Solar energy. Solar thermal collectors. Test methods

2015 ◽  
Keyword(s):  
Solar Energy ◽  
Test Methods ◽  
Solar Thermal ◽  
Solar Thermal Collectors

scholarly journals A Review of Photovoltaic Thermal (PVT) Technology for Residential Applications: Performance Indicators, Progress, and Opportunities

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3853
Author(s):  
Sree Harsha Bandaru ◽  
Victor Becerra ◽  
Sourav Khanna ◽  
Jovana Radulovic ◽  
David Hutchinson ◽  
...  
Keyword(s):  
Solar Energy ◽  
Performance Indicators ◽  
Heat Pumps ◽  
Solar Thermal ◽  
Cultural Barriers ◽  
Future Research ◽  
Energy Technologies ◽  
Solar Thermal Collector ◽  
Solar Thermal Collectors

Solar energy has been one of the accessible and affordable renewable energy technologies for the last few decades. Photovoltaics and solar thermal collectors are mature technologies to harness solar energy. However, the efficiency of photovoltaics decays at increased operating temperatures, and solar thermal collectors suffer from low exergy. Furthermore, along with several financial, structural, technical and socio-cultural barriers, the limited shadow-free space on building rooftops has significantly affected the adoption of solar energy. Thus, Photovoltaic Thermal (PVT) collectors that combine the advantages of photovoltaic cells and solar thermal collector into a single system have been developed. This study gives an extensive review of different PVT systems for residential applications, their performance indicators, progress, limitations and research opportunities. The literature review indicated that PVT systems used air, water, bi-fluids, nanofluids, refrigerants and phase-change material as the cooling medium and are sometimes integrated with heat pumps and seasonal energy storage. The overall efficiency of a PVT system reached up to 81% depending upon the system design and environmental conditions, and there is generally a trade-off between thermal and electrical efficiency. The review also highlights future research prospects in areas such as materials for PVT collector design, long-term reliability experiments, multi-objective design optimisation, techno-exergo-economics and photovoltaic recycling.

scholarly journals Eliminate obstacles of use the solar systems as buildings facades using multilayers optical interference filters

2021 ◽  
Vol 3 (8) ◽  
pp. 83-91
Author(s):  
Zainab I. AL-Assadi ◽  
Fawzia Asadi ◽  
Ban M. Alameri
Keyword(s):  
Solar Energy ◽  
Clean Energy ◽  
Solar Thermal ◽  
Design Stage ◽  
Solar Systems ◽  
Building Facades ◽  
Solar Thermal Collectors ◽  
Metallic Strip ◽  
Aesthetic Aspect ◽  
Black Color

The Building design in a correct way and totalitarian requires integration of using solar energy technologies in the architectural design stage of the roofs and facades as the most appropriate places to obtain solar energy because it greatly affects the architectural aesthetic. This integration has to be taken into account at the design stage, which leads to effective and attractive solutions. Architecture needs the energy to complete its functions to increases human effectiveness and ability to do its tasks better, solar energy is the main factor of providing the necessary energy due to its abundance as well as being clean energy and does not cause polluting emissions to the environment. To provide a comfortable indoor environment for the occupants, Solar Thermal Collectors (STC) and Photovoltaics Cells (PV) used, which convert solar energy into thermal energy and electrical energy, respectively. The main problem of this study is concerning with the problems of the black color, visible tubes, metallic strip gradients (absorption strip), and welding points of the solar systems which gives the facades of the buildings an undesirable view and weakens the aesthetic aspect of the buildings and limits the abilities of architects to use because of their black color and undesirable aspect. The aim of this study is a design of optical interference filter (multilayer coatings) prepared by RF magnetron sputtering as a solution to the problem of black color, visible tubes, metallic strip gradients (absorption strip), and welding points in solar thermal collectors and photovoltaic cells, which are the main reasons for not using solar systems as building facades, this technique works to increase the efficiency of the solar systems and increase the amount of clean energy generated, also enhancing the expressive and aesthetic aspect of facades of buildings. In the NIR region this filter works as an anti-reflective coating. Also the coating includes a high color reflection at a certain wavelength in the VIS region to give the solar system an aesthetic feature, which is used as building facades by using appropriate dielectric substances with high and low reflective indexes likes SiO2 and MgF2 respectively. The results of the study showed that the increase in the number of layers will lead to an increase in the visible reflectivity peak, while near of infrared region remains an anti-reflective with a high Transmission of solar rays, thus increasing solar systems efficiency.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Efficient Co-Harvesting of Solar Energy and Low-Grade Heat by Molecular Photoswitches for High Energy Density, Long-Term Stable Solar Thermal Battery

2019 ◽  
Author(s):  
Zhao-Yang Zhang ◽  
Tao LI
Keyword(s):  
Energy Density ◽  
Solar Energy ◽  
High Performance ◽  
High Energy ◽  
Solar Thermal ◽  
High Energy Density ◽  
Low Grade ◽  
Thermal Battery ◽  
Low Grade Heat

Solar energy and ambient heat are two inexhaustible energy sources for addressing the global challenge of energy and sustainability. Solar thermal battery based on molecular switches that can store solar energy and release it as heat has recently attracted great interest, but its development is severely limited by both low energy density and short storage stability. On the other hand, the efficient recovery and upgrading of low-grade heat, especially that of the ambient heat, has been a great challenge. Here we report that solar energy and ambient heat can be simultaneously harvested and stored, which is enabled by room-temperature photochemical crystal-to-liquid transitions of small-molecule photoswitches. The two forms of energy are released together to produce high-temperature heat during the reverse photochemical phase change. This strategy, combined with molecular design, provides high energy density of 320-370 J/g and long-term storage stability (half-life of about 3 months). On this basis, we fabricate high-performance, flexible film devices of solar thermal battery, which can be readily recharged at room temperature with good cycling ability, show fast rate of heat release, and produce high-temperature heat that is >20<sup> o</sup>C higher than the ambient temperature. Our work opens up a new avenue to harvest ambient heat, and demonstrate a feasible strategy to develop high-performance solar thermal battery.

Design, Installation, and Performance Characterization of a Laboratory-Scale Solar Thermal System for Experiments in Solar Energy Utilization

2012 ◽  
Author(s):  
Stephanie Drozek ◽  
Christopher Damm ◽  
Ryan Enot ◽  
Andrew Hjortland ◽  
Brandon Jackson ◽  
...  
Keyword(s):  
Renewable Energy ◽  
Solar Energy ◽  
Laboratory Scale ◽  
Energy Utilization ◽  
Solar Thermal ◽  
Thermal System ◽  
Performance Characterization ◽  
And Performance ◽  
Solar Thermal System

The purpose of this paper is to describe the implementation of a laboratory-scale solar thermal system for the Renewable Energy Systems Laboratory at the Milwaukee School of Engineering (MSOE). The system development began as a student senior design project where students designed and fabricated a laboratory-scale solar thermal system to complement an existing commercial solar energy system on campus. The solar thermal system is designed specifically for educating engineers. This laboratory equipment, including a solar light simulator, allows for variation of operating parameters to investigate their impact on system performance. The equipment will be utilized in two courses: Applied Thermodynamics, and Renewable Energy Utilization. During the solar thermal laboratories performed in these courses, students conduct experiments based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) 93-2010 standard for testing and performance characterization of solar thermal systems. Their measurements are then used to quantify energy output, efficiency and losses of the system and subsystem components.

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