Showing papers on "Photovoltaic thermal hybrid solar collector published in 1998"

Crystalline Silicon Solar Cells

Abstract: Photovoltaics. Solar Power. The Principles of Photovoltaics. The P-N Junction. The Physics of Solar Cells. High Efficiency Solar Cells. Si Solar Cell Technology. Selected Solar Cell Types. Analysis and Measuring Techniques. Appendices. Index.

A panel-shaped, hybrid photovoltaic/thermal device

Abstract: A panel-shaped hybrid photovoltaic/thermal device (1) comprising metal absorption means (6) for converting solar energy into thermal energy, and laminated, panel-shaped photovoltaic means (2) comprising photovoltaic cells (3) of a crystalline silicon for converting solar energy into electric energy. The photovoltaic means (2) and the absorption means (6) have been joined to form a single assembly with the interposition of a metal-containing plastic material (10) having bonding properties. The device (1) is constructionally simple and suited for optimizing the electric and thermal efficiency.

Transient simulation of conventional hybrid photovoltaic/thermal (PV/T) air heating collectors

Abstract: In the present investigation, the authors have developed a computer simulation model for predicting the transient performance of a conventional photovoltaic/thermal (PV/T) air heating collector with single- and double-glass configurations. In order to appreciate the model, numerical calculations have been made to evaluate the system performance corresponding to typical climate of Delhi, India. It has been observed that the hybrid PV/T systems are interesting in respect to system efficiencies, however, their adaptability in future must be weighed in terms of cost effectiveness of these systems. © 1998 John Wiley & Sons, Ltd.

Supply of cooling and heating with solar assisted absorption heat pumps: an energetic approach

Abstract: The primary energy consumption of two kinds of solar assisted absorption systems (solar assisted absorption chiller during summertime and heat pump during wintertime or solar assisted absorption chiller with direct gas combustion for heating during wintertime) is compared with the primary energy consumption of a compression chiller which can work as a heat pump during wintertime. For the absorption systems three technical options were considered: a single effect machine; a double effect machine with the solar energy delivered to the lower temperature desorber and combustion heat of a gas burner delivered to the higher temperature desorber; a double effect machine with both solar energy and combustion heat delivered to the higher temperature desorber. The analysis performed in this article shows that solar assisted absorption chillers, absorption heat pumps and direct solar heating systems even with low and intermediate solar fractions can operate with considerably less primary energy consumption than compression systems. Further, the necessary solar collector area to achieve that goal is compatible with roof area available in buildings. It was also verified that, for the double effect absorption machines, there is no advantage in delivering the solar energy to the higher temperature desorber, thus establishing as preferable the solution in which it is delivered to the lower temperature desorber.

Energy generating solar cell

Abstract: The solar cell is located under a layer of liquid and a cover provides a drive skin effect in the tub. The electrical and heat energy are obtained on the same surface of a box (2), e.g. of tin sheet. The solar cell and collector form a sandwich structure. The structure provides a higher total energy yield and the solar cell cooling increases its efficiency rate. There is a control circuit, to which are connected temp. sensors, flow meters, the solar cell, and valves, and which controls adjustment of temperature in the box.

Solar energy utilizing device

Abstract: PROBLEM TO BE SOLVED: To obtain a solar energy utilizing device which is capable of preventing a power generating function from lowering and promote the prolongation of lifetime. SOLUTION: A solar energy utilizing device constituting a plate-shaped pattern as a whole which comprises a power generation system 4 for conducting solar generation in which a plurality of solar cells 2 which are placed side by side on a plane are embedded in an adhesive resin layer 3 having translucency, and a solar energy collection system 7 which is deposited on the reverse side of the power generation system 4 provided with a heating medium pipe 6 on a solar energy collecting board 5 for collecting solar heat. A flat plate member 10 having substantially the same coefficient of linear expansion as those of the solar cells 2 in the power generation system 4 and having an electrically insulating property is adherently inserted between the power generation system 4 and the solar energy collection system 7 with an adhesive resin layer 11 being interposed between the flat plate member 10 and the solar energy collection system 7. COPYRIGHT: (C)1999,JPO

Performance of the Solar Two central receiver power plant

Abstract: Solar Two is a utility-led project to promote the commercialization of solar power towers by retrofitting the Solar One pilot plant from a water/steam-based system to a molten salt system. Solar Two is capable of producing 10 MW(e) net electricity with enough thermal storage capacity to operate the turbine for three hours after sunset. The plant was turned over to its operations and maintenance contractor in February 1998, marking transition from start-up to the test and evaluation phase. Solar Two has collected as much as 230 MWh thermal and generated as much as 72 MWh(e) gross electricity in one day. The plant has demonstrated dispatchability after dark, during clouds, and during sunshine hours. To date, Solar Two has collected thermal energy at a maximum rate of 39 MW(t) and generated gross electricity at a maximum rate of 11.1 MW(e). Important lessons have been learned in the areas of heat trace, valve selection, materials of construction, and steam generator design. Testing has begun in a number of areas relating to receiver performance, storage tank performance, salt chemistry, overnight thermal conditioning, electricity dispatching, performance monitoring and evaluation, availability tracking, and receiver controls.

Large-area, high-intensity PV arrays for systems using dish concentrating optics

Abstract: In this paper, we report on our efforts to fabricate monolithic interconnected modules (MIMs) using IIIV semiconductors with bandgaps appropriate for the terrestrial solar spectrum. The small size of the component cells comprising the MIM allows for operation at extremely high flux densities and relaxes the requirement for a small spot -size to be generated by the optics. This makes possible a PV option for the large dish concentrator systems that have been developed by the solar thermal community for use with Stirling engines. Additionally, the highly effective back surface reflector integrated into the MIM design is an effective tool for thermal management of the array. Development of this technology would radically alter the projections for PV manufacturing capacity because of the potential for extremely high power generation per unit area of semiconductor material.

Photovoltaics demonstration projects

Abstract: Among the many types of renewable energies, solar energy is considered promising as it is comparatively more evenly distributed geographically. A branch of solar energy research that has received worldwide attention is photovoltaics (PV). This paper studies the PV demonstration projects carried out in few countries. It aims to identify the common experience and conclusions drawn from the demonstration projects such as PV power system performance, PV cost effectiveness and grid interfacing problems. This paper also examines demonstration projects' achievements and limitations. The capacity of the projects analysed is limited to 20 kW per installation.

Analysis of the exergy efficiency and the energy efficiency of photothermal-and-voltaic systems

Abstract: The paper presents a theoretical analysis and describes a method for calculating the exergy efficiency and energy efficiency of the following basically different solar energy-converting systems: photothermal-and-voltaic systems and combined systems consisting of a flat-plate solar thermal collector and a separate solar battery.

Photovoltaic collector for current and heat generation for solar-powered energy plant

Abstract: The collector (1) has a top cover plate (2) provided with spaced solar cells (3) and underlying flow medium channels (4) embedded in a foam thermal insulation material (5), for independent extraction of current and heat from the incident solar radiation. The heat may be extracted via a pump for circulating the flow medium heated by the incident solar radiation through a heat storage device.

Optimal design of solar water heating systems

Abstract: Solar water heating systems are usually designed using simplified equation of annual efficiency of the heating system from solar radiation incident on the collector during the year and empirical values of annual efficiency. The pe1formance of the preliminary design is predicted by using either/chart method or by translate it simulation of solar heating system. Often, optimization is done off-line after correlating the annual contribution of solar energy to the heating load and collector area using simulation resu!ts by analytical methods. In this work, a methodology a11d a computer programme using univariant search method is developed for optimal design of solar water heating systein. The program uses the collector area and the storage tank volume as optimization parameters and the unit energy price of solar water heating system as objective function and the annual fraction of contribution of solar energy to the heating load is considered as constraint.

New solid sorption refrigerator

Abstract: A solar machine with 1.2 m collection surface was designed and studied to build in future an industrial refrigerator/dryer. It is an adsorption machine with very short (15 min) intermittent cycles that uses the active carbon fibre Busofit- ammonia air. The system management consists only in actuating the special type valves to change the heating circuit and water valves to change the water cooling circuit. The results show that, with a solar collector efficiency comprised between 0,5 and 0,6 it is possible to obtain a high solar COP 0.3-0.4. There is considerable scope for the application of such a hybrid gas(electricity) / solar-adsorption systems where intermittent ,or low solar insulation currently restricts their use. Such a working fluid and energy sources are attractive on environmental grounds. Calculations for a combined refrigeration and power-generation system operating on gas/solar energy shows that a COP of 0.75 is achievable. Further increases in performance may be realised using multi-effect systems. The research into the economical viability of such systems is required to assess their commercial potentials. Such research should take into account an anticipated changes in legislation governing the use and manufacture of conventional refrigerators.

Efficient Design of Desalination System Using Photovoltaic and Packed Bed Systems

Abstract: This work presents a new way to realize continuous operation of a solar desalination system to produce fresh water using solar energy for a dual purpose. Here, solar energy is used directly as heat energy through solar radiation incident on an inverse V-shape still cover during sunlight hours. At the same time, the solar energy can be converted through a photovoltaic (PV) array into electric energy, which is stored in the battery system during sunlight hours. To realize the continuity of still operation daily and overnight, the batteries are discharged during the night at a suitable rate to feed an electric heater. The electric heater is designed to generate the required heat for desalination during the night. The heat is equivalent to that which can be absorbed during the day and that gives the temperature difference to gain evaporation and fresh water (productivity). This modified still is provided with a packed bed layer installed in the bottom of the basin to assist the system during the day ...

Concentrator PV (CPV): A Solar Seed Ready for Colorado

Abstract: This paper discusses a relatively new high technology photovoltaic concept utilizing high-efficiency space-flight solar cells in a concentrating mode for terrestrial applications. A proposal for power generation in Colorado is presented.

Thermal solar system for heating domestic water supply e.g. for washing, washing machines, dishwashers

Abstract: The system has a solar collector (1) and a pressureless solar store (3) filled with a thermal transport medium and a used water heat exchanger (14). The solar collector is connected to the solar store by only one pipe (2). The heat transport medium is pumped to the solar collector from the solar store by pump (4) connected to a controller and can flow back to the solar store by the action of gravity.