Spectral Transmission of a Solar Collector and Fiber Optic Distribution Hybrid Lighting System

Author(s):  
L. C. Maxey ◽  
J. E. Parks ◽  
D. L. Beshears ◽  
D. D. Earl ◽  
M. V. Lapsa ◽  
...  

Increased use of solar energy will reduce requirements for non-renewable energy sources such as fossil fuels and reduce associated greenhouse gas emissions. The benefits of replacing fossil-based energy with solar energy are often dependent on the application and operational or duty cycle for power demand. One particularly efficient use of solar energy is hybrid lighting. In hybrid lighting, solar light is concentrated into optical fibers and then coupled with supplemental electrical lighting to maintain a constant level of illumination. The system is able to offer reliable lighting with less energy consumption from the electrical grid (which is often driven by non-renewable sources). This technique offers energy efficiency benefits since the solar light is used directly and suffers no conversion losses. Furthermore, the solar spectrum provides an illumination that lighting engineers value for it’s quality; office inhabitants appreciate for its comfort; and retailers believe leads to increased sales. When available solar light is low, the hybrid system allows traditional light sources to reliably meet lighting demands. The success of the solar hybrid lighting system is dependent on the collection and transmission efficiency of the system. In this study, the spectral transmission of a hybrid lighting system is characterized. The system is composed of a 200-sun concentration reflective solar collector and a plastic fiber optic distribution network. The ultraviolet (UV), visible, and near-infrared (NIR) spectral transmission was characterized over a spectral range of 200 nm to 2400 nm. The UV and NIR performance of the system is critical since optical fiber damage can be caused by both UV and NIR light; thus, optimal system design maximizes the collection and transmission of visible light while minimizing the transmission of the UV and NIR light. Spectral transmission data for all components in the hybrid system are presented, and performance properties relative to solar applications are discussed.

2021 ◽  
Vol 295 ◽  
pp. 04005
Author(s):  
Sergey Batukhtin ◽  
Andrey Batukhtin ◽  
Marina Baranovskaya

According to experts’ forecasts, by 2040 the global demand for energy will increase by 37%, and renewable energy sources in the next 20 years will become the fastest growing segment of the world energy, their share in the next decade will grow by about one and a half times. Solar energy is the fastest growing industry among all non-conventional energy sources and is gaining the highest rates of development in comparison with other renewable energy sources. In this article, the authors provide an overview of the technologies that increase the efficiency and productivity of solar panels, only the investigated methods are described that can speed up the process of introducing solar energy instead of traditional. All the methods described can increase the efficiency of systems that are based on the use of the sun as the main source of energy. The authors presented and described the scheme of a solar-air thermal power plant, which will improve energy efficiency through the use of a regenerative air solar collector with increased heat transfer efficiency. Strengthening will be achieved through the use of hemispherical depressions on the surface that receives solar radiation. A schematic diagram is given and the principle of operation of such a solar collector is described in detail. A comparative calculation of the intensification of the solar collector with the use of depressions and without the use as modernization was carried out, on the basis of which a conclusion was made about the efficiency of using this type of solar collector and the economic effect from the application of this method. A description of the method for calculating the solar collector is given, thanks to which this development can be used and implemented in existing heating and hot water supply systems.


2011 ◽  
Vol 374-377 ◽  
pp. 137-140
Author(s):  
Hua Zhang ◽  
Hui Zhang

The hybrid system of solar energy and geothermal heat pump (GHP) can put the advantages of the two renewable energy sources together and make up the deficiencies of each other. The concept and the development of the hybrid system are introduced; the work principle and the operational mode of the system are analyzed. Through the introduction of two instances, this paper analyzes the way of the system in buildings and the saving potential applying the hybrid system.


Author(s):  
Sean Lawless ◽  
Ravi Gorthala

This paper discusses a Fiber-Optic Hybrid Day-Lighting system that can cut energy consumed by buildings for lighting significantly. This system is designed for mobile applications such as military shelters. The system is comprised of two primary components: the solar collector and the Solar Hybrid Lighting Fixture. The first component, the solar collector, consists of a housing, structural stand, a dual axis tracking system, Fresnel Lenses, secondary optics, and fiber-optic cables. The collector is integrated into a dual-axis tracker, which is then mounted on a tripod. The tripod can be staked into the ground and weighed down to protect the system from any wind loading and the collector height can be adjusted so that there is no shading of the collector by nearby structures. The collector with an aluminum housing holds eight 10-inch diameter Fresnel Lenses that focus sunlight onto eight secondary optics based on TIR (total internal reflection) which filter UV/IR and deliver uniform light to the fiber-optic cables. The secondary optic is coupled to the fiber-optic cable with index matching gel so that Fresnel reflection losses are minimized. The solar collector tracks the sun’s movement through the day with a dual-axis tracker (azimuth/tilt), ensuring the light is concentrated into the fiber-optic cables. The optics has been designed to have a high half-acceptance of 1.75° and can accommodate a tracking accuracy of 1.50° or better. The opposite end of the fiber-optic cable attaches to the second part of the Day-Lighting system, the Solar Hybrid Light Fixture (SHLF). The SHLF comprises of two lighting systems: 1) a solar fiber-optic system and 2) an LED system. The fiber-optic cable is coupled to an acrylic light diffusing rod that evenly delivers the light into the room. During sunny periods, depending on the length of the cable, solar fiber-optic lighting could provide full illumination of the space. In order to keep lighting uniform even during fluctuations of the light output from the sun during cloudy periods, the LED portion of the light will allow for constant lighting at a lower power consumption. The LED lighting has dimming capabilities due to a photosensor that regulates the light output of the LEDs based on how much solar light is delivered by the fiber-optic cables. On a typical sunny day with an overall concentration factor of ∼400 from the Fresnel Lens system to the optical fiber, it is possible to generate an output of 2,000 lumens with a 20-foot cable, with each fiber-optic cable experiencing a 1% loss of light per foot of cable. The LED portion of the hybrid light fixture produces about 1,800 lumens as well.


Author(s):  
Anna Maria Klepacka

The paper emphasizes the differences in the concentration of investments with the use of photovoltaic panels and solar collectors in voivodships with significant potential for using solar energy. The subject of the paper addresses, among others, the significant changes in renewable energy sources (RES) and EU subsidies that affect the economics of solar micro-installations in Poland. The study applied data from the Ministry of Agriculture and Rural Development, which included completed operations under the rural development program (RDP) for the period 2007-2013. The percentage share of the number of photovoltaic panel installations in Lubelskie and Mazowieckie Voivodships constituted 22% of that type of investments in the country (13% and 9% respectively, with a total capacity of 2,634 kW). However, in the case of the number of solar collector installations, the percentage share in Lubelskie and Mazowieckie Voivodships accounted for 44% of such installations in Poland (29% and 15%, respectively, with a total capacity of 4,239 kW). The results confirm the view that the location is an important determinant of photovoltaic panel and solar collector installations in Poland as shown in the examined voivodships characterized by the favorable solar radiation conditions.


2018 ◽  
Vol 140 (2) ◽  
Author(s):  
Sean Lawless ◽  
Ravi Gorthala

The primary objective of this study was to develop a fiber-optic hybrid day-lighting system for mobile application such as military shelters in order to cut energy use and the use of fossil fuels. The scope included the design, development, and testing of a hybrid lighting system that is capable of producing about 16,000 lm output with design challenges including light-weight, compactness, and optics that can tolerate a high tracking misalignment. The designed system is comprised of two subsystems: the solar collector and the solar hybrid lighting fixture (SHLF). The solar collector, consists of a housing, a structural stand (tripod), a dual axis tracking system, Fresnel lenses, secondary optics, and fiber-optic cables. The collector is a telescoping aluminum box that holds eight 10-in diameter Fresnel lenses, which focus sunlight onto eight secondary optics and deliver uniform light to the fiber-optic cables. The secondary optics have filters to block UV/IR. The optics has been designed to have a high half-acceptance angle of 1.75 deg and can accommodate a tracking accuracy of 1.50 deg or better. This novel SHLF consists of two components: a solar fiber-optic system and a light emitting diode (LED) system. The fiber-optic cable is coupled to an acrylic light diffusing rod that delivers the sunlight into the room. During sunny periods, the solar fiber-optic lighting could provide full illumination level. In order to keep the same level of lighting during cloudy periods, the LED portion of the light fixture can supplement the output of the SHLF. A compact, light-weight prototype system was built and tested. The results showed that the system's output per lens for the 20 ft cable was about 1750±50 lm at a global solar illuminance of 115,000 lx. The total system was capable of delivering 14,000 lm of sunlight.


2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Longzhou Zhang ◽  
Dengwei Jing ◽  
Liang Zhao ◽  
Jinjia Wei ◽  
Liejin Guo

Photovoltaic (PV) power generation is one of the attractive choices for efficient utilization of solar energy. Considering that the efficiency and cost of PV cells cannot be significantly improved in near future, a relatively cheap concentrator to replace part of the expensive solar cells could be used. The photovoltaic thermal hybrid system (PV/T), combining active cooling with thermal electricity and providing both electricity and usable heat, can enhance the total efficiency of the system with reduced cell area. The effect of nonuniform light distribution and the heat dissipation on the performance of concentrating PV/T was discussed. Total utilization of solar light by spectral beam splitting technology was also introduced. In the last part, we proposed an integrated compound parabolic collector (CPC) plate with low precision solar tracking, ensuring effective collection of solar light with a significantly lowered cost. With the combination of beam splitting of solar spectrum, use of film solar cell, and active liquid cooling, efficient and full spectrum conversion of solar light to electricity and heat, in a low cost way, might be realized. The paper may offer a general guide to those who are interested in the development of low cost concentrating PV/T hybrid system.


Author(s):  
N. Jayanthi ◽  
M. Venkatesh ◽  
R. Suresh Kumar ◽  
S. Sekar

Energy from the Sun brings as Solar energy which is abundantly available and utilized for various applications. Owing to the increase in energy demand, having a limit of non-renewable energy sources, more interest is given to Solar energy. One of the most fundamental applications of using Solar energy is a Solar collector. The efficiency of the Solar collector depends upon the fluids used in the Solar collector and thermal performance also can be enhanced by using heat pipes in the Solar collector. Compared to flat plate solar collectors, the major disadvantage of heat loss can be rectified in heat pipe solar collectors. Still, to improve the performance of heat pipe solar collectors, nanofluids can be used instead of base fluids to improve thermal performance. In this review paper, the application of nanofluid in Solar collectors results in the percentage of improvement in heat transfer by nanofluid at optimum condition is discussed. This paper reviewed widely the recent development and upcoming research that can be done to enhance the working of heat pipe Solar collectors using nanofluids.


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