experimental investigation of solar powered diaphragm and helical pumps

Science.gov (United States)

For several years, many types of solar powered water pumping systems were evaluated, and in this paper, diaphragm and helical solar photovoltaic (PV) powered water pumping systems are discussed. Data were collected on diaphragm and helical pumps which were powered by different solar PV arrays at mul...

Photocatalytic hydrogen production under direct solar light in a CPC based solar reactor: Reactor design and preliminary results

International Nuclear Information System (INIS)

Jing Dengwei; Liu Huan; Zhang Xianghui; Zhao Liang; Guo Liejin

2009-01-01

In despite of so many types of solar reactors designed for solar detoxification purposes, few attempts have been made for photocatalytic hydrogen production, which in our option, is one of the most promising approaches for solar to chemical energy conversion. Addressing both the similarity and dissimilarity for these two processes and by fully considering the special requirements for the latter reaction, a Compound Parabolic Concentrator (CPC) based photocatalytic hydrogen production solar reactor has been designed for the first time. The design and optimization of this CPC based solar reactor has been discussed in detail. Preliminary results demonstrated that efficient photocatalytic hydrogen production under direct solar light can be accomplished by coupling tubular reactors with CPC concentrators. It is anticipated that this first demonstration of concentrator-based solar photocatalytic hydrogen production would draw attention for further studies in this promising direction.

Seminar on the news energy utilization in rural area of April 3 to March 24 , 1980 in Reo, Upper Volta[Energie renouvelable ; Zone rurale ; Gaz biologique ; Energie solaire ; Sechoir solaire]; Seminaire sur l'utilisation des energies nouvelles en zone rurale du 24 mars au3 avril 1980 a Reo, Haute Volta

Energy Technology Data Exchange (ETDEWEB)

NONE

1980-04-15

The access to energy by the populations remains a primary preoccupation for the Government of Upper Volta (currently Burkina Faso). Due to this reason, a seminar on the utilization of renewable energy in rural area has been organized under the sponsorship of the Economic Community of West Africa (CEAO), the Canadian Agency of International Expansion and the Scout Movement. The goal of this seminar was to teach participants of several countries on how to put into practice the use of new sources of energy such as the cooker with closed fire, biological gas, the solar water-heater and the solar drier. The adoption of these new sources of energy by the populations would help mitigate problems of desertification caused by the intensive deforestation in the country. All the participants in this meeting are thus sensitized so that they will be able to positively contribute, along with their community, for a better conservation of the available natural resources. This can be done through the erection of closed fire cookers which can help get two sources of energy. This type of cooker is of easy construction and can be usable only three days after its construction. It helps avoid the loss of energy which has characterized the traditional way of cooking (around 95% of energy loss); this comes to rhyme with consuming less wood while ensuring an output of about 60 to 70%. It was question for the participants in this seminar to be initiated to the installation of gas by following Chinese and Indian models. They have been thus initiated to the realization of technologies of biological gas production throughout mastering the general diagram of the process of discontinuous fermentation. In the same way, they have acquired the know-how on the techniques of installation of the solar-fired heater by solar furnace and the solar drier. These tools help not only save energy but also the solar drier is a conservation tool which allows a bigger storage capacity of dry products and a

Evaluation of solar energy over three dimensional objects

International Nuclear Information System (INIS)

Serposhan, S.; Yaghoubi, M.

2002-01-01

The knowledge of solar irradiation is important in heating and cooling of buildings architectural engineering, various solar energy utilizations, and for any system design exposed to sun radiation. In the present article, simulation is made to predict solar irradiation over any three-dimensional objects. Special consideration is made to evaluate solar radiation intensity distribution over semi-circular roof and domed roofs. For practical applications, hourly and average daily solar radiation distribution for a series of three Heller type huge cooling towers of Fars Power Plant is also determined

Solar-gas systems impact analysis study

Science.gov (United States)

Neill, C. P.; Hahn, E. F.; Loose, J. C.; Poe, T. E.; Hirshberg, A. S.; Haas, S.; Preble, B.; Halpin, J.

1984-07-01

The impacts of solar/gas technologies on gas consumers and on gas utilities were measured separately and compared against the impacts of competing gas and electric systems in four climatic regions of the U.S. A methodology was developed for measuring the benefits or penalties of solar/gas systems on a combined basis for consumers sand distribution companies. It is shown that the combined benefits associated with solar/gas systems are generally greatest when the systems are purchased by customers who would have otherwise chosen high-efficiency electric systems (were solar/gas systems not available in the market place). The role of gas utilities in encouraging consumer acceptance of solar/gas systems was also examined ion a qualitative fashion. A decision framework for analyzing the type and level of utility involvement in solar/gas technologies was developed.

Connectable solar air collectors

Energy Technology Data Exchange (ETDEWEB)

Oestergaard Jensen, S.; Bosanac, M.

2002-02-01

The project has proved that it is possible to manufacture solar air collector panels, which in an easy way can be connected into large collector arrays with integrated ducting without loss of efficiency. The developed connectable solar air collectors are based on the use of matrix absorbers in the form of perforated metal sheets. Three interconnected solar air collectors of the above type - each with an transparent area of approx. 3 m{sup 2} - was tested and compared with parallel tests on two single solar air collectors also with a transparent area of approx. 3 m{sup 2} One of the single solar air collectors has an identical absorber as the connectable solar air collectors while the absorber of the other single solar air collector was a fibre cloth. The efficiency of the three solar air collectors proved to be almost identical in the investigated range of mass flow rates and temperature differences. The solar air collectors further proved to be very efficient - as efficient as the second most efficient solar air collectors tested in the IEA task 19 project Solar Air Systems. Some problems remain although to be solved: the pressure drop across especially the connectable solar air collectors is too high - mainly across the inlets of the solar air collectors. It should, however, be possible to considerably reduce the pressure losses with a more aerodynamic design of the inlet and outlet of the solar air collectors; The connectable solar air collectors are easy connectable but the air tightness of the connections in the present form is not good enough. As leakage leads to lower efficiencies focus should be put on making the connections more air tight without loosing the easiness in connecting the solar air collectors. As a spin off of the project a simple and easy way to determine the efficiency of solar, air collectors for pre-heating of fresh air has been validated. The simple method of determining the efficiency has with success been compared with an advance method

Passive solar energy information user study

Energy Technology Data Exchange (ETDEWEB)

Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

1980-11-01

The results of a series of telephone interviews with groups of users of information on passive solar heating and cooling are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven passive groups respondents are analyzed in this report: Federally Funded Researchers, Manufacturer Representatives, Architects, Builders, Educators, Cooperative Extension Service County Agents, and Homeowners. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

Fabrication and Characterization of a Perovskite-Type Solar Cell with a Substrate Size of 70 mm

Directory of Open Access Journals (Sweden)

Takeo Oku

2015-10-01

Full Text Available A perovskite-type solar cell with a substrate size of 70 mm × 70 mm was fabricated by a simple spin-coating method using a mixed solution. The photovoltaic properties of the TiO2/CH3NH3PbI3-based photovoltaic devices were investigated by current density-voltage characteristic and incident photon to current conversion efficiency measurements. Their short-circuit current densities were almost constant over a large area. The photoconversion efficiency was influenced by the open-circuit voltage, which depended on the distance from the center of the cell.

Parameterization of solar flare dose

International Nuclear Information System (INIS)

Lamarche, A.H.; Poston, J.W.

1996-01-01

A critical aspect of missions to the moon or Mars will be the safety and health of the crew. Radiation in space is a hazard for astronauts, especially high-energy radiation following certain types of solar flares. A solar flare event can be very dangerous if astronauts are not adequately shielded because flares can deliver a very high dose in a short period of time. The goal of this research was to parameterize solar flare dose as a function of time to see if it was possible to predict solar flare occurrence, thus providing a warning time. This would allow astronauts to take corrective action and avoid receiving a dose greater than the recommended limit set by the National Council on Radiation Protection and Measurements (NCRP)

Leasing solar power instead of buying it; Solarpaechter statt Stromkaeufer

Energy Technology Data Exchange (ETDEWEB)

Oppen, Margarete von [Rechtsanwaltssozietaet Geiser und von Oppen, Berlin (Germany)

2012-11-01

Owners of PV systems wo let their tenants or neighbours use their solar power may make bigger profits than from reimbursement for power supply to the public grid. The contribution relates solar power price components to solar module types.

The Art of Doing Good Where Passion Meets Action

CERN Document Server

Bronfman, Charles

2012-01-01

How to turn personal passion into an organization with impact For anyone setting out to change the world, launching a nonprofit venture can be a powerful way to enact change. Whether bringing donated eyeglasses to children who have never seen clearly, revamping inner city schools, or bringing solar cookers to refugee camps, the act of doing good can be life-changing. Yet starting a nonprofit?and running it well?can also pose challenges. The Art of Doing Good is an essential companion for anyone looking to start an organization that makes a real difference. Drawing from their own leadership r

Gettering improvements of minority-carrier lifetimesin solar grade silicon

DEFF Research Database (Denmark)

Osinniy, Viktor; Nylandsted Larsen, Arne; Dahl, Espen

2012-01-01

The minority-carrier lifetime in p-type solar-grade silicon (SoG-Si) produced by Elkem Solar was investigated after different types of heat treatment. Two groups of samples differing by the as-grown lifetimes were exposed to internal and phosphorus gettering using constant and variable temperature...... processes. Optimal heat-treatment parameters for each group of samples were then identified which improved the minority-carrier lifetimes to values higher than the minimum value needed for solar cells. Phosphorus gettering using a variable temperature process enhanced in particular the lifetime within each...