Concentrating Sunlight with Fiber Optics AKA Hybrid Solar Lighting - Coursework Example

Hybrid Solar Lighting Introduction There has been an evolution of the use of sun as a light source of illumination in the building interiors; all through the 1900s. However, with time the sustainability and price of the electric lamp advanced, and this led to the sun displacement as the main source of illuminating buildings. Improved concern in day-lighting begun in 1970 at the period of embargo. Since the price and ease of electrical illumination source were very high, the awareness of installing the light source anywhere in the building was not implemented. Also, the disadvantages of the system which include the difficulty of control, variability and excessive illuminance were exposed (Beshears 55). The sunshine guidance technologies based on extremely efficient optic material has enhanced the direction of sunshine into interior of building that normal glazing cannot reach. The daylight interiors have beneficial effects on the well being, and also, energy conservation is permitted by the use of daylight as an alternative source of lighting interior buildings. The optical materials have been used to direct daylight in an efficient way into any part of storey buildings. TDGS is the most significant light technology which has succeeded. TDGS technology has been in use for the last nine or more years in most parts of the world with various applications. Many studies have done in light delivery methods can be used to provide comfortable and economical interior building conditions and TDGS integration with electrical lighting using various technologies. Current technologies that combine the delivery of electrical light and sunshine into the same place have been HLS. The technology moves daylight into the interior of the building where it combines with electrical light in the systems that are equipped with various controls to increase the use of available daylight. The only setback of this system is that there has been none or few post-installation studies published, and there is little information on the design methods the performance criteria of the system in use. (Mayhoub and Carter 267) Hybrid lighting systems In this technology of Hybrid Lighting Systems (HLS), daylight is combined with electrical light before delivery. Organizing of optics is more similar to artificial light and hence they may not look different. The author of the table has also included the estimates of system efficiencies for a certain storey applications. Information on individual components efficiency and size are represented in the table. The standards are focused on the projected efficiency of a building and referred principles of daylight (Mayhoub and Carter 270). Table 1.summary of hybrid lighting systems (Beshears 45-56) The HSL applies the use of a solar collector mounted on the roof top so as to concentrate detectable sunlight, into a bundle of plastic optical fibers. The sun rays spread in luminaries found in the building through a penetration of optic fiber. The sunlight is combined with lump lights by the hybrid luminaires, so as to maintain a steady intensity of illumination in the room. Figure1. Light transmission of fiber optic source: (Beshears 45-56) In a situation where there is much sunlight, optical fibers luminaire provide almost all the light required in a room. There is a sensor that controls the intensity of the man made lamps so that the desired level illumination level reaches; this happens when there is little sunlight. Different to traditional electric bulbs, the normal light produce no heat with an effectiveness of 225 L/W. The reason behind this is that the solar collector of the system removes the IR that generate much temperature in a regular bulb, from the sunlight. The heat is the cause of the light strength in fibers to misplace when the measurement lengthwise increases. In a particular storey spaces, HLS can be of great significance. The distance end to end of the current optic cable is 50 feet or less (Beshears 56). Figure2. Tracking solar collector source: (Beshears 45-56) This technology of hybrid solar lighting can separate and utilize various portions of sunlight for many applications. The Infra-Red causes generation of heat used to heat water or space, alternatively used in generating electrical energy; whereas the detectable light is applied straight in the various lighting application. There are many studies that are being conducted about optimal use of these wavelengths. Figure3. Conceptual illustration of a hybrid solar lighting system source: (Beshears 45-56) Originally, the hybrid lighting system used a glass main mirror that was uneconomical, very heavy and easy to crack or break. The system also relied on a third-party tracking system that was not configured for the product and hard in adaptation. The initial systems used fiber optics with large diameter the producer may not ensure whose continued availability. Eight singled fibers with ½ inch diameter used an adjustable tool to hold them, which aligned singled optical fiber. The minor reflector had a combination of 8 plane segment individual reflectors. The initial designs were time consuming in terms of the alignment process, expensive, required employees with many skills and experience, and labor intensive machines. Figure4. HSL fiber optic bundle source: (Sansoni et al. 17-30). The current hybrid lighting system has an innovative and improved design. A custom main mirror employed, which when compared to the original mirrors, its 1/5 and 1/10 less weight and cost respectively. The improvement has led toward simplification of minor mirror starting eight segments to one cryptic mirror. Also, the current tracking system has been optimized in terms of software and hardware so as to meet performance goals off the product. The design of the new system applies the use of a bundle of small fiber optics which is obtainable from many sources (Beshears 45-56), The working principle of HSL The hybrid lighting system collector (figure2) is a control board for sun tracking in figure 5. The most important function of the control board for solar tracking is calculating the position of solar based on its time, latitude and longitude. The solar location in the zenith and azimuth world based coordinate system controlled by the control board via a microcontroller installed in the board. Astronomical equations of US marine Observatory are computed by the microcontroller. The calculations help in the determination of the positions of the zenith and azimuth Earth based coordinate system by the use of universal time, longitudes and latitudes from a worldwide system receiver positioning. Track of 0.1accuracy is permitted due the precision (Beshears 45-56). There are two encoders in the collector systems which convert the coordinates to units that in turn help in the determination and detection of the collector’s location on each axis. Through the control panel, the sun-collector installed on the roof is capable of concentrating detectable sunshine into a group of fiber optics. The fiber optic then penetrates the roof through a collector mounting post which in return it is responsible for distribution of light from the sun to several hybrid luminaires within the storey building. The level of steady illumination in the building maintained by the use of modern luminaire that the mix sunlight and electrical radiance. Figure5.HSL collector source: (Beshears 45-56) The principle of operation of the controller is that it compares the real direction that is pointing to the position of the sun so as to enhance computation; and then determines whether the collector need to turn in either positive or negative direction that is matching to the position of the sun. If there is a condition or instruction that is sent to the collector’s microcontroller, then the motors are activated so as to move in a position and at a speed that is proportional to the difference in computed or actual positions. This course of action is continuously performed all along so as to keep track of the sun precisely. The control board can operate in a dc supply of 12v or 24v or by use of a PV solar cell with less than 2watts (Beshears 49). In a situation where there is much sunlight, the majority of the essential light is provided by the distribution that is fed by the fiber optic luminaires. However, in a situation where there is less or no sunlight the intensity of the light controlled by a sensor so as to maintain the required level of illumination (53). When the light is not needed in the building at all, the solar component can be switched off by setting the solar collector to a mode called off-sun. The hybrid lighting system separates diverse portions of sunlight as needed by a variety of applications. The graphs are shown below compare output of the spectrum produced by fluorescent, incandescent and hybrid lighting technologies. Figure6. Heat production comparison: incandescent, fluorescent and HSL technology source: (Beshears 45-56) Figure7. Controller board of HSL source: (Beshears 45-56) Classes of collectors There are three classes of collectors (A, B and C) as shown in table 2 below, in terms of optical characteristics. The first class (A) comprises solar collectors that have spherical surfaces. Class A is a type of sun collectors contain little span with span of 0.1mm. Class B collectors have their systems comprise of the parabolic mirror, and in the third class (C) they represent CMM conic solar collectors. B and C collector poses a good image eminence characteristic. They have complicated configuration, and they are expensive in terms of making than others, but the good thing is that they collect power that is three times the class A1 (Sansoni et al. 17-30). The A3 layout is a trade -off between the two solar collector types; since they have all their surfaces to be spherical but when it comes to the image quality, it is superb. The astral collect pupil’s diameters vary from 40m m - 70mm and optimization done from 400nm -1400 nm ethereal varieties. Figure8 shows instances of six optic systems. The fiber core in the diagram drawn as a dash loop, and the middle grey mark indicates the suns representation, two sideways dashed points indicate the mark size of r m s. Figure8. 6 collector’s images source: (Sansoni et al. 17-30). Table2. Features of the six optical configurations source: (Sansoni, et al 17-30) Classification Collector name Primary mirror Secondary mirror Other optical elements Max entrance pupil (mm) A1 Margin 1 Spherical Flat 40.0 A2 Margin 2 Spherical Spherical 52.0 A4 Margin 3 Spherical Spherical Correction lens 62.0 B1 Parabolic 1 Parabolic Flat 70.0 B2 Parabolic 2 with lens Parabolic Flat Spherical correction lens 71.1 C1 Conic CCM Elliptical Spherical 56.0 Enhanced tubular daylight guidance TDGS enhanced the initial development of hybrid lighting systems; this was an attempt to provide light at night. In this method, there is a combination of electrical illumination and daylight inside the guidance system relatively rather than its place of application. There have been many more developments in hybrid lighting systems that have come up (Mayhoub and Carter 264) Arthelio: This study led to the development of systems that combine electric light and sunlight from sulphur lamps. It also led into the assembly of big installation; with the first installation done in Milan in a warehouse as shown in figure9 (Mayhoub and Carter 267). The system uses a single axis light capture head based on a lens called Fresnel. Mirror of anabolic is used to reflect daylight to 13m long, span guide that is round and has a lining of prismatics substance. The system has a diffuse truncated cone-shaped component positioned at far end. The component is capable of delivering a sunlight operational flat surface which varies from 105-405 lux and depends on the season of the year. Two horizontal light prismatic guides that are powered by sulphur lamps connected, hence providing more uniform illuminance of 250 lux on work region by a control system that replaces the daylight as necessary. figure9. Warehouse Arthello (Mayhoub and Carter 261-276) Heliobus This system has many examples, but one suffices to illustrate the principle of operation. In figure 10 below shows, an example of a system that is partially lit by the use of a static mirror mounted on the roof. The reflector’s curving has the task of collecting and transmitting the biggest quantity of sunlight. A vertical prismatic light guide receives light, then light is distributed by a reflective diffusing extractor foil, over the whole surface to allow every floor receive the same amount of light (Mayhoub and Carter 261-276). Figure10. Heliobs image source: (Mayhoub and Carter 261-276) Hybrid solar lighting This system was developed by Oak Ridge National Laboratory; meant for use by public buildings in the United States where the radiation of direct solar is more that 4 Kwh/m/day and also a major design concern is the cold. The radio dish of daylight has a major span of 1.22 m spherical mirror for tracking solar with cryptic minor epitomize. The sunlight is delivered to the other side of the system thought a fiber optic, emitting acrylic rod found inside a usual electric luminaire; equipped with fluorescent bulbs that are dimmable (David 51). There is a control system that is responsible for tracking the sun; while the daylight levels are being monitored by the sensors; and the output of electrical light is being regulated by electronics dimming ballasts. End emission from the optic fiber is being used by the succeeding kind of luminaire and acts as a parabolic reflector lamp as in the distribution of light. Optical system for sunflowers In the sunflower plant, there are nine sunflowers; each flower contains eight solar collectors. Good stability and high level of stability required when it comes to assembling the solar collectors on the sunflowers. Conical mirror is installed so to allow coupling between the solar collector and optical fiber. It allows occurrence of possible misalignment when they mount or work. The introduction of the conical mirror helps to avoid misalignment of the entrance surface of fiber optic and the lens of the plane (Nair, Ramamurthy, and Ganesan 255). The figure below shows aspherical len coupling with a conical mirror and the optic filament. According to the figure the conical mirror should be placed behind the focus; this is because there is a convergence of those rays that emerge from the lens. The conical reflector improves the consistency of the ray and compensates the misalignment errors. So as to conduct the testing capability of the arrangement of the optical len the CM is applied to correct the system’s misalignment. Figure11. Conical mirror and optical fiber source: (Nair, Ramamurthy, and Ganesan 245-267) Calculations of converted solar energy by HLS The movement of the solar system for diverse hours is in the position of being calculated. The calculations can be possible by doing multiplications of the standard AM1.5G irradiance and the normalized values. In the collected sunlight part, receive power from the solar in two situations. The first situation is when the system of optics switching for solar energy saving, is switched off; whereby the whole spectrum of sunlight is reflected two times by the concentrator of the sunlight and focus directly to the solar cell. It can be represented by: (Sun, Tsuel, & Kuo, 495-503). Source: Sun, Tsuel, and Kuo 495-503. The next situation is when the system of optics switching for solar energy saving is put on. The PBS reflects the visible rays and then guides them to indoor lighting. The BPS can also transmit non visible rays to be collected by the solar cells. Conventional power from the sunlight; deliberated by the use of the following formulas. Source: Sun, Tsuel, and Kuo 495-503. Designing methods for HLS In the lighting industry, there is a common method standardized for collection of data, plan calculations and switch over. Daylight and electrical codes have set recommendation for equipments, a surface and illuminance property. According to a recent study, it is possible to propose tentative design methods for hybrid solar lighting based on the intensity distribution of luminous and the outputs of luminous flux (Mayhoub and Carter 261-276). There is a possibility of an external illuminance conditions when there is HLS estimate the luminous flux input. It is feasible to know the glacial arc and the luminous flux output for any calculation. HSL should be in a position to function at nighttime. Therefore, they must be designed in an electric system. The daylight function element under external conditions of the luminous flux outputs should be the displacement of the electric load, which are the provision of temporal illuminance variation. The two functions deserve additional work so as to do balancing of the remuneration of consumer fulfillment against the price of any improved electrical machine (Mayhoub and Carter 261-276). The future of HSL The use of artificial electrical lighting in commercial space costs the owners of buildings about $ 17 billion per annum (Núñez, Antón and G. Sala 222-224). In spite of the high consumption of electricity in electrical lightning, a conventional means of natural lighting has not been utilized fully since they illuminate only a small fraction of existing storey buildings. Architectural limitation is the biggest origin of limited exploit of ordinary daylight. Also, the nature of the sun is a limitation since it fluctuates and sometimes produces unwanted heat and glare. The outlook of solar lighting system is achievable. The countrywide trial programs that provide performance data and feedback from the users has been very crucial for this kind of solar technology. There has been a collaboration between university partners and the industry so as to reduce the costs of the component, increase the lifespan of the fiber optics and advancement of the system control. Research is being done on New -concrete (LED) luminaires so as to increase the efficiency of the HLS. Available resourceful segment of R&D for ORNL and the university and industry partners comprise the solar power utilization in hybrid solar lightening technology for production of hydrogen, heating water and space heating (Núñez, Antón, and Sala 221). The advantages of HLS The utmost users of electrical energy in lighting are the business building. Electricity generated near buildings through conventional power plants, causes air pollution in the building. Therefore, electrical energy is conserved by the use of HLS in high percentage to the existing daylight. The systems of full-spectrums solar have a lot of realistic and new opportunity large-ranging energy, economic profit and environmental friendly; since the HLS does not have IR component (Mayhoub and Carter 276). Advantages of hybrid lighting include: Possible leaks reduce since penetration in the roof is negligible and small. HLS are readily adjustable to multiple floors buildings which have moderately short ceiling height and inner walls. Although, at the moment optical fiber output is used on top two floors. Solitary systems of hybrid solar lighting give out sufficient daylight to illuminate numerous offices in a usual workplace block. Separation of UV and IR in sunlight is possible from the visible light, relatively is being transmitted into the office or house. There is a reduction of aeration, heating and air conditioning high voltage alternating current loads by 5 to 10% as compared to the convention electric illumination systems. Large area found between the drop ceiling and the roof (valuable plenum space) not needed. HLS is integrated easily into the current building design termed as a significant application. Also, the fiber optic can be easily rerouted to diverse areas as illumination requires change. Residents can control the intensity of disturbing sunlight by doing misalignment of the sun collector from the sunshine. Disadvantages of hybrid solar system The cost of the hybrid lighting system for a residential building is the terms of installation and maintenance is very high as compared to other conventional forms of electrical energy Another major setback of the hybrid solar lighting system is the geographic location; some parts of the globe receive fewer benefits of the solar systems. It does because of season revolutionize across the year. Hybrid solar systems are weather dependent; when there is no enough sunlight, the system does not work efficiently as little amount of light illuminated during that period. Another drawback of the hybrid solar lighting is that the technology has not been adapted in many countries hence getting installations technicians is hard since few people have trained in the systems Dust and water may leak into the fiber optics hence make the system inappropriate since the operation of the optical fiber is by reflection of light that doesn’t work appropriately in the absence of dust. Conclusion Many studies are being done in relation to optical systems for solar lighting. The modular components comprise of fiber optics, solar collectors, and electrical and mechanical systems for tracking the sun. The main component in this system is the concentrator of sunlight that is connected to the fiber optics for power transmission to the consumer. Analysis of hybrid solar lighting is being conducted with regards to efficiency of collection performance and characteristics of optical cable (Nair, Ramamurthy, and Ganesan 266). One of the most important areas of improvement in lightning inner buildings in few past days has been daylight guidance. Sunshine guidance has been interesting and eye-catching to the designer due to the wish to construct a less energy consumption building with better dispersion of sunshine. Daylight guidance has a big significance since they deliver natural light into inner parts of building ensure energy from the electrical light saved. Some of the hybrid solar systems can provide sufficient and large amount of daylight, and lit well a dark building. Hybrid solar lighting systems offer a very nice opportunities of transmitting light deeper into the building; no matter the floors without any bigger practical problems and setbacks, more so in the sector of fire precautions. Lighting practitioners have thrilling possibilities that are offered by HLS. They include- human response study in relation to hybrid lighting; developing a suitable design expansion criterion; design methods development; daylight guidance feasibility in various geographical areas; and economics that is long term for such systems (Mayhoub and Carter 253). Works Cited Beshears, David. "Hybrid solar lighting demonstration at the Sacramento municipal utility district customer service center." Energy Research and Development Division final project report 2 (2007): 45-56. Mayhoub, MS. and DJ Carter. "Hybrid Lighting Systems: Performance and Design." Lighting Research & Technology 44.3 (2012): 261-276. Academic Search Premier. Web. 20 June 2014. Nair, MG, K Ramamurthy, and AR Ganesan. "Classification of Indoor Daylight Enhancement Systems." Lighting Research & Technology 46.3 (2014): 245-267. Academic Search Premier .Web. 20 June 2014. "New Solar Lighting Is Nearing Market." ASHRAE Journal 49.7 (2007): 8. Academic Search Premier Web. 20 June 2014. Núñez, R., I. Antón, and G. Sala. "Hybrid Lighting-CPV. A New Efficient Concept Combining Illumination with CPV." AIP Conference Proceedings 1477.1 (2012): 221-224. Academic Search Premier. Web. 20 June 2014. Sansoni, P., et al. "Optical Design and Development f Fiber Coupled Compact Solar Collectors." Lighting Research & Technology 39.1 (2007): 17-30. 20 June 2014. Sun, W-S, C-H Tsuei, and C-C Kuo. "Calculating the Converted Solar Energy of Sunlight in The LED Hybrid Light Box Lighting System." Lighting Research & Technology 45.4 (2013): 495-503. Academic Search Premier. Web. 20 June 2014. Read More