Solar thermal technology evaluation, fiscal year 1982. Volume 1: Executive summary

Three primary solar concepts the central receiver, parabolic dish, and parabolic trough are investigated. To a lesser extent, the hemispherical bowl and salt-gradient solar pond are also being studied. Each technology is described

Design and Construction of Parabolic Solar Heater Using Polymer Matrix Composite

A parabolic dish is a type of concentrating reflective device that uses the shape of a circular paraboloid to collect or project energy such as light, sound, or radio waves. The parabolic reflector transforms an incoming plane wave traveling along the axis into a spherical wave converging toward the focus. In this work concentrating dish was moulded from polyester resin reinforced with fiber glass mat and inner surface lined with Aluminum foil to increase the reflectivity. The design was made up of a moulded dish of 246cm diameter with a height of 58.2cm which has a concentration factor of 54.9. The collector was mounted on a site with latitude 6 40 22.19 and longitude 3 09 47.12 and water at 270C was heated to a temperature of 850C within 20 minutes

Projection of distributed-collector solar-thermal electric power plant economics to years 1990-2000

A preliminary comparative evaluation of distributed-collector solar thermal power plants was undertaken by projecting power plant economics of selected systems to the 1990 to 2000 time frame. The selected systems include: (1) fixed orientation collectors with concentrating reflectors and vacuum tube absorbers, (2) one axis tracking linear concentrator including parabolic trough and variable slat designs, and (3) two axis tracking parabolic dish systems including concepts with small heat engine-electric generator assemblies at each focal point as well as approaches having steam generators at the focal point with pipeline collection to a central power conversion unit. Comparisons are presented primarily in terms of energy cost and capital cost over a wide range of operating load factors. Sensitvity of energy costs for a range of efficiency and cost of major subsystems/components is presented to delineate critical technological development needs

A novel portable device to measure the temperature of both the inner and the outer tubes of a parabolic receiver in the field

The performance of parabolic trough (PT) receiver tubes (RT) has a direct impact on Solar Thermal Energy (STE) plant production. As a result, one major need of operation and maintenance (O&M) in STE plants is to monitor the state of the receiver tube as a key element in the solar field. However the lack of specific devices so far has limited the proper evaluation of operating receiver tubés thermal performance. As a consequence non-accurate approximations have been accepted until now using infrared thermal images of the glass outer tube. In order to fulfill this need, Abengoa has developed a unique portable device for evaluating the thermal performance and vacuum state of parabolic trough receiver tubes placed in the field. The novel device described in this paper, simultaneously provides the temperature of both the inner steel tube and the outer glass tube enabling a check on manufacturers specifications. The on-field evaluation of any receiver tube at any operating temperature has become possible thanks to this new measuring device. The features and usability of this new measurement system as a workable portable device in operating solar fields provide a very useful tool for all companies in the sector contributing to technology progress. The originality of the device, patent pending P201431969, is not limited to the CSP sector, also having scientific significance in the general measuring instruments field. This paper presents the work carried out to develop and validate the device, also detailing its functioning properties and including the excellent results obtained in the laboratory to determine its accuracy and standard deviation. This information was validated with data collected by O&M teams using this instrument in a commercial CSP plant. The relevance of the device has been evidenced by evaluating a wide sample of RT and the results are discussed in this paper. Finally, all the on field collected data is used to demonstrate the high impact that using this unique portable device will have on a parabolic trough solar power plant

Parabolic Trough Solar Collector – Design, Construction and Testing

This paper presents the design, construction and investigates an experimental study of a parabolic Trough Solar Collector (PTSC). It is constructed of multi – piece glass mirror to form the parabolic reflector (1.8 m ? 2.8 m) its form were checked with help of a laser and carbon steel rectangular as receiver. Sun tracker has been developed (using two – axis) to track solar PTSC according to the direction of beam propagation of solar radiation. Using synthetic oil as a heat transfer its capability to heat transfer and load high temperature (?400 oc). The storage tank is fabricated with stainless steel of size 50 L. The experimental tests have been carried out in Baghdad climatic conditions (33.3o N, 44.4o E) during selective days of the months October and November. The performance of PTSC is evaluated using outdoor experimental measurements including the useful heat gain, the thermal instantaneous efficiency and the energy gained by the storage tank oil. The storage tank oil temperature is increased from 30oc at 9:30h to 136oc at 13:30h without draw – off oil. The experimental result shows the average thermal efficiency was 42% which is fairly acceptable assessment results of a PTSC locally

Form measurement and durability of mirror surfaces for concentrating solar power applications

Concentrating solar power systems currently have a high capital cost when compared with other energy generating systems. The solar energy is captured in the form of thermal energy rather than directly electrical, which is attractive as thermal energy is easier and currently cheaper to store in large amounts. It is also used directly as processing heat including desalination and water purification. For the technology to compete against other generating systems it is important to reduce the electrical energy cost to the $0.05 per kilowatt-hour level. One of the significant capital costs is the solar field, which contains the concentrators. To reduce the cost of this field, novel constructions and improvements to the durability and lifetime of the concentrators are required. Techniques for characterising the shape, durability and optical properties of such novel mirrors are the focus of this thesis. The thesis describes the development and validation of an inexpensive, highly portable photogrammetry technique, which has been used to measure the shape of large mirror facets for solar collectors. Photogrammetry has demonstrated its versatility and portability by successful measurements across concentrating solar power sites globally. The accuracy of the technique has been validated to show a measurement capability of better than 100 µm using a large coordinate measuring machine. Measurements performed on novel thin glass mirrors and their comparison with conventional thick glass mirrors are presented, showing that the increased flexibility of thin mirrors is an important consideration during installation, but that it is possible for such novel mirrors to perform to the same level. ...[cont.

Feasibility Study of Freeze Recovery Options in Parabolic Trough Collector Plants Working with Molten Salt as Heat Transfer Fluid

Parabolic trough collector (PTC) technology is currently the most mature solar technology, which has led to the accumulation of relevant operational experience. The overall performance and e ciency of these plants depends on several components, and the heat transfer fluid (HTF) is one of the most important ones. Using molten salts as HTFs has the advantage of being able to work at higher temperatures, but it also has the disadvantage of the potential freezing of the HTF in pipes and components. This paper models and evaluates two methods of freeze recovery, which is needed for this HTF system design: Heat tracing in pipes and components, and impedance melting in the solar field. The model is used to compare the parasitic consumption in three molten salts mixtures, namely Solar Salt, HiTec, and HiTec XL, and the feasibility of this system in a freezing event. After the investigation of each of these subsystems, it was concluded that freeze recovery for a molten salt plant is possible.Ministerio de Ciencia, Innovación y Universidades CDTI ITC-2011106Ministerio de Ciencia, Innovación y Universidades RTI2018-093849-B-C3

Potential high efficiency solar cells: Applications from space photovoltaic research

NASA involvement in photovoltaic energy conversion research development and applications spans over two decades of continuous progress. Solar cell research and development programs conducted by the Lewis Research Center's Photovoltaic Branch have produced a sound technology base not only for the space program, but for terrestrial applications as well. The fundamental goals which have guided the NASA photovoltaic program are to improve the efficiency and lifetime, and to reduce the mass and cost of photovoltaic energy conversion devices and arrays for use in space. The major efforts in the current Lewis program are on high efficiency, single crystal GaAs planar and concentrator cells, radiation hard InP cells, and superlattice solar cells. A brief historical perspective of accomplishments in high efficiency space solar cells will be given, and current work in all of the above categories will be described. The applicability of space cell research and technology to terrestrial photovoltaics will be discussed

Technical assessment report on solar thermal energy use in cork industry : António Almeida - Cortiças S.A.

ABSTRACT: Nowadays, current industrial applications seek, whenever possible, to meet thermal needs on sustainable technologies that are economically viable and environmentally friendly. Despite the high potential, a number of challenges still have to be overcame. Those include maximum attainable temperatures, seasonal and daily transience in solar heat supply and its integration in the industrial processes (among others). For that purpose, the implementation of solar thermal energy into industrial applications has been recognised and addressed by IEA Solar Heating & Cooling Programme (established in 1977), in a number of different research studies, including those ones found in Task 33 and Task 49 (IEA, 2015a; IEA, 2015b; and IEA, 2016) supported by the International Energy Agency (IEA) agenda. In this area, a task called Solar Heat for Industrial Processes (SHIP) emerges, which suggested that solar thermal systems have a significant potential in the sector, even though in an early stage of progress. This activity was led primary by the Commonwealth Science and Industrial Research Organization (Fuller, 2011). General motivations to implement solar systems in cork industry include: i) economics, with respect to worldwide increasing gas prices, and ii) environmental, with respect to the carbon-dioxide footprint associated to this specific industrial sector. The main objective of this report is to assess the technical assessment of solar thermal use in the cork industry, more specifically in the António Almeida - Cortiças S.A., located in the north of Portugal. For that purpose, a close collaboration was establish with this industry through several activities namely: i) energetic audit and ii) different actions of monitoring and implementation of the Energy Consumption Rationalization Agreement (ECRA).N/