Grid-connected distributed solar power systems

Science.gov (United States)

Moyle, R.; Chernoff, H.; Schweizer, T.

This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

Optimization Study of Small-Scale Solar Membrane Distillation Desalination Systems (s-SMDDS

Directory of Open Access Journals (Sweden)

Hsuan Chang

2014-11-01

Full Text Available Membrane distillation (MD, which can utilize low-grade thermal energy, has been extensively studied for desalination. By incorporating solar thermal energy, the solar membrane distillation desalination system (SMDDS is a potential technology for resolving energy and water resource problems. Small-scale SMDDS (s-SMDDS is an attractive and viable option for the production of fresh water for small communities in remote arid areas. The minimum cost design and operation of s-SMDDS are determined by a systematic method, which involves a pseudo-steady-state approach for equipment sizing and dynamic optimization using overall system mathematical models. Two s-SMDDS employing an air gap membrane distillation module with membrane areas of 11.5 m2 and 23 m2 are analyzed. The lowest water production costs are $5.92/m3 and $5.16/m3 for water production rates of 500 kg/day and 1000 kg/day, respectively. For these two optimal cases, the performance ratios are 0.85 and 0.91; the recovery ratios are 4.07% and 4.57%. The effect of membrane characteristics on the production cost is investigated. For the commercial membrane employed in this study, the increase of the membrane mass transfer coefficient up to two times is beneficial for cost reduction.

The Comparison of Photovoltaic with Small Solar Dish Stirling for Solar Home System 50 W{sub p} in Thailand, Medium Insolation Nature

Energy Technology Data Exchange (ETDEWEB)

Snidvongs, E. S.; Jindaruj, S.

2006-07-01

The Thai government initiated a project entitled Solar Home System which involved the provision of standalone Photovoltaic 50 Wp for houses without transmission lines in remote areas, 300,000 units. These units are provided at a low price with the government supporting half of the cost and the rest paid by the owners in installments. So far, more than 150,000 units have been installed and it is expected that the whole project would be completed by the end of the year 2005. A purpose of this research is to compare the original Thai government's Solar Home PV System with the new 50 Wp Small Solar Thermal Dish Stirling System in terms of their advantages and disadvantages for Thailand. The result of this would serve as a guide for the users to select the most suitable system in terms of price, maintenance, cost, economy, performance, reliability, and efficiency. Such comparison will be presented in the form of descriptive, photographs, statistics, and tables. As for the data involved, part of this is based on active fact such as construction cost, material cost, labor cost, rate of inflation, rate of interest. While some of these derives from the experience of researcher as well as facts and figures from Thai governments publications such as operation and maintenance cost. In addition to that some data are taken from basic experiments conducted either by the various universities and the researcher own laboratory. These include solar insolation, PV data and Stirling engine test with electric heater. And, of course, some data are based on simple estimation and prediction. Thailand is a country of 550 w/m2 with high humidity, soft-land and medium insolation. It locates near the equator at latitude 5 12 N, longitude 96 106 E. By using a parabolic shape satellite dish with solar tracker and a 60 W Four Cylinders gamma type Stirling engine with sinusoidal gear linear link, low offset space, and solid thermal storage to act as buffer between the solar energy and the

Thermal performance of small solar domestic hot water systems in theory, in the laboratory and in practice

DEFF Research Database (Denmark)

Andersen, Elsa

1998-01-01

for poor thermal performances of systems tested in practice are given. Based on theoretical calculations the negative impact on the thermal performance, due to a large number of different parameter variations are given. Recommendations for future developments of small solar domestic hot water systems...

Bringing solar home systems to rural El Salvador: lessons for small NGOs

International Nuclear Information System (INIS)

Balint, Peter J.

2006-01-01

This paper presents the results of case studies examining two independent projects that worked to bring solar home systems (SHSs) to isolated communities in El Salvador. Both projects were implemented by small nongovernmental organizations (NGOs) that did not have prior experience with SHSs. One project was market-based: families were given the opportunity to purchase the systems at going prices. The other was donor-based: residents were provided the equipment in return for their agreement to cooperate in local environmental protection efforts. Results of a comparative analysis support several conclusions. (1) For small NGOs, the promotion of markets is appealing because of the potential for financial sustainability; yet a reliance on markets may also heighten complexity and increase opportunities for failure. (2) In implementation of market-based projects, all stakeholders, including potential consumers, private-sector service providers, and the staff of NGOs acting as project managers, will face pressures to modify and adapt their attitudes and behaviors. (3) Alternative models for small-scale projects that integrate market-based and donor-based design features deserve consideration

K2 & Solar System Science

Science.gov (United States)

Lissauer, Jack

2015-01-01

All of the fields that K2 observes are near the ecliptic plane in order to minimize the spin-up of the spacecraft in response to the effects of solar irradiation. The fields observed by K2 are thus rich in Solar System objects including planets, asteroids and trans-Neptunian objects (TNOs). K2 has already performed observations of Neptune and its large moon Triton, 68 Trojan and Hilda asteroids, 5 TNOs (including Pluto) and Comet C/2013 A1 (Siding Springs). About 10,000 main-belt asteroids that fell into the pixel masks of stars have been serendipitously observed. Observations of small bodies are especially useful for determining rotation periods. Uranus will be observed in a future campaign (C8), as will many more small Solar System bodies. The status of various K2 Solar System studies will be reviewed and placed within the context of our current knowledge of the objects being observed.

Deployable Propulsion and Power Systems for Solar System Exploration

Science.gov (United States)

Johnson, Les; Carr, John

2017-01-01

NASA is developing thin-film based, deployable propulsion, power and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. The Near Earth Asteroid (NEA) Scout reconnaissance mission will demonstrate solar sail propulsion on a 6U CubeSat interplanetary spacecraft and lay the groundwork for their future use in deep space science and exploration missions. Solar sails use sunlight to propel vehicles through space by reflecting solar photons from a large, mirror-like sail made of a lightweight, highly reflective material. This continuous photon pressure provides propellantless thrust, allowing for very high delta V maneuvers on long-duration, deep space exploration. Since reflected light produces thrust, solar sails require no onboard propellant. The Lightweight Integrated Solar Array and Transceiver (LISA-T) is a launch stowed, orbit deployed array on which thin-film photovoltaic and antenna elements are embedded. Inherently, small satellites are limited in surface area, volume, and mass allocation; driving competition between power, communications, and GN&C (guidance navigation and control) subsystems. This restricts payload capability and limits the value of these low-cost satellites. LISA-T is addressing this issue, deploying large-area arrays from a reduced volume and mass envelope - greatly enhancing power generation and communications capabilities of small spacecraft. The NEA Scout mission, funded by NASA's Advanced Exploration Systems Program and managed by NASA MSFC, will use the solar sail as its primary propulsion system, allowing it to survey and image one or more NEA's of interest for possible future human exploration. NEA Scout uses a 6U cubesat (to be provided by NASA's Jet Propulsion Laboratory), an 86 sq m solar sail and will weigh less than 12 kilograms. NEA Scout will be launched on the first flight of the Space Launch System in 2018. Similar in concept

Deployable Propulsion, Power and Communications Systems for Solar System Exploration

Science.gov (United States)

Johnson, L.; Carr, J.; Boyd, D.

2017-01-01

NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication.

solar thermal power systems advanced solar thermal technology project, advanced subsystems development

Science.gov (United States)

1979-01-01

The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities.

Regional Analysis of Aids and Prices for Small-scale Grid-connected Solar Photovoltaic Systems in Spain

International Nuclear Information System (INIS)

Varela, M.; Ramirez, L.; Mora, L.; Sidrach de Cardona, M.

2002-01-01

Electricity production from small solar photovoltaic systems in Spain obtains a premium pnce of 0,36 ε/kWh over the electricity market price or a fix price of 0,40 ε/kWh. The development of these small systems in Spain clearly demonstrates that the established prime is not sufficient in the majority of locations. On the other hand, the prime revision set up by the RD 2818/98, considering the profitability of the renewable installations, demand a regional analysis of small PV systems profitability necessary in Spain. The accomplished results permit to conclude that the amount of the current prime is by itself insufficient to make profitable the small grid-connected PV systems in anywhere of the national geography. To guarantee the profitability of these systems it should be necessary to place the fix price at around 0,93 ε/kWh. However, if the duplication of the current price obtained by these installations was considered, this could ensure the profitability of these small systems in at least the 77% of the land. (Author) 12 refs

Space Solar Power Satellite Systems, Modern Small Satellites, and Space Rectenna

Science.gov (United States)

Bergsrud, Corey Alexis Marvin

Space solar power satellite (SSPS) systems is the concept of placing large satellite into geostationary Earth orbit (GEO) to harvest and convert massive amounts of solar energy into microwave energy, and to transmit the microwaves to a rectifying antenna (rectenna) array on Earth. The rectenna array captures and converts the microwave power into usable power that is injected into the terrestrial electric grid for use. This work approached the microwave power beam as an additional source of power (with solar) for lower orbiting satellites. Assuming the concept of retrodirectivity, a GEO-SSPS antenna array system tracks and delivers microwave power to lower orbiting satellites. The lower orbiting satellites are equipped with a stacked photovoltaic (PV)/rectenna array hybrid power generation unit (HPGU) in order to harvest solar and/or microwave energy for on-board use during orbit. The area, and mass of the PV array part of the HPGU was reduced at about 32% beginning-of-life power in order to achieve the spacecraft power requirements. The HPGU proved to offer a mass decrease in the PGU, and an increase in mission life due to longer living component life of the rectenna array. Moreover, greater mission flexibility is achieved through a track and power delivery concept. To validate the potential advantages offered by a HPGU, a mission concept was presented that utilizes modern small satellites as technology demonstrators. During launch, a smaller power receiving "daughter" satellite sits inside a larger power transmitting "mother" satellite. Once separated from the launch vehicle the daughter satellite is ejected away from the mother satellite, and each satellite deploys its respective power transmitting or power receiving hardware's for experimentation. The concept of close proximity mission operations between the satellites is considered. To validate the technology of the space rectenna array part of the HPGU, six milestones were completed in the design. The first

Solar cooling for small office buildings: Comparison of solar thermal and photovoltaic options for two different European climates

Energy Technology Data Exchange (ETDEWEB)

Hartmann, N. [University of Stuttgart, Institute of Energy Economics and the Rational Use of Energy (IER), Hessbruehlstr. 49a, 70565 Stuttgart (Germany); Glueck, C. [Karlsruhe Institute of Technology (KIT), Institute of Fluid Machinery (FSM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Schmidt, F.P. [Karlsruhe Institute of Technology (KIT), Institute of Fluid Machinery (FSM), Kaiserstr. 12, 76131 Karlsruhe (Germany); Fraunhofer ISE, Heidenhofstr. 2, 79110 Freiburg (Germany)

2011-05-15

We present a comparison of solar thermal and solar electric cooling for a typical small office building exposed to two different European climates (Freiburg and Madrid). The investigation is based on load series for heating and cooling obtained previously from annual building simulations in TRNSYS. A conventional compression chiller is used as the reference system against which the solar options are evaluated with respect to primary energy savings and additional cost. A parametric study on collector and storage size is carried out for the solar thermal system to reach achieve the minimal cost per unit of primary energy saved. The simulated solar electric system consists of the reference system, equipped with a grid connected photovoltaic module, which can be varied in size. For cost comparison of the two systems, the electric grid is assumed to function as a cost-free storage. A method to include macroeconomic effects in the comparison is presented and discussed. Within the system parameters and assumptions used here, the grid coupled PV system leads to lower costs of primary energy savings than the solar thermal system at both locations. The presumed macroeconomic advantages of the solar thermal system, due to the non-usage of energy during peak demand, can be confirmed for Madrid. (author)

Transient simulation of a solar heating system for a small-scale ethanol-water distillation plant: Thermal, environmental and economic performance

International Nuclear Information System (INIS)

Vargas-Bautista, Juan Pablo; García-Cuéllar, Alejandro Javier; Pérez-García, Santiago L.; Rivera-Solorio, Carlos I.

2017-01-01

Highlights: • Thermal simulation of a small solar ethanol distillation plant is performed. • The optimum collector area is obtained for two different thermal collectors types. • Higher solar fraction was found for parabolic trough collectors. • Economic analysis is performed for different scenarios to evaluate feasibility. - Abstract: The thermal, environmental and economic performance of a small-scale ethanol distillation system, where solar energy is used as primary energy source, was studied. Two different concentrations of ethanol at the feed stream (5 wt.% and 10 wt.%) were analysed to obtain a distillate product of 95 wt.% ethanol (hydrous ethanol). Evacuated tube solar collectors (ETC) and parabolic trough collectors (PTC) were considered for the solar heating system. A case of study for a specific geographical place (Monterrey, México) was developed herein to evaluate the solar ethanol distillation system; the results can be extended to other locations, weather conditions and operational parameters. The thermal results from the simulation showed that through an adequate selection of the solar collector area and an appropriate sizing of the different equipment of the solar distillation system, PTC represents a better option where energy savings of 80% and 71% can be achieved for 5 wt.% and 10 wt.% ethanol at the feed stream, respectively. However, the economic feasibility of the solar distillation system is achieved using ETC for a price of hydrous ethanol of 1.75 USD/L and a feed stream of 10 wt.% ethanol, reaching an internal rate of return (IRR) of 18.8% and payback period of 5.2 years. As an important technical result, selected ETC presented advantages over PTC where an average distillate product of 3.6 and 3.4 ml at 95 wt.% ethanol can be obtained per unit of solar energy (kW h) captured per area (m"2) of solar collector using 5 wt.% and 10 wt.% ethanol at the feed stream, respectively (36% more than PTC). The reduction of greenhouse gases (GHG

Deployable Propulsion, Power and Communication Systems for Solar System Exploration

Science.gov (United States)

Johnson, Les; Carr, John A.; Boyd, Darren

2017-01-01

NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that could provide a revolutionary new capability allowing small spacecraft exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, and miniaturized electronics, new mission-level capabilities will be enabled aboard lower-cost small spacecraft instead of their more expensive, traditional counterparts, enabling a new generation of frequent, inexpensive deep space missions. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication. Like their name implies, solar sails 'sail' by reflecting sunlight from a large, lightweight reflective material that resembles the sails of 17th and 18th century ships and modern sloops. Instead of wind, the sail and the ship derive their thrust by reflecting solar photons. Solar sail technology has been discussed in the literature for quite some time, but it is only since 2010 that sails have been proven to work in space. Thin-film photovoltaics are revolutionizing the terrestrial power generation market and have been found to be suitable for medium-term use in the space environment. When mounted on the thin-film substrate, these photovoltaics can be packaged into very small volumes and used to generate significant power for small spacecraft. Finally, embedded antennas are being developed that can be adhered to thin-film substrates to provide lightweight, omnidirectional UHF and X-band coverage, increasing bandwidth or effective communication ranges for small spacecraft. Taken together, they may enable a host of new deep space destinations to be reached by a generation of spacecraft smaller and more capable than ever before.

The solar system in close-up

CERN Document Server

Wilkinson, John

2016-01-01

In response to the new information gained about the Solar System from recent space probes and space telescopes, the experienced science author Dr. John Wilkinson presents the state-of-the art knowledge on the Sun, solar system planets and small solar system objects like comets and asteroids. He also describes space missions like the New Horizon’s space probe that provided never seen before pictures of the Pluto system; the Dawn space probe, having just visited the asteroid Vesta, and the dwarf planet Ceres; and the Rosetta probe inorbit around comet 67P/Churyumov–Gerasimenko that has sent extraordinary and most exciting pictures. Those and a number of other probes are also changing our understanding of the solar system and providing a wealth of new up close photos. This book will cover all these missions and discuss observed surface features of planets and moons like their compositions, geisers, aurorae, lightning phenomena etc. Presenting the fascinating aspects of solar system astronomy this book is a c...

Discovering the Solar System

Science.gov (United States)

Jones, Barrie W.

1999-04-01

Discovering the Solar System Barrie W. Jones The Open University, Milton Keynes, UK Discovering the Solar System is a comprehensive, up-to-date account of the Solar System and of the ways in which the various bodies have been investigated and modelled. The approach is thematic, with sequences of chapters on the interiors of planetary bodies, on their surfaces, and on their atmospheres. Within each sequence there is a chapter on general principles and processes followed by one or two chapters on specific bodies. There is also an introductory chapter, a chapter on the origin of the Solar System, and a chapter on asteroids, comets and meteorites. Liberally illustrated with diagrams, black and white photographs and colour plates, Discovering the Solar System also features: * tables of essential data * question and answers within the text * end of section review questions with answers and comments Discovering the Solar System is essential reading for all undergraduate students for whom astronomy or planetary science are components of their degrees, and for those at a more advanced level approaching the subject for the first time. It will also be of great interest to non-specialists with a keen interest in astronomy. A small amount of scientific knowledge is assumed plus familiarity with basic algebra and graphs. There is no calculus. Praise for this book includes: ".certainly qualifies as an authoritative text. The author clearly has an encyclopedic knowledge of the subject." Meteorics and Planetary Science ".liberally doused with relevant graphs, tables, and black and white figures of good quality." EOS, Transactions of the American Geophysical Union ".one of the best books on the Solar System I have seen. The general accuracy and quality of the content is excellent." Journal of the British Astronomical Association

Solar lanterns or solar home lighting systems - Community preferences in East Timor

Energy Technology Data Exchange (ETDEWEB)

Bond, M.; Aye, Lu; Fuller, R.J. [Renewable Energy and Energy Efficiency Group, Department of Civil and Environmental Engineering, The University of Melbourne, Victoria 3010 (Australia)

2010-05-15

Access to electrification in rural areas of East Timor is extremely limited with as few as 5% of rural households connected to electricity. The government of East Timor intends to increase rural access to electricity significantly in the coming decade. The introduction of small PV systems is envisaged for many households in the most remote areas. Several agencies have piloted the introduction of small solar home systems (SHS) and solar lanterns. In the Railaco sub-district of East Timor, some 1000 households have experience of using either SHS and/or solar lanterns and are in a unique position to indicate a preference regarding these forms of PV lighting technology. This paper reports on a survey of 76 households in Railaco investigating experience with PV lighting systems. Results of the survey indicate a strong preference by users for SHS rather than lanterns. The preference for SHS arose from a range of factors including: a perception of better light quality; ability to illuminate the whole house; reduced risk of damage to the PV equipment; and longer duration of nightly operation. The research indicates that where a single PV lighting system is provided, users are likely to prefer SHS to solar lanterns. (author)

Electrical design for origami solar panels and a small spacecraft test mission

Science.gov (United States)

Drewelow, James; Straub, Jeremy

2017-05-01

Efficient power generation is crucial to the design of spacecraft. Mass, volume, and other limitations prevent the use of traditional spacecraft support structures from being suitable for the size of solar array required for some missions. Folding solar panel / panel array systems, however, present a number of design challenges. This paper considers the electrical design of an origami system. Specifically, it considers how to provide low impedance, durable channels for the generated power and the electrical aspects of the deployment system and procedure. The ability to dynamically reconfigure the electrical configuration of the solar cells is also discussed. Finally, a small satellite test mission to demonstrate the technology is proposed, before concluding.

A novel small dynamic solar thermal desalination plant with a fluid piston converter

International Nuclear Information System (INIS)

Mahkamov, Khamid; Orda, Eugene; Belgasim, Basim; Makhkamova, Irina

2015-01-01

Highlights: • A dynamic solar desalination plant was developed which works cyclically. • It integrates an evacuated tube solar collector and fluid piston converter. • Pressure during desalination process varies with frequency of 2–4 Hz. • The system has a small increase in fresh water yield and provides pumping capacity. • Mathematical modelling provides accurate description of experimental performance. - Abstract: An innovative small dynamic water desalination plant was developed and tested under laboratory conditions. The system is a combination of a heat pipe evacuated tube solar collector, conventional condenser and novel fluid piston converter. Saline water is boiled and turned into vapour in the manifold of the solar collector. A small fraction of the solar energy supplied to the plant is used to drive the fluid piston converter. Oscillations of the fluid piston periodically change the volume and pressure in the plant. For the duration of approximately half of the periodic cycle the pressure in the plant drops below the atmospheric level causing flash boiling of saline water in the manifold of the solar collector. Generated vapour is turned into fresh water in the condenser which is surrounded by a cooling jacket with saline water. The flash boiling effect improves the fresh water production capacity of the plant. Additionally, the fluid piston converter drives a pump which provides lifting of saline water from a well and pumps this through the cooling jacket of the condenser to a saline water storage tank. This tank replenishes saline water in the manifold of the solar collector. Experimental investigations demonstrated the saline water self-circulation capability of the plant and increase in the fresh water production compared to the static mode of operation. Experimental data was also used to calibrate the mathematical model of the plant. Comparison of theoretical and experimental information demonstrates that the model accurately predicts the

Organics and Ices in the Outer Solar System: Connections to the Interstellar Medium

Science.gov (United States)

Pendleton, Y. J.; Cruikshank, D. P.

2017-01-01

The solar nebula, that aggregate of gas and dust that formed the birthplace of the Sun, planets and plethora of small bodies comprising the Solar System, originated in a molecular cloud that is thought to have spawned numerous additional stars, some with their own planets and attendant small bodies. The question of the chemical and physical reprocessing of the original interstellar materials in the solar nebula has challenged both theory and observations. The acquisition and analysis of samples of comet and asteroid solids, and a growing suite of in-situ and close-up analyses of relatively unaltered small Solar System bodies now adds critical new dimensions to the study of the origin and evolution of the early solar nebula. Better understanding the original composition of the material from which our solar nebula formed, and the processing that material experienced, will aid in formulations of chemistry that might occur in other solar systems. While we seek to understand the compositional history of planetary bodies in our own Solar System, we will inevitably learn more about the materials that comprise exoplanets and their surrounding systems.

Origin of Outer Solar System

Science.gov (United States)

Holman, Matthew J.; Lindstrom, David (Technical Monitor)

2005-01-01

Our ongoing research program combines extensive deep and wide-field observations using a variety of observational platforms with numerical studies of the dynamics of small bodies in the outer solar system in order to advance the main scientific goals of the community studying the Kuiper belt and the outer solar system. These include: (1) determining the relative populations of the known classes of KBOs as well as other possible classes; ( 2 ) determining the size distributions or luminosity function of the individual populations or the Kuiper belt as a whole; (3) determining the inclinations distributions of these populations; (4) establishing the radial extent of the Kuiper belt; ( 5 ) measuring and relating the physical properties of different types of KBOs to those of other solar system bodies; and, (6) completing our systematic inventory of the satellites of the outer planets.

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.

Fast electrons in small solar flares

International Nuclear Information System (INIS)

Lin, R.P.

1975-01-01

Because approximately 5-100 keV electrons are frequently accelerated and emitted by the Sun in small flares, it is possible to define a detailed characteristic physical picture of these events. The review summarizes both the direct spacecraft observations of non-relativistic solar electrons, and observations of the X-ray and radio emission generated by these particles at the Sun and in the interplanetary medium. These observations bear on the basic astrophysical process of particle acceleration in tenuous plasmas. It is found that in many small solar flares the approximately 5-100 keV electrons accelerated during flash phase constitute the bulk of the total flare energy. Thus the basic flare mechanism in these flares essentially converts the available flare energy into fast electrons. These electrons may produce the other flare electromagnetic emissions through their interactions with the solar atmosphere. In large proton flares these electrons may provide the energy to eject material from the Sun and to create a shock wave which could then accelerate nuclei and electrons to much higher energies. (Auth.)

Performance analysis of dish solar stirling power system; Stirling engine wo mochiita taiyonetsu hatsuden system no seino yosoku

Energy Technology Data Exchange (ETDEWEB)

Tsuchiya, K; Yamaguchi, I [Meiji University, Tokyo (Japan); Naito, Y; Momose, Y [Aisin Seiki Co. Ltd., Aichi (Japan)

1996-10-27

In order to estimate the performance of the dish solar Stirling power system, matching and control of each component system were studied, and the performance of the 25kWe class power system was estimated on the basis of direct solar radiation measured in Miyako island, Okinawa. Application of a Stirling engine to solar heat power generation is highly effective in spite of its small scale. The total system is composed of a converging system, heat receiver, engine/generator system and control system. As the simulation result, the generator output is nearly proportional to direct solar radiation, and the system efficiency approaches to a certain constant value with an increase in direct solar radiation. As accumulated solar radiation is large, the influence of slope error of the converging mirror is comparatively small. The optimum aperture opening ratio of the heat receiver determined on the basis of mean direct solar radiation (accumulated solar radiation/{Delta}t (simulated operation time of the system)), corresponds to the primary approximation of the opening ratio for a maximum total generated output under variable direct solar radiation. 6 refs., 6 figs., 1 tab.

System design package for SIMS Prototype System 4, solar heating and domestic hot water

Energy Technology Data Exchange (ETDEWEB)

1978-11-01

This report is a collation of documents and drawings that describe a prototype solar heating and hot water system using air type solar energy collection techniques. The system consists of a modular designed prepackaged solar unit containing solar collctors, a rock storage container, blowers, dampers, ducting, air-to-water heat exchanger, DHW preheat tank, piping and system controls. The system was designed to be installed adjacent to a small single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system are packaged for evaluation of the system with inforation sufficient to assemble a similar system. The prepackage solar unit has been installed at the Mississippi Power and Light Company, Training Facilities, Clinton, Mississippi.

Asteroid-comet continuum objects in the solar system.

Science.gov (United States)

Hsieh, Henry H

2017-07-13

In this review presented at the Royal Society meeting, 'Cometary science after Rosetta', I present an overview of studies of small solar system objects that exhibit properties of both asteroids and comets (with a focus on so-called active asteroids). Sometimes referred to as 'transition objects', these bodies are perhaps more appropriately described as 'continuum objects', to reflect the notion that rather than necessarily representing actual transitional evolutionary states between asteroids and comets, they simply belong to the general population of small solar system bodies that happen to exhibit a continuous range of observational, physical and dynamical properties. Continuum objects are intriguing because they possess many of the properties that make classical comets interesting to study (e.g. relatively primitive compositions, ejection of surface and subsurface material into space where it can be more easily studied, and orbital properties that allow us to sample material from distant parts of the solar system that would otherwise be inaccessible), while allowing us to study regions of the solar system that are not sampled by classical comets.This article is part of the themed issue 'Cometary science after Rosetta'. © 2017 The Author(s).

Amino Acid Chemistry as a Link Between Small Solar System Bodies and Carbonaceous Chondrites

Science.gov (United States)

Glavin, Daniel P.; Ehrenfreund, Pascale; Botta, Oliver; Cooper, George; Bada, Jeffrey L.

2000-01-01

Establishing chemical links between meteorites and small solar system bodies, such as comets and asteroids, provides a tool for investigating the processes that occurred during the formation of the solar system. Carbonaceous meteorites are of particular interest, since they may have seeded the early Earth with a variety of prebiotic organic compounds including amino acids, purines and pyrimidines, which are thought to be necessary for the origin of life. Here we report the results of high-performance liquid chromatography (HPLC) based amino acid analyses of the acid-hydrolyzed hot water extracts from pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna and the CM meteorites Murchison and Murray. We found that the CI meteorites Orgueil and Ivuna contained high abundances of beta-alanine and glycine, while only traces of other amino acids like alanine, alpha-amino-n-butryic acid (ABA) and alpha-aminoisobutyric acid (AIB) were detected in these meteorites. Carbon isotopic measurements of beta-alanine and glycine in Orgueil by gas chromatography combustion-isotope ratio mass spectrometry clearly indicate an extraterrestrial origin of these amino acids. The amino acid composition of Orgueil and Ivuna was strikingly different from the CM chondrites Murchison and Murray. The most notable difference was the high relative abundance of B-alanine in Orgueil and Ivuna compared to Murchison and Murray. Furthermore, AIB, which is one of the most abundant amino acids found in Murchison and Murray, was present in only trace amounts in Orgueil and Ivuna. Our amino acid data strongly suggest that the CI meteorites Orgueil and Ivuna came from a different type of parent body than the CM meteorites Murchison and Murray, possibly from an extinct comet. It is generally thought that carbonaceous meteorites are fragments of larger asteroidal bodies delivered via near Earth objects (NEO). Orbital and dynamic studies suggest that both fragments of main belt asteroids

Performance Evaluation of a Small Scale Modular Solar Trigeneration System

Directory of Open Access Journals (Sweden)

Handong Wang

2014-01-01

Full Text Available In order to improve the efficiency of solar thermal power (STP system, a novel modular system combining cooling, heating, and power generation (CCHP is proposed and introduced in this work. This modular CCHP system can simultaneously provide 10 kW electricity, −15~5°C coolant, and 60°C hot water to meet the requirements of cooling, heating, and electricity in a general family or other fields. The flow chart and working process of the modular system are introduced, based on which the energy and exergy efficiencies at the CCHP and STP operation modes are primarily evaluated and discussed. The results show that when the output electricity is constant, the overall efficiencies of energy and exergy of the system operating at the CCHP mode are 9.37 times and 2.62 times as big as those of the system operating at the STP mode, respectively. Thus, the modular solar thermal CCHP system can improve the energy and exergy efficiencies. Furthermore, calculation shows that both the overall energy and exergy efficiencies decrease with increase of inlet vapor temperature at given inlet vapor pressure, but both the efficiencies increase with increase of inlet vapor pressure at given inlet temperature.

Dynamical evolution of small bodies in the Solar System

Science.gov (United States)

Jacobson, Seth A.

2012-05-01

This thesis explores the dynamical evolution of small bodies in the Solar System. It focuses on the asteroid population but parts of the theory can be applied to other systems such as comets or Kuiper Belt objects. Small is a relative term that refers to bodies whose dynamics can be significantly perturbed by non-gravitational forces and tidal torques on timescales less than their lifetimes (for instance the collisional timescale in the Main Belt asteroid population or the sun impact timescale for the near-Earth asteroid population). Non-gravitational torques such as the YORP effect can result in the active endogenous evolution of asteroid systems; something that was not considered more than twenty years ago. This thesis is divided into three independent studies. The first explores the dynamics of a binary systems immediately after formation from rotational fission. The rotational fission hypothesis states that a rotationally torqued asteroid will fission when the centrifugal accelerations across the body exceed gravitational attraction. Asteroids must have very little or no tensile strength for this to occur, and are often referred to as "rubble piles.'' A more complete description of the hypothesis and the ensuing dynamics is provided there. From that study a framework of asteroid evolution is assembled. It is determined that mass ratio is the most important factor for determining the outcome of a rotational fission event. Each observed binary morphology is tied to this evolutionary schema and the relevant timescales are assessed. In the second study, the role of non-gravitational and tidal torques in binary asteroid systems is explored. Understanding the competition between tides and the YORP effect provides insight into the relative abundances of the different binary morphologies and the effect of planetary flybys. The interplay between tides and the BYORP effect creates dramatic evolutionary pathways that lead to interesting end states including stranded

Automated control of a solar microgrid-powered air compressor for use in a small-scale compressed air energy storage system

OpenAIRE

Williams, Joshua N.

2017-01-01

Approved for public release; distribution is unlimited As part of the Office of Naval Research's study of advanced energy technologies, this research examined the development and implementation of a control system for the compression phase of a small-scale compressed air energy storage system, using a solar-powered microgrid to store energy as compressed air for later use. The compression system is composed of numerous commercial-off-the-shelf components wherever possible. All electronic c...

Small space reactor power systems for unmanned solar system exploration missions

International Nuclear Information System (INIS)

Bloomfield, H.S.

1987-12-01

A preliminary feasibility study of the application of small nuclear reactor space power systems to the Mariner Mark II Cassini spacecraft/mission was conducted. The purpose of the study was to identify and assess the technology and performance issues associated with the reactor power system/spacecraft/mission integration. The Cassini mission was selected because study of the Saturn system was identified as a high priority outer planet exploration objective. Reactor power systems applied to this mission were evaluated for two different uses. First, a very small 1 kWe reactor power system was used as an RTG replacement for the nominal spacecraft mission science payload power requirements while still retaining the spacecraft's usual bipropellant chemical propulsion system. The second use of reactor power involved the additional replacement of the chemical propulsion system with a small reactor power system and an electric propulsion system. The study also provides an examination of potential applications for the additional power available for scientific data collection. The reactor power system characteristics utilized in the study were based on a parametric mass model that was developed specifically for these low power applications. The model was generated following a neutronic safety and operational feasibility assessment of six small reactor concepts solicited from U.S. industry. This assessment provided the validation of reactor safety for all mission phases and generatad the reactor mass and dimensional data needed for the system mass model

Solar Systems

Science.gov (United States)

1979-01-01

The solar collectors shown are elements of domestic solar hot water systems produced by Solar One Ltd., Virginia Beach, Virginia. Design of these systems benefited from technical expertise provided Solar One by NASA's Langley Research Center. The company obtained a NASA technical support package describing the d e sign and operation of solar heating equipment in NASA's Tech House, a demonstration project in which aerospace and commercial building technology are combined in an energy- efficient home. Solar One received further assistance through personal contact with Langley solar experts. The company reports that the technical information provided by NASA influenced Solar One's panel design, its selection of a long-life panel coating which increases solar collection efficiency, and the method adopted for protecting solar collectors from freezing conditions.

Hybrid solar-hydraulic electric power supply systems; Sistemas de fornecimento de energia eletrica hibrido solar hidraulico

Energy Technology Data Exchange (ETDEWEB)

Oliveira, Doriana Marinho Novaes; Silva, Selenio Rocha; Alvim Filho, Aymore de Castro [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Centro de Pesquisa e Desenvolvimento em Engenharia Eletrica]. E-mails: doriana@cpdee.ufmg.br; selenios@eee.ufmg.br; aymore@cpdee.ufmg.br; Martinez, Carlos Barreira [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Engenharia Hidraulica e Recursos Hidricos]. E-mail: martinez@cce.ufmg.br

2000-07-01

This work presents a comparative study among the direct solar energy utilization options ,through solar panels, coupled to the frequency inverter. These system store energy through batteries or through a reversible and hybrid solar/hydraulic system, coupled to a rectifier and a frequency inverter. There are two basic configurations for the systems being the first one composed of solar panels linked to a battery system , delivering electric energy through a three phase inverter. The second one is composed of solar panels connected to a small battery system and to a water reservoir that has the goal of operating as a reversible system during at night, or during load peak periods. In this ,it is presented a methodology for the designing and economic analysis, comparing this hybrid alternative, to the inverter plus batteries options. This methodology to the correct Energy Conversion System,which is economically advantageous due to the availability of the region. At the end, it is presented a 'case study' where viability of use , for the hybrid solar/hydraulic system in an isolated area, is verified. (author)

Instability timescale for the inclination instability in the solar system

Science.gov (United States)

Zderic, Alexander; Madigan, Ann-Marie; Fleisig, Jacob

2018-04-01

The gravitational influence of small bodies is often neglected in the study of solar system dynamics. However, this is not always an appropriate assumption. For example, mutual secular torques between low mass particles on eccentric orbits can result in a self-gravity instability (`inclination instability'; Madigan & McCourt 2016). During the instability, inclinations increase exponentially, eccentricities decrease (detachment), and orbits cluster in argument of perihelion. In the solar system, the orbits of the most distant objects show all three of these characteristics (high inclination: Volk & Malhotra (2017), detachment: Delsanti & Jewitt (2006), and argument of perihelion clustering: Trujillo & Sheppard (2014)). The inclination instability is a natural explanation for these phenomena.Unfortunately, full N-body simulations of the solar system are unfeasible (N ≈ O(1012)), and the behavior of the instability depends on N, prohibiting the direct application of lower N simulations. Here we present the instability timescale's functional dependence on N, allowing us to extrapolate our simulation results to that appropriate for the solar system. We show that ~5 MEarth of small icy bodies in the Sedna region is sufficient for the inclination instability to occur in the outer solar system.

Phase 1 of the First Small Power System Experiment (engineering Experiment No. 1). Volume 4: Commercial System Definition. [development and testing of a solar thermal power plant

Science.gov (United States)

Holl, R. J.

1979-01-01

The development and design of a modular solar thermal power system for application in the 1 to 10 MWe range is described. The system is used in remote utility applications, small communities, rural areas, and for industrial uses. The operational reliability, the minimum risk of failure, and the maintenance and repair characteristics are determined and the commercial system design is defined.

Theoretical and experimental study of a small unit for solar desalination using flashing process

International Nuclear Information System (INIS)

Nafey, A. Safwat; Mohamad, M.A.; El-Helaby, S.O.; Sharaf, M.A.

2007-01-01

A small unit for water desalination by solar energy and a flash evaporation process is investigated. The system is built at the Faculty of Petroleum and Mining Engineering at Suez, Egypt. The system consists of a solar water heater (flat plate solar collector) working as a brine heater and a vertical flash unit that is attached with a condenser/preheater unit. In this work, the system is investigated theoretically and experimentally at different real environmental conditions along Julian days of one year (2005). A mathematical model is developed to calculate the productivity of the system under different operating conditions. The BIRD's model for the calculation of solar insolation is used to predict the solar insolation instantaneously. Also, the solar insolation is measured by a highly sensitive digital pyranometer. Comparison between the theoretical and experimental results is performed. The average accumulative productivity of the system in November, December and January ranged between 1.04 to 1.45 kg/day/m 2 . The average summer productivity ranged between 5.44 to 7 kg/day/m 2 in July and August and 4.2 to 5 kg/day/m 2 in June

Theoretical and experimental study of a small unit for solar desalination using flashing process

Energy Technology Data Exchange (ETDEWEB)

Nafey, A. Safwat; El-Helaby, S.O.; Sharaf, M.A. [Department of Engineering Science, Faculty of Petroleum and Mining Engineering, Suez Canal University, Suez 43522 (Egypt); Mohamad, M.A. [Solar Energy Department, National Research Center, Cairo (Egypt)

2007-02-15

A small unit for water desalination by solar energy and a flash evaporation process is investigated. The system is built at the Faculty of Petroleum and Mining Engineering at Suez, Egypt. The system consists of a solar water heater (flat plate solar collector) working as a brine heater and a vertical flash unit that is attached with a condenser/preheater unit. In this work, the system is investigated theoretically and experimentally at different real environmental conditions along Julian days of one year (2005). A mathematical model is developed to calculate the productivity of the system under different operating conditions. The BIRD's model for the calculation of solar insolation is used to predict the solar insolation instantaneously. Also, the solar insolation is measured by a highly sensitive digital pyranometer. Comparison between the theoretical and experimental results is performed. The average accumulative productivity of the system in November, December and January ranged between 1.04 to 1.45 kg/day/m{sup 2}. The average summer productivity ranged between 5.44 to 7 kg/day/m{sup 2} in July and August and 4.2 to 5 kg/day/m{sup 2} in June. (author)

New solar telescope in Big Bear: evidence for super-diffusivity and small-scale solar dynamos?

International Nuclear Information System (INIS)

Goode, Philip R; Abramenko, Valentyna; Yurchyshyn, Vasyl

2012-01-01

The 1.6 m clear aperture New Solar Telescope (NST) in Big Bear Solar Observatory (BBSO) is now providing the highest resolution solar data ever. These data have revealed surprises about the Sun on small-scales including the observation that bright points (BPs), which can be used as proxies for the intense, compact magnetic elements that are apparent in photospheric intergranular lanes. The BPs are ever more numerous on ever smaller spatial scales as though there were no limit to how small the BPs can be. Here we discuss high resolution NST data on BPs that provide support for the ideas that a turbulent regime of super-diffusivity dominates in the quiet Sun, and there are local dynamos operating near the solar surface. (comment)

Heat engine development for solar thermal power systems

Science.gov (United States)

Pham, H. Q.; Jaffe, L. D.

The parabolic dish solar collector systems for converting sunlight to electrical power through a heat engine will, require a small heat engine of high performance long lifetime to be competitive with conventional power systems. The most promising engine candidates are Stirling, high temperature Brayton, and combined cycle. Engines available in the current market today do not meet these requirements. The development of Stirling and high temperature Brayton for automotive applications was studied which utilizes much of the technology developed in this automotive program for solar power engines. The technical status of the engine candidates is reviewed and the components that may additional development to meet solar thermal system requirements are identified.

Modeling the small-scale dish-mounted solar thermal Brayton cycle

Science.gov (United States)

Le Roux, Willem G.; Meyer, Josua P.

2016-05-01

The small-scale dish-mounted solar thermal Brayton cycle (STBC) makes use of a sun-tracking dish reflector, solar receiver, recuperator and micro-turbine to generate power in the range of 1-20 kW. The modeling of such a system, using a turbocharger as micro-turbine, is required so that optimisation and further development of an experimental setup can be done. As a validation, an analytical model of the small-scale STBC in Matlab, where the net power output is determined from an exergy analysis, is compared with Flownex, an integrated systems CFD code. A 4.8 m diameter parabolic dish with open-cavity tubular receiver and plate-type counterflow recuperator is considered, based on previous work. A dish optical error of 10 mrad, a tracking error of 1° and a receiver aperture area of 0.25 m × 0.25 m are considered. Since the recuperator operates at a very high average temperature, the recuperator is modeled using an updated ɛ-NTU method which takes heat loss to the environment into consideration. Compressor and turbine maps from standard off-the-shelf Garrett turbochargers are used. The results show that for the calculation of the steady-state temperatures and pressures, there is good comparison between the Matlab and Flownex results (within 8%) except for the recuperator outlet temperature, which is due to the use of different ɛ-NTU methods. With the use of Matlab and Flownex, it is shown that the small-scale open STBC with an existing off-the-shelf turbocharger could generate a positive net power output with solar-to-mechanical efficiency of up to 12%, with much room for improvement.

System design package for SIMS prototype system 4, solar heating and domestic hot water

Science.gov (United States)

1978-01-01

The system consisted of a modular designed prepackaged solar unit, containing solar collectors, a rock storage container, blowers, dampers, ducting, air-to-water heat exchanger, DHW preheat tank, piping, and system controls. The system was designed to be installed adjacent to a small single family dwelling. The description, performance specification, subsystem drawings, verification plan/procedure, and hazard analysis of the system were packaged for evaluation.

THE SUN'S SMALL-SCALE MAGNETIC ELEMENTS IN SOLAR CYCLE 23

International Nuclear Information System (INIS)

Jin, C. L.; Wang, J. X.; Song, Q.; Zhao, H.

2011-01-01

With the unique database from the Michelson Doppler Imager on board the Solar and Heliospheric Observatory in an interval embodying solar cycle 23, the cyclic behavior of solar small-scale magnetic elements is studied. More than 13 million small-scale magnetic elements are selected, and the following results are found. (1) The quiet regions dominated the Sun's magnetic flux for about 8 years in the 12.25 year duration of cycle 23. They contributed (0.94-1.44) x10 23 Mx flux to the Sun from the solar minimum to maximum. The monthly average magnetic flux of the quiet regions is 1.12 times that of the active regions in the cycle. (2) The ratio of quiet region flux to that of the total Sun equally characterizes the course of a solar cycle. The 6 month running average flux ratio of the quiet regions was larger than 90.0% for 28 continuous months from July 2007 to October 2009, which very well characterizes the grand solar minima of cycles 23-24. (3) From the small to the large end of the flux spectrum, the variations of numbers and total flux of the network elements show no correlation, anti-correlation, and correlation with sunspots, respectively. The anti-correlated elements, covering the flux of (2.9-32.0)x10 18 Mx, occupy 77.2% of the total element number and 37.4% of the quiet-Sun flux. These results provide insight into the reason for anti-correlations of small-scale magnetic activity during the solar cycle.

TIME DISTRIBUTIONS OF LARGE AND SMALL SUNSPOT GROUPS OVER FOUR SOLAR CYCLES

International Nuclear Information System (INIS)

Kilcik, A.; Yurchyshyn, V. B.; Abramenko, V.; Goode, P. R.; Cao, W.; Ozguc, A.; Rozelot, J. P.

2011-01-01

Here we analyze solar activity by focusing on time variations of the number of sunspot groups (SGs) as a function of their modified Zurich class. We analyzed data for solar cycles 20-23 by using Rome (cycles 20 and 21) and Learmonth Solar Observatory (cycles 22 and 23) SG numbers. All SGs recorded during these time intervals were separated into two groups. The first group includes small SGs (A, B, C, H, and J classes by Zurich classification), and the second group consists of large SGs (D, E, F, and G classes). We then calculated small and large SG numbers from their daily mean numbers as observed on the solar disk during a given month. We report that the time variations of small and large SG numbers are asymmetric except for solar cycle 22. In general, large SG numbers appear to reach their maximum in the middle of the solar cycle (phases 0.45-0.5), while the international sunspot numbers and the small SG numbers generally peak much earlier (solar cycle phases 0.29-0.35). Moreover, the 10.7 cm solar radio flux, the facular area, and the maximum coronal mass ejection speed show better agreement with the large SG numbers than they do with the small SG numbers. Our results suggest that the large SG numbers are more likely to shed light on solar activity and its geophysical implications. Our findings may also influence our understanding of long-term variations of the total solar irradiance, which is thought to be an important factor in the Sun-Earth climate relationship.

Design and Characterization of a Small-Scale Solar Sail Prototype by Integrating NiTi SMA and Carbon Fibre Composite

Directory of Open Access Journals (Sweden)

Girolamo Costanza

2017-01-01

Full Text Available Solar sails are propellantless systems where the propulsive force is given by the momentum exchange of reflecting photons. In this study, a self-deploying system based on NiTi shape memory wires and sheets has been designed and manufactured. A small-scale prototype of solar sail with carbon fibre loom has been developed. Different configurations have been tested to optimize material and structure design of the small-scale solar sail. In particular the attention has been focused on the surface/weight ratio and the deployment of the solar sail. By reducing weight and enlarging the surface, it is possible to obtain high values of characteristic acceleration that is one of the main parameters for a successful use of the solar sail as propulsion system. Thanks to the use of shape memory alloys for self-actuation of the system, complexity of the structure itself decreases. Moreover, sail deployment is simpler.

Efficient and Reliable Solar Panels for Small CubeSat Picosatellites

Directory of Open Access Journals (Sweden)

Ivo Vertat

2014-01-01

Full Text Available CubeSat picosatellites have a limited area of walls for solar cells assembling and the available area has to be effectively shared with other parts, such as planar antennas, optical sensors, camera lens, and access port. With standard size of solar cell strings, it is not possible to construct a reliable solar panel for CubeSat with redundant strings interconnection. Typical solar panels for CubeSat consist of two solar cell strings serially wired with no redundancy in case of solar string failure. The loss of electric energy from one solar panel can cause a serious problem for most picosatellites due to minimum margin in the blueprints of the picosatellite subsystem power budget. In this paper, we propose a new architecture of solar panels for PilsenCUBE CubeSat with a high level of redundancy in the case of solar string failure or following switched power regulator failure. Our solar panels use a high efficiency triple junction GaInP2/GaAs/Ge in the form of small triangle strings from the Spectrolab Company. A suitable technology for precise solar cell assembling is also discussed, because CubeSat picosatellites are usually developed by small teams with limited access to high-end facilities.

Solar Energy Systems for Ohioan Residential Homeowners

Science.gov (United States)

Luckett, Rickey D.

Dwindling nonrenewable energy resources and rising energy costs have forced the United States to develop alternative renewable energy sources. The United States' solar energy industry has seen an upsurge in recent years, and photovoltaic holds considerable promise as a renewable energy technology. The purpose of this case study was to explore homeowner's awareness of the benefits of solar energy. Disruptive-innovation theory was used to explore marketing strategies for conveying information to homeowners about access to new solar energy products and services. Twenty residential homeowners were interviewed face-to-face to explore (a) perceived benefits of solar energy in their county in Ohio, and (b) perceptions on the rationale behind the marketing strategy of solar energy systems sold for residential use. The study findings used inductive analyses and coding interpretation to explore the participants' responses that revealed 3 themes: the existence of environmental benefits for using solar energy systems, the expensive cost of equipment associated with government incentives, and the lack of marketing information that is available for consumer use. The implications for positive social change include the potential to enable corporate leaders, small business owners, and entrepreneurs to develop marketing strategies for renewable energy systems. These strategies may promote use of solar energy systems as a clean, renewable, and affordable alternative electricity energy source for the 21st century.

An innovative deployable solar panel system for Cubesats

Science.gov (United States)

Santoni, Fabio; Piergentili, Fabrizio; Donati, Serena; Perelli, Massimo; Negri, Andrea; Marino, Michele

2014-02-01

One of the main Cubesat bus limitations is the available on-board power. The maximum power obtained using body mounted solar panels and advanced triple junction solar cells on a triple unit Cubesat is typically less than 10 W. The Cubesat performance and the mission scenario opened to these small satellite systems could be greatly enhanced by an increase of the available power. This paper describes the design and realization of a modular deployable solar panel system for Cubesats, consisting of a modular hinge and spring system that can be potentially used on-board single (1U), double(2U), triple (3U) and six units (6U) Cubesats. The size of each solar panels is the size of a lateral Cubesat surface. The system developed is the basis for a SADA (Solar Array Drive Assembly), in which a maneuvering capability is added to the deployed solar array in order to follow the apparent motion of the sun. The system design trade-off is discussed, comparing different deployment concepts and architectures, leading to the final selection for the modular design. A prototype of the system has been realized for a 3U Cubesat, consisting of two deployable solar panel systems, made of three solar panels each, for a total of six deployed solar panels. The deployment system is based on a plastic fiber wire and thermal cutters, guaranteeing a suitable level of reliability. A test-bed for the solar panel deployment testing has been developed, supporting the solar array during deployment reproducing the dynamical situation in orbit. The results of the deployment system testing are discussed, including the design and realization of the test-bed, the mechanical stress given to the solar cells by the deployment accelerations and the overall system performance. The maximum power delivered by the system is about 50.4 W BOL, greatly enhancing the present Cubesat solar array performance.

Transient flows of the solar wind associated with small-scale solar activity in solar minimum

Science.gov (United States)

Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

Solar engine system

International Nuclear Information System (INIS)

Tan, K.K.; Bahrom Sanugi; Chen, L.C.; Chong, K.K.; Jasmy Yunus; Kannan, K.S.; Lim, B.H.; Noriah Bidin; Omar Aliman; Sahar Salehan; Sheikh Ab Rezan Sheikh A H; Tam, C.M.; Chen, Y.T.

2001-01-01

This paper reports the revolutionary solar engine system in Universiti Teknologi Malaysia (UTM). The solar engine is a single cylinder stirling engine driven by solar thermal energy. A first prototype solar engine has been built and demonstrated. A new-concept non-imaging focusing heliostat and a recently invented optical receiver are used in the demonstration. Second generation of prototype solar engine is described briefly. In this paper, the solar engine system development is reported. Measurement for the first prototype engine speed, temperature and specifications are presented. The benefits and potential applications for the future solar engine system, especially for the electricity generating aspect are discussed. (Author)

Investigations on physics of planetary atmospheres and small bodies of the Solar system, extrasolar planets and disk structures around the stars

Science.gov (United States)

Vidmachenko, A. P.; Delets, O. S.; Dlugach, J. M.; Zakhozhay, O. V.; Kostogryz, N. M.; Krushevska, V. M.; Kuznyetsova, Y. G.; Morozhenko, O. V.; Nevodovskyi, P. V.; Ovsak, O. S.; Rozenbush, O. E.; Romanyuk, Ya. O.; Shavlovskiy, V. I.; Yanovitskij, E. G.

2015-12-01

The history and main becoming stages of Planetary system physics Department of the Main astronomical observatory of National academy of Sciences of Ukraine are considered. Fundamental subjects of department researches and science achievements of employees are presented. Fields of theoretical and experimental researches are Solar system planets and their satellites; vertical structures of planet atmospheres; radiative transfer in planet atmospheres; exoplanet systems of Milky Way; stars having disc structures; astronomical engineering. Employees of the department carry out spectral, photometrical and polarimetrical observations of Solar system planets, exoplanet systems and stars with disc structures. 1. From the history of department 2. The main directions of department research 3. Scientific instrumentation 4. Telescopes and observation stations 5. Theoretical studies 6. The results of observations of planets and small Solar system bodies and their interpretation 7. The study of exoplanets around the stars of our galaxy 8. Spectral energy distribution of fragmenting protostellar disks 9. Cooperation with the National Technical University of Ukraine (KPI) and National University of Ukraine "Lviv Polytechnic" to study the impact of stratospheric aerosol changes on weather and climate of the Earth 10. International relations. Scientific and organizational work. Scientific conferences, congresses, symposia 11. The main achievements of the department 12. Current researches 13. Anniversaries and awards

A review of sustainable solar irrigation systems for Sub-Saharan Africa

OpenAIRE

Mohammed Wazed, S.; Hughes, B.R.; O’Connor, D.; Kaiser Calautit, J.

2018-01-01

This investigation focused on the research undertaken on solar photovoltaic (PV) and solar thermal technologies for pumping water generally for irrigation of remote rural farms specifically considering the Sub-Saharan African region. Solar PV systems have been researched extensively for irrigation purposes due to the rise in Oil prices and the upscaling in commercialisation of PV technology. Based on the literature the most effective PV system is presented for the irrigation of a small scare ...

A review of large-scale solar heating systems in Europe

International Nuclear Information System (INIS)

Fisch, M.N.; Guigas, M.; Dalenback, J.O.

1998-01-01

Large-scale solar applications benefit from the effect of scale. Compared to small solar domestic hot water (DHW) systems for single-family houses, the solar heat cost can be cut at least in third. The most interesting projects for replacing fossil fuels and the reduction of CO 2 -emissions are solar systems with seasonal storage in combination with gas or biomass boilers. In the framework of the EU-APAS project Large-scale Solar Heating Systems, thirteen existing plants in six European countries have been evaluated. lie yearly solar gains of the systems are between 300 and 550 kWh per m 2 collector area. The investment cost of solar plants with short-term storage varies from 300 up to 600 ECU per m 2 . Systems with seasonal storage show investment costs twice as high. Results of studies concerning the market potential for solar heating plants, taking new collector concepts and industrial production into account, are presented. Site specific studies and predesign of large-scale solar heating plants in six European countries for housing developments show a 50% cost reduction compared to existing projects. The cost-benefit-ratio for the planned systems with long-term storage is between 0.7 and 1.5 ECU per kWh per year. (author)

Effectiveness of pavement-solar energy system – An experimental study

International Nuclear Information System (INIS)

Zhou, Zhihua; Wang, Xiaojuan; Zhang, Xiaoyan; Chen, Guanyi; Zuo, Jian; Pullen, Stephen

2015-01-01

Highlights: • We built a small-scale pilot project of pavement-solar energy utilization. • Design an automatic monitoring system to record the operating data. • The average heat absorptivity of pavement-solar energy is 37%. • The average thermal storage effectiveness of the system is 17%. - Abstract: A small-scale pilot project was built for the pavement-solar energy utilization in this paper. An automatic data acquisition system was designed to measure the effectiveness of the pavement solar energy system based on the operation data of 24 h a day in both summer and winter. Through 69 days (1656 h) of operation in summer, 2821 kW h of heat energy were stored in soil underground. In the transitional season, 4598 kW h of heat energy were taken out from soil during 104 days (2496 h) of operation in winter. The analysis showed that in summer, solar heat collection of asphalt pavement could effectively reduce 7 °C of its temperature. Under conditions of natural radiation, the average heat absorptivity of pavement was 37% and the average thermal storage effectiveness of the system was 17%. The electrical energy consumed by the system is only 11% of stored heat. During the winter, the asphalt pavement absorbs heat from underground soil which effectively increases its temperature, cutting 32% days of surface temperature below the freezing point. This not only save the energy for ice/snow removal but also mitigate associated safety risks

Spacewatch Survey of the Solar System

Science.gov (United States)

McMillan, Robert S.

2000-01-01

The purpose of the Spacewatch project is to explore the various populations of small objects throughout the solar system. Statistics on all classes of small bodies are needed to infer their physical and dynamical evolution. More Earth Approachers need to be found to assess the impact hazard. (We have adopted the term "Earth Approacher", EA, to include all those asteroids, nuclei of extinct short period comets, and short period comets that can approach close to Earth. The adjective "near" carries potential confusion, as we have found in communicating with the media, that the objects are always near Earth, following it like a cloud.) Persistent and voluminous accumulation of astrometry of incidentally observed main belt asteroids MBAs will eventually permit the Minor Planet Center (MPQ to determine the orbits of large numbers (tens of thousands) of asteroids. Such a large body of information will ultimately allow better resolution of orbit classes and the determinations of luminosity functions of the various classes, Comet and asteroid recoveries are essential services to planetary astronomy. Statistics of objects in the outer solar system (Centaurs, scattered-disk objects, and Trans-Neptunian Objects; TNOs) ultimately will tell part of the story of solar system evolution. Spacewatch led the development of sky surveying by electronic means and has acted as a responsible interface to the media and general public on this discipline and on the issue of the hazard from impacts by asteroids and comets.

Fiscal 1976 Sunshine Project result report. Research on solar energy utilization systems (solar heat power generation); 1976 nendo taiyo energy riyo system chosa kenkyu seika hokokusho. Taiyonetsu hatsuden

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-03-01

Research was made on solar heat power generation following last fiscal year, as a part of solar energy utilization technologies. In this fiscal year, in particular, research was made on the following: selection of suitable sites for solar heat power plants in Japan, estimation of expected power supply, positioning of a solar heat power system among future power systems, operation policy of solar heat power systems, survey on suitable sites for the 1,000kW pilot power plant, operation characteristics of the small test plant, design of the 1,000kW pilot power plant, test methods and facilities for every element equipment of solar heat power systems, an environmental test method for mostly solar collectors, and the profitability of solar heat power systems. Optimum operation temperature levels were nearly 350 degrees C for distributed systems and nearly 400 degrees C for centralized ones. The distributed system is profitable in a unit capacity range less than 5-10MWe, while the centralized system is profitable in a range over 10MWe. Under some assumptions, the power cost of solar heat power systems was estimated to be 20-30yen/kWH. (NEDO)

FY 1995 report on the results of the investigational study on the technology development for the commercialization of solar systems for industrial use, etc. - Investigational study on the solar system. Investigational study on a solar heat utilization system; 1995 nendo sangyoyonado solar system jitsuyoka gijutsu kaihatsu seika hokokusho. Solar system no chosa kenkyu (taiyonetsu riyo system ni kansuru chosa kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

This survey clarifies the present situation of the solar heat utilization technology mostly for industrial use, makes a concrete concept of solar heat utilization clear, and extracts items of the technology development and evaluates sociality, economical efficiency, etc. It aims at working out a program for the future technology development. The following proposals were made: 1) technology development program; 2) simulation soft development program; 3) experimental field of the solar heat utilization technology. In 1), concepts of technology development are 'medical use boiling pasteurization,' 'temperature increase in the metal surface treatment process,' 'water purification using photo-catalyst,' 'distributed small power system,' and 'waste water treatment using bio-technology.' In 2), cost reduction is needed for commercialization/merchandising of technology, and therefore, the development of simulation software is studied. In 3), as the experimental field from commercial/residential use system to industrial use system, an large-scale and systematical experimental field is proposed where all that can be substituted for by solar energy among the energies required for the urban function are used. By this, the solar heat utilization system gets accustomed to the people, increases the reliability, and clearly leads to the course to the next stage of the R and D. (NEDO)

FY 1995 report on the results of the investigational study on the technology development for the commercialization of solar systems for industrial use, etc. - Investigational study on the solar system. Investigational study on a solar heat utilization system; 1995 nendo sangyoyonado solar system jitsuyoka gijutsu kaihatsu seika hokokusho. Solar system no chosa kenkyu (taiyonetsu riyo system ni kansuru chosa kenkyu)

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

This survey clarifies the present situation of the solar heat utilization technology mostly for industrial use, makes a concrete concept of solar heat utilization clear, and extracts items of the technology development and evaluates sociality, economical efficiency, etc. It aims at working out a program for the future technology development. The following proposals were made: 1) technology development program; 2) simulation soft development program; 3) experimental field of the solar heat utilization technology. In 1), concepts of technology development are 'medical use boiling pasteurization,' 'temperature increase in the metal surface treatment process,' 'water purification using photo-catalyst,' 'distributed small power system,' and 'waste water treatment using bio-technology.' In 2), cost reduction is needed for commercialization/merchandising of technology, and therefore, the development of simulation software is studied. In 3), as the experimental field from commercial/residential use system to industrial use system, an large-scale and systematical experimental field is proposed where all that can be substituted for by solar energy among the energies required for the urban function are used. By this, the solar heat utilization system gets accustomed to the people, increases the reliability, and clearly leads to the course to the next stage of the R and D. (NEDO)

Evaluation small scale, grid connected wind and solar distributed generation systems in Jordan

International Nuclear Information System (INIS)

Naji, G. J.; Tahboub, K. K.; Jalham, I. S.

2011-01-01

In this paper, the potential of utilizing wind and solar Private Distributed Generation (PDG) for utility interactive systems is investigated for 11 selected stations (sites) in Jordan. Six customer categories are considered: residential, office, commercial mall, school, hospital and hotel. The main goal of this study was to evaluate the potential of utilizing different grid connected PDG under different conditions such as their location, size, served building category, number of people who share and own the equipment and system type whether wind, solar or hybrid based. It was found that solar systems are still not attractive for all location due to their associated high cost, while wind systems would vary widely depending on the customer category, location and the size of the equipment. Based on the Benefit to Cost ratio criterion, the most attractive sites for installing wind PDGS for residential communities are Ras Muneef, Mafraq, Aqaba, Irbid and H5, while it doesn't seem attractive at Amman,Shoubak, Ghor Essafi, Deir Alla, Maan and H4. On the other hand, the wind on-grid PDGS is very attractive at Ras Muneef, mafraq and Aqaba for commercial buildings, less attractive at H5 and irbid, while it's not attractive at the other sites. The attraction for hybrid PDG systems is closer to those of wind systems alone. (authors).

Dimensioning of Solar Thermal Systems for Multi-Family Buildings in Lithuania: an Optimisation Study

OpenAIRE

Valančius, Rokas; Jurelionis, Andrius; Vaičiūnas, Juozas; Perednis, Eugenijus

2017-01-01

Small-scale solar thermal domestic hot water (DHW) systems in Lithuania can produce up to 523 kWh per year per one square meter of solar collector area. It is therefore one of the most common solar thermal applications in the country with the expected payback period of approximately 10 years. However, the number of solar water heating systems (SWH) installed in the renovated multi-family buildings is quite limited. On the other hand, the potential of integrating solar thermal systems in these...

Light incoupling in small molecule organic solar cells

Energy Technology Data Exchange (ETDEWEB)

Allinger, Nikola; Meiss, Jan; Riede, Moritz; Leo, Karl [Institut fuer Angewandte Photophysik, Technische Universitaet Dresden, 01069 Dresden (Germany); Gnehr, Wolf-Michael [Heliatek GmbH, Liebigstrasse 26, 01187 Dresden (Germany)

2008-07-01

Light incoupling is an essential topic for optimization of organic solar cells. In our group, we examine light incoupling of different kinds of transparent contacting materials as well as external dielectric coatings, using optical simulation of thin film systems and experimental methods. Thin films of small molecules are prepared by thermal evaporation in a multi-chamber UHV system. Complex refraction indices of various materials are calculated from reflection and transmission measurements of monolayers. For modelling of optical properties of thin film systems, we developed a numerical simulation program based on the transfer matrix method. The cell structures investigated consist of nanolayers of small molecules, using ZnPc/C60 as an acceptor-donor heterojunction. As contact materials, we compare the expensive standard material indium tin oxide (ITO) with more cost-efficient alternatives like thin Ag layers or spin-coated layers of the polymer PEDOT:PSS, and discuss the resulting cell properties. Additional dielectric layers of varying materials, like tris(8-hydroxy-quinolinate)-aluminum (Alq3) or N,N'-tetrakis(4-methoxyphenyl)-benzidine (MeO-TPD), are deposited on top of the stack and their influence on cell efficiencies is investigated.

Solar tracking system

Science.gov (United States)

Okandan, Murat; Nielson, Gregory N.

2016-07-12

Solar tracking systems, as well as methods of using such solar tracking systems, are disclosed. More particularly, embodiments of the solar tracking systems include lateral supports horizontally positioned between uprights to support photovoltaic modules. The lateral supports may be raised and lowered along the uprights or translated to cause the photovoltaic modules to track the moving sun.

Long-Lived In-Situ Solar System Explorer (LLISSE)

Science.gov (United States)

Kremic, Tibor; Hunter, Gary; Rock, Jennifer

2017-01-01

This presentation provides an update on development of the Long-Lived In-situ Solar System Explorer (LLISSE). LLISSE is a small probe being developed to provide long-term measurements of simple but important scientific parameters from the surface of Venus. High level summary of recent activities and progress is provided. LLISSE is a small and completely independent probe for Venus surface applications

Development of a Solar System Concept Inventory

Science.gov (United States)

Hornstein, Seth D.; Duncan, D.; S, C. A. T.

2009-01-01

Concept inventories can provide useful insight into students’ understanding of key physical concepts. Knowing what your students have learned during a course is a valuable tool for improving your own teaching. Unfortunately, current astronomy concept inventories are not suitable for an introductory solar system course because they either cover too broad of a range of topics (e.g. Astronomy Diagnostic Test) or are too narrowly focused (e.g. Greenhouse Effect Concept Inventory, Lunar Phase Concept Inventory). We have developed the Solar System Concept Inventory (SSCI) to cover those topics commonly taught in an introductory solar system course. The topics included on the SSCI were selected by having faculty identify the key concepts they address when teaching about the solar system. SSCI topics include formation mechanisms, planetary interiors, atmospheric effects, and small solar system bodies. Student interviews were conducted to identify common naive ideas and reasoning difficulties relating to these key topics. Preliminary development of the SSCI was completed at the University of Colorado and involved over 400 students. A larger, national, multi-institutional field test is planned for Spring 2009 as a Collaboration of Astronomy Teaching Scholars (CATS) research project. We present here the results from the preliminary development and proposed changes for the next stage of research. We would like to thank the NSF for funding under Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

Development of the Solar System Concept Inventory

Science.gov (United States)

Hornstein, S.; Prather, E.

2009-12-01

Concept inventories can provide useful insight into students’ understanding of key physical concepts. Knowing what your students have learned during a course is a valuable tool for improving your own teaching. Unfortunately, current astronomy concept inventories are not suitable for an introductory solar system course because they either cover too broad of a range of topics (e.g. Astronomy Diagnostic Test) or are too narrowly focused (e.g. Greenhouse Effect Concept Inventory, Lunar Phase Concept Inventory). We have developed the Solar System Concept Inventory (SSCI) to cover those topics commonly taught in an introductory solar system course. The topics included on the SSCI were selected by having faculty identify the key concepts they address when teaching about the solar system. SSCI topics include formation mechanisms, planetary interiors, atmospheric effects, and small solar system bodies. Student interviews were conducted to identify common naive ideas and reasoning difficulties relating to these key topics. The SSCI has been through two semesters of national, multi-institutional field-testing, involving over 1500 students. After the first semester of testing, question statistics were used to flag ineffective questions and flagged questions were revised or eliminated. We will present an overall outline of the SSCI development as well as our question-flagging criteria and question analyses from the latest round of field-testing. We would like to thank the NSF for funding under Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

Reliability and cost/worth evaluation of generating systems utilizing wind and solar energy

Science.gov (United States)

Bagen

The utilization of renewable energy resources such as wind and solar energy for electric power supply has received considerable attention in recent years due to adverse environmental impacts and fuel cost escalation associated with conventional generation. At the present time, wind and/or solar energy sources are utilized to generate electric power in many applications. Wind and solar energy will become important sources for power generation in the future because of their environmental, social and economic benefits, together with public support and government incentives. The wind and sunlight are, however, unstable and variable energy sources, and behave far differently than conventional sources. Energy storage systems are, therefore, often required to smooth the fluctuating nature of the energy conversion system especially in small isolated applications. The research work presented in this thesis is focused on the development and application of reliability and economic benefits assessment associated with incorporating wind energy, solar energy and energy storage in power generating systems. A probabilistic approach using sequential Monte Carlo simulation was employed in this research and a number of analyses were conducted with regards to the adequacy and economic assessment of generation systems containing wind energy, solar energy and energy storage. The evaluation models and techniques incorporate risk index distributions and different operating strategies associated with diesel generation in small isolated systems. Deterministic and probabilistic techniques are combined in this thesis using a system well-being approach to provide useful adequacy indices for small isolated systems that include renewable energy and energy storage. The concepts presented and examples illustrated in this thesis will help power system planners and utility managers to assess the reliability and economic benefits of utilizing wind energy conversion systems, solar energy conversion

WILL THE LARGE SYNOPTIC SURVEY TELESCOPE DETECT EXTRA-SOLAR PLANETESIMALS ENTERING THE SOLAR SYSTEM?

International Nuclear Information System (INIS)

Moro-Martin, Amaya; Turner, Edwin L.; Loeb, Abraham

2009-01-01

Planetesimal formation is a common by-product of the star formation process. Taking the dynamical history of the solar system as a guideline-in which the planetesimal belts were heavily depleted due to gravitational perturbation with the giant planets-and assuming similar processes have taken place in other planetary systems, one would expect the interstellar space to be filled with extra-solar planetesimals. However, not a single one of these objects has been detected so far entering the solar system, even though it would clearly be distinguishable from a solar system comet due to its highly hyperbolic orbit. The Large Synoptic Survey Telescope (LSST) will provide wide coverage maps of the sky to a very high sensitivity, ideal to detect moving objects like comets, both active and inactive. In anticipation of these observations, we estimate how many inactive 'interstellar comets' might be detected during the duration of the survey. The calculation takes into account estimates (from observations and models) of the number density of stars, the amount of solids available to form planetesimals, the frequency of planet and planetesimal formation, the efficiency of planetesimal ejection, and the possible size distribution of these small bodies.

Evaluation of a integral systems greenhouse - solar dryer for small growers; Evaluacion de un sistema integral invernadero - secadero solar para pequenos productores

Energy Technology Data Exchange (ETDEWEB)

Garcia, Victor O; Iriarte, Adolfo A [INENCO, Universidad Nacional de Catamarca, Catamarca (Argentina); Carabajal, Dante; Sabadzija, Gabriela; Tomalino, Luis [E.E.A. INTA, Catamarca, Catamarca (Argentina)

2000-07-01

Due to poor yielding capacity in the province of Catamarca, Argentina, it is necessary to improve solar drying systems in order to have a better quality final product. It is also essential to divide the costs of infrastructure with other complementary activities because of the need to make drying methods profitable. The system proposed in this work is a dryer-greenhouse with a double purposed macrotunnel greenhouse: during Winter it is used as a yielding system, and in Summer it is prepared to fulfill the functions of a solar dryer. The crops evaluated in winter were: small vegetable marrow (Curcubita maxima L), melon (Cucumis melo), ad cucumber (Cucuis sativus). Crop cycle, harvest time and tield in Kg/m were determined for each species. The assessment of the dryer was made using pepper for paprika observation of the thermal behavior of the product during drying and its final quality. The product obtained had a very good quality in color, taste and aroma with a classification of extra quality according to the Argentine Nutritional Code and the 7541 ISO Standard. Drying time decreased considerably compared to that observed in open air drying, 1995, 1996 and 1997 campaigns were economically assessed, and an evaluation of investments in five years was also conducted obtaining a positive VAN and a TIR above the cost of the best alternative for money expenditure. This integrated system is valid alternative in a sustainable production for small growers. [Spanish] Debido a las caracteristicas productivas de la Provincia de Catamarca Argentina, es necesario optimizar los procesos del secado solar teniendo en cuenta la calidad final del producto. Ademas, debido a la necesidad de rentabilizar los metodos de secado, imprescindible repartir los costos de infraestructura con otro tipo de actividad complementaria. El sistema propuesto en este trabajo es un invernadero secadero que utiliza un invernadero macrotunel que cumple una doble funcion, durante el invierno se usa como

Solar combi systems

DEFF Research Database (Denmark)

Andersen, Elsa

2007-01-01

The focus in the present Ph.D. thesis is on the active use of solar energy for domestic hot water and space heating in so-called solar combi systems. Most efforts have been put into detailed investigations on the design of solar combi systems and on devices used for building up thermal...... the thermal behaviour of different components, and the theoretical investigations are used to study the influence of the thermal behaviour on the yearly thermal performance of solar combi systems. The experimental investigations imply detailed temperature measurements and flow visualization with the Particle...... Image Velocimetry measurement method. The theoretical investigations are based on the transient simulation program TrnSys and Computational Fluid Dynamics. The Ph.D. thesis demonstrates the influence on the thermal performance of solar combi systems of a number of different parameters...

Hybrids of Solar Sail, Solar Electric, and Solar Thermal Propulsion for Solar-System Exploration

Science.gov (United States)

Wilcox, Brian H.

2012-01-01

Solar sails have long been known to be an attractive method of propulsion in the inner solar system if the areal density of the overall spacecraft (S/C) could be reduced to approx.10 g/sq m. It has also long been recognized that the figure (precise shape) of useful solar sails needs to be reasonably good, so that the reflected light goes mostly in the desired direction. If one could make large reflective surfaces with reasonable figure at an areal density of approx.10 g/sq m, then several other attractive options emerge. One is to use such sails as solar concentrators for solar-electric propulsion. Current flight solar arrays have a specific output of approx. 100W/kg at 1 Astronomical Unit (AU) from the sun, and near-term advances promise to significantly increase this figure. A S/C with an areal density of 10 g/sq m could accelerate up to 29 km/s per year as a solar sail at 1 AU. Using the same sail as a concentrator at 30 AU, the same spacecraft could have up to approx. 45 W of electric power per kg of total S/C mass available for electric propulsion (EP). With an EP system that is 50% power-efficient, exhausting 10% of the initial S/C mass per year as propellant, the exhaust velocity is approx. 119 km/s and the acceleration is approx. 12 km/s per year. This hybrid thus opens attractive options for missions to the outer solar system, including sample-return missions. If solar-thermal propulsion were perfected, it would offer an attractive intermediate between solar sailing in the inner solar system and solar electric propulsion for the outer solar system. In the example above, both the solar sail and solar electric systems don't have a specific impulse that is near-optimal for the mission. Solar thermal propulsion, with an exhaust velocity of the order of 10 km/s, is better matched to many solar system exploration missions. This paper derives the basic relationships between these three propulsion options and gives examples of missions that might be enabled by

Solar energy conversion systems

CERN Document Server

Brownson, Jeffrey R S

2013-01-01

Solar energy conversion requires a different mind-set from traditional energy engineering in order to assess distribution, scales of use, systems design, predictive economic models for fluctuating solar resources, and planning to address transient cycles and social adoption. Solar Energy Conversion Systems examines solar energy conversion as an integrative design process, applying systems thinking methods to a solid knowledge base for creators of solar energy systems. This approach permits different levels of access for the emerging broad audience of scientists, engineers, architects, planners

Solar system astrophysics background science and the inner solar system

CERN Document Server

Milone, Eugene F

2008-01-01

Solar System Astrophysics: A Text for the Science of Planetary Systems covers the field of solar system astrophysics beginning with basic tools of spherical astronomy, coordinate frames, and celestial mechanics. Historical introductions precede the development and discussion in most chapters. After a basic treatment of the two- and restricted three-body system motions in Background Science and the Inner Solar System, perturbations are discussed, followed by the Earth's gravitational potential field and its effect on satellite orbits. This is followed by analysis of the Earth-Moon system and the interior planets. In Planetary Atmospheres and the Outer Solar System, the atmospheres chapters include detailed discussions of circulation, applicable also to the subsequent discussion of the gas giants. The giant planets are discussed together, and the thermal excesses of three of them are highlighted. This is followed by chapters on moons and rings, mainly in the context of dynamical stability, comets and meteors, m...

Possibility of EV with solar cells on the new traffic system; Shinkotsu system ni okeru solar car no kanosei

Energy Technology Data Exchange (ETDEWEB)

Fujii, I; Kojima, S [Meiji University, Tokyo (Japan)

1997-11-25

A possibility of a new traffic system was studied for a solar car which is light in weight, small in size and low in speed (cruising speed: 20 km/h) and does not need so much power because of the use for short distance. In the new traffic system, people travel short distance in city by solar car, and use trains for travel between cities. By installing solar cells on roofs, etc. of houses and buildings such as garages around stations, power needed for solar car and incidentally required can be supplied. Assuming the short distance transportation, the car is for one person with a height of luggage space of 70cm, mean length of 165cm, and floor height of 50cm above the ground. In case that the power generation by solar cells (256.5W) is at maximum with no shading during travel on conditions of load weight of 10kg, personnel weight of 70kg, and total weight of 250kg, it was found that solar cells can supply 89% of the required output under test road travel at speed of 20 km/h. A viability of the solar car proposed here is great. A possibility at the time of mode road travel is also studied. 10 refs., 3 figs., 1 tab.

Appropriate technology for rural India - solar decontamination of water for emergency settings and small communities.

Science.gov (United States)

Kang, Gagandeep; Roy, Sheela; Balraj, Vinohar

2006-09-01

A commercial solar water heating system was evaluated for its effectiveness in decontaminating drinking water with a view to use in emergency situations. A total of 18 seeding experiments carried out over 6 months with 10(5) to 10(7)Escherichia coli/ml showed that the solar heater produced 125 l of bacteriologically safe water in 4 h when the ambient temperature was above 30 degrees C, with a holding time of at least 2 h. The solar water heating system is inexpensive, easy to transport and set up and could provide safer drinking water for 50 people a day. It would be effective in the decrease and prevention of waterborne disease in emergency situations, and is appropriate for use in small communities.

Solar system astrophysics background science and the inner solar system

CERN Document Server

Milone, Eugene F

2014-01-01

The second edition of Solar System Astrophysics: Background Science and the Inner Solar System provides new insights into the burgeoning field of planetary astronomy. As in the first edition, this volume begins with a rigorous treatment of coordinate frames, basic positional astronomy, and the celestial mechanics of two and restricted three body system problems. Perturbations are treated in the same way, with clear step-by-step derivations. Then the Earth’s gravitational potential field and the Earth-Moon system are discussed, and the exposition turns to radiation properties with a chapter on the Sun. The exposition of the physical properties of the Moon and the terrestrial planets are greatly expanded, with much new information highlighted on the Moon, Mercury, Venus, and Mars. All of the material is presented within a framework of historical importance. This book and its sister volume, Solar System Astrophysics: Planetary Atmospheres and the Outer Solar System, are pedagogically well written, providing cl...

Meteorites and the Evolution of Our Solar System

Science.gov (United States)

Nava, David F.

1999-01-01

The study of meteorites has long been of intense interest ever since these objects were discovered to be of extraterrestrial origin. Meteorite research contributes to unraveling the mysteries in understanding the formation and evolution processes of our solar system. Meteorites, of which there are a variety of widely diverse types of chemical and mineralogical compositions, are the most ancient of solar system objects that can be studied in the laboratory. They preserve a unique historical record of the astronomical and astrophysical events of our solar system. This record is being discerned by a host of ever evolving analytical laboratory methods. Recent discoveries of what are believed to be Martian meteorites, lunar meteorites, a meteorite containing indigenous water, and the recovery from the Cretaceous layer of a small meteorite fragment thought to be from the dinosaur-killing asteroid have fueled additional excitement for studying meteorites.

Solar Energy Systems

Science.gov (United States)

1984-01-01

Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

Villacidro solar demo plant: Integration of small-scale CSP and biogas power plants in an industrial microgrid

Science.gov (United States)

Camerada, M.; Cau, G.; Cocco, D.; Damiano, A.; Demontis, V.; Melis, T.; Musio, M.

2016-05-01

The integration of small scale concentrating solar power (CSP) in an industrial district, in order to develop a microgrid fully supplied by renewable energy sources, is presented in this paper. The plant aims to assess in real operating conditions, the performance, the effectiveness and the reliability of small-scale concentrating solar power technologies in the field of distributed generation. In particular, the potentiality of small scale CSP with thermal storage to supply dispatchable electricity to an industrial microgrid will be investigated. The microgrid will be realized in the municipal waste treatment plant of the Industrial Consortium of Villacidro, in southern Sardinia (Italy), which already includes a biogas power plant. In order to achieve the microgrid instantaneous energy balance, the analysis of the time evolution of the waste treatment plant demand and of the generation in the existing power systems has been carried out. This has allowed the design of a suitable CSP plant with thermal storage and an electrochemical storage system for supporting the proposed microgrid. At the aim of obtaining the expected energy autonomy, a specific Energy Management Strategy, which takes into account the different dynamic performances and characteristics of the demand and the generation, has been designed. In this paper, the configuration of the proposed small scale concentrating solar power (CSP) and of its thermal energy storage, based on thermocline principle, is initially described. Finally, a simulation study of the entire power system, imposing scheduled profiles based on weather forecasts, is presented.

Control of Solar Energy Systems

CERN Document Server

Camacho, Eduardo F; Rubio, Francisco R; Martínez, Diego

2012-01-01

Control of Solar Energy Systems details the main solar energy systems, problems involved with their control, and how control systems can help in increasing their efficiency.  After a brief introduction to the fundamental concepts associated with the use of solar energy in both photovoltaic and thermal plants, specific issues related to control of solar systems are embarked upon. Thermal energy systems are then explored in depth, as well as  other solar energy applications such as solar furnaces and solar refrigeration systems. Problems of variable generation profile and of the contribution of many solar plants to the same grid system are considered with the necessary integrated and supervisory control solutions being discussed. The text includes material on: ·         A comparison of basic and advanced control methods for parabolic troughs from PID to nonlinear model-based control; ·         solar towers and solar tracking; ·         heliostat calibration, characterization and off...

Developing a hybrid solar/wind powered irrigation system for crops in the Great Plains

Science.gov (United States)

Some small scale irrigation systems (powered by wind or solar do not require subsidies, but this paper discusses ways to achieve an economical renewable energy powered center pivot irrigation system for crops in the Great Plains. By adding a solar-photovoltaic (PV) array together with a wind...

New Markets for Solar Photovoltaic Power Systems

Science.gov (United States)

Thomas, Chacko; Jennings, Philip; Singh, Dilawar

2007-10-01

Over the past five years solar photovoltaic (PV) power supply systems have matured and are now being deployed on a much larger scale. The traditional small-scale remote area power supply systems are still important and village electrification is also a large and growing market but large scale, grid-connected systems and building integrated systems are now being deployed in many countries. This growth has been aided by imaginative government policies in several countries and the overall result is a growth rate of over 40% per annum in the sales of PV systems. Optimistic forecasts are being made about the future of PV power as a major source of sustainable energy. Plans are now being formulated by the IEA for very large-scale PV installations of more than 100 MW peak output. The Australian Government has announced a subsidy for a large solar photovoltaic power station of 154 MW in Victoria, based on the concentrator technology developed in Australia. In Western Australia a proposal has been submitted to the State Government for a 2 MW photovoltaic power system to provide fringe of grid support at Perenjori. This paper outlines the technologies, designs, management and policies that underpin these exciting developments in solar PV power.

Assessment of distributed solar power systems: Issues and impacts

Science.gov (United States)

Moyle, R. A.; Chernoff, H.; Schweizer, T. C.; Patton, J. B.

1982-11-01

The installation of distributed solar-power systems presents electric utilities with a host of questions. Some of the technical and economic impacts of these systems are discussed. Among the technical interconnect issues are isolated operation, power quality, line safety, and metering options. Economic issues include user purchase criteria, structures and installation costs, marketing and product distribution costs, and interconnect costs. An interactive computer program that allows easy calculation of allowable system prices and allowable generation-equipment prices was developed as part of this project. It is concluded that the technical problems raised by distributed solar systems are surmountable, but their resolution may be costly. The stringent purchase criteria likely to be imposed by many potential system users and the economies of large-scale systems make small systems (less than 10 to 20 kW) less attractive than larger systems. Utilities that consider life-cycle costs in making investment decisions and third-party investors who have tax and financial advantages are likely to place the highest value on solar-power systems.

Baby Solar System

Science.gov (United States)

Currie, Thayne; Grady, Carol

2012-01-01

What did our solar system look like in its infancy,...... when the planets were forming? We cannot travel back in time to take an image of the early solar system, but in principle we can have the next best thing: images of infant planetary systems around Sun-like stars with ages of 1 to 5 million years, the time we think it took for the giant planets to form. Infant exoplanetary systems are critically important because they can help us understand how our solar system fits within the context of planet formation in general. More than 80% of stars are born with gas- and dust-rich disks, and thus have the potential to form planets. Through many methods we have identified more than 760 planetary systems around middle-aged stars like the Sun, but many of these have architectures that look nothing like our solar system. Young planetary systems are important missing links between various endpoints and may help us understand how and when these differences emerge. Well-known star-forming regions in Taurus, Scorpius. and Orion contain stars that could have infant planetary systems. But these stars are much more distant than our nearest neighbors such as Alpha Centauri or Sirius, making it extremely challenging to produce clear images of systems that can reveal signs of recent planet formation, let alone reveal the planets themselves. Recently, a star with the unassuming name LkCa 15 may have given us our first detailed "baby picture" of a young planetary system similar to our solar system. Located about 450 light-years away in the Taurus starforming region. LkCa 15 has a mass comparable to the Sun (0.97 solar mass) and an age of l to 5 million years, comparable to the time at which Saturn and perhaps Jupiter formed. The star is surrounded by a gas-rich disk similar in structure to the one in our solar system from which the planets formed. With new technologies and observing strategies, we have confirmed suspicions that LkCa 15's disk harbors a young planetary system.

Models of f(R) cosmic acceleration that evade solar system tests

International Nuclear Information System (INIS)

Hu, Wayne; Sawicki, Ignacy

2007-01-01

We study a class of metric-variation f(R) models that accelerates the expansion without a cosmological constant and satisfies both cosmological and solar-system tests in the small-field limit of the parameter space. Solar-system tests alone place only weak bounds on these models, since the additional scalar degree of freedom is locked to the high-curvature general-relativistic prediction across more than 25 orders of magnitude in density, out through the solar corona. This agreement requires that the galactic halo be of sufficient extent to maintain the galaxy at high curvature in the presence of the low-curvature cosmological background. If the galactic halo and local environment in f(R) models do not have substantially deeper potentials than expected in ΛCDM, then cosmological field amplitudes |f R | > or approx.10 -6 will cause the galactic interior to evolve to low curvature during the acceleration epoch. Viability of large-deviation models therefore rests on the structure and evolution of the galactic halo, requiring cosmological simulations of f(R) models, and not directly on solar-system tests. Even small deviations that conservatively satisfy both galactic and solar-system constraints can still be tested by future, percent-level measurements of the linear power spectrum, while they remain undetectable to cosmological-distance measures. Although we illustrate these effects in a specific class of models, the requirements on f(R) are phrased in a nearly model-independent manner

The Virtual Solar Observatory: Still a Small Box

Science.gov (United States)

Gurman, J. B.; Bogart, R. S.; Davey, A. R.; Dimitoglou, G.; Hill, F.; Hourcle, J. A.; Martens, P. C.; Surez-Sola, I.; Tian, K. Q.; Wampler, S.

2005-01-01

Two and a half years after a design study began, and a year and a half after development commenced, version 1.0 of the Virtual Solar Observatory (VSO) was released at the 2004 Fall AGU meeting. Although internal elements of the VSO have changed, the basic design has remained the same, reflecting the team's belief in the importance of a simple, robust mechanism for registering data provider holdings, initiating queries at the appropriate provider sites, aggregating the responses, allowing the user to iterate before making a final selection, and enabling the delivery of data directly from the providers. In order to make the VSO transparent, lightweight, and portable, the developers employed XML for the registry, SOAP for communication between a VSO instance and data services, and HTML for the graphic user interface (GUI's). We discuss the internal data model, the API, and user responses to various trial GUI's as typical design issues for any virtual observatory. We also discuss the role of the "small box" of data search, identification, and delivery services provided by the VSO in the larger, Sun-Solar System Connection virtual observatory (VxO) scheme.

Long-range order between the planets in the Solar system

DEFF Research Database (Denmark)

Bohr, Jakob; Olsen, Kasper

2010-01-01

The Solar System is investigated for positional correlations between the planets using a logarithmic distance scale. The pair correlation function for the logarithm of the semimajor axis shows a regular distribution with 5-7 consecutive peaks, and the Fourier transform hereof shows reciprocal peaks...... the number of data points is small. The pair correlation function of the permutated planets lacks the sequence of equidistant peaks and its Fourier transform has no second order peak. This analysis demonstrates the existence of longer ranged correlations in the Solar System....

PV solar system feasibility study

International Nuclear Information System (INIS)

Ashhab, Moh’d Sami S.; Kaylani, Hazem; Abdallah, Abdallah

2013-01-01

Highlights: ► This research studies the feasibility of PV solar systems. ► The aim is to develop the theory and application of a hybrid system. ► Relevant research topics are reviewed and some of them are discussed in details. ► A prototype of the PV solar system is designed and built. - Abstract: This research studies the feasibility of PV solar systems and aims at developing the theory and application of a hybrid system that utilizes PV solar system and another supporting source of energy to provide affordable heating and air conditioning. Relevant research topics are reviewed and some of them are discussed in details. Solar heating and air conditioning research and technology exist in many developed countries. To date, the used solar energy has been proved to be inefficient. Solar energy is an abundant source of energy in Jordan and the Middle East; with increasing prices of oil this source is becoming more attractive alternative. A good candidate for the other system is absorption. The overall system is designed such that it utilizes solar energy as a main source. When the solar energy becomes insufficient, electricity or diesel source kicks in. A prototype of the PV solar system that operates an air conditioning unit is built and proper measurements are collected through a data logging system. The measured data are plotted and discussed, and conclusions regarding the system performance are extracted.

Evaluating a Small Structural Insulated Panel (SIP) Designed Solar Kiln in Southwestern New Mexico - Part 1

Science.gov (United States)

Richard D. Bergman; Ted E.M. Bilek

2012-01-01

With increasing energy costs, using small dry kilns for drying lumber for small-volume value-added wood products has become more of an option when compared with conventional drying. Small solar kilns are one such option, and a number of solar kiln designs exist and are in use. However, questions remain about the design and operation of solar kilns, particularly during...

Continued Development of the Solar System Concept Inventory

Science.gov (United States)

Hornstein, Seth D.; Prather, E. E.; English, T. R.; Desch, S. M.; Keller, J. M.; CATS

2010-01-01

The Solar System Concept Inventory (SSCI) was developed in order to provide a pre-/post-instruction assessment instrument suitable for use in an introductory solar system course. The topics included on the SSCI focus on formation mechanisms, planetary interiors, atmospheric and surface effects, and small solar system bodies. These topics were selected by having faculty identify the key concepts they address when teaching about the solar system. Student interviews were then conducted to identify common naive ideas and reasoning difficulties relating to these key topics. As of December 2009, the SSCI has been through four semesters of both pre- and post-instruction classroom testing, involving over 2000 students and 11 institutions (ranging from two-year colleges to doctoral/research universities). After each semester of testing, item analysis statistics such as point biserial, percentage correct on pre- or post-testing, and frequently-chosen distracters (incorrect answers) were used to flag ineffective questions. Flagged questions were revised or eliminated. We present an overall outline of the SSCI development as well as our question-flagging criteria and question analyses from the latest round of field-testing. We would like to thank the NSF for funding under Grant No. 0715517, a CCLI Phase III Grant for the Collaboration of Astronomy Teaching Scholars (CATS) Program.

Sizing solar home systems for optimal development impact

International Nuclear Information System (INIS)

Bond, M.; Fuller, R.J.; Aye, Lu

2012-01-01

The paper compares the development impact of three different sized solar home systems (SHS) (10, 40 and 80 W p ) installed in rural East Timor. It describes research aimed to determine whether the higher cost of the larger systems was justified by additional household benefits. To assess the development impact of these different sizes of SHS the research used a combination of participatory and quantitative tools. Participatory exercises were conducted with seventy-seven small groups of SHS users in twenty-four rural communities and supplemented with a household survey of 195 SHS users. The combined results of these evaluation processes enabled the three sizes of SHS to be compared for two types of benefits—those associated with carrying out important household tasks and attributes of SHS which were advantageous compared to the use of non-electric lighting sources. The research findings showed that the small, 10 W p SHS provided much of the development impact of the larger systems. It suggests three significant implications for the design of SHS programs in contexts such as East Timor: provide more small systems rather than fewer large ones; provide lighting in the kitchen wherever possible; and carefully match SHS operating costs to the incomes of rural users. - Highlights: ► We compare development benefits for 3 sizes of solar home systems—10, 40 and 80 W p . ► Benefit assessment uses a combination of qualitative and quantitative approaches. ► Small systems are found to provide much of the benefits of the larger systems. ► To maximise benefits systems should be fitted with luminaires in kitchen areas. ► Financial benefits are important to users and may not accrue for large systems.

Experiences with a small scale Solar/Wind pilot installation for basic electrification in the chilean altiplano

Energy Technology Data Exchange (ETDEWEB)

Sapiain, Raul; Ovalle, Ricardo; Torres, Ariel; Brockmeyer, Ricarda; Schmidt, Reinhold [Centro de Energias Renovables/Universidad de Tarapaca, Arica, (Chile); Meer, Andreas V. [Solar Institute, Juelich (Germany)

1997-12-31

Basic rural electrification programmes are already carried out in the rural areas of northern Chile by local communities and local governments using photovoltaic systems. Solar Home Systems, 12 VDC are installed for individual households while systems for schools, public lighting etc. are realized with bigger systems, 220 VAC. Within a cooperation with the Solar Institute of the Fachhochschule Juelich, Germany, the Renewable Energy Center of the University of Tarapaca designed, installed and evaluated the first solar/wind hybrid installation for basic electrification in northern Chile, realized in Colpitas, a typical small village in the chilean altiplano. The following paper presents results and experiences of this first pilot installation. [Espanol] Ya se estan llevando a cabo programas de electrificacion rural basica en las areas rurales del Norte de Chile por las comunidades y los gobiernos locales, usando sistemas fotovoltaicos. Se instalan Sistemas Domesticos Solares de 12VDC para casas-habitacion individuales, mientras que los sistemas para escuelas, alumbrado publico, etc., se ejecutan con sistemas mas grandes de 220VAC. Con la coperacion del Instituto Solar de la Fachhochschule en Julich, Alemania, el Centro de Energia Renovable de la Universidad de Tarapaca, diseno, instalo y evaluo, la primera instalacion hibrida solar/viento para electrificacion basica en el Norte de Chile, realizado en Colpitas, un pueblo tipico pequeno del altiplano chileno. El siguiete articulo presenta los resultados y experiencias de esta primera instalacion piloto.

Experiences with a small scale Solar/Wind pilot installation for basic electrification in the chilean altiplano

Energy Technology Data Exchange (ETDEWEB)

Sapiain, Raul; Ovalle, Ricardo; Torres, Ariel; Brockmeyer, Ricarda; Schmidt, Reinhold [Centro de Energias Renovables/Universidad de Tarapaca, Arica, (Chile); Meer, Andreas V [Solar Institute, Juelich (Germany)

1998-12-31

Basic rural electrification programmes are already carried out in the rural areas of northern Chile by local communities and local governments using photovoltaic systems. Solar Home Systems, 12 VDC are installed for individual households while systems for schools, public lighting etc. are realized with bigger systems, 220 VAC. Within a cooperation with the Solar Institute of the Fachhochschule Juelich, Germany, the Renewable Energy Center of the University of Tarapaca designed, installed and evaluated the first solar/wind hybrid installation for basic electrification in northern Chile, realized in Colpitas, a typical small village in the chilean altiplano. The following paper presents results and experiences of this first pilot installation. [Espanol] Ya se estan llevando a cabo programas de electrificacion rural basica en las areas rurales del Norte de Chile por las comunidades y los gobiernos locales, usando sistemas fotovoltaicos. Se instalan Sistemas Domesticos Solares de 12VDC para casas-habitacion individuales, mientras que los sistemas para escuelas, alumbrado publico, etc., se ejecutan con sistemas mas grandes de 220VAC. Con la coperacion del Instituto Solar de la Fachhochschule en Julich, Alemania, el Centro de Energia Renovable de la Universidad de Tarapaca, diseno, instalo y evaluo, la primera instalacion hibrida solar/viento para electrificacion basica en el Norte de Chile, realizado en Colpitas, un pueblo tipico pequeno del altiplano chileno. El siguiete articulo presenta los resultados y experiencias de esta primera instalacion piloto.

Modelling of a solar stove: small scale concentrating system with heat storage: potential for cooking in rural areas, Zimbabwe

Energy Technology Data Exchange (ETDEWEB)

Chikukwa, Actor

2007-10-15

The central objective of the present research is to serve as an in-depth technical introduction to small-scale concentrating systems tailored for application especially in rural areas in Africa located outside the national electricity grids. For example, MSc and doctoral-students recently matriculated on NUFU-sponsorship at some universities in Africa (i.e Mozambique, Uganda, Tanzania, South Africa and Ethiopia) for research in solar-concentrator technologies will find most of the material in this work quite useful. Chapter 1 discusses the premise on which this research is based. It essentially highlights the gravity of the energy crisis as experienced by the impoverished masses living in most parts of Africa. The situation in Zimbabwe was discussed in detail (for case-studies1) because it is a suitable example added to the convenience of being the country of the author's origin. The second chapter is thus a detailed study on the solar energy resource situation in Zimbabwe. It describes the availability and patterns of solar energy based on the existing solar radiation data obtained from meteorological stations scattered throughout the country. These results were necessary for assessing the potential of the proposed system in Zimbabwe, and can also be extended for use in other solar energy projects. Chapter 3 focuses on the collection of solar radiation using parabolic concentrators. Major determinants that include errors and optical sensitivity of parabolic solar collectors, the correlation between receiver configuration and the parabolic collector are expounded. Arguments for and the main principle on how-to incorporate a mechanical solar tracking device are also laid-out in this part of the thesis. A very critical component of the concentrating system: the volumetric fibrous receiver, is described in the 4th chapter. Here, the theory on which one of the major computer programmes developed in this research, is given an in-depth treatment. The gist of this

Modelling of a solar stove: small scale concentrating system with heat storage: potential for cooking in rural areas, Zimbabwe

Energy Technology Data Exchange (ETDEWEB)

Chikukwa, Actor

2007-10-15

The central objective of the present research is to serve as an in-depth technical introduction to small-scale concentrating systems tailored for application especially in rural areas in Africa located outside the national electricity grids. For example, MSc and doctoral-students recently matriculated on NUFU-sponsorship at some universities in Africa (i.e Mozambique, Uganda, Tanzania, South Africa and Ethiopia) for research in solar-concentrator technologies will find most of the material in this work quite useful. Chapter 1 discusses the premise on which this research is based. It essentially highlights the gravity of the energy crisis as experienced by the impoverished masses living in most parts of Africa. The situation in Zimbabwe was discussed in detail (for case-studies1) because it is a suitable example added to the convenience of being the country of the author's origin. The second chapter is thus a detailed study on the solar energy resource situation in Zimbabwe. It describes the availability and patterns of solar energy based on the existing solar radiation data obtained from meteorological stations scattered throughout the country. These results were necessary for assessing the potential of the proposed system in Zimbabwe, and can also be extended for use in other solar energy projects. Chapter 3 focuses on the collection of solar radiation using parabolic concentrators. Major determinants that include errors and optical sensitivity of parabolic solar collectors, the correlation between receiver configuration and the parabolic collector are expounded. Arguments for and the main principle on how-to incorporate a mechanical solar tracking device are also laid-out in this part of the thesis. A very critical component of the concentrating system: the volumetric fibrous receiver, is described in the 4th chapter. Here, the theory on which one of the major computer programmes developed in this research, is given an in-depth treatment. The gist of this

Maximum-power-point tracking control of solar heating system

KAUST Repository

Huang, Bin-Juine

2012-11-01

The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.

Solar Energy and Other Appropriate Technologies for Small Potable Water Systems in Puerto Rico

Science.gov (United States)

This Region 2 research demonstration project presentation studied the efficacy of sustainable solar-powered water delivery and monitoring systems to reduce the economic burden of operating and maintaining Non-PRASA drinking water systems and to reduce the impact of climate change...

Monitoring and evaluation of Solar Home Systems. Experiences with applications of solar PV for households in developing countries

International Nuclear Information System (INIS)

Nieuwenhout, F.D.J.; Van Dijk, A.; Van Dijk, V.A.P.; Hirsch, D.; Lasschuit, P.E.; Van Roekel, G.; Arriaza, H.; Hankins, M.; Sharma, B.D.; Wade, H.

2000-09-01

Solar energy is a promising solution to meet demand for electricity services of rural households in remote locations in developing countries. After some early successes, more and more doubts have arisen about the effectiveness and suitability of small PV systems for rural development. Many organisational, financial and technical problems appear difficult to tackle. A literature survey has been conducted to make an inventory of experiences with solar photovoltaic applications for households in developing countries. The major conclusion from the extensive literature research performed during this study is that there is not enough information available about the performance of solar home systems and projects. This slows down further development and successful dissemination. refs

Meteorites and cosmic dust: Interstellar heritage and nebular processes in the early solar system

Directory of Open Access Journals (Sweden)

Engrand C.

2012-01-01

Full Text Available Small solar system bodies like asteroids and comets have escaped planetary accretion. They are the oldest and best preserved witnesses of the formation of the solar system. Samples of these celestial bodies fall on Earth as meteorites and interplanetary dust. The STARDUST mission also recently returned to Earth cometary dust from comet 81P/Wild 2, a Jupiter Family Comet (JFC. These samples provide unique insights on the physico-chemical conditions and early processes of the solar system. They also contain some minute amount of materials inherited from the local interstellar medium that have survived the accretion processes in the solar system.

Homemade Solar Systems

Science.gov (United States)

1981-01-01

Through the use of NASA Tech Briefs, Peter Kask, was able to build a solarized domestic hot water system. Also by applying NASA's solar energy design information, he was able to build a swimming pool heating system with minimal outlay for materials.

Experience with solar home systems in developing countries. A review

International Nuclear Information System (INIS)

Nieuwenhout, F.D.J.; Van Dijk, A.L.; Lasschuit, P.E.; Van Roekel, G.M.; Van Dijk, V.A.P.; Hirsch, D.; Arriaza, H.; Hankins, M.; Sharma, B.D.; Wade, H.

2002-01-01

Solar Energy is widely perceived as a promising technology for electricity generation in remote locations in developing countries. It is estimated that 1.3 million solar home systems had been installed by early 2000. An estimated one-third of installed systems were backed by foreign donor support in government programmes and two-thirds supplied by commercial dealers. The estimated growth in the deployment of solar lanterns is less than for SHS. One out of every 100 households that gain access to electricity in developing countries uses solar power. In spite of these successes, doubts have arisen about the effectiveness and suitability of small PV systems for rural development. Many organisational, financial and technical problems appear to present difficulties. A literature survey has been conducted to make an inventory of experience with solar PV applications for households in developing countries. The main finding is that an adequate service infrastructure is required to make projects viable. Household choice in system sizes is often too restricted in donor-funded projects. Smaller systems sold for cash can be a good alternative to credit systems by offering to increased affordability. Gaps in existing knowledge have been identified, which could be overcome by field monitoring programmes. 77 refs

On the anomalous acceleration in the solar system

International Nuclear Information System (INIS)

Palle, D.

2005-01-01

We study an impact of the cosmological environment on the cosmological environment on the solar gravitational system by the imbedding formalism of Gautreau. It turns out that the cosmic mean-mass density and the cosmological constant give negligible small contribution to the gravity potentials. On the other hand, the cosmic acceleration beyond the Robertson-Walker geometry can considerably influence the curvature of spacetime in the solar system. The resulting anomalous constant acceleration towards the Sun is order of magnitude smaller than that measured by Pioneer 10 and 11. However, it is larger than the second order terms of potentials, thus well within the sensitivity of new gravity probes such as the LATOR mission (Author)

Formation of amino acid precursors in the Solar System small bodies using Aluminium-26 as an energy source

Science.gov (United States)

Kebukawa, Yoko; Kobayashi, Kensei; Kawai, Jun; Mita, Hajime; Tachibana, Shogo; Yoda, Isao; Misawa, Shusuke

2016-07-01

Carbonaceous chondrites contain various organic matter including amino acids that may have played an important role for origin of life on the early Earth. The parent bodies of the chondritic meteorites likely formed from silicate dust grains containing some water ice and organic compounds. These planetesimals are known to contain short-lived radio isotopes such as ^{26}Al, and the heat generated from the decay of ^{26}Al was considered to be used for melting ice. The liquid water, for example, changed anhydrous silicates into hydrous silicates, i.e., aqueous alteration. The liquid water would act also as an ideal reaction medium for various organic chemistry. Cody et al. [1] proposed IOM formation via formose reaction starting with formaldehyde and glycolaldehyde during aqueous activity in the small bodies. Additional hydrothermal experiments showed that ammonia enhanced the yields of IOM like organic solids [2]. Formaldehyde and ammonia are ubiquitous in the Solar System and beyond, e.g., comets contain H _{2}CO : NH _{3} : H _{2}O = 0.4-4 : 0.5-1.5 : 100 [3]. Thus these molecules can be expected to have existed in some Solar System small bodies. We study the liquid phase chemistry of the formaldehyde and ammonia, including formations of amino acid precursor molecules, via hydrothermal experiments at isothermal temperatures of 90 °C to 200 °C. We also evaluate the effects of gamma-ray which is released from the decay of ^{26}Al with gamma-ray irradiation experiments using a ^{60}Co gamma-ray source at Tokyo Institute of Technology. Amino acids were detected mostly after acid hydrolysis of heated or irradiated solutions, indicating that most of the amino acids in the products exist as precursors. Some samples contained 'free' amino acids that were detected without acid hydrolysis, but much lower abundance than after acid hydrolysis. Kendrick mass defect (KMD) analyses of High resolution mass spectra obtained using ESI-MS revealed that various CHO and CHNO

Solar heating and cooling of residential buildings: design of systems, 1980 edition

Energy Technology Data Exchange (ETDEWEB)

None

1980-09-01

This manual was prepared primarily for use in conducting a practical training course on the design of solar heating and cooling systems for residential and small office buildings, but may also be useful as a general reference text. The content level is appropriate for persons with different and varied backgrounds, although it is assumed that readers possess a basic understanding of heating, ventilating, and air-conditioning systems of conventional (non-solar) types. This edition is a revision of the manual with the same title, first printed and distributed by the US Government Printing Office in October 1977. The manual has been reorganized, new material has been added, and outdated information has been deleted. Only active solar systems are described. Liquid and air-heating solar systems for combined space and service water heating or service water heating are included. Furthermore, only systems with proven experience are discussed to any extent.

Small Bodies, Big Discoveries: NASA's Small Bodies Education Program

Science.gov (United States)

Mayo, L.; Erickson, K. J.

2014-12-01

2014 is turning out to be a watershed year for celestial events involving the solar system's unsung heroes, small bodies. This includes the close flyby of comet C/2013 A1 / Siding Spring with Mars in October and the historic Rosetta mission with its Philae lander to comet 67P/Churyumov-Gerasimenko. Beyond 2014, the much anticipated 2015 Pluto flyby by New Horizons and the February Dawn Mission arrival at Ceres will take center stage. To deliver the excitement and wonder of our solar system's small bodies to worldwide audiences, NASA's JPL and GSFC education teams in partnership with NASA EDGE will reach out to the public through multiple venues including broadcast media, social media, science and math focused educational activities, observing challenges, interactive visualization tools like "Eyes on the Solar System" and more. This talk will highlight NASA's focused education effort to engage the public in small bodies mission science and the role these objects play in our understanding of the formation and evolution of the solar system.

Solar heating systems for houses. A design handbook for solar combisystems

International Nuclear Information System (INIS)

Weiss, W.

2003-11-01

A handbook giving guidance on systems for providing combined solar space heating and solar water heating for houses has been produced by an international team. The guidance focuses on selection of the optimum combi-system for groups of single-family houses and multi-family houses. Standard classification and evaluation procedures are described. The book should be a valuable tool for building engineers, architects, solar manufacturers and installers of solar solar energy systems, and anyone interested in optimizing combined water and space heating solar systems

Energy harvesting concepts for small electric unmanned systems

Science.gov (United States)

Qidwai, Muhammad A.; Thomas, James P.; Kellogg, James C.; Baucom, Jared N.

2004-07-01

In this study, we identify and survey energy harvesting technologies for small electrically powered unmanned systems designed for long-term (>1 day) time-on-station missions. An environmental energy harvesting scheme will provide long-term, energy additions to the on-board energy source. We have identified four technologies that cover a broad array of available energy sources: solar, kinetic (wind) flow, autophagous structure-power (both combustible and metal air-battery systems) and electromagnetic (EM) energy scavenging. We present existing conceptual designs, critical system components, performance, constraints and state-of-readiness for each technology. We have concluded that the solar and autophagous technologies are relatively matured for small-scale applications and are capable of moderate power output levels (>1 W). We have identified key components and possible multifunctionalities in each technology. The kinetic flow and EM energy scavenging technologies will require more in-depth study before they can be considered for implementation. We have also realized that all of the harvesting systems require design and integration of various electrical, mechanical and chemical components, which will require modeling and optimization using hybrid mechatronics-circuit simulation tools. This study provides a starting point for detailed investigation into the proposed technologies for unmanned system applications under current development.

BIRDY - Interplanetary CubeSat for planetary geodesy of Small Solar System Bodies (SSSB).

Science.gov (United States)

Hestroffer, D.; Agnan, M.; Segret, B.; Quinsac, G.; Vannitsen, J.; Rosenblatt, P.; Miau, J. J.

2017-12-01

We are developing the Birdy concept of a scientific interplanetary CubeSat, for cruise, or proximity operations around a Small body of the Solar System (asteroid, comet, irregular satellite). The scientific aim is to characterise the body's shape, gravity field, and internal structure through imaging and radio-science techniques. Radio-science is now of common use in planetary science (flybys or orbiters) to derive the mass of the scientific target and possibly higher order terms of its gravity field. Its application to a nano-satellite brings the advantage of enabling low orbits that can get closer to the body's surface, hence increasing the SNR for precise orbit determination (POD), with a fully dedicated instrument. Additionally, it can be applied to two or more satellites, on a leading-trailing trajectory, to improve the gravity field determination. However, the application of this technique to CubeSats in deep space, and inter-satellite link has to be proven. Interplanetary CubeSats need to overcome a few challenges before reaching successfully their deep-space objectives: link to ground-segment, energy supply, protection against radiation, etc. Besides, the Birdy CubeSat — as our basis concept — is designed to be accompanying a mothercraft, and relies partly on the main mission for reaching the target, as well as on data-link with the Earth. However, constraints to the mothercraft needs to be reduced, by having the CubeSat as autonomous as possible. In this respect, propulsion and auto-navigation are key aspects, that we are studying in a Birdy-T engineering model. We envisage a 3U size CubeSat with radio link, object-tracker and imaging function, and autonomous ionic propulsion system. We are considering two case studies for autonomous guidance, navigation and control, with autonomous propulsion: in cruise and in proximity, necessitating ΔV up to 2m/s for a total budget of about 50m/s. In addition to the propulsion, in-flight orbit determination (IFOD

Construction and operation of a solar lighting system | Asuquo ...

African Journals Online (AJOL)

A solar lighting system which can make a 3w lamp glow continuously for about one hour if the battery is fully charged has been constructed. The device can be used for small-scale lighting applications in remote areas that are far away from the power grid. The system has a panel to collect the sun's energy, a battery to store ...

Improving the efficiency of gas turbine systems with volumetric solar receivers

International Nuclear Information System (INIS)

Petrakopoulou, Fontina; Sánchez-Delgado, Sergio; Marugán-Cruz, Carolina; Santana, Domingo

2017-01-01

Highlights: • Study of small and large-scale solar-combined cycle plants with volumetric receivers. • Increase of inlet temperature of combustion air using solar energy. • The combustion exergy efficiency starts to decrease over a certain temperature. • Indications obtained from the energy and exergy analyses differ. - Abstract: The combustion process of gas turbine systems is typically associated with the highest thermodynamic inefficiencies among the system components. A method to increase the efficiency of a combustor and, consequently that of the gas turbine, is to increase the temperature of the entering combustion air. This measure reduces the consumption of fuel and improves the environmental performance of the turbine. This paper studies the incorporation of a volumetric solar receiver into existing gas turbines in order to increase the temperature of the inlet combustion air to 800 °C and 1000 °C. For the first time, detailed thermodynamic analyses involving both energy and exergy principles of both small-scale and large-scale hybrid (solar-combined cycle) power plants including volumetric receivers are realized. The plants are based on real gas turbine systems, the base operational characteristics of which are derived and reported in detail. It is found that the indications obtained from the energy and exergy analyses differ. The addition of the solar plant achieves an increase in the exergetic efficiency when the conversion of solar radiation into thermal energy (i.e., solar plant efficiency) is not accounted for in the definition of the overall plant efficiency. On the other hand, it is seen that it does not have a significant effect on the energy efficiency. Nevertheless, when the solar efficiency is included in the definition of the overall efficiency of the plants, the addition of the solar receiver always leads to an efficiency reduction. It is found that the exergy efficiency of the combustion chamber depends on the varying air

SPIN–SPIN COUPLING IN THE SOLAR SYSTEM

International Nuclear Information System (INIS)

Batygin, Konstantin; Morbidelli, Alessandro

2015-01-01

The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In this work, we explore the rotational evolution of such systems with specific emphasis on quadrupole–quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin–spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensurabilities and apply our results to the illustrative examples of (87) Sylvia and (216) Kleopatra asteroid systems. Cumulatively, our results suggest that spin–spin coupling may be consequential for highly elongated, tightly orbiting binary objects

SPIN–SPIN COUPLING IN THE SOLAR SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Batygin, Konstantin [Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 (United States); Morbidelli, Alessandro, E-mail: kbatygin@gps.caltech.edu [Departement Lagrange, Observatoire de la Côte d’Azur, F-06304 Nice (France)

2015-09-10

The richness of dynamical behavior exhibited by the rotational states of various solar system objects has driven significant advances in the theoretical understanding of their evolutionary histories. An important factor that determines whether a given object is prone to exhibiting non-trivial rotational evolution is the extent to which such an object can maintain a permanent aspheroidal shape, meaning that exotic behavior is far more common among the small body populations of the solar system. Gravitationally bound binary objects constitute a substantial fraction of asteroidal and TNO populations, comprising systems of triaxial satellites that orbit permanently deformed central bodies. In this work, we explore the rotational evolution of such systems with specific emphasis on quadrupole–quadrupole interactions, and show that for closely orbiting, highly deformed objects, both prograde and retrograde spin–spin resonances naturally arise. Subsequently, we derive capture probabilities for leading order commensurabilities and apply our results to the illustrative examples of (87) Sylvia and (216) Kleopatra asteroid systems. Cumulatively, our results suggest that spin–spin coupling may be consequential for highly elongated, tightly orbiting binary objects.

Solar power satellite system; Uchu hatsuden system

Energy Technology Data Exchange (ETDEWEB)

Sasaki, S [Institute of Space and Astronautical Science, Tokyo (Japan)

1995-09-05

The solar power satellite system is a system that converts solar energy into electric energy in the space, transmits power to earth through wireless resort such as microwave and supplies energy of new concept. In order to realize this system it is necessary to have new technologies such as space power transmission at low cost, construction of large space buildings and wireless high power transmission. In this paper, the principles, characteristics and the necessary technology of this system were explained. Besides Japan`s SPS2000 Plan (cooperative research by universities, government agencies and private corporations on the model of solar power satellite) the group of Europe, Russia and the United States has also proposed some ideas concerning the solar power satellite system. As far as the microwave power transmission, which is the key technology for solar power satellite system, is concerned, ground demonstration tests at the level of several tens of kW are discussed in Canada and France. 3 refs., 3 figs.

Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

OpenAIRE

M. Z. H. Khan; M. R. Al-Mamun; S. Sikdar; P. K. Halder; M. R. Hasan

2016-01-01

This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experi...

New views of the solar system

CERN Document Server

2009-01-01

Is your library up to date on the Solar System? When the International Astronomical Union redefined the term "planet," Pluto was stripped of its designation as the solar system''s ninth planet. New Views of the Solar System looks at scientists'' changing perspectives on the solar system, with articles on Pluto, the eight chief planets, and dwarf planets. Brilliant photos and drawings showcase the planets, asteroids, comets, and more, providing a stunning collection of vivid and detailed images of the solar system.

Exploring the solar system

CERN Document Server

Bond, Peter

2012-01-01

The exploration of our solar system is one of humanity's greatest scientific achievements. The last fifty years in particular have seen huge steps forward in our understanding of the planets, the sun, and other objects in the solar system. Whilst planetary science is now a mature discipline - involving geoscientists, astronomers, physicists, and others - many profound mysteries remain, and there is indeed still the tantalizing possibility that we may find evidence of life on another planet in our system.Drawing upon the latest results from the second golden age of Solar System exploration, aut

Solar system astrophysics planetary atmospheres and the outer solar system

CERN Document Server

Milone, Eugene F

2008-01-01

Solar System Astrophysics opens with coverage of the atmospheres, ionospheres and magnetospheres of the Earth, Venus and Mars and the magnetosphere of Mercury. The book then provides an introduction to meteorology and treating the physics and chemistry of these areas in considerable detail. What follows are the structure, composition, particle environments, satellites, and rings of Jupiter, Saturn, Uranus and Neptune, making abundant use of results from space probes. Solar System Astrophysics follows the history, orbits, structure, origin and demise of comets and the physics of meteors and provides a thorough treatment of meteorites, the asteroids and, in the outer solar system, the Kuiper Belt objects. The methods and results of extrasolar planet searches, the distinctions between stars, brown dwarfs, and planets, and the origins of planetary systems are examined. Historical introductions precede the development and discussion in most chapters. A series of challenges, useful as homework assignments or as foc...

Solar thermally driven cooling systems: Some investigation results and perspectives

International Nuclear Information System (INIS)

Ajib, Salman; Günther, Wolfgang

2013-01-01

Highlights: ► Two types of solar thermally driven absorption refrigeration machines (ARMs) have been investigated. ► We investigated the influence of the operating conditions on the effectiveness of the ARMs. ► The influence of the flow rate of the work solution on the effectiveness of the ARMs has been tested. ► Two laboratory test plants have been built and tested under different operating conditions. - Abstract: A big increase in the number of solar thermal cooling installations and research efforts could be seen over the last years worldwide. Especially the producers of solar thermal collectors and systems have been looking for thermal chillers in the small capacity range to provide air conditioning for one or two family houses. Furthermore, many developments aim to increase the efficiency of the system and to decrease the specific costs of the produced refrigeration capacity. The growth in the use of solar thermal cooling systems amounted about 860% from 52 units in 2004 to 450 units in 2009 [1]. This tendency is expected to be continuously in the next years. The practical examinations on solar thermally driven absorption machines with refrigeration capacity of 15, 10 and 5 kW have shown that this technology has a good chance to be standardized and to replace partly the conventional one. These systems can save more primary energy at high fraction of solar thermally driving by suitable control and regulation of the system. The investing costs still higher as the conventional one, however, the operating costs are less than the conventional one. The Coefficient of Performance (COP) depends on the kind of the system, work temperatures and conditions as well as the refrigeration capacity of the systems. It lies between 0.4 and 1.2. In the framework of the research on this field, we built, tested and measured two prototypes. After measuring the first prototype, the chillers were redesigned to reduce internal heat losses and make the heat and mass transfer

Modeling and control of a small solar fuel cell hybrid energy system

Institute of Scientific and Technical Information of China (English)

LI Wei; ZHU Xin-jian; CAO Guang-yi

2007-01-01

This paper describes a solar photovoltaic fuel cell (PVEC) hybrid generation system consisting of a photovoltaic (PV) generator, a proton exchange membrane fuel cell (PEMFC), an electrolyser, a supercapacitor, a storage gas tank and power conditioning unit (PCU). The load is supplied from the PV generator with a fuel cell working in parallel. Excess PV energy when available is converted to hydrogen using an electrolyser for later use in the fuel cell. The individual mathematical model for each component is presented. Control strategy for the system is described. MATLAB/Simulink is used for the simulation of this highly nonlinear hybrid energy system. The simulation results are shown in the paper.

Investigations of solar combi systems

DEFF Research Database (Denmark)

Andersen, Elsa

2005-01-01

). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more......A large variety of solar combi systems are on the marked to day. The best performing systems are highly advanced energy systems with thermal stratification manifolds, an efficient boiler and only one control system, which controls both the boiler and the solar collector loop (Weiss et al., 2003...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical...

Solar System Dynamics

Science.gov (United States)

Wisdom, Jack

2002-01-01

In these 18 years, the research has touched every major dynamical problem in the solar system, including: the effect of chaotic zones on the distribution of asteroids, the delivery of meteorites along chaotic pathways, the chaotic motion of Pluto, the chaotic motion of the outer planets and that of the whole solar system, the delivery of short period comets from the Kuiper belt, the tidal evolution of the Uranian arid Galilean satellites, the chaotic tumbling of Hyperion and other irregular satellites, the large chaotic variations of the obliquity of Mars, the evolution of the Earth-Moon system, and the resonant core- mantle dynamics of Earth and Venus. It has introduced new analytical and numerical tools that are in widespread use. Today, nearly every long-term integration of our solar system, its subsystems, and other solar systems uses algorithms that was invented. This research has all been primarily Supported by this sequence of PGG NASA grants. During this period published major investigations of tidal evolution of the Earth-Moon system and of the passage of the Earth and Venus through non-linear core-mantle resonances were completed. It has published a major innovation in symplectic algorithms: the symplectic corrector. A paper was completed on non-perturbative hydrostatic equilibrium.

Development of Design Methodology for a Small Solar-Powered Unmanned Aerial Vehicle

Directory of Open Access Journals (Sweden)

Parvathy Rajendran

2018-01-01

Full Text Available Existing mathematical design models for small solar-powered electric unmanned aerial vehicles (UAVs only focus on mass, performance, and aerodynamic analyses. Presently, UAV designs have low endurance. The current study aims to improve the shortcomings of existing UAV design models. Three new design aspects (i.e., electric propulsion, sensitivity, and trend analysis, three improved design properties (i.e., mass, aerodynamics, and mission profile, and a design feature (i.e., solar irradiance are incorporated to enhance the existing small solar UAV design model. A design validation experiment established that the use of the proposed mathematical design model may at least improve power consumption-to-take-off mass ratio by 25% than that of previously designed UAVs. UAVs powered by solar (solar and battery and nonsolar (battery-only energy were also compared, showing that nonsolar UAVs can generally carry more payloads at a particular time and place than solar UAVs with sufficient endurance requirement. The investigation also identified that the payload results in the highest effect on the maximum take-off weight, followed by the battery, structure, and propulsion weight with the three new design aspects (i.e., electric propulsion, sensitivity, and trend analysis for sizing consideration to optimize UAV designs.

Fiscal 1976 Sunshine Project result report. Research on solar energy utilization systems (total system); 1976 nendo taiyo energy riyo system chosa kenkyu seika hokokusho. Total system

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-03-01

For every solar energy utilization field, its background, feasibility, impact in practical use, and R and D policy in Japan were studied. Heating and hot water supply by solar energy are already practical because of less technical problems and reasonable profitability, and cooling is also practical as far as a technical viewpoint. At present, the technical level of solar heat power generation is in the stage of basic technology, however, in the future, development of economically reasonable systems will be demanded as well as establishment of its technology. The most difficult problem for realizing practical solar cell power generation systems is cost reduction. It is also another problem that a big demand of Si for solar cells further exceeds the current yield of Si in a semiconductor industry. A small-scale hybrid solar cell power generation system applicable to the roof of general residences is already feasible. Although a solar furnace is still poor in application to industrial fields, it is expected as the leading part for a future solar heat chemical industry. (NEDO)

Thermal destratification in small standard solar tanks due to mixing during tapping

DEFF Research Database (Denmark)

Andersen, Elsa; Furbo, Simon

1999-01-01

The aim of the project is to investigate the thermal destratification in small standard solar tanks due to mixing during tapping. Three different cold water inlet designs are tested. A model of the tested solar tank is verified. Based on the measurements and the calculations it is elucidated how...

A-π-D-π-A Electron-Donating Small Molecules for Solution-Processed Organic Solar Cells: A Review.

Science.gov (United States)

Wang, Zhen; Zhu, Lingyun; Shuai, Zhigang; Wei, Zhixiang

2017-11-01

Organic solar cells based on semiconducting polymers and small molecules have attracted considerable attention in the last two decades. Moreover, the power conversion efficiencies for solution-processed solar cells containing A-π-D-π-A-type small molecules and fullerenes have reached 11%. However, the method for designing high-performance, photovoltaic small molecules still remains unclear. In this review, recent studies on A-π-D-π-A electron-donating small molecules for organic solar cells are introduced. Moreover, the relationships between molecular properties and device performances are summarized, from which inspiration for the future design of high performance organic solar cells may be obtained. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Accident and everyday use for small PV power supply system. 2; Saigaiji ken`yo kogata taiyoko hatsuden system. 2

Energy Technology Data Exchange (ETDEWEB)

Yokoyama, S.; Sano, N.; Itsumi, J. [Kumamoto Institute of Technology, Kumamoto (Japan)

1997-11-25

Study is under way for the development of a small power source system capable of supplying power to public facilities and home appliances at normal times and capable of turning immediately into a self-sustained power source in case of emergency. This study discusses a power source that is a combination of solar cell modules and a storage battery, which is subjected to analysis for its match with a light or a data-processing computer imposed as a load on the power source. In the experiment, the power source consists of solar cell modules and a rectangular wave inverter. The battery is a 12V/28Ah automotive battery, the solar cells are two 75W (17V/4.4A) modules, and the load is a fluorescent lamp, fan, electric bulb, or a computer. It is found that the system can operate near the maximum power point of the solar cell modules when the load is light and that the system still works on even when the load consumes more than what the solar cells module produce, this thanks to the battery serving as a backup. In the future, a test-dedicated small power source now under construction will be put to continuous operation for further study. 4 refs., 4 figs., 1 tab.

Physics and chemistry of the solar system

CERN Document Server

Lewis, John S

2004-01-01

Physics and Chemistry of the Solar System, 2nd Edition, is a comprehensive survey of the planetary physics and physical chemistry of our own solar system. It covers current research in these areas and the planetary sciences that have benefited from both earth-based and spacecraft-based experimentation. These experiments form the basis of this encyclopedic reference, which skillfully fuses synthesis and explanation. Detailed chapters review each of the major planetary bodies as well as asteroids, comets, and other small orbitals. Astronomers, physicists, and planetary scientists can use this state-of-the-art book for both research and teaching. This Second Edition features extensive new material, including expanded treatment of new meteorite classes, spacecraft findings from Mars Pathfinder through Mars Odyssey 2001, recent reflections on brown dwarfs, and descriptions of planned NASA, ESA, and Japanese planetary missions.* New edition features expanded treatment of new meteorite classes, the latest spacecraft...

Solar system fault detection

Science.gov (United States)

Farrington, R.B.; Pruett, J.C. Jr.

1984-05-14

A fault detecting apparatus and method are provided for use with an active solar system. The apparatus provides an indication as to whether one or more predetermined faults have occurred in the solar system. The apparatus includes a plurality of sensors, each sensor being used in determining whether a predetermined condition is present. The outputs of the sensors are combined in a pre-established manner in accordance with the kind of predetermined faults to be detected. Indicators communicate with the outputs generated by combining the sensor outputs to give the user of the solar system and the apparatus an indication as to whether a predetermined fault has occurred. Upon detection and indication of any predetermined fault, the user can take appropriate corrective action so that the overall reliability and efficiency of the active solar system are increased.

The solar system

International Nuclear Information System (INIS)

Ryan, P.

1981-01-01

A comprehensive review is given of the most recent findings on the solar system. The physical processes in the sun are presented, their interactions in the interplanetary space, and the planets and moons of the solar system. The sun and its moon are discussed in great detail. The text is supplemented by excellent satellite pictures, including the latest pictures of Jupiter, Saturn, and their moons. (HM) [de

Small-scale installations. Solar concentration system for architectural integration; Instalaciones de pequeno tamano. Sistema de concetracion solar para integracion arquitectonica

Energy Technology Data Exchange (ETDEWEB)

Chemisana, D.; Rosell, J.

2010-07-01

Concentration solar systems now practically limit its use in large installations with devices of considerable size, such as generator systems central tower parabolic trough concentrators for power generation. Disco-parabolic concentrators with Stirling engine or the great fans that support two-axis Fresnel lenses in combination with occasional multilayered cells with or without secondary concentrator. (Author) 11 refs.

The New Solar System

Science.gov (United States)

Beatty, J. Kelly; Collins Petersen, Carolyn; Chaikin, Andrew

1999-01-01

As the definitive guide for the armchair astronomer, The New Solar System has established itself as the leading book on planetary science and solar system studies. Incorporating the latest knowledge of the solar system, a distinguished team of researchers, many of them Principal Investigators on NASA missions, explain the solar system with expert ease. The completely-revised text includes the most recent findings on asteroids, comets, the Sun, and our neighboring planets. The book examines the latest research and thinking about the solar system; looks at how the Sun and planets formed; and discusses our search for other planetary systems and the search for life in the solar system. In full-color and heavily-illustrated, the book contains more than 500 photographs, portrayals, and diagrams. An extensive set of tables with the latest characteristics of the planets, their moon and ring systems, comets, asteroids, meteorites, and interplanetary space missions complete the text. New to this edition are descriptions of collisions in the solar system, full scientific results from Galileo's mission to Jupiter and its moons, and the Mars Pathfinder mission. For the curious observer as well as the student of planetary science, this book will be an important library acquisition. J. Kelly Beatty is the senior editor of Sky & Telescope, where for more than twenty years he has reported the latest in planetary science. A renowned science writer, he was among the first journalists to gain access to the Soviet space program. Asteroid 2925 Beatty was named on the occasion of his marriage in 1983. Carolyn Collins Petersen is an award-winning science writer and co-author of Hubble Vision (Cambridge 1995). She has also written planetarium programs seen at hundreds of facilities around the world. Andrew L. Chaikin is a Boston-based science writer. He served as a research geologist at the Smithsonian Institution's Center for Earth and Planetary Studies. He is a contributing editor to

Solar system for exploitation of the whole collected energy

Science.gov (United States)

Ciamberlini, C.; Francini, F.; Longobardi, G.; Piattelli, M.; Sansoni, P.

2003-09-01

An innovative architecture for the exploitation of the whole collected solar energy is described. A sun pointing optical concentrator focuses the received energy, containing the part of the required solar spectrum, in a low loss optical fibre transmission line. The optical panel is small in size and able to follow the sun in order to collect the maximum of its energy. The support is flat, 5 mm thick and includes four optical concentrators. The efficiency of the optical system depends on the optical configuration and on the material utilised for the optical components. Single commercial connector to the fixed fibres connects the fibre optics' four free ends. The energy is therefore properly transported to any user's end with an easy installation. The system was experimented for lightening, during the day, dissipated in a dark load in order to produce heat in some equipment and for photovoltaic applications. The total efficiency of the system was between 68% and 72%. Once the solar energy reaches the end of the transmission line, it can be addressed to the required utilisation by means of an optical switch, which redirects the sunlight towards the desired applicator. This procedure allows utilising the 100% of the sun-collected energy. Since the size of the panel was small, it can be placed, on the roof, on the garden, on the window-sill, on the field and on all sides exposed to sunlight.

Estimation of monthly solar radiation distribution for solar energy system analysis

International Nuclear Information System (INIS)

Coskun, C.; Oktay, Z.; Dincer, I.

2011-01-01

The concept of probability density frequency, which is successfully used for analyses of wind speed and outdoor temperature distributions, is now modified and proposed for estimating solar radiation distributions for design and analysis of solar energy systems. In this study, global solar radiation distribution is comprehensively analyzed for photovoltaic (PV) panel and thermal collector systems. In this regard, a case study is conducted with actual global solar irradiation data of the last 15 years recorded by the Turkish State Meteorological Service. It is found that intensity of global solar irradiance greatly affects energy and exergy efficiencies and hence the performance of collectors. -- Research highlights: → The first study to apply global solar radiation distribution in solar system analyzes. → The first study showing global solar radiation distribution as a parameter of the solar irradiance intensity. → Time probability intensity frequency and probability power distribution do not have similar distribution patterns for each month. → There is no relation between the distribution of annual time lapse and solar energy with the intensity of solar irradiance.

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.

The Physics of Small Molecule Acceptors for Efficient and Stable Bulk Heterojunction Solar Cells

KAUST Repository

Gasparini, Nicola

2018-01-29

Organic bulk heterojunction solar cells based on small molecule acceptors have recently seen a rapid rise in the power conversion efficiency with values exceeding 13%. This impressive achievement has been obtained by simultaneous reduction of voltage and charge recombination losses within this class of materials as compared to fullerene-based solar cells. In this contribution, the authors review the current understanding of the relevant photophysical processes in highly efficient nonfullerene acceptor (NFA) small molecules. Charge generation, recombination, and charge transport is discussed in comparison to fullerene-based composites. Finally, the authors review the superior light and thermal stability of nonfullerene small molecule acceptor based solar cells, and highlight the importance of NFA-based composites that enable devices without early performance loss, thus resembling so-called burn-in free devices.

The Physics of Small Molecule Acceptors for Efficient and Stable Bulk Heterojunction Solar Cells

KAUST Repository

Gasparini, Nicola; Wadsworth, Andrew; Moser, Maximilian; Baran, Derya; McCulloch, Iain; Brabec, Christoph J.

2018-01-01

Organic bulk heterojunction solar cells based on small molecule acceptors have recently seen a rapid rise in the power conversion efficiency with values exceeding 13%. This impressive achievement has been obtained by simultaneous reduction of voltage and charge recombination losses within this class of materials as compared to fullerene-based solar cells. In this contribution, the authors review the current understanding of the relevant photophysical processes in highly efficient nonfullerene acceptor (NFA) small molecules. Charge generation, recombination, and charge transport is discussed in comparison to fullerene-based composites. Finally, the authors review the superior light and thermal stability of nonfullerene small molecule acceptor based solar cells, and highlight the importance of NFA-based composites that enable devices without early performance loss, thus resembling so-called burn-in free devices.

Exploring the Solar System? Let the Math Teachers Help!

Science.gov (United States)

Charles, Karen; Canales, J. D.; Smith, Angela; Zimmerman, Natalie

2012-01-01

Scale measurement and ratio and proportion are topics that fall clearly in the middle-grades mathematics curriculum in Texas. So does the solar system. In their experience, the authors have found that students have trouble manipulating, much less comprehending, very large numbers and very small numbers. These concepts can be brought into students'…

A CONCEPT OF SOLAR TRACKER SYSTEM DESIGN

OpenAIRE

Meita Rumbayan *, Muhamad Dwisnanto Putro

2017-01-01

Improvement of solar panel efficiency is an ongoing research work recently. Maximizing the output power by integrating with the solar tracker system becomes a interest point of the research. This paper presents the concept in designing a solar tracker system applied to solar panel. The development of solar panel tracker system design that consist of system display prototype design, hardware design, and algorithm design. This concept is useful as the control system for solar tracker to improve...

A hybrid solar chemical looping combustion system with a high solar share

International Nuclear Information System (INIS)

Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

2014-01-01

Highlights: • A novel hybrid solar chemical looping combustion system is presented. • This hybrid CLC system integrates a CLC plant with a solar thermal energy plant. • The oxygen carrier particles are used for chemical and sensible thermal energy storage. • A solar cavity reactor is proposed for fuel reactor. • The calculations show a total solar share of around 60% can be achieved. - Abstract: A novel hybrid solar chemical looping combustion (Hy-Sol-CLC) is presented, in which the oxygen carrier particles in a CLC system are employed to provide thermal energy storage for concentrated solar thermal energy. This hybrid aims to take advantage of key features of a chemical looping combustion (CLC) system that are desirable for solar energy systems, notably their inherent chemical and sensible energy storage systems, the relatively low temperature of the “fuel” reactor (to which the concentrated solar thermal energy is added in a hybrid) relative to that of the final temperature of the product gas and the potential to operate the fuel reactor at a different pressure to the heated gas stream. By this approach, it is aimed to achieve high efficiency of the solar energy, infrastructure sharing, economic synergy, base load power generation and a high solar fraction of the total energy. In the proposed Hy-Sol-CLC system, a cavity solar receiver has been chosen for fuel reactor while for the storage of the oxygen carrier particles two reservoirs have been added to a conventional CLC. A heat exchanger is also proposed to provide independent control of the temperatures of the storage reservoirs from those of solar fuel and air reactors. The system is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The operating temperature of the fuel reactor, solar absorption efficiency, solar share, fraction of the solar thermal energy stored within the solar reactor, the fractions of sensible and

Solar system exploration

International Nuclear Information System (INIS)

Briggs, G.A.; Quaide, W.L.

1986-01-01

Two fundamental goals lie at the heart of U.S. solar system exploration efforts: first, to characterize the evolution of the solar system; second, to understand the processes which produced life. Progress in planetary science is traced from Newton's definition of the principles of gravitation through a variety of NASA planetary probes in orbit, on other planets and traveling beyond the solar system. It is noted that most of the planetary data collected by space probes are always eventually applied to improving the understanding of the earth, moon, Venus and Mars, the planets of greatest interest to humans. Significant data gathered by the Mariner, Viking, Apollo, Pioneer, and Voyager spacecraft are summarized, along with the required mission support capabilities and mission profiles. Proposed and planned future missions to Jupiter, Saturn, Titan, the asteroids and for a comet rendzvous are described

Solar air heating system for combined DHW and space heating

Energy Technology Data Exchange (ETDEWEB)

Oestergaard Jensen, S.; Bosanac, M.

2002-12-01

The project deals with the development and testing of a simple system for utilization of the summer excess heat from small solar air heating systems for preheating of fresh air. The principle of the system is to lead the heated air down around a domestic hot water tank letting the surface of the tank act as heat exchanger between the air and the water. In order to increase the heat transfer, coefficient fins into the air stream were mounted on the tank. A complete system with 3 m{sup 2} solar air collector, ductworks and a 85 litre storage were set up and extensively monitored. The air stream through the system was created by a fan connected directly to one or two PV-panels leading to a solar radiation dependent flow rate without the use of any other control. Based on monitoring results the system was characterized and a TRNSYS model of the system was developed and calibrated/validated. The monitoring and the simulations with the TRNSYS model revealed several interesting things about the system. The monitoring revealed that the system is capable of bringing the temperature of the water in the storage above 60 deg. C at warm days with clear sky conditions. The storage is very stratified, which is beneficial as usable hot water temperatures rather quickly are obtained. The performance was highly dependent on the airflow rate through the system. It can be concluded that the investigated system will have a performance in the order of 500 kWh during the winter, spring and autumn months and around 250 kWh during the four summer months - or in total a yearly performance of 750 kWh/m{sup 2}. A small traditional solar heating system for preheating of domestic hot water would have a higher performance during the four summer months, but no performance during the rest of the year if the system is installed in a summer house, which only is occupied during the summer. The parametric analysis further indicates that it is possible to further optimise the system when the thermal

Dark matter, neutrinos, and our solar system

CERN Document Server

Prakash, Nirmala

2013-01-01

Dark Matter, Neutrinos, and Our Solar System is a unique enterprise that should be viewed as an important contribution to our understanding of dark matter, neutrinos and the solar system. It describes these issues in terms of links, between cosmology, particle and nuclear physics, as well as between cosmology, atmospheric and terrestrial physics. It studies the constituents of dark matter (classified as hot warm and cold) first in terms of their individual structures (baryonic and non-baryonic, massive and non-massive, interacting and non-interacting) and second, in terms of facilities available to detect these structures (large and small). Neutrinos (an important component of dark matter) are treated as a separate entity. A detailed study of these elusive (sub-atomic) particles is done, from the year 1913 when they were found as byproducts of beta decay -- until the discovery in 2007 which confirmed that neutrino flavors were not more than three (as speculated by some). The last chapter of the book details t...

A survey of manufacturers of solar thermal energy systems

Science.gov (United States)

Levine, N.; Slonski, M. L.

1982-01-01

Sixty-seven firms that had received funding for development of solar thermal energy systems (STES) were surveyed. The effect of the solar thermal technology systems program in accelerating (STES) were assessed. The 54 firms still developing STES were grouped into a production typology comparing the three major technologies with three basic functions. It was discovered that large and small firms were developing primarily central receiver systems, but also typically worked on more than one technology. Most medium-sized firms worked only on distributed systems. Federal support of STES was perceived as necessary to allow producers to take otherwise unacceptable risks. Approximately half of the respondents would drop out of STES if support were terminated, including a disproportionate number of medium-sized firms. A differentiated view of the technology, taking into account differing firm sizes and the various stages of technology development, was suggested for policy and planning purposes.

Energy savings for solar heating systems; Solvarmeanlaegs energibesparelser

Energy Technology Data Exchange (ETDEWEB)

Furbo, S.; Fan, J.

2011-01-15

Energy savings for a number of new solar heating systems in one family houses have been determined by means of information on the energy consumption of the houses before and after installation of the solar heating systems. The investigated solar heating systems are marketed by Velux Danmark A/S, Sonnnenkraft Scandinavia A/S and Batec Solvarme A/S. Solar domestic hot water systems as well as solar combi systems are included in the investigations The houses have different auxiliary energy supply systems: Natural gas boilers, oil fired burners, electrical heating and district heating. Some of the houses have a second auxiliary energy supply system. The collector areas vary from 1.83 m{sup 2} to 9.28 m{sup 2}. Some of the solar heating systems are based on energy units with a new integrated natural gas boiler and a heat storage for the solar heating system. The existing energy systems in the houses are for most of the houses used as the auxiliary energy systems for the solar heating systems. The yearly energy savings for the houses where the only change is the installation of the solar heating system vary from 300 kWh per m{sup 2} solar collector to 1300 kWh per m{sup 2} solar collector. The average yearly energy savings is about 670 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector are not influenced by the solar heating system type, the company marketing the system, the auxiliary energy supply system, the collector area, the collector tilt, the collector azimuth, the energy consumption of the house or the location of the house. The yearly energy savings for the houses with solar heating systems based on energy units including a new natural gas boiler vary from 790 kWh per m{sup 2} solar collector to 2090 kWh per m{sup 2} solar collector. The average yearly energy savings is about 1520 kWh per m{sup 2} solar collector for these solar heating systems. The energy savings per m{sup 2} solar collector for

High performance in low-flow solar domestic hot water systems

Energy Technology Data Exchange (ETDEWEB)

Dayan, M.

1997-12-31

Low-flow solar hot water heating systems employ flow rates on the order of 1/5 to 1/10 of the conventional flow. Low-flow systems are of interest because the reduced flow rate allows smaller diameter tubing, which is less costly to install. Further, low-flow systems result in increased tank stratification. Lower collector inlet temperatures are achieved through stratification and the useful energy produced by the collector is increased. The disadvantage of low-flow systems is the collector heat removal factor decreases with decreasing flow rate. Many solar domestic hot water systems require an auxiliary electric source to operate a pump in order to circulate fluid through the solar collector. A photovoltaic driven pump can be used to replace the standard electrical pump. PV driven pumps provide an ideal means of controlling the flow rate, as pumps will only circulate fluid when there is sufficient radiation. Peak performance was always found to occur when the heat exchanger tank-side flow rate was approximately equal to the average load flow rate. For low collector-side flow rates, a small deviation from the optimum flow rate will dramatically effect system performance.

Small-Sized Parabolic Trough Collector System for Solar Dehumidification Application: Design, Development, and Potential Assessment

Directory of Open Access Journals (Sweden)

Ghulam Qadar Chaudhary

2018-01-01

Full Text Available The current study presents a numerical and real-time performance analysis of a parabolic trough collector (PTC system designed for solar air-conditioning applications. Initially, a thermodynamic model of PTC is developed using engineering equation solver (EES having a capacity of around 3 kW. Then, an experimental PTC system setup is established with a concentration ratio of 9.93 using evacuated tube receivers. The experimental study is conducted under the climate of Taxila, Pakistan in accordance with ASHRAE 93-1986 standard. Furthermore, PTC system is integrated with a solid desiccant dehumidifier (SDD to study the effect of various operating parameters such as direct solar radiation and inlet fluid temperature and its impact on dehumidification share. The experimental maximum temperature gain is around 5.2°C, with the peak efficiency of 62% on a sunny day. Similarly, maximum thermal energy gain on sunny and cloudy days is 3.07 kW and 2.33 kW, respectively. Afterwards, same comprehensive EES model of PTC with some modifications is used for annual transient analysis in TRNSYS for five different climates of Pakistan. Quetta revealed peak solar insolation of 656 W/m2 and peak thermal energy 1139 MJ with 46% efficiency. The comparison shows good agreement between simulated and experimental results with root mean square error of around 9%.

Combined heat and power solar system

International Nuclear Information System (INIS)

Anon

2000-01-01

An Australian-designed photovoltaic (PV) power system that also supplies hot water is close to commercial release. PVs have been around for decades and solar concentrators have been efficiently heating water for nearly a century. The Australian National University, Department of Engineering - Centre for Sustainable Energy systems (CSES), has designed a domestic scale modular system that not only generates electricity but also provides concentrated thermal energy to heat water for a Solahart hot water system and is designed to be deployed into small to medium scale applications such as hospitals, schools and dwellings with an easily assembled galvanised steel frame. A market research was carried out and is envisaged that at least 7,500 units will be installed annually by the year 2005 and up to 25,000 units by 2008

Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

International Nuclear Information System (INIS)

Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van; Rodríguez, J. Blanco; Iniesta, J. C. Del Toro; Suárez, D. Orozco; Schmidt, W.; Pillet, V. Martínez; Knölker, M.

2017-01-01

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields

Energy Technology Data Exchange (ETDEWEB)

Chitta, L. P.; Peter, H.; Solanki, S. K.; Barthol, P.; Gandorfer, A.; Gizon, L.; Hirzberger, J.; Riethmüller, T. L.; Noort, M. van [Max-Planck-Institut für Sonnensystemforschung, Justus-von-Liebig-Weg 3, D-37077 Göttingen (Germany); Rodríguez, J. Blanco [Grupo de Astronomía y Ciencias del Espacio, Universidad de Valencia, E-46980 Paterna, Valencia (Spain); Iniesta, J. C. Del Toro; Suárez, D. Orozco [Instituto de Astrofísica de Andalucía (CSIC), Apartado de Correos 3004, E-18080 Granada (Spain); Schmidt, W. [Kiepenheuer-Institut für Sonnenphysik, Schöneckstr. 6, D-79104 Freiburg (Germany); Pillet, V. Martínez [National Solar Observatory, 3665 Discovery Drive, Boulder, CO 80303 (United States); Knölker, M., E-mail: chitta@mps.mpg.de [High Altitude Observatory, National Center for Atmospheric Research, P.O. Box 3000, Boulder, CO 80307-3000 (United States)

2017-03-01

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the solar corona. To address the above question, we use high-resolution line-of-sight magnetic field data from the Imaging Magnetograph eXperiment instrument on the Sunrise balloon-borne observatory and coronal observations from the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory of an emerging active region. We find that the coronal loops are often rooted at the locations with minor small-scale but persistent opposite-polarity magnetic elements very close to the larger dominant polarity. These opposite-polarity small-scale elements continually interact with the dominant polarity underlying the coronal loop through flux cancellation. At these locations we detect small inverse Y-shaped jets in chromospheric Ca ii H images obtained from the Sunrise Filter Imager during the flux cancellation. Our results indicate that magnetic flux cancellation and reconnection at the base of coronal loops due to mixed polarity fields might be a crucial feature for the supply of mass and energy into the corona.

Solar cell concentrating system

International Nuclear Information System (INIS)

Garg, H.P.; Sharma, V.K.; Agarwal, R.K.

1986-11-01

This study reviews fabrication techniques and testing facilities for different solar cells under concentration which have been developed and tested. It is also aimed to examine solar energy concentrators which are prospective candidates for photovoltaic concentrator systems. This may provide an impetus to the scientists working in the area of solar cell technology

Performance evaluation of a state-of-the-art solar air-heating system with auxiliary heat pump

Science.gov (United States)

1980-01-01

The system in Solar House 2 consists of 57.9 sq. m. of Solaron Series 300 Collectors, 10.3 cu. m. of pebble bed storage, domestic water preheating capability and a Carrier air-to-air heat pump as an auxiliary heater. Although the control subsystem was specially constructed to facilitate experimental changes and data reduction, the balance of the solar system was assembled with off-the-shelf components. Since all components of the system are commercially available the system is considered to be a state of the art solar air-heating system. The system design is one that is recommended for residential and small office buildings.

Tandem planet formation for solar system-like planetary systems

Directory of Open Access Journals (Sweden)

Yusuke Imaeda

2017-03-01

Full Text Available We present a new united theory of planet formation, which includes magneto-rotational instability (MRI and porous aggregation of solid particles in a consistent way. We show that the “tandem planet formation” regime is likely to result in solar system-like planetary systems. In the tandem planet formation regime, planetesimals form at two distinct sites: the outer and inner edges of the MRI suppressed region. The former is likely to be the source of the outer gas giants, and the latter is the source for the inner volatile-free rocky planets. Our study spans disks with a various range of accretion rates, and we find that tandem planet formation can occur for M˙=10−7.3-10−6.9M⊙yr−1. The rocky planets form between 0.4–2 AU, while the icy planets form between 6–30 AU; no planets form in 2–6 AU region for any accretion rate. This is consistent with the gap in the solid component distribution in the solar system, which has only a relatively small Mars and a very small amount of material in the main asteroid belt from 2–6 AU. The tandem regime is consistent with the idea that the Earth was initially formed as a completely volatile-free planet. Water and other volatile elements came later through the accretion of icy material by occasional inward scattering from the outer regions. Reactions between reductive minerals, such as schreibersite (Fe3P, and water are essential to supply energy and nutrients for primitive life on Earth.

Solar Irradiance & On Grid Solar Power Systems with Net Metering in Pakistan

Directory of Open Access Journals (Sweden)

Haleema Qamar

2016-06-01

Full Text Available This paper presents a case study of solar irradiance and scope of on-grid solar power systems with net-metering in Pakistan. Detailed analysis of solar irradiance in Pakistan is being carried out by developing the dedicated solar excel sheets. The need of on grid solar power systems for the present energy crisis in developing countries like Pakistan is also discussed. It also presents the inclination of many countries especially USA and Europe towards it. Identification of barriers for implementing on grid net metered solar power systems in Pakistan along with solutions of these barriers is carried out.

Performance test of solar energy distillation system; Taiyonetsu riyo kaisui tansuika system no zosui seino shiken

Energy Technology Data Exchange (ETDEWEB)

Kawahara, T; Toyoshima, Y [Keio University, Tokyo (Japan); Narasaki, Y; Kamiya, I [Ebara Corp., Tokyo (Japan); Sato, H [Keio University, Tokyo (Japan). Faculty of Science and Technology

1997-11-25

In order to develop a seawater desalination equipment utilizing solar heat, a performance test was performed on a three-stage solar heat vacuum distiller. The equipment can evaporate and condense water at low temperatures by reducing the pressure in a distilling section. Solar heat is collected by a heat collecting plate, by which water as the working fluid is evaporated and moved to a heat conducting section in an evaporation pipe in a state of steam. The steam is condensed in a low-temperature heat conducting pipe, the heat is released outside the heat conducting pipe, and seawater is evaporated under low pressure condition. The working fluid is circulated for repetitive use. Solar cells are used as a motive power source for a vacuum pump, hence the system is self-sustainable even if installed in a desert area and the like places. The construction is simple, highly durable, and easy in maintenance. The system has high water producing performance, uses no harmful substances whatsoever such as fluorocarbons, and is a friendly system to the global environment. Because of evaporation at low temperatures, heat loss to the surroundings and sensible heat due to temperature rise are small, and the system response is quick. The solar heat can be utilized more effectively as multiple effects. When a heat collecting plate of 7.76 m {sup 2} was used, maximum yield of 105.45 kg/day was obtained. The system`s distillation efficiency is higher than other types of solar heat utilizing distillers. 7 refs., 5 figs.

Interactions in the early solar system

International Nuclear Information System (INIS)

Dormand, J.R.; Woolfson, M.M.

1977-01-01

The capture theory of the origin of the solar system predicts protoplanets formed in near coplanar elliptical orbits with fairly high eccentricities. A resisting medium, which would be a byproduct of the capture event, would serve to round-off the orbits in a time which is short compared to the age of the solar system. It is shown that such a medium would also give rise to differential rotations of the lines of apses of the early planetary orbits, leading to a high probability of close interactions or collisions between planets. The consequences of a collision between two planets are considered. It is found that the larger planet could, in some cases, be expelled from the solar system and that the fragments of the small planet could give rise to some of the terrestrial planets. Moreover, it is suggested that the Earth-Moon system could be formed as as result of the capture of a major satellite of one of the colliding planets by a large fragment of the other planet. Mars is also identified in the satellite system of the ejected planet. Various types of debris from the collision could have produced the asteroids, meteorites and comets. An alternative explanation, in terms of the original event, is also given for the comets. The hypothesis is examined that Pluto is a byproduct of the collision, reaching its present orbit by interactions with Neptune. It is shown that as a consequence of such an interaction, Triton could have been perturbed sufficiently to reverse an initially prograde orbital motion. The transfer of Pluto from the collision region to the vicinity of Neptune could have occurred through multiple planetary perturbation. The outer satellites of Jupiter and Saturn are discussed in relation to the proposition that they originated from the debris of asteroid collisions within the spheres of influence of those planets. (author)

Solar desalination system of combined solar still and humidification-dehumidification unit

Science.gov (United States)

Ghazy, Ahmed; Fath, Hassan E. S.

2016-11-01

Solar stills, as a simple technology, have many advantages such as simple design; unsophisticated fabrication; low capital and operation costs and easily maintained. However, their low daily production has put constraints on their usage. A radical improvement in the performance of solar stills can be achieved by the partial recovery of the energy losses from the glass cover of the still. This paper simulates a direct solar distillation system of combined solar still with an air heating humidification-dehumidification (HDH) sub-system. The main objective of the Still-HDH system is to improve the productivity and thermal efficiency of the conventional solar still by partially recovering the still energy losses to the ambient for additional water production. Various procedures have been employed to improve the thermal performance of the integrated system by recovering heat losses from one component in another component of the system. Simulations have been carried out for the performance of the Still-HDH system under different weather conditions. A comparison has been held between the Still-HDH system and a conventional solar still of the same size and under the same operating conditions.

Exergy and economic analysis of a pyramid-shaped solar water purification system: Active and passive cases

International Nuclear Information System (INIS)

Kianifar, Ali; Zeinali Heris, Saeed; Mahian, Omid

2012-01-01

An exergy analysis has been conducted to show the effect of a small fan on the exergy efficiency in a pyramid-shaped solar still. The tests were carried out in Mashhad (36° 36′ N), for two solar still systems. One of them was equipped with a small fan (active system), to enhance the evaporation rate while the other one was tested in passive condition (no fan). To examine the effects of radiation and water depth on exergy efficiency, experiments in two seasons and two different depths of water in the solar still basin were performed. The results show that during summer, active unit has higher exergy efficiency than passive one while in winter there is no considerable difference between the exergy efficiency of the units. Results also reveal that the exergy efficiency is higher when the water depth in the basin is lower. Finally, the economic analysis shows a considerable reduction in production cost of the water (8–9%) when the active system is used. -- Highlights: ► Using a small fan in the solar still; reduces the productive cost of fresh water up to 9%. ► Effects of the fan and basin depth on the exergy efficiency during summer and winter were examined. ► Utilizing an active system will increase the daily productivity of fresh water by 20%.

Origins of Inner Solar Systems

Science.gov (United States)

Dawson, Rebekah Ilene

2017-06-01

Over the past couple decades, thousands of extra-solar planetshave been discovered orbiting other stars. The exoplanets discovered to date exhibit a wide variety of orbital and compositional properties; most are dramatically different from the planets in our own Solar System. Our classical theories for the origins of planetary systems were crafted to account for the Solar System and fail to account for the diversity of planets now known. We are working to establish a new blueprint for the origin of planetary systems and identify the key parameters of planet formation and evolution that establish the distribution of planetary properties observed today. The new blueprint must account for the properties of planets in inner solar systems, regions of planetary systems closer to their star than Earth’s separation from the Sun and home to most exoplanets detected to data. I present work combining simulations and theory with data analysis and statistics of observed planets to test theories of the origins of inner solars, including hot Jupiters, warm Jupiters, and tightly-packed systems of super-Earths. Ultimately a comprehensive blueprint for planetary systems will allow us to better situate discovered planets in the context of their system’s formation and evolution, important factors in whether the planets may harbor life.

Testing solar panels for small-size satellites: the UPMSAT-2 mission

Science.gov (United States)

Roibás-Millán, E.; Alonso-Moragón, A.; Jiménez-Mateos, A. G.; Pindado, S.

2017-11-01

At present, the development of small-size satellites by universities, companies and research institutions has become usual practice, and is spreading rapidly. In this kind of project cost plays a significant role. One of the main areas are the assembly, integration and test (AIT) plans, which carry an associated cost for simulating environmental conditions. For instance, in the power subsystems test and, in particular, in the testing of solar panels, the irradiance and temperature conditions might be optimum so the performance of the system can be shown next to real operational conditions. To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase in cost for testing the equipment. The aim of this paper is to present an alternative and inexpensive way to perform AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I-V characteristics obtained are compared with a theoretical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely on the manufacturer’s data.

Testing solar panels for small-size satellites: the UPMSAT-2 mission

International Nuclear Information System (INIS)

Roibás-Millán, E; Alonso-Moragón, A; Jiménez-Mateos, A G; Pindado, S

2017-01-01

At present, the development of small-size satellites by universities, companies and research institutions has become usual practice, and is spreading rapidly. In this kind of project cost plays a significant role. One of the main areas are the assembly, integration and test (AIT) plans, which carry an associated cost for simulating environmental conditions. For instance, in the power subsystems test and, in particular, in the testing of solar panels, the irradiance and temperature conditions might be optimum so the performance of the system can be shown next to real operational conditions. To reproduce the environmental conditions in terms of irradiance, solar simulators are usually used, which carries an associated increase in cost for testing the equipment. The aim of this paper is to present an alternative and inexpensive way to perform AIT plans on spacecraft power subsystems, from a testing campaign performed using outdoor clean-sky conditions and an isolation system to protect the panels. A post-process of the measured data is therefore needed, taking into account the conditions in which the test has been accomplished. The I–V characteristics obtained are compared with a theoretical 1-diode/2-resistor equivalent electric circuit, achieving enough precision based solely on the manufacturer’s data. (paper)

Efficacy of solar power units for small-scale businesses in a remote rural area, South Africa

Energy Technology Data Exchange (ETDEWEB)

Hajat, A.; Shackleton, C.M. [Dept of Environmental Science, Rhodes University, Grahamstown 6140 (South Africa); Banks, D.; Aiken, R. [Restio Energy, 14 Clifton Road, Mowbray, Cape Town (South Africa)

2009-12-15

Much work has considered the practicalities and affordability of solar systems for domestic energy supplies in remote rural areas. There is less understanding of its utility for small-scale business enterprises in such areas. We examined the patterns of use of two 12 V and one 24 V systems for small-scale enterprises housed in transportable containers. Monitoring of load shed and top of charge indicated that the 12 V systems were inadequate to meet the requirements of the enterprises. The 24 V operation performed a lot better. Despite some technical limitations the system offered a number of social, economic and environmental positives; primarily the offering of business products not otherwise available in the area, incomes to the entrepreneurs and greater connectivity with regional centres through office services such as cell-phone charging and faxing. Customers of the small-scale enterprises felt that their presence in the area saved them some money because they no longer had to travel as frequently to regional urban centres. (author)

Adaptive, full-spectrum solar energy system

Science.gov (United States)

Muhs, Jeffrey D.; Earl, Dennis D.

2003-08-05

An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

Development of smart solar tanks

DEFF Research Database (Denmark)

Furbo, Simon; Andersen, Elsa

1999-01-01

The aim of the project is to develop smart solar tanks. A smart solar tank is a tank in which the domestic water can bee heated both by solar collectors and by an auxiliary energy supply system. The auxiliary energy supply system heats up the hot-water tank from the top and the water volume heated...... by the auxiliary energy supply system is fitted to the hot water consumption and consumption pattern. In periods with a large hot-water demand the volume is large, in periods with a small hot-water demand the volume is small. Based on measurements and calculations the advantage of smart SDHW systems is visualised....

Development of Solar Powered Irrigation System

International Nuclear Information System (INIS)

Abdelkerim, A I; Eusuf, M M R Sami; Salami, M J E; Aibinu, A; Eusuf, M A

2013-01-01

Development of a solar powered irrigation system has been discussed in this paper. This system would be SCADA-based and quite useful in areas where there is plenty of sunshine but insufficient water to carry out farming activities, such as rubber plantation, strawberry plantation, or any plantation, that requires frequent watering. The system is powered by solar system as a renewable energy which uses solar panel module to convert Sunlight into electricity. The development and implementation of an automated SCADA controlled system that uses PLC as a controller is significant to agricultural, oil and gas monitoring and control purpose purposes. In addition, the system is powered by an intelligent solar system in which solar panel targets the radiation from the Sun. Other than that, the solar system has reduced energy cost as well as pollution. The system is equipped with four input sensors; two soil moisture sensors, two level detection sensors. Soil moisture sensor measures the humidity of the soil, whereas the level detection sensors detect the level of water in the tank. The output sides consist of two solenoid valves, which are controlled respectively by two moistures sensors

A Small Mission Concept to the Sun-Earth Lagrangian L5 Point for Innovative Solar, Heliospheric and Space Weather Science

Science.gov (United States)

Lavraud, B.; Liu, Y.; Segura, K.; He, J.; Qin, G.; Temmer, M.; Vial, J.-C.; Xiong, M.; Davies, J. A.; Rouillard, A. P.;

Solar air-conditioning. Proceedings

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-07-01

Within the 3rd International Conference on solar air-conditioning in Palermo (Italy) at 30th September to 2nd October, 2009 the following lectures were held: (1) Removal of non-technological barriers to solar cooling technology across Southern European islands (Stefano Rugginenti); (2) The added economic and environmental value of solar thermal systems in microgrids with combined heat and power (Chris Marney); (3) Australian solar cooling interest group (Paul Kohlenbach); (4) Designing of a technology roadmap for solar assisted air conditioning in Austria (Hilbert Focke); (5) Solar cooling in the new context of renewable policies at European level (Raffaele Piria); (6) Prototype of a solar driven steam jet ejector chiller (Clemens Pollerberg); (7) New integrated solar air conditioning system (Joan Carlos Bruno); (8) Primary energy optimised operation of solar driven desiccant evaporative cooling systems through innovative control strategies; (9) Green chiller association (Uli Jakob); (10) Climate Well {sup registered} (Olof Hallstrom); (11) Low capacity absorption chillers for solar cooling applications (Gregor Weidner); (12) Solar cooling in residential, small scale commercial and industrial applications with adsorption technology (Walter Mittelbach); (13) French solar heating and cooling development programme based on energy performance (Daniel Mugnier); (14) Mirrox fresnel process heat collectors for industrial applications and solar cooling (Christian Zahler); (15) Modelling and analyzing solar cooling systems in polysun (Seyen Hossein Rezaei); (16) Solar cooling application in Valle Susa Italy (Sufia Jung); (17) Virtual case study on small solar cooling systems within the SolarCombi+Project (Bjoern Nienborg); (18) Design of solar cooling plants under uncertainty (Fernando Dominguez-Munoz); (19) Fast pre-design of systems using solar thermally driven chillers (Hans-Martin Henning); (20) Design of a high fraction solar heating and cooling plant in southern

Solar home systems in Nepal

Energy Technology Data Exchange (ETDEWEB)

Henryson, Jessica; Haakansson, Teresa

1999-04-01

Photovoltaic (PV) technology is a clean and environmentally friendly technology that does not require any fuels. The high reliability of operation and little need for maintenance makes it ideally suited for rural areas. Today PV systems are used in Nepal to power telecommunications centres, navigational aids, in pumping systems for irrigation and drinking water, and for household electrification. A solar home system consists of a PV module, a battery, a charge controller and 3-4 fluorescent light bulbs with fixture. The system provides power for lighting and operation of household appliances for several hours. The success of donor supported programs have shown that solar home systems can be a practical solution for many rural households. In 1996 the Government of Nepal launched a subsidy program for solar home systems, which dramatically has increased the demand for solar home systems among rural customers. This report includes a survey of 52 households with solar home systems in two villages. The field-study shows that the villagers are very happy with their systems and the technical performance of the systems in both villages is satisfactory. The study also shows the positive impact electricity has on education, health, income generation and quality of life. The beneficiaries of introducing electricity in remote areas are the children and the women 39 refs, 18 tabs. Examination paper

A hybrid solar and chemical looping combustion system for solar thermal energy storage

International Nuclear Information System (INIS)

Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

2013-01-01

Highlights: ► A novel solar–CLC hybrid system is proposed which integrates a CLC with solar thermal energy. ► The oxygen carrier particles are used as storage medium for thermal energy storage. ► A solar cavity reactor is proposed for fuel reactor. ► The absorbed solar energy is stored in the particles to produce a base heat load. -- Abstract: A novel hybrid of a solar thermal energy and a chemical looping combustion (CLC) system is proposed here, which employs the oxygen carrier particles in a CLC system to provide diurnal thermal energy storage for concentrated solar thermal energy. In taking advantage of the chemical and sensible energy storage systems that are an inherent part of a CLC system, this hybrid offers potential to achieve cost effective, base load power generation for solar energy. In the proposed system, three reservoirs have been added to a conventional CLC system to allow storage of the oxygen carrier particles, while a cavity solar receiver has been chosen for the fuel reactor. The performance of the system is evaluated using ASPEN PLUS software, with the model being validated using independent simulation result reported previously. Operating temperature, solar efficiency, solar fraction, exergy efficiency and the fraction of the solar thermal energy stored for a based load power generation application are reported.

Early accretion of water and volatile elements to the inner Solar System: evidence from angrites.

Science.gov (United States)

Sarafian, Adam R; Hauri, Erik H; McCubbin, Francis M; Lapen, Thomas J; Berger, Eve L; Nielsen, Sune G; Marschall, Horst R; Gaetani, Glenn A; Righter, Kevin; Sarafian, Emily

2017-05-28

Inner Solar System bodies are depleted in volatile elements relative to chondrite meteorites, yet the source(s) and mechanism(s) of volatile-element depletion and/or enrichment are poorly constrained. The timing, mechanisms and quantities of volatile elements present in the early inner Solar System have vast implications for diverse processes, from planetary differentiation to the emergence of life. We report major, trace and volatile-element contents of a glass bead derived from the D'Orbigny angrite, the hydrogen isotopic composition of this glass bead and that of coexisting olivine and silicophosphates, and the 207 Pb- 206 Pb age of the silicophosphates, 4568 ± 20 Ma. We use volatile saturation models to demonstrate that the angrite parent body must have been a major body in the early inner Solar System. We further show via mixing calculations that all inner Solar System bodies accreted volatile elements with carbonaceous chondrite H and N isotope signatures extremely early in Solar System history. Only a small portion (if any) of comets and gaseous nebular H species contributed to the volatile content of the inner Solar System bodies.This article is part of the themed issue 'The origin, history and role of water in the evolution of the inner Solar System'. © 2017 The Author(s).

Solar Thermal Upper Stage Cryogen System Engineering Checkout Test

Science.gov (United States)

Olsen, A. D; Cady, E. C.; Jenkins, D. S.

1999-01-01

The Solar Thermal Upper Stage technology (STUSTD) program is a solar thermal propulsion technology program cooperatively sponsored by a Boeing led team and by NASA MSFC. A key element of its technology program is development of a liquid hydrogen (LH2) storage and supply system which employs multi-layer insulation, liquid acquisition devices, active and passive thermodynamic vent systems, and variable 40W tank heaters to reliably provide near constant pressure H2 to a solar thermal engine in the low-gravity of space operation. The LH2 storage and supply system is designed to operate as a passive, pressure fed supply system at a constant pressure of about 45 psia. During operation of the solar thermal engine over a small portion of the orbit the LH2 storage and supply system propulsively vents through the enjoy at a controlled flowrate. During the long coast portion of the orbit, the LH2 tank is locked up (unvented). Thus, all of the vented H2 flow is used in the engine for thrust and none is wastefully vented overboard. The key to managing the tank pressure and therefore the H2 flow to the engine is to manage and balance the energy flow into the LH2 tank with the MLI and tank heaters with the energy flow out of the LH2 tank through the vented H2 flow. A moderate scale (71 cu ft) LH2 storage and supply system was installed and insulated at the NASA MSFC Test Area 300. The operation of the system is described in this paper. The test program for the LH2 system consisted of two parts: 1) a series of engineering tests to characterize the performance of the various components in the system: and 2) a 30-day simulation of a complete LEO and GEO transfer mission. This paper describes the results of the engineering tests, and correlates these results with analytical models used to design future advanced Solar Orbit Transfer Vehicles.

Radiation Environments for Future Human Exploration Throughout the Solar System.

Science.gov (United States)

Schwadron, N.; Gorby, M.; Linker, J.; Riley, P.; Torok, T.; Downs, C.; Spence, H. E.; Desai, M. I.; Mikic, Z.; Joyce, C. J.; Kozarev, K. A.; Townsend, L. W.; Wimmer-Schweingruber, R. F.

2016-12-01

Acute space radiation hazards pose one of the most serious risks to future human and robotic exploration. The ability to predict when and where large events will occur is necessary in order to mitigate their hazards. The largest events are usually associated with complex sunspot groups (also known as active regions) that harbor strong, stressed magnetic fields. Highly energetic protons accelerated very low in the corona by the passage of coronal mass ejection (CME)-driven compressions or shocks and from flares travel near the speed of light, arriving at Earth minutes after the eruptive event. Whether these particles actually reach Earth, the Moon, Mars (or any other point) depends on their transport in the interplanetary magnetic field and their magnetic connection to the shock. Recent contemporaneous observations during the largest events in almost a decade show the unique longitudinal distributions of this ionizing radiation broadly distributed from sources near the Sun and yet highly isolated during the passage of CME shocks. Over the last decade, we have observed space weather events as the solar wind exhibits extremely low densities and magnetic field strengths, representing states that have never been observed during the space age. The highly abnormal solar activity during cycles 23 and 24 has caused the longest solar minimum in over 80 years and continues into the unusually small solar maximum of cycle 24. As a result of the remarkably weak solar activity, we have also observed the highest fluxes of galactic cosmic rays in the space age and relatively small particle radiation events. We have used observations from LRO/CRaTER to examine the implications of these highly unusual solar conditions for human space exploration throughout the inner solar system. While these conditions are not a show-stopper for long-duration missions (e.g., to the Moon, an asteroid, or Mars), galactic cosmic ray radiation remains a significant and worsening factor that limits

Photovoltaic assisted solar drying system

International Nuclear Information System (INIS)

Ruslan, M.H.; Othman, M.Y.; Baharuddin Yatim; Kamaruzzaman Sopian; Ali, M.I.; Ibarahim, Z.

2006-01-01

A photovoltaic assisted solar drying system has been constructed at the Solar Energy Research Park, Universiti Kebangsaan Malaysia. This drying system uses a custom designed parallel flow V-groove type collector. A fan powered by photovoltaic source assists the air flow through the drying system. A funnel with increasing diameter towards the top with ventilator turbine is incorporated into the system to facilitate the air flow during the absence of photovoltaic energy source. This drying system is designed with high efficiency and portability in mind so that it can readily be used at plantation sites where the crops are harvested or produced. A daily mean efficiency about 44% with mean air flow rate 0.16 kgs -1 has been achieved at mean daily radiation intensity of 800 Wm -2 . daily mean temperature of air drying chamber under the above conditions is 46 o C. Study has shown that the air flow and air temperature increase with the increase of solar radiation intensity. On a bright sunny day with instantaneous solar intensity about 600 Wm -2 , the temperature of air entering the drying chamber of 45 o C has been measured. In the absence of photovoltaic or in natural convection flow, the instantaneous efficiency decreased when solar radiation increased. The instantaneous efficiency recorded are 35% and 27% respectively at 570 Wm -2 and 745 Wm -2 of solar radiation. The temperature of drying chamber for the same amount of solar radiation are 42 o C and 48 o C respectively. Thus, the solar dryer shows a great potential for application in drying process of agricultural produce

Origin of the solar system

International Nuclear Information System (INIS)

Hayashi, Chushiro; Nakazawa, Kiyoshi; Miyama, S.M.

1989-01-01

The study on the origin of the solar system entered a stage of synthetic and positivistic science around 1960, as the observation and the theory of protostars began to develop, the solar chemical composition became almost definite, and the amounts of chemical and mineralogical data greatly increased. In accordance with this scientific situation, the first research meeting in Japan on the origin of the solar system was held in 1965 at the Research Institute for Fundamental Physics, Kyoto University. It was discussed how a variety of the data on the solar system can be explained in a unified way. Since 1977, the workshop on the origin has been held annually. Through a series of the workshops, so-called Kyoto model has been talked and discussed frequently. For three years from 1985, the workshop in Kyoto was supported by the Ministry of Education, Science and Culture, and one of the main items of this grant was to publish the results of the workshop as the Supplement of the Progress of Theoretical Physics. The chronology of the solar system, the formation processes of protostars, the stability of solar nebulae, the physical processes in solar nebulae, the physical processes related to planetary growth, the growth of planets, and the formation of asteroids and meteorites are described in this book. (K.I.)

Structural considerations for solar installers : an approach for small, simplified solar installations or retrofits.

Energy Technology Data Exchange (ETDEWEB)

Richards, Elizabeth H.; Schindel, Kay (City of Madison, WI); Bosiljevac, Tom; Dwyer, Stephen F.; Lindau, William (Lindau Companies, Inc., Hudson, WI); Harper, Alan (City of Madison, WI)

2011-12-01

Structural Considerations for Solar Installers provides a comprehensive outline of structural considerations associated with simplified solar installations and recommends a set of best practices installers can follow when assessing such considerations. Information in the manual comes from engineering and solar experts as well as case studies. The objectives of the manual are to ensure safety and structural durability for rooftop solar installations and to potentially accelerate the permitting process by identifying and remedying structural issues prior to installation. The purpose of this document is to provide tools and guidelines for installers to help ensure that residential photovoltaic (PV) power systems are properly specified and installed with respect to the continuing structural integrity of the building.

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)

Renewable Energy Systems: Development and Perspectives of a Hybrid Solar-Wind System

Directory of Open Access Journals (Sweden)

C. Shashidhar

2012-02-01

Full Text Available Considering the intermittent natural energy resources and the seasonal un-balance, a phtovoltaic-wind hybrid electrical power supply system was developed to accommodate remote locations where a conventional grid connection is inconvenient or expensive. However, the hybrid system can also be applied with grid connection and owners are allowed to sell excessive power back to the electric utility. The proposed set-up consists of a photo-voltaic solar-cell array, a mast mounted wind generator, lead-acid storage batteries, an inverter unit to convert DC to AC, electrical lighting loads, electrical heating loads, several fuse and junction boxes and associated wiring, and test instruments for measuring voltages, currents, power factors, and harmonic contamination data throughout the system. The proposed hybrid solar-wind power generating system can be extensively used to illustrate electrical concepts in hands-on laboratories and also for demonstrations in the Industrial Technology curriculum. This paper describes an analysis of local PV-wind hybrid systems for supplying electricity to a private house, farmhouse or small company with electrical power depending on the site needs. The major system components, work principle and specific working condition are presented.

Solar photovoltaic (PV) energy; latest developments in the building integrated and hybrid PV systems

International Nuclear Information System (INIS)

Zahedi, A.

2006-01-01

Environmental concerns are growing and interest in environmental issues is increasing and the idea of generating electricity with less pollution is becoming more and more attractive. Unlike conventional generation systems, fuel of the solar photovoltaic energy is available at no cost. And solar photovoltaic energy systems generate electricity pollution-free and can easily be installed on the roof of residential as well as on the wall of commercial buildings as grid-connected PV application. In addition to grid-connected rooftop PV systems, solar photovoltaic energy offers a solution for supplying electricity to remote located communities and facilities, those not accessible by electricity companies. The interest in solar photovoltaic energy is growing worldwide. Today, more than 3500MW of photovoltaic systems have been installed all over the world. Since 1970, the PV price has continuously dropped [8]. This price drop has encouraged worldwide application of small-scale residential PV systems. These recent developments have led researchers concerned with the environment to undertake extensive research projects for harnessing renewable energy sources including solar energy. The usage of solar photovoltaic as a source of energy is considered more seriously making future of this technology looks promising. The objective of this contribution is to present the latest developments in the area of solar photovoltaic energy systems. A further objective of this contribution is to discuss the long-term prospect of the solar photovoltaic energy as a sustainable energy supply. [Author

Isotopic ratios in the solar system

International Nuclear Information System (INIS)

1985-01-01

This colloquium is aimed at presentation of isotope ratio measurements in different objects of solar system and surrounding interstellar space and evaluation of what information on composition and structure of primitive solar nebula and on chemical evolution of interstellar space in this part of the galaxy can be deduced from it. Isotope ratio in solar system got from laboratory study of extraterrestrial materials is a subject of this colloquium. Then isotope ratio measured in solar wind, planets and comets. Measurements either are made in-situ by mass spectrometry of ions in solar wind or planetery atmosphere gases either are remote measurements of spectra emitted by giant planets and comets. At last, planetology and astrophysics implications are presented and reviewed. Consraints for solar system formation model can be deduced from isotope ratio measurement. Particularly, isotope anomalies are marks of the processes, which have influenced the primitive solar nebula contraction [fr

Solution processable organic polymers and small molecules for bulk-heterojunction solar cells: A review

International Nuclear Information System (INIS)

Sharma, G. D.

2011-01-01

Solution processed bulk heterojunction (BHJ) organic solar cells (OSCs) have gained wide interest in past few years and are established as one of the leading next generation photovoltaic technologies for low cost power production. Power conversion efficiencies up to 6% and 6.5% have been reported in the literature for single layer and tandem solar cells, respectively using conjugated polymers. A recent record efficiency about 8.13% with active area of 1.13 cm 2 has been reported. However Solution processable small molecules have been widely applied for photovoltaic (PV) devices in recent years because they show strong absorption properties, and they can be easily purified and deposited onto flexible substrates at low cost. Introducing different donor and acceptor groups to construct donor--acceptor (D--A) structure small molecules has proved to be an efficient way to improve the properties of organic solar cells (OSCs). The power conversion efficiency about 4.4 % has been reported for OSCs based on the small molecules. This review deals with the recent progress of solution processable D--A structure small molecules and discusses the key factors affecting the properties of OSCs based on D--A structure small molecules: sunlight absorption, charge transport and the energy level of the molecules.

Dynamics of the solar system

International Nuclear Information System (INIS)

Sidlichovsky, M.

1987-01-01

The conference proceedings contains a total of 31 papers of which 7 have not been incorporated in INIS. The papers mainly discuss the mathematical methods of calculating the movement of planets, their satellites and asteroids in the solar system and the mathematical modelling of the past development of the solar system. Great attention is also devoted to resonance in the solar system and to the study of many celestial bodies. Four papers are devoted to planetary rings and three to modern astrometry. (M.D.). 63 figs., 10 tabs., 520 refs

Dark matter in the outer solar system

Science.gov (United States)

Owen, T.; Cruikshank, D.; De Bergh, C.; Geballe, T.

1994-01-01

There are now a large number of small bodies in the outer solar system that are known to be covered with dark material. Attempts to identify that material have been thwarted by the absence of discrete absorption features in the reflection spectra of these planetesimals. An absorption at 2.2 micrometers that appeared to be present in several objects has not been confirmed by new observations. Three absorptions in the spectrum of the unusually red planetesimal 5145 Pholus are well-established, but their identity remains a mystery.

ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS CROSS-CUTTING R&D ON ADAPTIVE FULL-SPECTRUM SOLAR ENERGY SYSTEMS FOR MORE EFFICIENT AND AFFORDABLE USE OF SOLAR ENERGY IN BUILDINGS AND HYBRID PHOTOBIOREACTORS

Energy Technology Data Exchange (ETDEWEB)

Byard D. Wood; Jeff D. Muhs

2004-08-01

This RD&D project is a three year team effort to develop a hybrid solar lighting (HSL) system that transports daylight from a paraboloidal dish concentrator to a luminaire via a bundle of small core or a large core polymer fiber optics. The luminaire can be a device to distribute sunlight into a space for the production of algae or it can be a device that is a combination of daylighting and electric lighting for space/task lighting. In this project, the sunlight is collected using a one-meter paraboloidal concentrator dish with two-axis tracking. For the second generation (alpha) system, the secondary mirror is an ellipsoidal mirror that directs the visible light into a bundle of small-core fibers. The IR spectrum is filtered out to minimize unnecessary heating at the fiber entrance region. This report describes the following investigations of various aspects of the system. Taken as a whole, they confirm significant progress towards the technical feasibility and commercial viability of this technology. (1) TRNSYS Modeling of a Hybrid Lighting System: Building Energy Loads and Chromaticity Analysis; (2) High Lumens Screening Test Setup for Optical Fibers; (3) Photo-Induced Heating in Plastic Optical Fiber Bundles; (4) Low-Cost Primary Mirror Development; (5) Potential Applications for Hybrid Solar Lighting; (6) Photobioreactor Population Experiments and Productivity Measurements; and (7) Development of a Microalgal CO2-Biofixation Photobioreactor.

solaR: Solar Radiation and Photovoltaic Systems with R

Directory of Open Access Journals (Sweden)

Oscar Perpiñan Lamigueiro

2012-08-01

Full Text Available The solaR package allows for reproducible research both for photovoltaics (PV systems performance and solar radiation. It includes a set of classes, methods and functions to calculate the sun geometry and the solar radiation incident on a photovoltaic generator and to simulate the performance of several applications of the photovoltaic energy. This package performs the whole calculation procedure from both daily and intradaily global horizontal irradiation to the final productivity of grid-connected PV systems and water pumping PV systems.It is designed using a set of S4 classes whose core is a group of slots with multivariate time series. The classes share a variety of methods to access the information and several visualization methods. In addition, the package provides a tool for the visual statistical analysis of the performance of a large PV plant composed of several systems.Although solaR is primarily designed for time series associated to a location defined by its latitude/longitude values and the temperature and irradiation conditions, it can be easily combined with spatial packages for space-time analysis.

A Green Energy Application in Energy Management Systems by an Artificial Intelligence-Based Solar Radiation Forecasting Model

Directory of Open Access Journals (Sweden)

Ping-Huan Kuo

2018-04-01

Full Text Available The photovoltaic (PV systems generate green energy from the sunlight without any pollution or noise. The PV systems are simple, convenient to install, and seldom malfunction. Unfortunately, the energy generated by PV systems depends on climatic conditions, location, and system design. The solar radiation forecasting is important to the smooth operation of PV systems. However, solar radiation detected by a pyranometer sensor is strongly nonlinear and highly unstable. The PV energy generation makes a considerable contribution to the smart grids via a large number of relatively small PV systems. In this paper, a high-precision deep convolutional neural network model (SolarNet is proposed to facilitate the solar radiation forecasting. The proposed model is verified by experiments. The experimental results demonstrate that SolarNet outperforms other benchmark models in forecasting accuracy as well as in predicting complex time series with a high degree of volatility and irregularity.

Numerical Study on Radiation Effects to Evaporator in Natural Vacuum Solar Desalination System

Science.gov (United States)

Siregar, R. E. T.; Ronowikarto, A. D.; Setyawan, E. Y.; Ambarita, H.

2018-01-01

The need for clean water is increasing day by day due to the increasing factor of living standard of mankind, hence designed natural vacuum solar desalination. The natural vacuum Solar desalination is studied experimentally. A small-scale natural vacuum desalination study consists of evaporator and condenser as the main components designed and manufactured. To transfer heat from the solar collector into the evaporator, the fluid transfer system uses a pump powered by a solar cell. Thus, solar collectors are called hybrid solar collectors. The main purpose of this exposure is to know the characteristics of the radiation effects on incoming energy on the evaporator during the process. This system is tested by exposing the unit to the solar radiation in the 4th floor building in Medan. The experiment was conducted from 8.00 to 16.00 local time. The results show that natural vacuum solar desalination with hybrid solar collectors can be operated perfectly. If the received radiation is high, then the incoming energy received by the evaporator will also be high. From measurements with HOBO microstation, obtained the highest radiation 695.6 W/m2, and the calculation result of incoming energy received evaporator obtained highest result 1807.293 W.

Small and Shaping the Future Energy Eco-house System

Science.gov (United States)

Furukawa, Ryuzo; Takahashi, Hideyuki; Sato, Yoshinori; Sasaki, Hiroshi; Isu, Norifumi; Ohtsuka, Masuo; Tohji, Kazuyuki

2010-11-01

The objective of this research is to develop the elemental technology of the small and thin energy collection system from water, wind, and others in the house, and examine them at the eco-house which will be built at Tohoku University on March 2010. This small energy storage system will contribute to reduce 10% of greenhouse gas emission from household electricity. This project is done by three following groups. 1st group (NEC-Tokin Co. Ltd.) will develop the technologies on the accumulation of electric power pressured from low electric power in which electricity is generated and on the cooperation with AC power supply used for domestic use for this eco-house system. 2nd group (INAX Co. Ltd.) will develop the elemental technology of the slight energy collection system from tap water in the home using a small hydroelectric generator for this eco-house system. 3rd group (Shoei Co. Ltd.) will develop the technologies on existent magnetic gear device, health appliances (Exercise bike), wind power generator, for this eco-house system. Tokoku University compiles these groups. Furthermore, I develop a search of unused small energy and the use technology, and propose a new energy supply system using solar cell and Li ion secondary battery.

Reuniting the Solar System: Integrated Education and Public Outreach Projects for Solar System Exploration Missions and Programs

Science.gov (United States)

Lowes, Leslie; Lindstrom, Marilyn; Stockman, Stephanie; Scalice, Daniela; Klug, Sheri

2003-01-01

The Solar System Exploration Education Forum has worked for five years to foster Education and Public Outreach (E/PO) cooperation among missions and programs in order to leverage resources and better meet the needs of educators and the public. These efforts are coming together in a number of programs and products and in '2004 - The Year of the Solar System.' NASA's practice of having independent E/PO programs for each mission and its public affairs emphasis on uniqueness has led to a public perception of a fragmented solar system exploration program. By working to integrate solar system E/PO, the breadth and depth of the solar system exploration program is revealed. When emphasis is put on what missions have in common, as well as their differences, each mission is seen in the context of the whole program.

Development of Solar Biomass Drying System

Directory of Open Access Journals (Sweden)

Atnaw Samson Mekbib

2017-01-01

Full Text Available The purpose of this paper focuses on the experimental pre-treatment of biomass in agricultural site using solar energy as power source and contribution of common use and efficiency solar dryer system for consumer. The main purpose of this design for solar cabinet dryer is to dry biomass via direct and indirect heating. Direct heating is the simplest method to dry biomass by exposing the biomass under direct sunlight. The solar cabinet dryer traps solar heat to increase the temperature of the drying chamber. The biomass absorbs the heat and transforms the moisture content within the biomass into water vapour and then leaves the chamber via the exhaust air outlet. This problem however can be solved by adopting indirect solar drying system. High and controllable temperatures can be achieved as a fan is used to move the air through the solar collector. This project has successfully created a solar cabinet dryer that combines both direct and indirect solar drying systems and functions to dry biomass as well as crops effectively and efficiently with minimal maintenance. Hence, it is indeed a substitution for conventional dryers which are affordable to local farmers.

On the Solar System-Debris Disk Connecction

OpenAIRE

Moro-Martin, Amaya

2007-01-01

This paper emphasizes the connection between solar and extra-solar debris disks: how models and observations of the Solar System are helping us understand the debris disk phenomenon, and vice versa, how debris disks are helping us place our Solar System into context.

A dynamic model of an innovative high-temperature solar heating and cooling system

Directory of Open Access Journals (Sweden)

Buonomano Annamaria

2016-01-01

Full Text Available In this paper a new simulation model of a novel solar heating and cooling system based on innovative high temperature flat plate evacuated solar thermal collector is presented. The system configuration includes: flat-plate evacuated solar collectors, a double-stage LiBr-H2O absorption chiller, gas-fired auxiliary heater, a closed loop cooling tower, pumps, heat exchangers, storage tanks, valves, mixers and controllers. The novelty of this study lies in the utilization of flat-plate stationary solar collectors, manufactured by TVP Solar, rather than concentrating ones (typically adopted for driving double-stage absorption chillers. Such devices show ultra-high thermal efficiencies, even at very high (about 200°C operating temperatures, thanks to the high vacuum insulation. Aim of the paper is to analyse the energy and economic feasibility of such novel technology, by including it in a prototypal solar heating and cooling system. For this purpose, the solar heating and cooling system design and performance were analysed by means of a purposely developed dynamic simulation model, implemented in TRNSYS. A suitable case study is also presented. Here, the simulated plant is conceived for the space heating and cooling and the domestic hot water production of a small building, whose energy needs are fulfilled through a real installation (settled also for experimental purposes built up close to Naples (South Italy. Simulation results show that the investigated system is able to reach high thermal efficiencies and very good energy performance. Finally, the economic analysis shows results comparable to those achieved through similar renewable energy systems.

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.

UP-scaling of inverted small molecule based organic solar cells

DEFF Research Database (Denmark)

Patil, Bhushan Ramesh; Madsen, Morten

Organic solar cells (OSC), in spite of being a promising technology, still face challenges regarding large-scale fabrication. Although efficiencies of up to 12 % has been reached for small molecule OSC, their performance, both in terms of device efficiency and stability, is significantly reduced...... during up-scaling processes. The work presented here is focused on an approach towards up-scaling of small molecule based OSC with inverted device configuration. Bilayer OSC from Tetraphenyldibenzoperiflanthene (DBP) and Fullerenes (C70), as electron donor and acceptor respectively, with cell area...

The Utilisation of Solar System in Combined Heating System of Water

Directory of Open Access Journals (Sweden)

Ján Jobbágy

2017-01-01

Full Text Available The paper assessed the topicality and returns of solar system utilization to heating of water. Practical measurements were conducted after reconstruction of the family house. (in Nesvady, Slovak republic, on which the solar system were assembled. The system consists of the gas heater, solar panels, distributions and circulation pump. The solar system was assembled due to decreasing of operation costs and connected with conventional already used gas heating system by boiler Quantum (V = 115 L. The conventional system was used for 21 days to gather basic values for evaluation. At this point it was observed that 11.93 m3 of gas is needed to heat up 1 m3 of water. Used water in this case was heated from initial 16.14 °C to 52.04 °C of output temperature. Stand by regime of boiler was characterized by 0.012 m3.h-1 consumption of gas. The rest of the measurements represent the annual (from 03/2013 to 02/2014 operation process of boiler Tatramat VTS 200L (trivalent with 200 litres of volume (as a part of Thermosolar solar system. The solar collectors TS 300 are also part of the solar system. An input and output temperatures of heating water we observed along with water and gas consumption, intensity of solar radiation and actual weather conditions. The amount of heat produced by solar system was then calculated. Total investment on solar system were 2,187.7 € (1,475.7 € with subsidy. Therefore, return on investment for the construction of the solar system was set at 23 years even with subsidy.

Battery charging characteristics in small scaled photovoltaic system using resonant DC-DC converter with electric isolation

International Nuclear Information System (INIS)

Isoda, H.; Kimura, G.; Shioya, M.

1990-01-01

The solar energy has been drawing attention of the whole world as a clean and infinite energy, since the globe resource, the globe ecology and so on came into question. The wide applications of the solar energy are being expected in a range from electric power plants to household systems. But the output power induced in the photovoltaic modules is influenced by an intensity of the solar radiation, a temperature of the solar cells and so on, so the various useful forms of the solar energy are being proposed for a purpose of stable power supply. a system described in this paper is a small scaled photovoltaic system with storage batteries. This paper describes the theoretical analyses of the photovoltaic system using a resonant DC-DC converter in order to clarify a desirable circuit condition, besides the experimental results of the battery charging characteristics are presented

Design, Fabrication, and Efficiency Study of a Novel Solar Thermal Water Heating System: Towards Sustainable Development

Directory of Open Access Journals (Sweden)

M. Z. H. Khan

2016-01-01

Full Text Available This paper investigated a novel loop-heat-pipe based solar thermal heat-pump system for small scale hot water production for household purposes. The effective use of solar energy is hindered by the intermittent nature of its availability, limiting its use and effectiveness in domestic and industrial applications especially in water heating. The easiest and the most used method is the conversion of solar energy into thermal energy. We developed a prototype solar water heating system for experimental test. We reported the investigation of solar thermal conversion efficiency in different seasons which is 29.24% in summer, 14.75% in winter, and 15.53% in rainy season. This paper also discusses the DC heater for backup system and the current by using thermoelectric generator which are 3.20 V in summer, 2.120 V in winter, and 1.843 V in rainy season. This solar water heating system is mostly suited for its ease of operation and simple maintenance. It is expected that such novel solar thermal technology would further contribute to the development of the renewable energy (solar driven heating/hot water service and therefore lead to significant environmental benefits.

Solar-hydrogen energy systems: an authoritative review of water-splitting systems by solar beam and solar heat : hydrogen production, storage, and utilisation

National Research Council Canada - National Science Library

Ōta, Tokio

1979-01-01

... An Authoritative Review of Watersplitting Systems by Solar Beam and Solar Heat: Hydrogen Production, Storage and Utilisation edited by TOKIO OHTA Professor of Materials Science and Energy System Yoko...

Solar cooling systems. Classification and energetic evaluation; Solare Kuehlsysteme. Klassifizierung und energetische Bewertung

Energy Technology Data Exchange (ETDEWEB)

Hennig, Jakob [Technische Univ. Bergakademie Freiberg (Germany); Hafner, Armin [SINTEF Energy Research, Trondheim (Norway); Eikevik, Trygve M. [NTNU, Trondheim (Norway)

2012-07-01

The investigation of alternative, sustainable concepts for cold production is worthwhile in times of increasing energy demand for cooling and air conditioning applications. Energy sources such as solar radiation can help to reduce the burden on the environment and energy networks. Solar electricity from photovoltaic cells or solar power from solar collectors can be used in refrigerating equipment (such as cold vapor compression chiller, absorption chiller, adsorption chillers, open systems, thermo-mechanical systems or ejector-based systems) are fed in order to produce the desired coldness. In many cases, the temporal coincidence of radiation supply and cooling requirements makes the solar cooling to a promising concept, especially at sites with a high solar radiation, large cooling demand, high energy prices, or insufficient access to public power grids. A model-based investigation of different solar cooling systems with an equivalent cooling capacity was carried out. The results show that the performance potential strongly depends on the selected technology and the site of the system. A balanced daily energy balance can be achieved with an appropriately dimensioned solar power plant with cooling concept. Depending on the system and interpretation, primary energy savings or a primary energy overhead can be achieved within a year in comparison to a conventional system.

Small-Scale Flat Plate Collectors for Solar Thermal Scavenging in Low Conductivity Environments

Directory of Open Access Journals (Sweden)

Emmanuel Ogbonnaya

2017-01-01

Full Text Available There is great opportunity to develop power supplies for autonomous application on the small scale. For example, remote environmental sensors may be powered through the harvesting of ambient thermal energy and heating of a thermoelectric generator. This work investigates a small-scale (centimeters solar thermal collector designed for this application. The absorber is coated with a unique selective coating and then studied in a low pressure environment to increase performance. A numerical model that is used to predict the performance of the collector plate is developed. This is validated based on benchtop testing of a fabricated collector plate in a low-pressure enclosure. Model results indicate that simulated solar input of about 800 W/m2 results in a collector plate temperature of 298 K in ambient conditions and up to 388 K in vacuum. The model also predicts the various losses in W/m2 K from the plate to the surroundings. Plate temperature is validated through the experimental work showing that the model is useful to the future design of these small-scale solar thermal energy collectors.

Fiscal 1974 Sunshine Project result report. Research on solar energy utilization systems (solar heat power generation); 1974 nendo taiyo energy riyo system chosa kenkyu seika hokokusho. Taiyonetsu hatsuden

Energy Technology Data Exchange (ETDEWEB)

NONE

1975-03-01

This report summarizes the fiscal 1974 research result on solar heat power generation. The following are promising as solar heat power plant sites in Japan: Large-scale sites such as the foot of volcanos, riverbed, railway site and road, medium-scale sites such as isolated island, saltpan site and industrial park, and small-scale sites such as factory site, factory roof floor, housing complex, warehouse and school. Based on the primary concept design of both curved reflector type and tower type 1,000kW class solar heat power plants, various requirements were clarified roughly. It was clarified that food, fiber and non-ferrous metal factories can cover 80-90% of their thermal energy requirements with high- temperature solar heat, while factories related to food and fiber can cover even nearly 100% of their electric power requirements with solar heat. Study was also made on specifications of a solar simulator as common use facility necessary for characteristic evaluation of equipment and materials for solar heat power generation systems. (NEDO)

Competitive solar heating systems for residential buildings

DEFF Research Database (Denmark)

Furbo, Simon; Thür, Alexander; Fiedler, Frank

2005-01-01

The paper describes the ongoing research project “Competitive solar heating systems for residential buildings”. The aim of the project is to develop competitive solar combisystems which are attractive to buyers. The solar combisystems must be attractive compared to traditional energy systems, both....... In Denmark and Norway the focus is on solar heating/natural gas systems, and in Sweden and Latvia the focus is on solar heating/pellet systems. Additionally, Lund Institute of Technology and University of Oslo are studying solar collectors of various types being integrated into the roof and facade......, are the universities: Technical University of Denmark, Dalarna University, University of Oslo, Riga Technical University and Lund Institute of Technology, as well as the companies: Metro Therm A/S (Denmark), Velux A/S (Denmark), Solentek AB (Sweden) and SolarNor (Norway). The project consists of a number of Ph...

Chaos in the Solar System

Science.gov (United States)

Lecar, Myron; Franklin, Fred A.; Holman, Matthew J.; Murray, Norman J.

2001-01-01

The physical basis of chaos in the solar system is now better understood: In all cases investigated so far, chaotic orbits result from overlapping resonances. Perhaps the clearest examples are found in the asteroid belt. Overlapping resonances account for its kirkwood gaps and were used to predict and find evidence for very narrow gaps in the outer belt. Further afield, about one new "short-peroid" comet is discovered each year. They are believed to come from the "Kuiper Belt" (at 40 AU or more) via chaotic orbits produced by mean-motion and secular resonances with Neptune. Finally, the planetary system itself is not immune from chaos. In the inner solar system, overlapping secular resonances have been identified as the possible source of chaos. For example, Mercury in 1012 years, may suffer a close encounter with Venus or plunge into the Sun. In the outer solar system, three-body resonances have been identified as a source of chaos, but on an even longer time scale of 109 times the age of the solar system. On the human time scale, the planets do follow their orbits in a stately procession, and we can predict their trajectories for hundreds of thousands of years. That is because the mavericks, with shorter instability times, have long since been ejected. The solar system is not stable; it is just old!

Cost and optimal feed-in tariff for small scale photovoltaic systems in China

International Nuclear Information System (INIS)

Rigter, Jasper; Vidican, Georgeta

2010-01-01

China has recently become a dominant player in the solar photovoltaic (PV) industry, producing more than one-third of the global supply of solar cells in 2008. However, as of 2008, less than 1% of global installations were based in China. Recently, the government has stated its grand ambitions of expanding the share of electricity derived from solar power. As part of this initiative, policy makers are currently in the process of drafting a feed-in tariff policy to support the development of the solar energy market. In this paper, we aim to calculate what the level of such a tariff should be. We develop a closed form equation for the cost of PV, and use forecasts on prices of solar systems to derive an optimal feed-in tariff, including a digression rate. The focus is on the potential of residential and small scale commercial solar PV installations. We show that the cost of small scale PV in China has decreased rapidly during the period 2005-2009. Our analysis also shows that optimal feed-in tariffs vary widely between regions within China, and that grid parity could be reached in large parts of the country depending on the expected escalation in electricity prices. (author)

DEVELOPMENT OF A SMART SOLAR TANK

DEFF Research Database (Denmark)

Furbo, Simon; Andersen, Elsa

1999-01-01

Theoretical and experimental investigations of small SDHW systems based on so-called smart solar tanks are presented. A smart solar tank is a hot water tank in which the domestic water can both be heated by solar collectors and by an auxiliary energy supply system. The auxiliary energy supply sys...

Views of the solar system

Energy Technology Data Exchange (ETDEWEB)

Hamilton, C.

1995-02-01

Views of the Solar System has been created as an educational tour of the solar system. It contains images and information about the Sun, planets, moons, asteroids and comets found within the solar system. The image processing for many of the images was done by the author. This tour uses hypertext to allow space travel by simply clicking on a desired planet. This causes information and images about the planet to appear on screen. While on a planet page, hyperlinks travel to pages about the moons and other relevant available resources. Unusual terms are linked to and defined in the Glossary page. Statistical information of the planets and satellites can be browsed through lists sorted by name, radius and distance. History of Space Exploration contains information about rocket history, early astronauts, space missions, spacecraft and detailed chronology tables of space exploration. The Table of Contents page has links to all of the various pages within Views Of the Solar System.

Solar system sputtering

Science.gov (United States)

Tombrello, T. A.

1982-01-01

The sites and materials involved in solar system sputtering of planetary surfaces are reviewed, together with existing models for the processes of sputtering. Attention is given to the interaction of the solar wind with planetary atmospheres in terms of the role played by the solar wind in affecting the He-4 budget in the Venus atmosphere, and the erosion and differentiation of the Mars atmosphere by solar wind sputtering. The study is extended to the production of isotopic fractionation and anomalies in interplanetary grains by irradiation, and to erosion effects on planetary satellites with frozen volatile surfaces, such as with Io, Europa, and Ganymede. Further measurements are recommended of the molecular form of the ejected material, the yields and energy spectra of the sputtered products, the iosotopic fractionation sputtering causes, and the possibility of electronic sputtering enhancement with materials such as silicates.

Solar/electric heating systems for the future energy system

Energy Technology Data Exchange (ETDEWEB)

Furbo, S.; Dannemand, M.; Perers, B. [and others

2013-05-15

The aim of the project is to elucidate how individual heating units for single family houses are best designed in order to fit into the future energy system. The units are based on solar energy, electrical heating elements/heat pump, advanced heat storage tanks and advanced control systems. Heat is produced by solar collectors in sunny periods and by electrical heating elements/heat pump. The electrical heating elements/heat pump will be in operation in periods where the heat demand cannot be covered by solar energy. The aim is to use the auxiliary heating units when the electricity price is low, e.g. due to large electricity production by wind turbines. The unit is equipped with an advanced control system where the control of the auxiliary heating is based on forecasts of the electricity price, the heat demand and the solar energy production. Consequently, the control is based on weather forecasts. Three differently designed heating units are tested in a laboratory test facility. The systems are compared on the basis of: 1) energy consumption for the auxiliary heating; 2) energy cost for the auxiliary heating; 3) net utilized solar energy. Starting from a normal house a solar combi system (for hot water and house heating) can save 20-30% energy cost, alone, depending on sizing of collector area and storage volume. By replacing the heat storage with a smart tank based on electric heating elements and a smart control based on weather/load forecast and electricity price information 24 hours ahead, another 30-40% can be saved. That is: A solar heating system with a solar collector area of about 10 m{sup 2}, a smart tank based on electric heating element and a smart control system, can reduce the energy costs of the house by at least 50%. No increase of heat storage volume is needed to utilize the smart control. The savings in % are similar for different levels of building insulation. As expected a heat pump in the system can further reduce the auxiliary electricity

The Impacts of Different Expansion Modes on Performance of Small Solar Energy Firms: Perspectives of Absorptive Capacity

Directory of Open Access Journals (Sweden)

Hsing Hung Chen

2013-01-01

Full Text Available The characteristics of firm’s expansion by differentiated products and diversified products are quite different. However, the study employing absorptive capacity to examine the impacts of different modes of expansion on performance of small solar energy firms has never been discussed before. Then, a conceptual model to analyze the tension between strategies and corporate performance is proposed to filling the vacancy. After practical investigation, the results show that stronger organizational institutions help small solar energy firms expanded by differentiated products increase consistency between strategies and corporate performance; oppositely, stronger working attitudes with weak management controls help small solar energy firms expanded by diversified products reduce variance between strategies and corporate performance.

Performance evaluation of a flow-down collecting solar system; Ryuka shunetsushiki solar system no seino hyoka

Energy Technology Data Exchange (ETDEWEB)

Kanayama, K; Li, X; Baba, H; Endo, N [Kitami Institute of Technology, (Japan)

1997-11-25

The paper evaluated performance of a flow-down collecting solar system. The solar heat pump PV system is composed of a solar system, heat pump and PV, of which the heat collecting portion is a water-use horizontal evacuated double glass tube solar collector. As a result of the performance measurement, the necessity of fundamental improvement arose. Under an idea of disproving common sense of the original forced circulation solar system, a system was designed in which heat is collected by making the heat media reversely circulate and flow down in accordance with gravity. When the flow rate was 2m{sup 3}/h, the collecting rate reached a maximum, approximately 54% (36.9% before improvement). When the flow rate was 1.3-1.5m{sup 3}/h, the system can realize the maximum merit, and the collecting efficiency became approximately 50%. Helped by reduction in consumed power, the average system performance coefficient reached more than 85% (28.9% before improvement). The obtainable energy rate rapidly increased to 2.9 times more than before improvement. Further, the consumed power of pump was decreased 65% from before improvement when the flow rate was 2.4m{sup 3}/h. 2 refs., 5 figs.

Solar Thermoelectricity via Advanced Latent Heat Storage: A Cost-Effective Small-Scale CSP Application

Energy Technology Data Exchange (ETDEWEB)

Glatzmaier, Greg C.; Rea, J.; Olsen, Michele L.; Oshman, C.; Hardin, C.; Alleman, Jeff; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, Philip A.; Siegel, N. P.; Toberer, Eric S.; Ginley, David S.

2017-06-27

We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

Solar thermoelectricity via advanced latent heat storage: A cost-effective small-scale CSP application

Science.gov (United States)

Glatzmaier, G. C.; Rea, J.; Olsen, M. L.; Oshman, C.; Hardin, C.; Alleman, J.; Sharp, J.; Weigand, R.; Campo, D.; Hoeschele, G.; Parilla, P. A.; Siegel, N. P.; Toberer, E. S.; Ginley, D. S.

2017-06-01

We are developing a novel concentrating solar electricity-generating technology that is both modular and dispatchable. Solar ThermoElectricity via Advanced Latent heat Storage (STEALS) uses concentrated solar flux to generate high-temperature thermal energy, which directly converts to electricity via thermoelectric generators (TEGs), stored within a phase-change material (PCM) for electricity generation at a later time, or both allowing for simultaneous charging of the PCM and electricity generation. STEALS has inherent features that drive its cost-competitive scale to be much smaller than current commercial concentrating solar power (CSP) plants. Most obvious is modularity of the solid-state TEG, which favors smaller scales in the kilowatt range as compared to CSP steam turbines, which are minimally 50 MWe for commercial power plants. Here, we present techno-economic and market analyses that show STEALS can be a cost-effective electricity-generating technology with particular appeal to small-scale microgrid applications. We evaluated levelized cost of energy (LCOE) for STEALS and for a comparable photovoltaic (PV) system with battery storage. For STEALS, we estimated capital costs and the LCOE as functions of the type of PCM including the use of recycled aluminum alloys, and evaluated the cost tradeoffs between plasma spray coatings and solution-based boron coatings that are applied to the wetted surfaces of the PCM subsystem. We developed a probabilistic cost model that accounts for uncertainties in the cost and performance inputs to the LCOE estimation. Our probabilistic model estimated LCOE for a 100-kWe STEALS system that had 5 hours of thermal storage and 8-10 hours of total daily power generation. For these cases, the solar multiple for the heliostat field varied between 1.12 and 1.5. We identified microgrids as a likely market for the STEALS system. We characterized microgrid markets in terms of nominal power, dispatchability, geographic location, and

Origin of the solar system

International Nuclear Information System (INIS)

Nakazawa, Kiyoshi; Nakagawa, Yoshitsugu

1982-01-01

Many studies on the origin of the solar system have so far been made until now. These are divided into three categories; Cameron's model, Safronov's model and Kyoto model. In Cameron's model, as an initial stage of the formation of the solar system, a massive solar nebula is assumed whose mass is as large as one solar mass. This solar nebula is unstable against gravitational fragmentation, which leads to massive gaseous protoplanets. On the other hand, in both models of Safronov and us, the mass of the nebula is of the order of a few percent of the solar mass or less. However, a significant difference between Safronov's and ours lies in the continuing accumulation process of planetesimals; in the former, the accumulation is assumed to proceed in a gas-free space, but in the latter, the gas drag effect of the solar nebula is fully taken into account on the planetary growth. In this paper, the scenario of Kyoto model is reviewed, which has been developed by Hayashi and his co-workers in Kyoto group for these ten years. We will see that the gas of the solar nebula has played extensively important roles on the various stages of the planetary formation. (author)

Dawn of small worlds dwarf planets, asteroids, comets

CERN Document Server

Moltenbrey, Michael

2016-01-01

This book gives a detailed introduction to the thousands and thousands of smaller bodies in the solar system. Written for interested laymen, amateur astronomers and students it describes the nature and origin of asteroids, dwarf planets and comets, and gives detailed information about their role in the solar system. The author nicely reviews the history of small-world-exploration and describes past, current and future space craft missions studying small worlds, and presents their results. Readers will learn that small solar system worlds have a dramatically different nature and appearance than the planets. Even though research activity on small worlds has increased in the recent past many of their properties are still in the dark and need further research.

Streaming of interstellar grains in the solar system

Science.gov (United States)

Gustafson, B. A. S.; Misconi, N. Y.

1979-01-01

Results of a theoretical study of the interactions between interstellar grains streaming through the solar system and the solar wind are presented. It is shown that although elongated core-mantle interstellar particles of a characteristic radius of about 0.12 microns are subject to a greater force due to radiation pressure than to gravitational attraction, they are still able to penetrate deep inside the solar system. Calculations of particle trajectories within the solar system indicate substantial effects of the solar activity cycle as reflected in the interplanetary magnetic field on the distribution of 0.12- and 0.0005-micron interstellar grains streaming through the solar system, leading to a 50-fold increase in interstellar grain densities 3 to 4 AU ahead of the sun during years 8 to 17 of the solar cycle. It is noted that during the Solar Polar Mission, concentrations are expected which will offer the opportunity of detecting interstellar grains in the solar system.

24 CFR 203.18a - Solar energy system.

Science.gov (United States)

2010-04-01

... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any addition...

Probing the Structure of Our Solar System's Edge

Science.gov (United States)

Hensley, Kerry

2018-02-01

or plasma instabilities. Fully kinetic models, on the other hand, are too computationally expensive to be used for global time-dependent simulations.In order to combine the strengths of MHD and kinetic models, the authors also use adaptive mesh refinement a technique in which the grid size is whittled down at key locations where small-scale physics can have a large effect to resolve the important kinetic processes taking place at the heliopause while lowering the overall computational cost.Physics of the BorderTop: Simulation results for the plasma density observed by Voyager 1 along its trajectory. Bottom: Voyager 1 observations of plasma waves. An increase in the plasma wave frequency corresponds to an increase in the ambient plasma density. Click for a closer look. [Adapted from Pogorelov et al. 2017]The authors varied the ISMs density and magnetic field, exploring how this changed the interaction between the ISM and the solar wind. Among their many results, the authors found:There exists a plasma density drop and magnetic field strength increase in the ISM, just beyond the heliopause. This narrow boundary region is similar to a plasma depletion layer formed upstream from the Earths magnetopause as the solar wind streams around it.The authors model for the plasma density along the trajectory of Voyager 1 is consistent with the actual plasma density inferred from Voyager 1s measurements.The heliospheric magnetic field likely dissipates in the region between the termination shock the point at which the solar wind speed drops below the speed of sound and the heliopause.While this work by Pogorelov and collaborators has brought to light new aspects of the boundary between the solar wind and the ISM, the challenge of linking data and models continues. Future simulations will help us further interpret observations by IBEX and the Voyager spacecraft and advance our understanding of how our solar system interacts with the surrounding ISM.CitationN. V. Pogorelov et al 2017

Fundamental characteristics on electric system of solar electric vehicle; Solar car no denki keito ni kansuru kiso tokusei

Energy Technology Data Exchange (ETDEWEB)

Fujita, S; Sasaki, M; Kaga, T; Koyama, N [Hachinohe Institute of Technology, Aomori (Japan)

1996-10-27

The electric system of a solar vehicle was removed and the fundamental characteristics examined in order to carry out a basic experiment on the electric system. Using a basic circuit with panels, batteries and loads connected, the voltage and current were measured in the presence/absence of the trackers, batteries, etc., and then, their effects were examined. Simultaneously, the quantity of solar radiation was also measured. The lowering of the output voltage was somewhat relaxed with the use of the trackers. Further, with the trackers used, the output voltage of the panel was small in spite of a large quantity of solar radiation compared to the case without the trackers, which was due to the restriction of the output voltage by the trackers. When measured without batteries, the output voltage of the panel was such that the load current was also influenced by the variation of insolation, so that, with a large decrease in insolation, the load current was decreased with the supply of current suspended from the panel. 7 figs., 1 tab.

Investigations of medium sized solar combi systems

DEFF Research Database (Denmark)

Andersen, Elsa; Furbo, Simon

2006-01-01

A large variety of solar combi systems are on the market, but it is still too early to draw conclusions on optimum design of solar combi systems. Among others, the following questions need to be answered: Is an external domestic hot water preparation more desirable than an internal? What...... is the advantage by using inlet stratifiers? To answer the questions, theoretical investigations are carried out for differently designed solar combi systems. The work is carried out within the Solar Heating and Cooling Programme of the International Energy Agency (IEA SHC), Task 32 Advanced storage concepts...... for solar houses and low energy buildings....

Washington, D.C. | Midmarket Solar Policies in the United States | Solar

Science.gov (United States)

development have kept SREC prices high. Recent DC solar initiatives (e.g., the Solar Advantage Plus Program ) have targeted low-income residents. Small businesses may be able to leverage resources from the DC residential and commercial customer-generators with systems powered by renewable-energy sources. DC's net

The efficiency of an open-cavity tubular solar receiver for a small-scale solar thermal Brayton cycle

International Nuclear Information System (INIS)

Le Roux, W.G.; Bello-Ochende, T.; Meyer, J.P.

2014-01-01

Highlights: • Results show efficiencies of a low-cost stainless steel tubular cavity receiver. • Optimum ratio of 0.0035 is found for receiver aperture area to concentrator area. • Smaller receiver tube and higher mass flow rate increase receiver efficiency. • Larger tube and smaller mass flow rate increase second law efficiency. • Large-tube receiver performs better in the small-scale solar thermal Brayton cycle. - Abstract: The first law and second law efficiencies are determined for a stainless steel closed-tube open rectangular cavity solar receiver. It is to be used in a small-scale solar thermal Brayton cycle using a micro-turbine with low compressor pressure ratios. There are many different variables at play to model the air temperature increase of the air running through such a receiver. These variables include concentrator shape, concentrator diameter, concentrator rim angle, concentrator reflectivity, concentrator optical error, solar tracking error, receiver aperture area, receiver material, effect of wind, receiver tube diameter, inlet temperature and mass flow rate through the receiver. All these variables are considered in this paper. The Brayton cycle requires very high receiver surface temperatures in order to be successful. These high temperatures, however, have many disadvantages in terms of heat loss from the receiver, especially radiation heat loss. With the help of ray-tracing software, SolTrace, and receiver modelling techniques, an optimum receiver-to-concentrator-area ratio of A′ ≈ 0.0035 was found for a concentrator with 45° rim angle, 10 mrad optical error and 1° tracking error. A method to determine the temperature profile and net heat transfer rate along the length of the receiver tube is presented. Receiver efficiencies are shown in terms of mass flow rate, receiver tube diameter, pressure drop, maximum receiver surface temperature and inlet temperature of the working fluid. For a 4.8 m diameter parabolic dish, the

Protecting solar collector systems from corrosion

Energy Technology Data Exchange (ETDEWEB)

1978-01-01

The main cause of the reduced life of a solar heating system is corrosion of the exterior parts and the internal components. This report outlines ways of reducing the cost of solar heating by reducing the corrosion in solar heating systems, and hence increasing the system's service life. Mechanisms for corrosion are discussed: these include galvanic corrosion and crevice corrosion. Means of minimizing corrosion at the design stage are then described. Such methods, when designing the solar collector, involve ensuring proper drainage of exterior water; eliminating situations where moisture, dirt and pollutants may collect; preventing condensation inside the collector; using proper gaskets and sealants at appropriate places; and selecting optimum materials and coatings. Interior corrosion can be minimized at the design stage by choosing a good heat transfer fluid and corrosion inhibitor, in the case of systems where liquids are used; ensuring a low enough flow rate to avoid erosion; designing the system to avoid crevices; and avoiding situations where galvanic corrosion could occur. Other procedures are given for minimizing corrosion in the construction and operation of solar heating systems. 7 figs., 7 tabs.

Wind in the Solar System

Science.gov (United States)

McIntosh, Gordon

2010-01-01

As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

Solar system for soil drainage

International Nuclear Information System (INIS)

Kocic, Z.R.; Stojanovic, J.B.; Antic, M.A.; Pavlovic, T.M.

1999-01-01

The paper reviews solar system for drainage of the cultivable agricultural surfaces which can be situated near the rivers in plains. These are usually very fertile surfaces which cannot be cultivated die to constant presence of the water. Using such solar systems should increase the percentage of cultivable surfaces. These systems can also be installed on the cultivable agricultural surfaces, where the water surfaces or so called still waters appear, which make impossible the application of agritechnical measures on these surfaces, significantly decreasing crops and creating conditions for the growth of pond plants and animals. Increasing the percentage of cultivable agricultural surfaces would increase national agricultural income. At the same time, increasing the percentage of cultivable agricultural surfaces decreases the surfaces of unhealthy bog, swamp and marshland soils, where many insect breed. They are the cause for soil spraying from the air, which causes the pollution of environment. Solar systems do not pollute the environment because they use solar energy as the purest source of energy. Their usage has special significance in the places where there is no electricity distribution network

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)

Innovative Design of Solar-Powered Desalination (SPD System using Vacuum-Multi Effect Membrane Distillation (V-MEMD Process

Directory of Open Access Journals (Sweden)

Chafidz Achmad

2018-01-01

Full Text Available This research focused on the development of an innovative design of solar-powered desalination (SPD system which was expected to solve the water and energy problem simultaneously. We have developed a portable and hybrid solar-powered desalination (SPD system for producing potable water from saline water. It is a self-contained and integrated system which combines solar-thermal collector and solar-photovoltaic for its operation, and thus the system can operate to produce water by only using solar energy. Therefore, the system is highly suitable to be implemented in remote arid and coastal areas without infrastructures or connection to the grid (water and power, but blessed with abundant solar irradiation, like in Saudi Arabia. A Memsys Vacuum Multi-Effect Membrane Distillation (V-MEMD unit was used as the core of the SPD system. A heat pump was also integrated into the SPD system for energy recovery and to improve the performance of the system. The system could be considered as sustainable and “green” desalination technology, which will be very useful for the Kingdom of Saudi Arabia. To study the performance of the system, small-scale tests have been carried out at the Engineering College - King Saud University, Saudi Arabia. Based on the experimental results, the system has run successfully by only utilizing solar energy.

The space-age solar system

International Nuclear Information System (INIS)

Baugher, J.F.

1988-01-01

This book is a description of the sun, planets, moons, asteroids, and comets in the solar system. Discussion is based heavily on results obtained from recent space probes to Mercury, Venus, Mars Jupiter, Saturn, and Uranus. Offers detailed descriptions of the moons of Jupiter and Saturn, and the results of the recent probes of Halley's comet. A discussion of meteorites leads to a description of the current models of the solar system. Introductory chapters present theories of the solar system from the ancient Greeks to the present day. Other topics covered include the sun, its structure, and how it generates energy; the surfaces, internal structures, and histories of the planets, from innermost Mercury to farthest Pluto, and their moons

Small Satellite Constellations for Geospace Sciences

Science.gov (United States)

Spence, H. E.

2016-12-01

The recent National Academy of Sciences Solar and Space Physics Decadal Survey (DS) identified community-consensus science priorities for the decade spanning 2013 - 2022. In this talk, we discuss the ways by which small satellite constellations are already and may soon accelerate progress toward achieving many of these science targets. The DS outlined four overarching science goals: (1) determine the origins of the Sun's activity and predict the variations in the space environment; (2) determine the dynamics and coupling of Earth's magnetosphere, ionosphere, and atmosphere and their response to solar and terrestrial inputs; (3) determine the interaction of the Sun with the solar system and the interstellar medium; and, (4) discover and characterize fundamental processes that occur both within the heliosphere and throughout the universe. These DS science goals provide the context for key science challenges in the three connected parts of the system that encompass all of solar and space physics, herein referred to as geospace: the Sun and heliosphere; the coupled solar wind-magnetosphere system; and, the coupled atmosphere-ionosphere-magnetosphere system. The DS further presented the role that small satellites play in resolving many of these science challenges, with a particular emphasis on the role that constellations of small satellites will play. While once considered by many as being "futuristic" or even "unrealizable", constellations of small satellites are already making important contributions to geospace science and with the promise for more to come. Using the DS as a guidepost, in this presentation, we outline representative small satellite constellation missions alread underway, some in development, and others notionally proposed over the next several years that employ small satellite constellations to tackle large science imperatives. Finally, we give examples of key small satellite technologies in development that will potentially enable great scientific

Force convective solar drying system

International Nuclear Information System (INIS)

Ruslan, M.H.; Othman, M.Y.; Baharuddin Yatim; Kamaruzzaman Sopian; Ibarahim, Z.

2006-01-01

This paper presents design and performance of V-groove back-pass solar collector for solar drying system. In this study three V-groove back-pass solar collector each with dimension of 4.6 m x 1.0 m x 0.15 m have been fabricated for solar drying system. An outdoor test at mean solar intensity for 600-800 Wm -2 by using 0.15m 3 s -1 of air flow rate which also been suggested by (Zeroul et al. 1994) was carried out at Solar Research Energy Park. Universiti Kebangsaan Malaysia. Analysis on the collector performance based on daily data was reported that the value of FR ) e and FRUL was 0.709 ± 0.001 and 5.89 ± 0.31 Wm -2o C -1 respectively with 60-70 o C of output temperature (Ruslan et al. 2001). The three V-groove collectors each with dimension 4.6 m x 0.15 m were connected in series array mounted on the roof of a solar assisted drying system. By using two electric fans of 85W and 2700 rpm each, the speed of air was regulated at 0.11 kgs -1 to 0.31 kgs -1 using a voltage regulator. Performance of the collector based on the thermal analysis showed that at mean daily solar radiation 700 Wm -2 , the output temperature of 52 o C to 73 o C could be achieved using 0.11-0.31 kgs -1 of flow rate. Thermal analysis also showed that the efficiencies of 45% to 61% could be obtains using the same flow rate and solar radiation. Analysis of daily data showed that for radiation from 300 Wm -2 to 1000 Wm -2 the power generated from the collector was within 1.5 kW to 8.9 kW. The study concluded that the levels of the levels of the solar radiation and flow rate used influenced the performance of the collector

Energy Efficient Hybrid Dual Axis Solar Tracking System

Directory of Open Access Journals (Sweden)

Rashid Ahammed Ferdaus

2014-01-01

Full Text Available This paper describes the design and implementation of an energy efficient solar tracking system from a normal mechanical single axis to a hybrid dual axis. For optimizing the solar tracking mechanism electromechanical systems were evolved through implementation of different evolutional algorithms and methodologies. To present the tracker, a hybrid dual-axis solar tracking system is designed, built, and tested based on both the solar map and light sensor based continuous tracking mechanism. These light sensors also compare the darkness and cloudy and sunny conditions assisting daily tracking. The designed tracker can track sun’s apparent position at different months and seasons; thereby the electrical controlling device requires a real time clock device for guiding the tracking system in seeking solar position for the seasonal motion. So the combination of both of these tracking mechanisms made the designed tracker a hybrid one. The power gain and system power consumption are compared with a static and continuous dual axis solar tracking system. It is found that power gain of hybrid dual axis solar tracking system is almost equal to continuous dual axis solar tracking system, whereas the power saved in system operation by the hybrid tracker is 44.44% compared to the continuous tracking system.

Solar water heating for small cheese factories in Peru

Energy Technology Data Exchange (ETDEWEB)

Oliveros Donohue, A A

1982-03-01

Plans are described for the implementation of 40 small plants to be used for cheese production. As a start, a demonstration plant has been built in San Juan de Chuquibambilla-Puno, Peru. Design and testing of a flat plate solar collector, to be used for water heating purposes, are described. The cheese making process is discussed. Essentially two pots are required, one at 32/sup 0/C and one at 80/sup 0/. Two flat plate collectors (1.12 m/sup 2/ each) are connected to a 150 l storage tank. Instrumentation and results are discussed. Total efficiency of the process is given as 40%. It is concluded that future installations should consider using biogas digesters and wind driven water pumps in addition to the solar collectors. A brief discussion of the climate, population distribution, and economy of Peru is given. (MJJ)

Solar heating systems

International Nuclear Information System (INIS)

1993-01-01

This report is based on a previous, related, one which was quantitative in character and relied on 500 telephone interviews with house-owners. The aim of this, following, report was to carry out a more deep-going, qualitative analysis focussed on persons who already own a solar heating system (purchased during 1992) or were/are considering having one installed. Aspects studied were the attitudes, behaviour and plans of these two groups with regard to solar heating systems. Some of the key questions asked concerned general attitudes to energy supply, advantages and disadvantages of using solar heating systems, related decision-making factors, installation problems, positive and negative expectations, evaluation of the information situation, suggestions related to information systems regarding themes etc., dissemination of information, sources of advice and information, economical considerations, satisfaction with the currently-owned system which would lead to the installation of another one in connection with the purchase of a new house. The results of this investigation directed at Danish house-owners are presented and discussed, and proposals for following activities within the marketing situation are given. It is concluded that the basic attitude in both groups strongly supports environmental protection, renewable energy sources and is influenced by considerations of prestige and independence. Constraint factors are confusion about environmental factors, insecurity in relation to the effect of established supplementary energy supply and suspicion with regard to the integrity of information received. (AB)

Photovoltaic Thermal panels in collective thermal solar systems

International Nuclear Information System (INIS)

Elswijk, M.J.; Strootman, K.J.; Jong, M.J.M.; De Lange, E.T.N.; Smit, W.F.

2003-12-01

A feasibility study has been carried out to assess the options to apply photovoltaic/thermal panels (PVT-panels) in collective solar thermal systems in urban areas in the Netherlands. The study was focused on the technical (architecture and installations) and the economical feasibility of collective PVT-systems in comparison with conventional solar thermal systems and combinations of photovoltaic (PV) panels and solar collectors. The results of the study also give insight into cost and the market for PVT-panels. Three case studies in which collective solar collector systems were applied are analyzed again by simulating the installation of a PVT-panels system and a separate solar thermal PV system [nl

Our Solar System. Our Solar System Topic Set

Science.gov (United States)

Phelan, Glen

2006-01-01

This book examines the planets and other objects in space that make up the solar system. It also shows how technology helps students learn about our neighbors in space. The suggested age range for this book is 3-8 with a guided reading level of Q-R. The Fry level is 3.2.

Environmental benefits of domestic solar energy systems

International Nuclear Information System (INIS)

Kalogirou, Soteris A.

2004-01-01

All nations of the world depend on fossil fuels for their energy needs. However the obligation to reduce CO 2 and other gaseous emissions in order to be in conformity with the Kyoto agreement is the reason behind which countries turn to non-polluting renewable energy sources. In this paper the pollution caused by the burning of fossil fuels is initially presented followed by a study on the environmental protection offered by the two most widely used renewable energy systems, i.e. solar water heating and solar space heating. The results presented in this paper show that by using solar energy, considerable amounts of greenhouse polluting gasses are avoided. For the case of a domestic water heating system, the saving, compared to a conventional system, is about 80% with electricity or Diesel backup and is about 75% with both electricity and Diesel backup. In the case of space heating and hot water system the saving is about 40%. It should be noted, however, that in the latter, much greater quantities of pollutant gasses are avoided. Additionally, all systems investigated give positive and very promising financial characteristics. With respect to life cycle assessment of the systems, the energy spent for manufacture and installation of the solar systems is recouped in about 1.2 years, whereas the payback time with respect to emissions produced from the embodied energy required for the manufacture and installation of the systems varies from a few months to 9.5 years according to the fuel and the particular pollutant considered. Moreover, due to the higher solar contribution, solar water heating systems have much shorter payback times than solar space heating systems. It can, therefore, be concluded that solar energy systems offer significant protection to the environment and should be employed whenever possible in order to achieve a sustainable future

Thermal destratification in small standard solar tanks due to mixing during tapping

DEFF Research Database (Denmark)

Andersen, Elsa; Furbo, Simon

1999-01-01

performance caused by mixing during draw-offs can be as high as 23% if a marketed cold-water inlet design is used. Other tested inlet designs result in a decrease of 2-3% of the yearly thermal performance caused by mixing. Based on the investigations recommendations on the design of the cold-water inlet......-off is relatively long. In order to reduce this waiting time to an acceptable level, the flow rate during draw-off is often very large – typically about 20 l/min. – at least at the start of the draw-off. As long as the flow rate during draw-off is small, the mixing rate inside the tank is small. However......, if the flow rate is large, as mentioned above, the mixing rate can be relatively large if the cold-water inlet design is poor. Mixing results in destratification in the solar tank and with that reduced thermal performance of the SDHW system. Investigations indicate that the decrease of the yearly thermal...

Thermal destratification in small standard solar tanks due to mixing during tapping

DEFF Research Database (Denmark)

Andersen, Elsa; Furbo, Simon

1999-01-01

performance caused by mixing during draw-offs can be as high as 23 % if a marketed cold water inlet design is used. Other tested inlet designs result in a decrease of 2-3 % of the yearly thermal performance caused by mixing. Based on the investigations recommendations on the design of the cold water inlet......-off is relatively long. In order to reduce this waiting time to an acceptable level, the flow rate during draw-off is often very large - typically about 20 l/min - at least at the start of the draw-off. As long as the flow rate during draw-off is small, the mixing rate inside the tank is small. However, if the flow...... rate is large, as mentioned above, the mixing rate can be relatively large if the cold water inlet design is poor. Mixing results in destratification in the solar tank and with that reduced thermal performance of the SDHW system. Investigations indicate that the decrease of the yearly thermal...

Energy Savings for Solar Heating Systems

DEFF Research Database (Denmark)

Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

2004-01-01

, various simulations of solar heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal system. For some conditions the fuel reduction can be up to the double of the solar......In this paper the realistic behaviour and efficiency of heating systems were analysed, based on long term monitoring projects. Based on the measurements a boiler model was evaluated. Comparisons of measured and calculated fuel consumptions showed a good degree of similarity. With the boiler model...... gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated in this paper....

Hybrid solar lighting distribution systems and components

Science.gov (United States)

Muhs, Jeffrey D [Lenoir City, TN; Earl, Dennis D [Knoxville, TN; Beshears, David L [Knoxville, TN; Maxey, Lonnie C [Powell, TN; Jordan, John K [Oak Ridge, TN; Lind, Randall F [Lenoir City, TN

2011-07-05

A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

Solar thermophotovoltaic system using nanostructures.

Science.gov (United States)

Ungaro, Craig; Gray, Stephen K; Gupta, Mool C

2015-09-21

This paper presents results on a highly efficient experimental solar thermophotovoltaic (STPV) system using simulated solar energy. An overall power conversion efficiency of 6.2% was recorded under solar simulation. This was matched with a thermodynamic model, and the losses within the system, as well as a path forward to mitigate these losses, have been investigated. The system consists of a planar, tungsten absorbing/emitting structure with an anti-reflection layer coated laser-microtextured absorbing surface and single-layer dielectric coated emitting surface. A GaSb PV cell was used to capture the emitted radiation and convert it into electrical energy. This simple structure is both easy to fabricate and temperature stable, and contains no moving parts or heat exchange fluids.

Experimental study on a new solar boiling water system with holistic track solar funnel concentrator

International Nuclear Information System (INIS)

Xiaodi, Xue; Hongfei, Zheng; Kaiyan, He; Zhili, Chen; Tao, Tao; Guo, Xie

2010-01-01

A new solar boiling water system with conventional vacuum-tube solar collector as primary heater and the holistic solar funnel concentrator as secondary heater had been designed. In this paper, the system was measured out door and its performance was analyzed. The configuration and operation principle of the system are described. Variations of the boiled water yield, the temperature of the stove and the solar irradiance with local time have been measured. Main factors affecting the system performance have been analyzed. The experimental results indicate that the system produced large amount of boiled water. And the performance of the system has been found closely related to the solar radiance. When the solar radiance is above 600 W/m 2 , the boiled water yield rate of the system has reached 20 kg/h and its total energy efficiency has exceeded 40%.

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....

Potential of solar home systems in Pakistan

International Nuclear Information System (INIS)

Memon, M.; Harijan, K.; Uqaili, M. A.

2007-01-01

About 68% of the population of Pakistan resides in rural areas. Most of the rural households have no access to electricity and meet lighting requirements through kerosene which is a major source of indoor air pollution and other environmental and health hazards. Rural villages are scattered over a large area and located far from the main electric grids. They have low population density and requires small load. About 67% of the conventional electricity in Pakistan is generated from fossil fuels with 51% and 16% share of gas and oil respectively. The indigenous reserves of oil and gas are limited and the country heavily depends on imported oil. The oil import bill is a serious strain on the country's economy. The combustion of fossil fuels also causes serious environmental pollution. The conventional power is even not sufficient for meeting the growing demand of electricity from the existing customers. Further more the extension of existing centralized grid system to far away from grid line rural areas with very low population density and small-scattered loads are economically and technically unfeasible. Hence there are remote chances of getting grid connection to most of the rural population in the near future. This whole situation requires urgent measures on priority basis for the development of indigenous, environment friendly, renewable energy sources such as solar energy. This paper presents the assessment of potential of solar home systems (SHS) for rural electrification in Pakistan. The country lies in an excellent solar belt range and receives 16-21 MJ/m 2 per day of solar radiation as an annual mean value, with 19 MJ/m 2 per day over most areas of the country. It is estimated that about 7 million households in Pakistan do not have access to electricity (in 2004). Assuming that about 50% of the households in rural areas without electricity today would be electrified up to 2010, and only 25% of the remaining households could afford and would be willing to pay

Large solar energy systems within IEA task 14

NARCIS (Netherlands)

Geus, A.C. de; Isakson, P.; Bokhoven, T.P.; Vanoli, K.; Tepe, R.

1996-01-01

Within IEA Task 14 (Advanced Solar Systems) a working group was established dealing with large advanced solar energy systems (the Large Systems Working group). The goal of this working group was to generate a common base of experiences for the design and construction of advanced large solar systems.

Investigation of Annealing and Blend Concentration Effects of Organic Solar Cells Composed of Small Organic Dye and Fullerene Derivative

Directory of Open Access Journals (Sweden)

Yasser A. M. Ismail

2011-01-01

Full Text Available We have fabricated bulk heterojunction organic solar cells using coumarin 6 (C6 as a small organic dye, for light harvesting and electron donation, with fullerene derivative [6,6]-phenyl-C61 butyric acid methyl ester (PCBM, acting as an electron acceptor, by spin-coating technique. We have investigated thermal annealing and blend concentration effects on light harvesting, photocurrent, and performance parameters of the solar cells. In this work, we introduced an experimental method by which someone can easily detect the variation in the contact between active layer and cathode due to thermal annealing after cathode deposition. We have showed, in this work, unusual behavior of solar cell composed of small organic molecules under the influence of thermal annealing at different conditions. This behavior seemed uncommon for polymer solar cells. We try from this work to understand device physics and to locate a relationship between production parameters and performance parameters of the solar cell based on small organic molecules.

How Normal is Our Solar System?

Science.gov (United States)

Kohler, Susanna

2015-10-01

To date, weve discovered nearly 2000 confirmed exoplanets, as well as thousands of additional candidates. Amidst this vast sea of solar systems, how special is our own? A new study explores the answer to this question.Analyzing DistributionsKnowing whether our solar system is unique among exoplanetary systems can help us to better understand future observations of exoplanets. Furthermore, if our solar system is typical, this allows us to be optimistic about the possibility of life existing elsewhere in the universe.In a recent study, Rebecca Martin (University of Nevada, Las Vegas) and Mario Livio (Space Telescope Science Institute) examine how normal our solar system is, by comparing the properties of our planets to the averages obtained from known exoplanets.Comparing PropertiesSo how do we measure up?Densities of planets as a function of their mass. Exoplanets (N=287) are shown in blue, planets in our solar system are shown in red. [MartinLivio 2015]Planet masses and densitiesThose of the gas giants in our solar system are pretty typical. The terrestrial planets are on the low side for mass, but thats probably a selection effect: its very difficult to detect low-mass planets.Age of the solar systemRoughly half the stars in the disk of our galaxy are younger than the Sun, and half are older. Were definitely not special in age.Orbital locations of the planetsThis is actually a little strange: our solar system is lacking close-in planets. All of our planets, in fact, orbit at a distance that is larger than the mean distance observed in exoplanetary systems. Again, however, this might be a selection effect at work: its easier to detect large planets orbiting very close to their stars.Eccentricities of the planets orbitsOur planets are on very circular orbits and that actually makes us somewhat special too, compared to typical exoplanet systems. There is a possible explanation though: eccentricity of orbits tends to decrease with more planets in the system. Because

Drainback solar thermal systems

DEFF Research Database (Denmark)

Botpaev, R.; Louvet, Y.; Perers, Bengt

2016-01-01

Although solar drainback systems have been used for a long time, they are still generating questions regarding smooth functioning. This paper summarises publications on drainback systems and compiles the current knowledge, experiences, and ideas on the technology. The collective research exhibits...... of this technology has been developed, with a brief description of each hydraulic typology. The operating modes have been split into three stages: filling, operation, and draining, which have been studied separately. A difference in the minimal filling velocities for a siphon development in the solar loop has been...

MAKING PLANET NINE: A SCATTERED GIANT IN THE OUTER SOLAR SYSTEM

International Nuclear Information System (INIS)

Bromley, Benjamin C.; Kenyon, Scott J.

2016-01-01

Correlations in the orbits of several minor planets in the outer solar system suggest the presence of a remote, massive Planet Nine. With at least 10 times the mass of the Earth and a perihelion well beyond 100 au, Planet Nine poses a challenge to planet formation theory. Here we expand on a scenario in which the planet formed closer to the Sun and was gravitationally scattered by Jupiter or Saturn onto a very eccentric orbit in an extended gaseous disk. Dynamical friction with the gas then allowed the planet to settle in the outer solar system. We explore this possibility with a set of numerical simulations. Depending on how the gas disk evolves, scattered super-Earths or small gas giants settle on a range of orbits, with perihelion distances as large as 300 au. Massive disks that clear from the inside out on million-year timescales yield orbits that allow a super-Earth or gas giant to shepherd the minor planets as observed. A massive planet can achieve a similar orbit in a persistent, low-mass disk over the lifetime of the solar system.

MAKING PLANET NINE: A SCATTERED GIANT IN THE OUTER SOLAR SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Bromley, Benjamin C. [Department of Physics and Astronomy, University of Utah, 115 South 1400 East, Room 201, Salt Lake City, UT 84112 (United States); Kenyon, Scott J., E-mail: bromley@physics.utah.edu, E-mail: skenyon@cfa.harvard.edu [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States)

2016-07-20

Correlations in the orbits of several minor planets in the outer solar system suggest the presence of a remote, massive Planet Nine. With at least 10 times the mass of the Earth and a perihelion well beyond 100 au, Planet Nine poses a challenge to planet formation theory. Here we expand on a scenario in which the planet formed closer to the Sun and was gravitationally scattered by Jupiter or Saturn onto a very eccentric orbit in an extended gaseous disk. Dynamical friction with the gas then allowed the planet to settle in the outer solar system. We explore this possibility with a set of numerical simulations. Depending on how the gas disk evolves, scattered super-Earths or small gas giants settle on a range of orbits, with perihelion distances as large as 300 au. Massive disks that clear from the inside out on million-year timescales yield orbits that allow a super-Earth or gas giant to shepherd the minor planets as observed. A massive planet can achieve a similar orbit in a persistent, low-mass disk over the lifetime of the solar system.

Making Planet Nine: A Scattered Giant in the Outer Solar System

Science.gov (United States)

Bromley, Benjamin C.; Kenyon, Scott J.

2016-07-01

Correlations in the orbits of several minor planets in the outer solar system suggest the presence of a remote, massive Planet Nine. With at least 10 times the mass of the Earth and a perihelion well beyond 100 au, Planet Nine poses a challenge to planet formation theory. Here we expand on a scenario in which the planet formed closer to the Sun and was gravitationally scattered by Jupiter or Saturn onto a very eccentric orbit in an extended gaseous disk. Dynamical friction with the gas then allowed the planet to settle in the outer solar system. We explore this possibility with a set of numerical simulations. Depending on how the gas disk evolves, scattered super-Earths or small gas giants settle on a range of orbits, with perihelion distances as large as 300 au. Massive disks that clear from the inside out on million-year timescales yield orbits that allow a super-Earth or gas giant to shepherd the minor planets as observed. A massive planet can achieve a similar orbit in a persistent, low-mass disk over the lifetime of the solar system.

Small molecule solution-processed bulk heterojunction solar cells with inverted structure using porphyrin donor

Science.gov (United States)

Yamamoto, Takaki; Hatano, Junichi; Nakagawa, Takafumi; Yamaguchi, Shigeru; Matsuo, Yutaka

2013-01-01

Utilizing tetraethynyl porphyrin derivative (TE-Por) as a small molecule donor material, we fabricated a small molecule solution-processed bulk heterojunction (BHJ) solar cell with inverted structure, which exhibited 1.6% power conversion efficiency (JSC (short-circuit current) = 4.6 mA/cm2, VOC (open-circuit voltage) = 0.90 V, and FF (fill factor) = 0.39) in the device configuration indium tin oxide/TiOx (titanium sub-oxide)/[6,6]-phenyl-C61-butyric acid methyl ester:TE-Por (5:1)/MoOx (molybdenum sub-oxide)/Au under AM1.5 G illumination at 100 mW/cm2. Without encapsulation, the small molecule solution-processed inverted BHJ solar cell also showed remarkable durability to air, where it kept over 73% of its initial power conversion efficiency after storage for 28 days under ambient atmosphere in the dark.

Performance Comparisons and Down Selection of Small Motors for Two-Blade Heliogyro Solar Sail 6U CubeSat

Science.gov (United States)

Wiwattananon, Peerawan; Bryant, Robert G.

2015-01-01

This report compiles a review of 130 commercial small scale motors (piezoelectric and electric motors) and almost 20 researched-type small scale piezoelectricmotors for potential use in a 2 blades Heliogyro Solar Sail 6U CubeSat. In this application, a motor and gearhead (drive system) will deploy a roll of solar sailthin film (2 um thick)accommodated in a 2U CubeSat (100 x 200 x 100 mm) housing. The application requirements are: space rated, output torque at fulldeployment of 0.8 Nm, reel speed of 3 rpm, drive system weight limited to 150 grams, diameter limited to 50 mm, and the length not to exceed 40 mm. The 50mm diameter limit was imposed as motors with larger diameters would likely weigh too much and use more space on the satellite wall. This would limit theamount of the payload. The motors performance are compared between small scale, volume within 3x102 cm3 (3x105 mm3), commercial electric DC motors,commercial piezoelectric motors, and researched-type (non-commercial) piezoelectric motors extracted from scientific and product literature. The comparisonssuggest that piezoelectric motors without a gearhead exhibit larger output torque with respect to their volume and weight and require less input power toproduce high torque. A commercially available electric motor plus a gearhead was chosen through a proposed selection process to meet the applications designrequirements.

Energy Savings for Solar Heating Systems

DEFF Research Database (Denmark)

Thür, Alexander; Furbo, Simon; Shah, Louise Jivan

2006-01-01

showed a good degree of similarity. With the boiler model, various simulations of solar domestic hot water heating systems were done for different hot water demands and collector sizes. The result shows that the potential of fuel reduction can be much higher than the solar gain of the solar thermal...... system. For some conditions the fuel reduction can be up to the double of the solar gain due to a strong increase of the system efficiency. As the monitored boilers were not older than 3 years, it can be assumed that the saving potential with older boilers could be even higher than calculated......In this paper the realistic behaviour and efficiency of heating systems were analysed, based on long term monitoring projects. Based on the measurements a boiler model used to calculate the boiler efficiency on a monthly basis was evaluated. Comparisons of measured and calculated fuel consumptions...

Evolution of the solar system in the presence of a solar companion star

International Nuclear Information System (INIS)

Hut, P.

1986-01-01

A review is presented of the dynamical implications of a companion star in a wide orbit around the sun, with a semimajor axis of about half a parsec. The motivation behind the hypothesis of a solar companion star is reviewed briefly along with alternative hypotheses, and the general problem of solar system dynamics with a solar companion star is discussed. Four principal questions are posed and answered concerning the consistency of the solar companion theory in providing the required modulation in comet arrival times: (1) What is the expected lifetime of a solar companion? (2) How stable is the orbital period? (3) Does a single perihelion passage of a solar companion perturb enough comets? (4) Do repeated perihelion passages of a solar companion perturb too many comets? Some applications outside the solar system involving wide binaries, interstellar clouds, and dark matter in the Galactic disk are discussed, and the viability of the solar companion theory is critically assessed

Market potential of solar thermal system in Malaysia

International Nuclear Information System (INIS)

Othman, M.Y.H.; Sopian, K.; Dalimin, M.N.

1992-01-01

This paper reviews the market potential for solar thermal systems in Malaysia. Our study indicates that solar thermal systems such as solar drying, solar water heating and process heating have a good potential for commercialization. The primary obstacle facing the utilization of these technologies is the financial aspects. (author)

Study of an active wall solar heating system

International Nuclear Information System (INIS)

Kassem, Talal

2006-01-01

An active wall solar heating system was built and tested. In the same time a compatible computer program has been according to set the recommended dimensions for the solar collectors where (F-Chart) method used to set the ratio of monthly solar sharing average for the examined heating system. Some parameters, such as collectors' areas, its tilt angle and near earth reflecting were experimentally investigated, affecting the executed active solar heating system performance. The study explain the ability of using this system which is simple, Low coast and high performance in heating residential and public buildings and heating water with ratio of yearly solar sharing achieves the needed saving of using this system.(Author)

Basics of Solar Heating & Hot Water Systems.

Science.gov (United States)

American Inst. of Architects, Washington, DC.

In presenting the basics of solar heating and hot water systems, this publication is organized from the general to the specific. It begins by presenting functional and operational descriptions of solar heating and domestic hot water systems, outlining the basic concepts and terminology. This is followed by a description of solar energy utilization…

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

Developing solar: PV solar system markets in Africa

International Nuclear Information System (INIS)

Asali, Karim

2002-01-01

Governments, NGO's and UN organisations are increasingly convinced that renewable energies not only help to solve energy problems in Africa but are indispensable in alleviating regional disparities, social problems and bridging the digital gap. Still, many years after introducing high efficiency solar PV systems the necessary breakthrough of implementing them on a mass scale is still not a reality. The author provides perspectives on developing solar PV in Africa. (Author)

A hybrid desalination system using humidification-dehumidification and solar stills integrated with evacuated solar water heater

International Nuclear Information System (INIS)

Sharshir, S.W.; Peng, Guilong; Yang, Nuo; Eltawil, Mohamed A.; Ali, Mohamed Kamal Ahmed; Kabeel, A.E.

2016-01-01

Highlights: • Evacuated solar water heater integrated with humidification-dehumidification system. • Reuse of warm water drained from humidification-dehumidification to feed solar stills. • The thermal performance of hybrid system is increased by 50% and maximum yield is 63.3 kg/day. • The estimated price of the freshwater produced from the hybrid system is $0.034/L. - Abstract: This paper offers a hybrid solar desalination system comprising a humidification-dehumidification and four solar stills. The developed hybrid desalination system reuses the drain warm water from humidification-dehumidification to feed solar stills to stop the massive warm water loss during desalination. Reusing the drain warm water increases the gain output ratio of the system by 50% and also increased the efficiency of single solar still to about 90%. Furthermore, the production of a single solar still as a part of the hybrid system was more than that of the conventional one by approximately 200%. The daily water production of the conventional one, single solar still, four solar still, humidification- dehumidification and hybrid system were 3.2, 10.5, 42, 24.3 and 66.3 kg/day, respectively. Furthermore, the cost per unit liter of distillate from conventional one, humidification- dehumidification and hybrid system were around $0.049, $0.058 and $0.034, respectively.

Factibilidad del uso de la climatización solar de pequeña capacidad; Feasibility of the use of solar cooling of small capacity

Directory of Open Access Journals (Sweden)

César Arnaldo Cisneros Ramírez

2015-04-01

Full Text Available En el trabajo se presenta la evaluación económica de la implementación de la climatización con empleo de la energía solar para las condiciones de radiación y temperatura ambiente en La Habana, Cuba. La evaluación se realizó para máquinas de pequeña capacidad (7-35 kW las cuales se encuentran en el mercado internacional. El estudio se realizó empleando el tiempo de recuperación de la inversión y el ahorro en el ciclo de vida como criterios de medida. Además se analizó la influencia que tiene la relación volumen de almacenamiento/área de captación (V/A sobre la fracción solar, la energía auxiliar, el costo de la energía ahorrada, ahorro de la energía primaria y ahorro en la cantidad de CO2 emitido. Se empleó el método P1-P2 para los cálculos económicos así como el método Φ-fchart para la obtención de la fracción solar. El precio del petróleo se varió entre los 100 y 200 $/barril.  This work presents an economical evaluation of implementing a solar air-conditioning system using solar energy in Havana, Cuba. It was studied the feasibility of systems of small and medium capacities (7-35 kW of absorption refrigeration machines which be in the world market. The parameters that were taken for the feasibility were the payback time and life cycle savings. Also it was analyzed the influence of the ratio storage volume/solar collector area (V/A on solar fraction, auxiliary energy, saved energy cost, saved primary energy and emitted CO2. Besides, it was used the P1-P2 method for the economical aspects and the Φ-fchart method in order to determine de solar fraction. The price of petroleum was varied from 100 to 200$/barrel.

Regional Analysis of Aids and Prices for Small-scale Grid-connected Solar Photovoltaic Systems in Spain; Analisis Regional de Precios y Ayudas para Sistemas fotovoltaicos de Pequena Escala Conectados a Red Electrica en Espana

Energy Technology Data Exchange (ETDEWEB)

Varela, M; Ramirez, L; Mora, L; Sidrach de Cardona, M

2002-07-01

Electricity production from small solar photovoltaic systems in Spain obtains a premium pnce of 0,36 Euros/kWh over the electricity market price or a fix price of 0.40 Euros/kWh. The development of these small systems, in Spain clearly demonstrates that the established prime is not sufficient in the majority of locations. On the other hand, the prime revision set up by the RD 2818/98. considering the profitability of the renewable installations, demand a regional analysis of small PV systems profitability necessary in Spain. The accomplished results permit to conclude that the amount of the current prime is by itself insufficient to make profitable the small grid-connected PV systems in anywhere of the national geography. To guarantee the profitability of these systems is should be necessary to place the fix price at around 0,93 Euros/k Wh. However, if the duplication of the current price obtained by these installations was considered, this could ensure the profitability of these small systems in at least the 77% of the land. (Author) 12 refs.

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...

A Miniaturized Seismometer for Surface Measurements in the Outer Solar System

Science.gov (United States)

Banerdt, W. B.; Pike, W. T.

2001-01-01

Seismology is a powerful tool for investigating the inner structure and dynamic processes of a planetary body. The interior structure information derived from seismic measurements is complementary to other methods of probing the subsurface (such as gravity and electromagnetics), both in terms of spatial and depth resolution and the relevant types of material properties being sensed. The propagation of seismic waves is sensitive to composition (via density and elastic parameters), temperature (via attenuation) and physical state (solid vs. liquid). In addition, the seismicity (level and distribution in space and time of seismic activity) provides information on the impact flux and tectonic forces currently active within the body. The major satellites of the outer solar system provide obvious targets for seismic investigations. In addition, small bodies, such as asteroids and comets, can also benefit from seismic measurements. We have developed an extremely small, lightweight, low-power seismometer for planetary applications which is ideally suited for use in the outer solar system. This instrument has previously been proposed and selected for use on a comet (on the Rosetta Lander, subsequently deselected for programmatic reasons) and Mars (on the NetLander mission). Additional information is contained in the original extended abstract.

Trojan Tour and Rendezvous (TTR): A New Frontiers Mission to Explore the Origin and Evolution of the Early Solar System

Science.gov (United States)

Bell, J. F., III; Olkin, C.; Castillo, J. C.

2015-12-01

The orbital properties, compositions, and physical properties of the diverse populations of small outer solar system bodies provide a forensic map of how our solar system formed and evolved. Perhaps the most potentially diagnostic, but least explored, of those populations are the Jupiter Trojan asteroids, which orbit at ~5 AU in the L4 and L5 Lagrange points of Jupiter. More than 6200 Jupiter Trojans are presently known, but these are predicted to be only a small fraction of the 500,000 to 1 million Trojans >1 km in size. The Trojans are hypothesized to be either former Kuiper Belt Objects (KBOs) that were scattered into the inner solar system by early giant planet migration and then trapped in the 1:1 Jupiter mean motion resonance, or bodies formed near 5 AU in a much more quiescent early solar system, and then trapped at L4 and L5. The 2011 Planetary Science Decadal Survey identified important questions about the origin and evolution of the solar system that can be addressed by studying of the Trojan asteroids, including: (a) How did the giant planets and their satellite systems accrete, and is there evidence that they migrated to new orbital positions? (b) What is the relationship between large and small KBOs? Is the small population derived by impact disruption of the large one? (c) What kinds of surface evolution, radiation chemistry, and surface-atmosphere interactions occur on distant icy primitive bodies? And (d) What are the sources of asteroid groups (Trojans and Centaurs) that remain to be explored by spacecraft? The Trojan Tour and Rendezvous (TTR) is a New Frontiers-class mission designed to answer these questions, and to test hypotheses for early giant planet migration and solar system evolution. Via close flybys of a large number of these objects,, and orbital characterization of at least one large Trojan, TTR will enable the first-time exploration of this population. Our primary mission goals are to characterize the overall surface geology

Overview of Small and Large-Scale Space Solar Power Concepts

Science.gov (United States)

Potter, Seth; Henley, Mark; Howell, Joe; Carrington, Connie; Fikes, John

2006-01-01

An overview of space solar power studies performed at the Boeing Company under contract with NASA will be presented. The major concepts to be presented are: 1. Power Plug in Orbit: this is a spacecraft that collects solar energy and distributes it to users in space using directed radio frequency or optical energy. Our concept uses solar arrays having the same dimensions as ISS arrays, but are assumed to be more efficient. If radiofrequency wavelengths are used, it will necessitate that the receiving satellite be equipped with a rectifying antenna (rectenna). For optical wavelengths, the solar arrays on the receiving satellite will collect the power. 2. Mars Clipper I Power Explorer: this is a solar electric Mars transfer vehicle to support human missions. A near-term precursor could be a high-power radar mapping spacecraft with self-transport capability. Advanced solar electric power systems and electric propulsion technology constitute viable elements for conducting human Mars missions that are roughly comparable in performance to similar missions utilizing alternative high thrust systems, with the one exception being their inability to achieve short Earth-Mars trip times. 3. Alternative Architectures: this task involves investigating alternatives to the traditional solar power satellite (SPS) to supply commercial power from space for use on Earth. Four concepts were studied: two using photovoltaic power generation, and two using solar dynamic power generation, with microwave and laser power transmission alternatives considered for each. All four architectures use geostationary orbit. 4. Cryogenic Propellant Depot in Earth Orbit: this concept uses large solar arrays (producing perhaps 600 kW) to electrolyze water launched from Earth, liquefy the resulting hydrogen and oxygen gases, and store them until needed by spacecraft. 5. Beam-Powered Lunar Polar Rover: a lunar rover powered by a microwave or laser beam can explore permanently shadowed craters near the lunar

Solar Powered Automatic Shrimp Feeding System

Directory of Open Access Journals (Sweden)

Dindo T. Ani

2015-12-01

Full Text Available - Automatic system has brought many revolutions in the existing technologies. One among the technologies, which has greater developments, is the solar powered automatic shrimp feeding system. For instance, the solar power which is a renewable energy can be an alternative solution to energy crisis and basically reducing man power by using it in an automatic manner. The researchers believe an automatic shrimp feeding system may help solve problems on manual feeding operations. The project study aimed to design and develop a solar powered automatic shrimp feeding system. It specifically sought to prepare the design specifications of the project, to determine the methods of fabrication and assembly, and to test the response time of the automatic shrimp feeding system. The researchers designed and developed an automatic system which utilizes a 10 hour timer to be set in intervals preferred by the user and will undergo a continuous process. The magnetic contactor acts as a switch connected to the 10 hour timer which controls the activation or termination of electrical loads and powered by means of a solar panel outputting electrical power, and a rechargeable battery in electrical communication with the solar panel for storing the power. By undergoing through series of testing, the components of the modified system were proven functional and were operating within the desired output. It was recommended that the timer to be used should be tested to avoid malfunction and achieve the fully automatic system and that the system may be improved to handle changes in scope of the project.

Evaluation of the environmental sustainability of a micro CHP system fueled by low-temperature geothermal and solar energy

International Nuclear Information System (INIS)

Ruzzenenti, Franco; Bravi, Mirko; Tempesti, Duccio; Salvatici, Enrica; Manfrida, Giampaolo; Basosi, Riccardo

2014-01-01

Highlights: • Binary, ORC technology avoids CO 2 , but raises questions about environmental impact. • We proposed a micro-size system that combines geothermal energy with solar energy. • The small scale and the solar energy input edges the energy profitability. • The system’s performance is appreciable if applied to existing wells. • The feasibility of exploiting abandoned wells is preliminarily evaluated. - Abstract: In this paper we evaluate the environmental sustainability of a small combined heat and power (CHP) plant operating through an Organic Rankine Cycle (ORC). The heat sources of the system are from geothermal energy at low temperature (90–95 °C) and solar energy. The designed system uses a solar field composed only of evacuated, non-concentrating solar collectors, and work is produced by a single turbine of 50 kW. The project addresses an area of Tuscany, but it could be reproduced in areas where geothermal energy is extensively developed. Therefore, the aim is to exploit existing wells that are either unfit for high-enthalpy technology, abandoned or never fully developed. Furthermore, this project aims to aid in downsizing the geothermal technology in order to reduce the environmental impact and better tailor the production system to the local demand of combined electric and thermal energy. The environmental impact assessment was performed through a Life Cycle Analysis and an Exergy Life Cycle Analysis. According to our findings the reservoir is suitable for a long-term exploitation of the designed system, however, the sustainability and the energy return of this latter is edged by the surface of the heat exchanger and the limited running hours due to the solar plant. Therefore, in order to be comparable to other renewable resources or geothermal systems, the system needs to develop existing wells, previously abandoned

Climatic effects during passage of the solar system through interstellar clouds

International Nuclear Information System (INIS)

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

1976-01-01

It is thought likely that the solar system passes through regions where there are a large number of dense interstellar clouds. When this occurs several processes may cause significant changes in the climate of the Earth and other planets. Matters here discussed include the influences of compression of the solar wind cavity, accretion of matter by the Sun, and particulate input into the Earth's atmosphere. Gravitational energy released by the accretion of interstellar material by the Sun may enhance the solar luminosity, and considerations of terrestrial heat balance suggest that luminosity enhancements of 1% or more will produce significant variations of climate. Observational evidence suggests that there is some mechanism producing a relationship between solar wind flow and climate. One proposed mechanism is that contemporary solar wind modulation of galactic cosmic rays influences climate, and the fact that the Earth would be outside the solar wind cavity for all or part of the year may have an effect on terrestrial climate. Relatively small variations of solar UV radiation input may have perceptible influences on climate, and if a 1% variation in radiation input to the stratosphere has a significant effect then accretion may have a large impact on terrestrial conditions, even though the change in the total heat balance is negligible.With regard to dust input into the Earth's atmosphere it is estimated that during the lifetime of the solar system the mass of dust grains accreted by the Earth should have been about 10 16 to 10 18 g; the matter of evidence for their presence is discussed. It is concluded that the processes proposed have very complex implications for global weather patterns; and at present it is not possible to evaluate which, if any, will unquestionably affect the Earth's climate. (U.K.)

Proof-of-Concept Testing of the Passive Cooling System (T-CLIP™) for Solar Thermal Applications at an Elevated Temperature

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Jun [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Quintana, Donald L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Vigil, Gabrielle M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Perraglio, Martin Juan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Farley, Cory Wayne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Tafoya, Jose I. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology; Martinez, Adam L. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States). Applied Engineering and Technology

2015-11-30

The Applied Engineering and Technology-1 group (AET-1) at Los Alamos National Laboratory (LANL) conducted the proof-of-concept tests of SolarSPOT LLC’s solar thermal Temperature- Clipper, or T-CLIP™ under controlled thermal conditions using a thermal conditioning unit (TCU) and a custom made environmental chamber. The passive T-CLIP™ is a plumbing apparatus that attaches to a solar thermal collector to limit working fluid temperature and to prevent overheating, since overheating may lead to various accident scenarios. The goal of the current research was to evaluate the ability of the T-CLIP™ to control the working fluid temperature by using its passive cooling mechanism (i.e. thermosiphon, or natural circulation) in a small-scale solar thermal system. The assembled environmental chamber that is thermally controlled with the TCU allows one to simulate the various possible weather conditions, which the solar system will encounter. The performance of the T-CLIP™ was tested at two different target temperatures: 1) room temperature (70 °F) and 2) an elevated temperature (130 °F). The current test campaign demonstrated that the T-CLIP™ was able to prevent overheating by thermosiphon induced cooling in a small-scale solar thermal system. This is an important safety feature in situations where the pump is turned off due to malfunction or power outages.

The origin of the solar system

International Nuclear Information System (INIS)

Dormand, J.R.; Woolfson, M.M.

1989-01-01

This book describes in detail the capture theory of the origin of the solar system. Traces the history of solar system theories from pre-Christian Greece through the late 1920's. The authors examine the shortcomings of modern theories, and show how new knowledge supports the capture hypothesis

Solar pumped laser and its application to hydrogen production

International Nuclear Information System (INIS)

Imasaki, K.; Saiki, T.; Li, D.; Motokosi, S.; Nakatsuka, M.

2007-01-01

Solar pumped laser has been studied. Recently, a small ceramic laser pumped by pseudo solar light shows high efficiency of more than 40% which exceeds a solar cell. Such solar pumped laser can concentrate the large area of solar energy in a focused spot of small area. This fact implies the application of such laser for clean and future renewable energy source as hydrogen. For this purpose, 100 W level laboratory solar laser HELIOS is completed using disk ceramic active mirror laser to achieve high temperature. This laser is a kind of MOPA system. Oscillator of additional small laser is used. Laser light is generated in oscillator and is amplified in ceramic disks of solar pumped. The temperature from this system is to be more than 1500 K. We will use a simple graphite cavity for laser power absorption and to get a high temperature. We are also designing a 10 MW CW laser based on this technology. This may be expected an application of solar energy for hydrogen production with total efficiency of 30%

Exploring the Trans-Neptunian Solar System

Science.gov (United States)

1998-01-01

A profound question for scientists, philosophers and, indeed, all humans concerns how the solar system originated and subsequently evolved. To understand the solar system's formation, it is necessary to document fully the chemical and physical makeup of its components today, particularly those parts thought to retain clues about primordial conditions and processes.] In the past decade, our knowledge of the outermost, or trans-neptunian, region of the solar system has been transformed as a result of Earth-based observations of the Pluto-Charon system, Voyager 2's encounter with Neptune and its satellite Triton, and recent discoveries of dozens of bodies near to or beyond the orbit of Neptune. As a class, these newly detected objects, along with Pluto, Charon, and Triton, occupy the inner region of a hitherto unexplored component of the solar system, the Kuiper Belt. The Kuiper Belt is believed to be a reservoir of primordial objects of the type that formed in the solar nebula and eventually accreted to form the major planets. The Kuiper Belt is also thought to be the source of short-period comets and a population of icy bodies, the Centaurs, with orbits among the giant planets. Additional components of the distant outer solar system, such as dust and the Oort comet cloud, as well as the planet Neptune itself, are not discussed in this report. Our increasing knowledge of the trans-neptunian solar system has been matched by a corresponding increase in our capabilities for remote and in situ observation of these distant regions. Over the next 10 to 15 years, a new generation of ground- and space-based instruments, including the Keck and Gemini telescopes and the Space Infrared Telescope Facility, will greatly expand our ability to search for and conduct physical and chemical studies on these distant bodies. Over the same time span, a new generation of lightweight spacecraft should become available and enable the first missions designed specifically to explore the icy

New views of the solar system

CERN Document Server

2007-01-01

Suitable for ages 10-17, this work takes a look at the developments in research about the solar system, including articles on Pluto, the eight chief planets, and dwarf planets. It includes photos and drawings that showcase the planets, asteroids, comets, and also a collection of images of the solar system.

Long-term influence of asteroids on planet longitudes and chaotic dynamics of the solar system

Science.gov (United States)

Woillez, E.; Bouchet, F.

2017-11-01

Over timescales much longer than an orbital period, the solar system exhibits large-scale chaotic behavior and can thus be viewed as a stochastic dynamical system. The aim of the present paper is to compare different sources of stochasticity in the solar system. More precisely we studied the importance of the long term influence of asteroids on the chaotic dynamics of the solar system. We show that the effects of asteroids on planets is similar to a white noise process, when those effects are considered on a timescale much larger than the correlation time τϕ ≃ 104 yr of asteroid trajectories. We computed the timescale τe after which the effects of the stochastic evolution of the asteroids lead to a loss of information for the initial conditions of the perturbed Laplace-Lagrange secular dynamics. The order of magnitude of this timescale is precisely determined by theoretical argument, and we find that τe ≃ 104 Myr. Although comparable to the full main-sequence lifetime of the sun, this timescale is considerably longer than the Lyapunov time τI ≃ 10 Myr of the solar system without asteroids. This shows that the external sources of chaos arise as a small perturbation in the stochastic secular behavior of the solar system, rather due to intrinsic chaos.

Development of III-Sb Quantum Dot Systems for High Efficiency Intermediate Band Solar Cells

Energy Technology Data Exchange (ETDEWEB)

Huffaker, Diana [Univ. of California, Los Angeles, CA (United States); Hubbard, Seth [Rochester Inst. of Technology, NY (United States); Norman, Andrew [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-07-31

This project aimed to develop solar cells that can help reduce cost per watt. This work focused on developing solar cells that utilize quantum dot (QD) nanomaterials to provide multijunction solar cell efficiency at the cost of single junction solar cell. We focused on a novel concept known as intermediate band solar cells (IBSC) where an additional energy band is inserted in a single solar cell to accommodate sub-bandgap photons absorption which otherwise are lost through transmission. The additional energy band can be achieved by growing QDs within a solar cell p-n junction. Though numerous studies have been conducted to develop such QD systems, very small improvements in solar energy conversion efficiency have been reported. This is mainly due to non-optimal material parameters such as band gap, band offset etc. In this work, we identified and developed a novel QD material system that meets the requirements of IBSC more closely than the current state-of-the-art technology. To achieve these goals, we focused on three important areas of solar cell design: band structure calculations of new materials, efficient device design for high efficiency, and development of new semiconductor materials. In this project, we focused on III-Sb materials as they possess a wide range of energy bandgaps from 0.2 eV to 2eV. Despite the difficulty involved in realizing these materials, we were successfully developed these materials through a systematic approach. Materials studied in this work are AlAsSb (Aluminum Arsenide Antimonide), InAlAs (Indium Aluminum Arsenide) and InAs (Indium Arsenide). InAs was used to develop QD layers within AlAsSb and InAlAs p-n junctions. As the QDs have very small volume, up to 30 QD layers been inserted into the p-n junction to enhance light absorption. These QD multi-stack devices helped in understanding the challenges associated with the development of quantum dot solar cells. The results from this work show that the quantum dot solar cells indeed

Interplay between efficiency and device architecture for small molecule organic solar cells.

Science.gov (United States)

Williams, Graeme; Sutty, Sibi; Aziz, Hany

2014-06-21

Small molecule organic solar cells (OSCs) have experienced a resurgence of interest over their polymer solar cell counterparts, owing to their improved batch-to-batch (thus, cell-to-cell) reliability. In this systematic study on OSC device architecture, we investigate five different small molecule OSC structures, including the simple planar heterojunction (PHJ) and bulk heterojunction (BHJ), as well as several planar-mixed structures. The different OSC structures are studied over a wide range of donor:acceptor mixing concentrations to gain a comprehensive understanding of their charge transport behavior. Transient photocurrent decay measurements provide crucial information regarding the interplay between charge sweep-out and charge recombination, and ultimately hint toward space charge effects in planar-mixed structures. Results show that the BHJ/acceptor architecture, comprising a BHJ layer with high C60 acceptor content, generates OSCs with the highest performance by balancing charge generation with charge collection. The performance of other device architectures is largely limited by hole transport, with associated hole accumulation and space charge effects.

Solar Adaptive Optics

Directory of Open Access Journals (Sweden)

Thomas R. Rimmele

2011-06-01

Full Text Available Adaptive optics (AO has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO and Ground-Layer AO (GLAO will be given.

A dissipative model of solar system

Science.gov (United States)

Vladimir, V. G.

2009-04-01

In classical model of Solar system of a planet are represented by the material points cooperating under the law of universal gravitation. This model remains fair if planet to consider as absolutely firm spheres with spherical distribution of density. The gravitational potential of such body coincides with potential of a material point, and rotation of each sphere concerning his centre of weights occurs to constant angular speed. Movement concerning the centre of weights of a sphere is represented by rotation with constant angular speed concerning an axis of an any direction, and movement of the centers of weights of spherical planets identically to movement in the appropriate problem of N points. Let's notice, that forms of planets of Solar system are close to spherical as dominant forces at formation of planets are gravitational forces to which forces of molecular interaction in substance of a planet counteract. The model of the isolated Solar system submitted in a not indignant condition N by homogeneous viscoelastic spheres is considered. Under action of own rotation and tidal gravitational forces the spherical planet changes the form: there is "flattening" a planet in a direction of a vector of its angular speed and formation of tidal humps on the lines connecting the centre of a planet with the centers of other planets. From a variational principle of Hamilton the full system of the equations describing movements of the centers of weights of planets, rotations of systems of coordinates, by integrated image connected with planets, and deformations of planets be relative these of systems of coordinates is received. It is supposed, that tidal gravitational, centrifugal and elastic forces result in small change of the spherical form of a planet. In system there are small parameters - inversely proportional of the Young modules of materials of the planets, providing small deformations of planets at influence on them of the centrifugal forces produced by own

Beam-Forming Concentrating Solar Thermal Array Power Systems

Science.gov (United States)

Cwik, Thomas A. (Inventor); Dimotakis, Paul E. (Inventor); Hoppe, Daniel J. (Inventor)

2016-01-01

The present invention relates to concentrating solar-power systems and, more particularly, beam-forming concentrating solar thermal array power systems. A solar thermal array power system is provided, including a plurality of solar concentrators arranged in pods. Each solar concentrator includes a solar collector, one or more beam-forming elements, and one or more beam-steering elements. The solar collector is dimensioned to collect and divert incoming rays of sunlight. The beam-forming elements intercept the diverted rays of sunlight, and are shaped to concentrate the rays of sunlight into a beam. The steering elements are shaped, dimensioned, positioned, and/or oriented to deflect the beam toward a beam output path. The beams from the concentrators are converted to heat at a receiver, and the heat may be temporarily stored or directly used to generate electricity.

Elementary Students' Mental Models of the Solar System

Science.gov (United States)

Calderon-Canales, Elena; Flores-Camacho, Fernando; Gallegos-Cazares, Leticia

2013-01-01

This research project aimed to identify and analyze Mexican primary school students' ideas about the components of the solar system. In particular, this study focused on conceptions of the solar system and representations of the dynamics of the solar system based on the functional and structural models that students make in school. Using a…

Solar thermochemical processing system and method

Science.gov (United States)

Wegeng, Robert S.; Humble, Paul H.; Krishnan, Shankar; Leith, Steven D.; Palo, Daniel R.; Dagle, Robert A.

2018-04-24

A solar thermochemical processing system is disclosed. The system includes a first unit operation for receiving concentrated solar energy. Heat from the solar energy is used to drive the first unit operation. The first unit operation also receives a first set of reactants and produces a first set of products. A second unit operation receives the first set of products from the first unit operation and produces a second set of products. A third unit operation receives heat from the second unit operation to produce a portion of the first set of reactants.

Solar-Biomass hybrid system for process heat supply in medium scale hotels in Sri Lanka

OpenAIRE

Abeywardana, Asela M.A.J.

2016-01-01

This study aimed at evaluating and demonstrating the feasibility of using Concentrated Solar Thermal technology combined with biomass energy technology as a hybrid renewable energy system to supply the process heat requirements in small scale industries in Sri Lanka. Particularly, the focus was to apply the concept to the expanding hotel industry, for covering the thermal energy demand of a medium scale hotel. Solar modules utilize the rooftop area of the building to a valuable application. L...

The Solar Bank concept

International Nuclear Information System (INIS)

Eckhart, M.T.

1999-01-01

The Solar Bank is proposed to be established as a multinational wholesale lending institution supporting the adoption of solar photovoltaic (PV) systems by as much as 40% of the world's population. It would supply capital resources to local lending institutions such as banks, credit unions, cooperatives, and rural lending organizations in the developing countries, and to financial institutions in the developed countries. The Solar Bank is intended to be global in scope, with operations in the major countries. The Solar Bank will bring a degree of standardization to the process of making small loans to many people for the purchase of PV systems, and it will provide technical support and training to its participating financial institutions. 'Solar Bank International' is likely to be headquartered in Europe. (orig.)

Solar thermal systems successful planning and construction

CERN Document Server

Peuser, Dr Felix A; Schnauss, Martin

2013-01-01

Solar Thermal Systems summarizes the theoretical and practical knowledge gained from over 20 years of research, implementation and operation of thermal solar installations. This work provides answers to a variety of key questions by examining current solar installations, drawing upon past experiences and making proposals for future planning.- how do system components and materials behave under continuous operation?- which components have proven themselves and how are they used properly?- what are the causes of defects and how can they be avoided?- how long is the service life of modern solar i

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

Delivery of Exogenous Complex Organic Compounds by Solar System Small Bodies and Space Dusts and Its Relevance to Origins of Life

Science.gov (United States)

Kobayashi, Kensei; Fushimi, Hidehiko; Motoyama, Takuya; Kaneko, Takeo; Obayashi, Yumiko; Yoshida, Satoshi; Mita, Hajime; Yabuta, Hikaru; Okudaira, Kyoko; Hashimoto, Hirofumi; Yokobori, Shin-Ichi; Yamagishi, Akihiko

A wide variety of organic compounds including amino acid precursors have been detected in such extraterrestrial bodies as carbonaceous chondrites and comets. It was suggested that these organics were formed in quite cold environments. We irradiated frozen mixtures of possible constituents of ice mantles of interstellar dust particles including water, methanol and ammonia with high-energy heavy ions from HIMAC, National Institute of Radiological Science, Japan. Amino acid precursors with complex structures were detected whose molecular weights are up to a few thousands. Such complex amino acid precursors are much stronger than free amino acids against radiation. Such organics could have been incorporated in solar system small bodies after the formation of the solar system and delivered to the primitive Earth. Possible carriers of such organics are meteorites, comets and interplanetary dust particles (IDPs) that were formed from comets and meteorites. It is suggested that IDPs brought much more organics than meteorites and comets. However, nature of organics in IDPs is little known, since they have been collected only in terrestrial biosphere. We are planning a space experiments named Tanpopo, where IDPs would be collected in aerogel equipped on the Exposure Facility of the International Space Station. In addition, amino acids and their relating compounds would be exposed to space environments to see their possible alteration processes in the interplanetary space. We will report some preliminary results for the preparation of the mission including the capture of amino acid-containing particles at high velocity with ultra-low density aerogel.

New Low Cost Structure for Dual Axis Mount Solar Tracking System Using Adaptive Solar Sensor

DEFF Research Database (Denmark)

Argeseanu, Alin; Ritchie, Ewen; Leban, Krisztina Monika

2010-01-01

A solar tracking system is designed to optimize the operation of solar energy receivers. The objective of this paper is proposing a new tracking system structure with two axis. The success strategy of this new project focuses on the economical analysis of solar energy. Therefore it is important...... to determine the most cost effective design, to consider the costs of production and maintenance, and operating. The proposed tracking system uses a new solar sensor position with an adaptive feature....

THE PRECAMBRIAN HISTORY OF THE ORIGIN AND EVOLUTION OF THE SOLAR SYSTEM AND EARTH. PART 1

Directory of Open Access Journals (Sweden)

M. I. Kuz’min

2014-01-01

Full Text Available The paper provides a review of early stages of development the Solar System and the geological history of Earth with reference to the latest data on the origin of the Solar System and the formation of the first continental rocks and results of studies of zircon, the oldest mineral so far dated on Earth. The formation of the Solar System from a gas-and-dust nebula is estimated to have begun 4.568 billion years ago. Ice was formed 1.5 million years later; it concentrated at the periphery of the system and served as the material for the largest planets, Jupiter and Saturn. In the central areas of the system, asteroids with diameters of about 10 km were formed. Their small bodies were composed of the basic material of the solar nebula, as evidenced by carbonaceous chondrite, CI, which composition is similar to the composition of the Sun, with the exception of hydrogen, helium, and volatile components that served as the main material for peripheral planets of the Solar System. Due to collision and partial merger of such small bodies, the formation of embryos of the terrestrial planets was initiated. Gravity made such embryos to cluster into larger bodies. After 7 million years, large asteroids and planet Mars were formed. It took 11 million years to form Planet Earth with a mass of 63 %, and 30 million years to form 93 % of its mass. Almost from the beginning of the formation of the Earth, short-lived radionuclides, 26Al and 60Fe, caused warming up of the small planetary bodies which led to the formation of their cores. During the initial stages, small magma reservoirs were formed, and molten iron particles gathered in the centres of the planetary bodies. As suggested by the ratio of 182W/184W, the major part of the core was formed within 20 million years, while its full mass accumulated completely within the next 50 million years. In 30–40 million years after the creation of the Solar System, the Earth collided with a cosmic body which mass was

Consequences of the Solar System passage through dense interstellar clouds

Directory of Open Access Journals (Sweden)

A. G. Yeghikyan

2003-06-01

Full Text Available Several consequences of the passage of the solar system through dense interstellar molecular clouds are discussed. These clouds, dense (more than 100 cm-3, cold (10–50 K and extended (larger than 1 pc, are characterized by a gas-to-dust mass ratio of about 100, by a specific power grain size spectrum (grain radii usually cover the range 0.001–3 micron and by an average dust-to-gas number density ratio of about 10-12. Frequently these clouds contain small-scale (10–100 AU condensations with gas concentrations ranging up to 10 5 cm-3. At their casual passage over the solar system they exert pressures very much enhanced with respect to today’s standards. Under these conditions it will occur that the Earth is exposed directly to the interstellar flow. It is shown first that even close to the Sun, at 1 AU, the cloud’s matter is only partly ionized and should mainly interact with the solar wind by charge exchange processes. Dust particles of the cloud serve as a source of neutrals, generated by the solar UV irradiation of dust grains, causing the evaporation of icy materials. The release of neutral atoms from dust grains is then followed by strong influences on the solar wind plasma flow. The behavior of the neutral gas inflow parameters is investigated by a 2-D hydrodynamic approach to model the interaction processes. Because of a reduction of the heliospheric dimension down to 1 AU, direct influence of the cloud’s matter to the terrestrial environment and atmosphere could be envisaged.Key words. Interplanetary physics (heliopause and solar wind termination; interplanetary dust; interstellar gas

Consequences of the Solar System passage through dense interstellar clouds

Directory of Open Access Journals (Sweden)

A. G. Yeghikyan

Full Text Available Several consequences of the passage of the solar system through dense interstellar molecular clouds are discussed. These clouds, dense (more than 100 cm^-3, cold (10–50 K and extended (larger than 1 pc, are characterized by a gas-to-dust mass ratio of about 100, by a specific power grain size spectrum (grain radii usually cover the range 0.001–3 micron and by an average dust-to-gas number density ratio of about 10^-12. Frequently these clouds contain small-scale (10–100 AU condensations with gas concentrations ranging up to 10 5 cm^-3. At their casual passage over the solar system they exert pressures very much enhanced with respect to today’s standards. Under these conditions it will occur that the Earth is exposed directly to the interstellar flow. It is shown first that even close to the Sun, at 1 AU, the cloud’s matter is only partly ionized and should mainly interact with the solar wind by charge exchange processes. Dust particles of the cloud serve as a source of neutrals, generated by the solar UV irradiation of dust grains, causing the evaporation of icy materials. The release of neutral atoms from dust grains is then followed by strong influences on the solar wind plasma flow. The behavior of the neutral gas inflow parameters is investigated by a 2-D hydrodynamic approach to model the interaction processes. Because of a reduction of the heliospheric dimension down to 1 AU, direct influence of the cloud’s matter to the terrestrial environment and atmosphere could be envisaged.

Key words. Interplanetary physics (heliopause and solar wind termination; interplanetary dust; interstellar gas

Simulation of the parabolic trough solar energy generation system with Organic Rankine Cycle

International Nuclear Information System (INIS)

He, Ya-Ling; Mei, Dan-Hua; Tao, Wen-Quan; Yang, Wei-Wei; Liu, Huai-Liang

2012-01-01

Highlights: ► A parabolic trough solar power generation system with ORC is numerically simulated. ► The effects of key parameters on collector field and system performance are studied. ► Collector heat loss increases with small absorber and glass tube interlayer pressure. ► Heat collecting efficiency increases with initial increase of absorber HTO flow rate. ► Recommended thermal storage system volumes are different in year four typical days. -- Abstract: A model for a typical parabolic trough solar thermal power generation system with Organic Rankine Cycle (PT-SEGS–ORC) was built within the transient energy simulation package TRNSYS, which is formed by integrating several submodels for the trough collector system, the single-tank thermal storage system, the auxiliary power system and the heat-electricity conversion system. With this model, the effects of several key parameters, including the interlayer pressure between the absorber tube and the glass tube (p inter ), the flow rate of high temperature oil in the absorber tube (v), solar radiation intensity (I dn ) and incidence angle (θ), on the performance of the parabolic trough collector field based on the meteorological data of Xi’an city were examined. The study shows that the heat loss of the solar collector (q loss ) increases sharply with the increase in p inter at beginning and then reaches to an approximately constant value. The variation of heat collecting efficiency (η hc ) with v is quite similar to the variation of q loss with p inter . However, I dn and θ exhibit opposite effect on η hc . In addition, it is found that the optimal volume of the thermal storage system is sensitively dependent on the solar radiation intensity. The optimal volumes are 100, 150, 50, and 0 m 3 for spring equinox, summer solstice, autumnal equinox and winter solstice, respectively.

Solar Heating System with Building-Integrated Heat Storage

DEFF Research Database (Denmark)

Heller, Alfred

1996-01-01

Traditional solar heating systems cover between 5 and 10% of the heat demand fordomestic hot water and comfort heating. By applying storage capacity this share can beincreased much. The Danish producer of solar heating systems, Aidt-Miljø, markets such a system including storage of dry sand heated...... by PP-pipe heat exchanger. Heat demand is reduced due to direct solar heating, and due to storage. Heat demand is reduced due to direct solar heating, due to storage and due to lower heat losses through the ground. In theory, by running the system flow backwards through the sand storage, active heating...... can be achieved.The objective of the report is to present results from measured system evaluation andcalculations and to give guidelines for the design of such solar heating systems with building integrated sand storage. The report is aimed to non-technicians. In another report R-006 the main results...

Solar cell power source system

Energy Technology Data Exchange (ETDEWEB)

Shimizu, Yoichi; Toma, Kunio; Fukuwa, Shinji

1988-05-14

This invention aims to supply a power source system with stable power output by reducing the power loss due to switching in the voltage stabilization even when the power source is a solar cell with frequent voltage variation. For this purpose, in a solar cell power source system consisting of a solar cell, a storage battery, a switching regulator placed between the storage cell and the load, and a load, arrangement was made that, by judging the input voltage from the storage battery, switch-acting the transistor of the switching regulator, if the input voltage is higher than the specified voltage; is the input voltage is lower than the specified voltage, the transistor is put in a full-on state. By this, the supply voltage can be stabilized even when the voltage fluctuates, and system gets more efficient as the switching loss decreases in the voltage stabilizing means. (1 fig)

Solution-processed small molecule:fullerene bulk-heterojunction solar cells: impedance spectroscopy deduced bulk and interfacial limits to fill-factors.

Science.gov (United States)

Guerrero, Antonio; Loser, Stephen; Garcia-Belmonte, Germà; Bruns, Carson J; Smith, Jeremy; Miyauchi, Hiroyuki; Stupp, Samuel I; Bisquert, Juan; Marks, Tobin J

2013-10-21

Using impedance spectroscopy, we demonstrate that the low fill factor (FF) typically observed in small molecule solar cells is due to hindered carrier transport through the active layer and hindered charge transfer through the anode interfacial layer (IFL). By carefully tuning the active layer thickness and anode IFL in BDT(TDPP)2 solar cells, the FF is increased from 33 to 55% and the PCE from 1.9 to 3.8%. These results underscore the importance of simultaneously optimizing active layer thickness and IFL in small molecule solar cells.

The Main Asteroid Belt: The Crossroads of the Solar System

Science.gov (United States)

Michel, Patrick

2015-08-01

Orbiting the Sun between Mars and Jupiter, main belt asteroids are leftover planetary building blocks that never accreted enough material to become planets. They are therefore keys to understanding how the Solar System formed and evolved. They may also provide clues to the origin of life, as similar bodies may have delivered organics and water to the early Earth.Strong associations between asteroids and meteorites emerged thanks to multi-technique observations, modeling, in situ and sample return analyses. Spacecraft images revolutionized our knowledge of these small worlds. Asteroids are stunning in their diversity in terms of physical properties. Their gravity varies by more orders of magnitude than its variation among the terrestrial planets, including the Moon. Each rendezvous with an asteroid thus turned our geological understanding on its head as each asteroid is affected in different ways by a variety of processes such as landslides, faulting, and impact cratering. Composition also varies, from ice-rich to lunar-like to chondritic.Nearly every asteroid we see today, whether of primitive or evolved compositions, is the product of a complex history involving accretion and one or more episodes of catastrophic disruption that sometimes resulted in families of smaller asteroids that have distinct and indicative petrogenic relationships. These families provide the best data to study the impact disruption process at scales far larger than those accessible in laboratory. Tens, perhaps hundreds, of early asteroids grew large enough to thermally differentiate. Their traces are scattered pieces of their metal-rich cores and, more rarely, their mantles and crusts.Asteroids represent stages on the rocky road to planet formation. They have great stories to tell about the formation and evolution of our Solar System as well as other planetary systems: asteroid belts seem common around Sun-like stars. We will review our current knowledge on their properties, their link to

Performance Enhancement of Small Molecular Solar Cells by Bilayer Cathode Buffer.

Science.gov (United States)

Sun, Qinjun; Zhao, Huanbin; Zhou, Miao; Gao, Liyan; Hao, Yuying

2016-04-01

An effective composite bilayer cathode buffer structure is proposed for use in small molecular solar cells. CsF was doped in Alq3 to form the first cathode buffer, leading to small serial resistances. BCP was used as the second cathode buffer to block the holes to the electrode. The optimized bilayer cathode buffer significantly increased the short circuit and fill factor of devices. By integrating this bilayer cathode buffer, the CuPc/C60 small molecular heterojunction cell exhibited a power conversion efficiency of up to 0.8%, which was an improvement of 56% compared to a device with only the Alq3 cathode buffer. Meanwhile, the bilayer cathode buffer still has a good protective effect on the performance of the device.

Solar active region display system

Science.gov (United States)

Golightly, M.; Raben, V.; Weyland, M.

2003-04-01

The Solar Active Region Display System (SARDS) is a client-server application that automatically collects a wide range of solar data and displays it in a format easy for users to assimilate and interpret. Users can rapidly identify active regions of interest or concern from color-coded indicators that visually summarize each region's size, magnetic configuration, recent growth history, and recent flare and CME production. The active region information can be overlaid onto solar maps, multiple solar images, and solar difference images in orthographic, Mercator or cylindrical equidistant projections. Near real-time graphs display the GOES soft and hard x-ray flux, flare events, and daily F10.7 value as a function of time; color-coded indicators show current trends in soft x-ray flux, flare temperature, daily F10.7 flux, and x-ray flare occurrence. Through a separate window up to 4 real-time or static graphs can simultaneously display values of KP, AP, daily F10.7 flux, GOES soft and hard x-ray flux, GOES >10 and >100 MeV proton flux, and Thule neutron monitor count rate. Climatologic displays use color-valued cells to show F10.7 and AP values as a function of Carrington/Bartel's rotation sequences - this format allows users to detect recurrent patterns in solar and geomagnetic activity as well as variations in activity levels over multiple solar cycles. Users can customize many of the display and graph features; all displays can be printed or copied to the system's clipboard for "pasting" into other applications. The system obtains and stores space weather data and images from sources such as the NOAA Space Environment Center, NOAA National Geophysical Data Center, the joint ESA/NASA SOHO spacecraft, and the Kitt Peak National Solar Observatory, and can be extended to include other data series and image sources. Data and images retrieved from the system's database are converted to XML and transported from a central server using HTTP and SOAP protocols, allowing

Modeling and Control of DC/DC Boost Converter using K-Factor Control for MPPT of Solar PV System

DEFF Research Database (Denmark)

Vangari, Adithya; Haribabu, Divyanagalakshmi; Sakamuri, Jayachandra N.

2015-01-01

This paper is focused on the design of a controller for the DC/DC boost converter using K factor control, which is based on modified PI control method, for maximum power point tracking (MPPT) of solar PV system. A mathematical model for boost converter based on small signal averaging approach...... is presented. Design of the passive elements of the boost converter as per the system specifications is also illustrated. The performance of the proposed K factor control method is verified with the simulations for MPPT on solar PV system at different atmospheric conditions. A new circuit based model for solar...... PV array, which includes the effect of solar insolation and temperature on PV array output, for the application in power system transient simulations, is also presented. The performance of the PV array model is verified with simulations at different atmospheric conditions. A 160W PV module from BP...

Cryovolcanism in the outer solar system

Science.gov (United States)

Geissler, Paul E.

2015-01-01

Cryovolcanism is defined as the extrusion of liquids and vapors of materials that would be frozen solid at the planetary surface temperatures of the icy bodies of the outer solar system. Active cryovolcanism is now known to occur on Saturn's moon Enceladus and on Neptune's moon Triton and is suspected on Jupiter's moon Europa, while evidence for past cryovolcanic activity is widespread throughout the outer solar system. This chapter examines the mechanisms and manifestations of cryovolcanism, beginning with a review of the materials that make up these unusual ‘‘magmas’’ and the means by which they might erupt and concluding with a volcanologist's tour of the farthest reaches of the solar system.

Solar electricity and solar fuels

Science.gov (United States)

Spiers, David J.

1989-04-01

The nature of solar radiation and its variation with location is described. The distribution of energy in the solar spectrum places immediate limits on the theoretical efficiency of conversion processes, since practical absorbers cannot convert all wavelengths received to useful energy. The principles of solar energy conversion methods are described. Absorption of solar energy can give rise to direct electrical generation, heating, or chemical change. Electrical generation from sunlight can be achieved by photovoltaic systems directly or by thermal systems which use solar heat to drive a heat engine and generator. The technology used and under research for promising ways of producing electricity or fuel from solar energy is described. Photovoltaic technology is established today for remote area, small power applications, and photovoltaic module sales alone are over 100 million dollars per year at present. The photovoltaic market has grown steadily since the mid-1970's, as prices have fallen continuously. Future energy options are briefly described. The merits of a sustainable energy economy, based on renewable energy resources, including solar energy, are emphasized, as this seems to provide the only hope of eliminating the problems caused by the build-up of atmospheric carbon dioxide, acid rain pollution and nuclear waste disposal. There is no doubt that clean fuels which were derived from solar energy and either did not involve carbon dioxide and used atmospheric carbon dioxide as the source dioxide as the source of carbon would be a worthy ideal. Methods described could one day achieve this.

Design and Analysis of Hybrid Solar Lighting and Full-Spectrum Solar Energy Systems

International Nuclear Information System (INIS)

Muhs, J.D.

2001-01-01

This paper describes a systems-level design and analysis of a new approach for improving the energy efficiency and affordability of solar energy in buildings, namely, hybrid solar lighting and full-spectrum solar energy systems. By using different portions of the solar spectrum simultaneously for multiple end-use applications in buildings, the proposed system offers unique advantages over other alternatives for using sunlight to displace electricity (conventional topside daylighting and solar technologies). Our preliminary work indicates that hybrid solar lighting, a method of collecting and distributing direct sunlight for lighting purposes, will alleviate many of the problems with passive daylighting systems of today, such as spatial and temporal variability, glare, excess illumination, cost, and energy efficiency. Similarly, our work suggests that the most appropriate use of the visible portion of direct, nondiffuse sunlight from an energy-savings perspective is to displace electric light rather than generate electricity. Early estimates detailed in this paper suggest an anticipated system cost of well under$2.0/Wp and 5-11(cents)/kWh for displaced and generated electricity in single-story commercial building applications. Based on a number of factors discussed in the paper, including sunlight availability, building use scenarios, time-of-day electric utility rates, cost, and efficacy of the displaced electric lights, the simple payback of this approach in many applications could eventually be well under 5 years

The application of Fourier transform spectroscopy to the remote identification of solids in the solar system

Science.gov (United States)

Larson, H. P.; Fink, U.

1977-01-01

The techniques of Fourier transform spectroscopy combined with large aperture telescopes and advances in detector technology now permit infrared (at a wavelength greater than 1 micron) observations of the surfaces of small solar system objects such as asteroids and satellites. The results demonstrate that this activity can produce important new compositional information related to the origin and evolution of the solar system. The detection of water ice in Saturn's rings and on some of the satellites of Jupiter and Saturn confirm expectations that ices are important mineralogical components in the chemistry of the outer solar system. More recent studies of the mineralogical composition of the surfaces of asteroids provide a new observational link to the origin of meteorites and the early thermal history of the solar system. These results have been dependent upon supporting laboratory studies of the spectral behavior of ices and minerals to define the potential, and limitations, of the method. Since many of the astronomical observations have been exploratory in nature, prospects are good that continued refinement of the techniques will lead to additional insights.

Modeling Small Scale Solar Powered ORC Unit for Standalone Application

Directory of Open Access Journals (Sweden)

Enrico Bocci

2012-01-01

Full Text Available When the electricity from the grid is not available, the generation of electricity in remote areas is an essential challenge to satisfy important needs. In many developing countries the power generation from Diesel engines is the applied technical solution. However the cost and supply of fuel make a strong dependency of the communities on the external support. Alternatives to fuel combustion can be found in photovoltaic generators, and, with suitable conditions, small wind turbines or microhydroplants. The aim of the paper is to simulate the power generation of a generating unit using the Rankine Cycle and using refrigerant R245fa as a working fluid. The generation unit has thermal solar panels as heat source and photovoltaic modules for the needs of the auxiliary items (pumps, electronics, etc.. The paper illustrates the modeling of the system using TRNSYS platform, highlighting standard and “ad hoc” developed components as well as the global system efficiency. In the future the results of the simulation will be compared with the data collected from the 3 kW prototype under construction in the Tuscia University in Italy.

THE ASTEROID BELT AS A RELIC FROM A CHAOTIC EARLY SOLAR SYSTEM

Energy Technology Data Exchange (ETDEWEB)

Izidoro, André; Raymond, Sean N.; Pierens, Arnaud [Laboratoire d’astrophysique de Bordeaux, Université de Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, F-33615 Pessac (France); Morbidelli, Alessandro [University of Nice-Sophia Antipolis, CNRS, Observatoire de la Côte d’Azur, Laboratoire Lagrange, BP 4229, F-06304 Nice Cedex 4 (France); Winter, Othon C. [UNESP, Univ. Estadual Paulista—Grupo de Dinâmica Orbital and Planetologia, Guaratinguetá, CEP 12.516-410, São Paulo (Brazil); Nesvorny' , David, E-mail: izidoro.costa@gmail.com [Department of Space Studies, Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States)

2016-12-10

The orbital structure of the asteroid belt holds a record of the solar system’s dynamical history. The current belt only contains ∼10{sup −3} Earth masses yet the asteroids’ orbits are dynamically excited, with a large spread in eccentricity and inclination. In the context of models of terrestrial planet formation, the belt may have been excited by Jupiter’s orbital migration. The terrestrial planets can also be reproduced without invoking a migrating Jupiter; however, as it requires a severe mass deficit beyond Earth’s orbit, this model systematically under-excites the asteroid belt. Here we show that the orbits of the asteroids may have been excited to their current state if Jupiter’s and Saturn’s early orbits were chaotic. Stochastic variations in the gas giants’ orbits cause resonances to continually jump across the main belt and excite the asteroids’ orbits on a timescale of tens of millions of years. While hydrodynamical simulations show that the gas giants were likely in mean motion resonance at the end of the gaseous disk phase, small perturbations could have driven them into a chaotic but stable state. The gas giants’ current orbits were achieved later, during an instability in the outer solar system. Although it is well known that the present-day solar system exhibits chaotic behavior, our results suggest that the early solar system may also have been chaotic.

Cheap electricity with autonomous solar cell systems

International Nuclear Information System (INIS)

Ouwens, C.D.

1993-01-01

A comparison has been made between the costs of an autonomous solar cell system and a centralized electricity supply system. In both cases investment costs are the main issue. It is shown that for households in densely populated sunny areas, the use of autonomous solar cell systems is - even with today's market prices - only as expensive or even cheaper than a grid connection, as long as efficient electric appliances are used. The modular nature of solar cell systems makes it possible to start with any number of appliances, depending on the amount of money available to be spent. (author)

A hybrid system for solar irradiance specification

Science.gov (United States)

Tobiska, W.; Bouwer, S.

2006-12-01

Space environment research and space weather operations require solar irradiances in a variety of time scales and spectral formats. We describe the development of solar irradiance characterization using four models and systems that are also used for space weather operations. The four models/systems include SOLAR2000 (S2K), SOLARFLARE (SFLR), APEX, and IDAR, which are used by Space Environment Technologies (SET) to provide solar irradiances from the soft X-rays through the visible spectrum. SFLR uses the GOES 0.1 0.8 nm X-rays in combination with a Mewe model subroutine to provide 0.1 30.0 nm irradiances at 0.1 nm spectral resolution, at 1 minute time resolution, and in a 6-hour XUV EUV spectral solar flare evolution forecast with a 7 minute latency and a 2 minute cadence. These irradiances have been calibrated with the SORCE XPS observations and we report on the inclusion of these irradiances into the S2K model. The APEX system is a real-time data retrieval system developed in conjunction with the University of Southern California Space Sciences Center (SSC) to provide SOHO SEM data processing and distribution. SSC provides the updated SEM data to the research community and SET provides the operational data to the space operations community. We describe how the SOHO SEM data, and especially the new S10.7 index, is being integrated directly into the S2K model for space weather operations. The IDAR system has been developed by SET to extract coronal hole boundaries, streamers, coronal loops, active regions, plage, network, and background (internetwork) features from solar images for comparison with solar magnetic features. S2K, SFLR, APEX, and IDAR outputs are integrated through the S2K solar irradiance platform that has become a hybrid system, i.e., a system that is able to produce irradiances using different processes, including empirical and physics-based models combined with real-time data integration.

Solar warming systems of water installed in Colombia. Photovoltaic solar systems installed in the Country

International Nuclear Information System (INIS)

Rodriguez P, F.

1995-01-01

Between the systems that operate as of solar energy, the solar collectors to heat water have had wide use and application in the Country. Basically, a solar collector is constituted by: Box, thermal insulator, ducts and transparent roof. Generally, the used materials are the following: As thermal insulator: Polyurethane or glass fiber; as absorbent plate: Copper or aluminum, painting in dull black or selective surfaces; for the ducts: Generally it is used copper pipeline; and for the cover: Common glass or temperate glass

Performance assesment of solar heating and cooling systems

Energy Technology Data Exchange (ETDEWEB)

Shesho, Igor; Armenski, Slave [Faculty of Mechanical Engineering, ' Ss. Cyril and Methodius' University, Skopje (Macedonia, The Former Yugoslav Republic of); others, and

2014-07-01

Thermal performance of the solar thermal systems are estimated using numerical methods and software since the solar processes are transitient in nature been driven by time dependent forcing functions and loads. The system components are defined with mathematical relationships that describe how components function. They are based on the first principles (energy balances, mass balances, rate equations and equilibrium relationships) at one extreme or empirical curve fits to operating data from specific machines such as absorption chillers. The component models are programed, i.e. they represent written subroutines which are simultaneously solved with the executive program. In this paper for executive program is chosen TRNSYS containing library with solar thermal system component models. Validation of the TRNSYS components models is performed, i.e. the simulation results are compared with experimental measurements. Analysis is performed for solar assisted cooling system in order to determine the solar fractions and efficiencies for different collector types, areas and storage tanks. Specific indicators are derived in order to facilitate the techno-economic analysis and design of solar air-conditioning systems. (Author)

Trapping of Solar Energetic Particles by Small-Scale Topology of Solar Wind Turbulence

Science.gov (United States)

Ruffolo, D.; Matthaeus, W. H.; Chuychai, P.

2004-05-01

The transport of energetic particles perpendicular to the mean magnetic field in space plasmas long has been viewed as a diffusive process. However, there is an apparent conflict between recent observations of solar energetic particles (SEP): 1) impulsive solar flares can exhibit ``dropouts" in which SEP intensity near Earth repeatedly disappears and reappears, indicating a filamentary distribution of SEPs and little diffusion across these boundaries. 2) Observations by the IMP-8 and Ulysses spacecraft, while they were on opposite sides of the Sun, showed similar time-intensity profiles for many SEP events, indicating rapid lateral diffusion of particles throughout the inner solar system within a few days. We explain these seemingly contradictory observations using a theoretical model, supported by computer simulations, in which many particles are temporarily trapped within topological structures in statistically homogeneous magnetic turbulence, and ultimately escape to diffuse at a much faster rate. This work was supported by the Thailand Research Fund, the Rachadapisek Sompoj Fund of Chulalongkorn University, and the NASA Sun-Earth Connections Theory Program (grant NAG5-8134).

Economic and policy analysis for solar PV systems in Indiana

International Nuclear Information System (INIS)

Jung, Jinho; Tyner, Wallace E.

2014-01-01

In recent years, the energy market in the US and globally is expanding the production of renewable energy. Solar energy for electricity is also expanding in the US. Indiana is one of the states expanding solar energy with solar photovoltaic (PV) systems. Therefore, we conduct benefit cost analysis with several uncertain input variables to determine the economics of adopting solar PV systems in Indiana based on policy instruments that could increase adoption of solar PV systems. The specific objectives are analyses of the cost distribution of solar PV systems compared with grid electricity in homes and estimating the probability that solar can be cheaper than electricity from grids under different policy combinations. We first do the analysis under current policy and then the analysis under potential policy options for a variety of scenarios. Also, the results inform government policy makers on how effective the alternative policies for encouraging solar PV systems are. The results show that current policies are important in reducing the cost of solar PV systems. However, with current policies, there is only 50–50 chance of solar being cheaper than electricity from grids. If potential policies are implemented, solar PV systems can be more economical than grid electricity. - Highlights: • We investigate the economics of solar PV systems based on policy instruments. • We do scenario analyses under different combinations of policies. • We examine the probability of solar being cheaper than grid electricity for each scenario. • With current policies, there is 50–50 chance of solar being cheaper than the grid. • With depreciation and carbon tax, solar is much more economical than the grid

Quarterly overviews of thermal solar energy systems 1993

International Nuclear Information System (INIS)

Warmerdam, J.M.; Stap, C.A.M.

1994-08-01

The title overviews were compiled to support the market introduction campaign for solar water heaters in the Netherlands. Use has been made of the data-banks of the Dutch subsidy administrator 'Senter'. 88% of the 1,883 systems, that were installed in 1993, are solar water heaters. Considering the solar collector surface the largest contribution is from the use of mainly uncovered collectors in swimming pools: 51% (37% for the collector surface of solar water heaters). Energy utilities are involved in the installation of 70% of the solar heating systems (even 77% for the solar water heaters). Next to the quarterly overviews, the subsidy data for the period 1988 up to and including 1993 are analyzed. 70% of the installed systems has been purchased and 30% was rented. At the end of 1993 preparations were made to install more than 3,000 solar boilers in 1994 and 1995. 3 figs., 21 tabs

New Isotopic clues to solar system formation

International Nuclear Information System (INIS)

Lee, T.

1979-01-01

The presence of two new extinct nuclides 26 Al and 107 Pd with half-lives approx.10 6 years in the early solar system implies that there were nucleosynthetic activities involving a great many elements almost at the instant of solar system formation. Rare gas and oxygen isotopic abundance variations [''anomalies''] relative to the ''cosmic'' composition were observed in a variety of planetary objects indicating that isotopic heterogeneities caused by the incomplete mixing of distinct nucleosynthetic components permeate of the entire solar system. The correlated nuclear [''FUN''] anomalies in O, Mg, Si, Ca, Sr, Ba, Nd, and Sm were found in three rare inclusions in the Allende meteorite, which show large mass-dependent isotopic fractionation effects. The signature of the nuclear component required to explain these anomalies suggests a source which has received a catastrophic neutron burst [e.g., an r-process event]. These extinct nuclides and nucleosynthetic anomalies provide new clues to solar system formation. In particular, these results have led to the speculation that a nearby supernova had injected freshly synthesized material into the early solar nebula and possibly triggered the collapse of the proto-solar interstellar cloud. Furthermore, these new results have major implications on cosmochronology, nucleosynthesis theory, star formation, planetary heating, and the genetic relationship between different planetary bodies

Self-assembled ultra small ZnO nanocrystals for dye-sensitized solar cell application

Energy Technology Data Exchange (ETDEWEB)

Patra, Astam K.; Dutta, Arghya; Bhaumik, Asim, E-mail: msab@iacs.res.in

2014-07-01

We demonstrate a facile chemical approach to produce self-assembled ultra-small mesoporous zinc oxide nanocrystals using sodium salicylate (SS) as a template under hydrothermal conditions. These ZnO nanomaterials have been successfully fabricated as a photoanode for the dye-sensitized solar cell (DSSC) in the presence of N719 dye and iodine–triiodide electrolyte. The structural features, crystallinity, purity, mesophase and morphology of the nanostructure ZnO are investigated by several characterization tools. N{sub 2} sorption analysis revealed high surface areas (203 m{sup 2} g{sup −1}) and narrow pore size distributions (5.1–5.4 nm) for different samples. The mesoporous structure and strong photoluminescence facilitates the high dye loading at the mesoscopic void spaces and light harvesting in DSSC. By utilizing this ultra-small ZnO photoelectrode with film thickness of about 7 μm in the DSSC with an open-circuit voltage (V{sub OC}) of 0.74 V, short-circuit current density (J{sub SC}) of 3.83 mA cm{sup −2} and an overall power conversion efficiency of 1.12% has been achieved. - Graphical abstract: Ultra-small ZnO nanocrystals have been synthesized with sodium salicylate as a template and using it as a photoanode in a dye-sensitized solar cell 1.12% power conversion efficiency has been observed. - Highlights: • Synthesis of self-assembled ultra-small mesoporous ZnO nanocrystals by using sodium salicylate as a template. • Mesoporous ZnO materials have high BET surface areas and void space. • ZnO nanoparticles serve as a photoanode for the dye-sensitized solar cell (DSSC). • Using ZnO nanocrystals as photoelectrode power conversion efficiency of 1.12% has been achieved.

System performance and economic analysis of solar-assisted cooling/heating system

KAUST Repository

Huang, B.J.; Wu, J.H.; Yen, R.H.; Wang, J.H.; Hsu, H.Y.; Hsia, C.J.; Yen, C.W.; Chang, J.M.

2011-01-01

The long-term system simulation and economic analysis of solar-assisted cooling/heating system (SACH-2) was carried out in order to find an economical design. The solar heat driven ejector cooling system (ECS) is used to provide part of the cooling

Solar combisystems with forecast control to increase the solar fraction and lower the auxiliary energy cost

DEFF Research Database (Denmark)

Perers, Bengt; Furbo, Simon; Fan, Jianhua

2011-01-01

Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...

Assessment of solar-assisted gas-fired heat pump systems

Science.gov (United States)

Lansing, F. L.

1981-01-01

As a possible application for the Goldstone Energy Project, the performance of a 10 ton heat pump unit using a hybrid solar gas energy source was evaluated in an effort to optimize the solar collector size. The heat pump system is designed to provide all the cooling and/or heating requirements of a selected office building. The system performance is to be augmented in the heating mode by utilizing the waste heat from the power cycle. A simplified system analysis is described to assess and compute interrrelationships of the engine, heat pump, and solar and building performance parameters, and to optimize the solar concentrator/building area ratio for a minimum total system cost. In addition, four alternative heating cooling systems, commonly used for building comfort, are described; their costs are compared, and are found to be less competitive with the gas solar heat pump system at the projected solar equipment costs.

Evaluation of the performance in the solar assisted heat pump system; Taiyonetsu riyo heat pump system no seino hyoka ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Saito, Y [Osaka Institute of Technology, Osaka (Japan)

1996-10-27

Performance of a solar heating system with a hydrothermal source heat pump was evaluated and compared with that of a direct solar heating system. The sun-dependency rates ({Sigma}D and {Sigma}H)of the direct system and heat pump (HP)-provided system were expressed as a function of the rate ({alpha}) of the auxiliary heat against the collected heat and as a function of the performance coefficient and {alpha}, respectively. When the sun-dependency rates are compared, it is found that the HP-provided system is the more advantageous when {Sigma}H/{Sigma}D>1. The relationship between the {alpha}`s of the two systems was clarified and computation was performed to compare the sun-dependency rates on condition that the two are equal in the heat collecting area. Although the sun-dependence rate cannot be elevated to 100% in the HP-provided system, it achieves a sun-dependency rate higher than that of the direct system even when the heat collecting area is small. In cases where the building is economically limited, for instance, with respect to the area for solar collector installation, it is advantageous to employ the HP-provided system. 5 figs., 1 tab.

Consumer attitudes towards domestic solar power systems

International Nuclear Information System (INIS)

Faiers, Adam; Neame, Charles

2006-01-01

The success of the UK policy to reduce carbon emissions is partly dependent on the ability to persuade householders to become more energy efficient, and to encourage installation of domestic solar systems. Solar power is an innovation in the UK but the current policy of stimulating the market with grants is not resulting in widespread adoption. This case study, using householders in central England, investigates householder attitudes towards characteristics of solar systems and identifies some of the barriers to adoption. The study utilises Diffusion of Innovations theory to identify attitudes towards system attributes, and isolates the characteristics that are preventing a pragmatic 'early majority' from adopting the technology. A group of 'early adopters', and a group of assumed 'early majority' adopters of solar power were surveyed and the results show that overall, although the 'early majority' demonstrate a positive perception of the environmental characteristics of solar power, its financial, economic and aesthetic characteristics are limiting adoption. Differences exist between the two groups showing support for the concept of a 'chasm' between adopter categories after Moore (Crossing the Chasm: Marketing and Selling High-tech Products to Mainstream Customers, second ed. Harper Perennial, New York). However, if consumers cannot identify the relative advantage of solar power over their current sources of power, which is supplied readily and cheaply through a mains system, it is unlikely that adoption will follow. Recommendations concerning the marketing and development of solar products are identified

Experimental study of a combined system of solar Kang and solar air collector

International Nuclear Information System (INIS)

Wei, Wei; Ji, Jie; Chow, Tin-Tai; He, Wei; Chen, Haifei; Guo, Chao; Yu, Hancheng

2015-01-01

Highlights: • A combined system of solar Kang and solar air collector is proposed. • An experimental study on the combined system is made. • The mean air temperature reaches 18.5 °C and maintains above 18 °C for 13 h. • The corresponding mean indoor air temperature of the reference room is 8.9 °C. • The Kang surface temperature reaches 27 °C and maintains above 18 °C for 23 h. - Abstract: Chinese Kang is widely used as heated bed and for heat recovery of cooking stove in Northern China. However there are main drawbacks of indoor and outdoor air pollutant generation and heavy demands on solid fuel handling. A novel combined Kang system, which integrates solar Kang and solar air collector, is here proposed. Experiments were conducted to examine the alternative operating modes: (i) only solar air collector in service, (ii) only solar Kang in service, and (iii) both solar Kang and solar air collector in service. The results show that these three modes behave differently and have distinct effects on room thermal environment in winter. When this pollution-free system operates under the third combined mode, the room temperature increases significantly and the vertical temperature gradient reduces. The Kang surface temperature increases and its uniformity is improved. It is also found that the room air temperature is closely related to the Kang surface temperature. Furthermore, most of the time the thermal environment meets the occupant need. This paper reports the experimental work and investigates into the effects on indoor thermal environment as in rural residences in Northern China

Evidence of small-scale magnetic concentrations dragged by vortex motion of solar photospheric plasma

Science.gov (United States)

Balmaceda, L.; Vargas Domínguez, S.; Palacios, J.; Cabello, I.; Domingo, V.

2010-04-01

Vortex-type motions have been measured by tracking bright points in high-resolution observations of the solar photosphere. These small-scale motions are thought to be determinant in the evolution of magnetic footpoints and their interaction with plasma and therefore likely to play a role in heating the upper solar atmosphere by twisting magnetic flux tubes. We report the observation of magnetic concentrations being dragged towards the center of a convective vortex motion in the solar photosphere from high-resolution ground-based and space-borne data. We describe this event by analyzing a series of images at different solar atmospheric layers. By computing horizontal proper motions, we detect a vortex whose center appears to be the draining point for the magnetic concentrations detected in magnetograms and well-correlated with the locations of bright points seen in G-band and CN images.

Magnetotails in the solar system

CERN Document Server

Keiling, Andreas; Delamere, Peter

2014-01-01

All magnetized planets in our solar system (Mercury, Earth, Jupiter, Saturn, Uranus, and Neptune) interact strongly with the solar wind and possess well developed magnetotails. It is not only the strongly magnetized planets that have magnetotails. Mars and Venus have no global intrinsic magnetic field, yet they possess induced magnetotails. Comets have magnetotails that are formed by the draping of the interplanetary magnetic field. In the case of planetary  satellites (moons), the magnetotail refers to the wake region behind the satellite in the flow of either the solar wind or the magnetosp

Solar Adaptive Optics.

Science.gov (United States)

Rimmele, Thomas R; Marino, Jose

Adaptive optics (AO) has become an indispensable tool at ground-based solar telescopes. AO enables the ground-based observer to overcome the adverse effects of atmospheric seeing and obtain diffraction limited observations. Over the last decade adaptive optics systems have been deployed at major ground-based solar telescopes and revitalized ground-based solar astronomy. The relatively small aperture of solar telescopes and the bright source make solar AO possible for visible wavelengths where the majority of solar observations are still performed. Solar AO systems enable diffraction limited observations of the Sun for a significant fraction of the available observing time at ground-based solar telescopes, which often have a larger aperture than equivalent space based observatories, such as HINODE. New ground breaking scientific results have been achieved with solar adaptive optics and this trend continues. New large aperture telescopes are currently being deployed or are under construction. With the aid of solar AO these telescopes will obtain observations of the highly structured and dynamic solar atmosphere with unprecedented resolution. This paper reviews solar adaptive optics techniques and summarizes the recent progress in the field of solar adaptive optics. An outlook to future solar AO developments, including a discussion of Multi-Conjugate AO (MCAO) and Ground-Layer AO (GLAO) will be given. Supplementary material is available for this article at 10.12942/lrsp-2011-2.

Design of a solar-assisted drying system using the double-pass solar collector

International Nuclear Information System (INIS)

Sopian, K.; Daud, W.R.; Supranto; Othman, M.Y.; Yatim, B.

2000-01-01

A solar-assisted drying system that uses the double-pass solar collector with porous media in the second channel has been designed and constructed at the Solar Energy Research Park, Universiti Kebangsaan Malaysia. The drying system has a total of six double-pass solar collectors. Each collector has a length of 240 cm and a width of 120 cm. The upper channel depth is 3.5 cm and the lower channel depth is 10.5 cm. The lower channel is filled up with steel wool as the porous media. The solar collectors are arranged as 2 banks of 3 collectors each in series. Internal manifold are used to connect the collectors. An auxiliary heater source is installed to supply heat under unfavourable solar radiation conditions. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 80-90 0 C can be achieved at a solar radiation range of 800-900 W/m 3 , ambient temperature of 29 degree C and flow rate of O.20 kg/s. (Author)

Design and realization of an autonomous solar system

Science.gov (United States)

Gaga, A.; Diouri, O.; Es-sbai, N.; Errahimi, F.

2017-03-01

The aim of this work is the design and realization of an autonomous solar system, with MPPT control, a regulator charge/discharge of batteries, an H-bridge multi-level inverter with acquisition system and supervising based on a microcontroller. The proposed approach is based on developing a software platform in the LabVIEW environment which gives the system a flexible structure for controlling, monitoring and supervising the whole system in real time while providing power maximization and best quality of energy conversion from DC to AC power. The reliability of the proposed solar system is validated by the simulation results on PowerSim and experimental results achieved with a solar panel, a Lead acid battery, solar regulator and an H-bridge cascaded topology of single-phase inverter.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-01

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Measured Performance of a Varied Airflow Small-Diameter Duct System

Energy Technology Data Exchange (ETDEWEB)

Poerschke, Andrew [IBACOS, Inc., Pittsburgh, PA (United States)

2017-03-16

This study tests the performance of a variable airflow small-diameter duct heating, ventilation, and air conditioning (HVAC) system in a new construction unoccupied low-load test house in Pittsburgh, Pennsylvania. The duct system was installed entirely in conditioned space and was operated from the winter through summer seasons. Measurements were collected on the in-room temperatures and energy consumed by the air handler and heat pump unit. Operation modes with three different volumes of airflow were compared to determine the ideal airflow scenario that maximizes room-to-room thermal uniformity while minimizing fan energy consumption. Black felt infrared imagery was used as a measure of diffuser throw and in-room air mixing. Measured results indicate the small-diameter, high velocity airflow system can provide comfort under some conditions. Solar heat gains resulted in southern rooms drifting beyond acceptable temperature limits. Insufficient airflow to some bedrooms also resulted in periods of potential discomfort. Homebuilders or HVAC contractors can use these results to assess whether this space conditioning strategy is an attractive alternative to a traditional duct system. The team performed a cost analysis of two duct system configurations: (1) a conventional diameter and velocity duct system, and (2) the small-diameter duct system. This work applies to both new and retrofit homes that have achieved a low heating and cooling density either by energy conservation or by operation in a mild climate with few heating or cooling degree days. Guidance is provided on cost trade-offs between the conventional duct system and the small-diameter duct system.

Small Body Exploration Technologies as Precursors for Interstellar Robotics