Distribution of electrical power pdf

The PPF distribution in the horizontal plane 40 cm from the lighting panel for indirect light delivery A second set of tests was conducted in which op- involved; and 2 non-uniformity of the PPF was sig- tical fibers were inserted at the lighting panel verti- nificant because each fiber in the cable tends to carry cally see Fig.

In this case 36 fibers from coefficient of variance of the data were also high one concentrator were inserted horizontally into the as shown in Fig. Results summarized in Table trough lighting panel Fig. A summary of the data is given in Table were the same for both cases. One technical differ- 7. This was caused by the fact that the light output from the Xe arc light source was Xe Arc Lamp Lighting Data close to parallel beams.

Because of this, the reflected light was primarily directed to the left without going PPF distribution and internal chamber lighting effi- through multiple reflections. Figure The Hot Mirror placed between the light source and the lighting chamber efficiency for this configuration us- fiber optic cable to characterize the ability to remove ing the Xe arc lamp is The hot mirror attenuated wave- light sources were taken between and nm lengths between and nm, thereby reducing at 2 nm intervals.

Measurements were made with the overall irradiant heat load to the chamber. The difference between the PAR wavelengths 20, As the non-PAR photons do not contribute without the hot mirror filter. Spectral characteristics of solar light in the lighting chamber with and without a hot mirror placed between the light source and the optical fiber cable regime is a thermal burden to the system.

The tegration and evaluation of a laboratory model of difference between the PAR with and without the the solar plant lighting system for controlled envi- hot mirror is due to the Fresnel reflections on the ronment crop production.

The PAR Ph. Nakamura is were compatible with plant lighting requirements. The lighting efficiency, i. The system is based on the use of optical fi- difference from solar light with regard to PPF dis- bers for transmission of solar radiation, the concept tribution and the filter screened spectral character- Dr. Nakamura pioneered in while he was at istics. Following Placing a hot mirror filter between the light source his graduate work, Mr.

Van Pelt joined New Focus, and the inlet of the optical fiber cable significantly Inc. This clearly shows the lasers and related optoelectronics. At Physical Sci- feasibility of reducing the thermal input to a plant ences Inc.

Incorporation of direct solar lighting schemes for plant growth should significantly re- Neil C. Yorio earned a B. Alan Drysdale has a B. Drysdale, A. Re-evaluation of plant lighting cal systems. He has developed computer models for a bioregenerative life support system on the Moon. ICES ; Optimizing a plant habitat for analysis.

He is currently a consultant in life support space. ICES, ; Hoffman, S. Ray Wheeler is a plant physiologist in the Biological 6. Kato, D. Ray received a B. Cariou, J. Transport of solar versity. Solar Energy 29 5 ; as a postdoctoral associate in the Department of Theoretical limits of Horticulture at the University of Wisconsin and as optical fiber solar furnace.

Kennedy Space Center. His research interests over 9. George, D. A fiber optic lighting sys- the years have included plant canopy gas exchange tem for horticultural production.

Paper American studies, plant response to lighting, plant responses Society of Agricultural Engineers, St.

Joseph, MI; Mori, K. Photoautotrophic bioreactor using visible solar to CO2, and hydroponics. John C. Sager is senior biological engineer for Space Res.

Gilmore, V. Sunflower over Tokyo. Popular Sci. Nakamura, T. Optical waveguide solar light- at Johnson Space Center. Sager received his ing system for space-based plant growing. Pennsylvania State University in Agricultural En- Optical waveguide gineering. He has served on several academic ad- solar energy system for lunar material processing. He previously was em- space. Cuello, J.

Hybrid solar and artificial lighting for space life engineer in developing controlled environment support. Since joining Optical components for space-based solar plant lighting — development and NASA in , he has focused on developing the evaluation of key components. Paper , 32nd enabling technologies and components for regenera- International Conference on Environmental Systems, San tive life support system development. Antonio, TX; July Solar plant lighting with electric power generation.

MacElroy, R. Life support Multi-use solar thermal system for oxygen production from systems for Mars transit. July Wheeler, R. Deitzer, G. In: Tibbitts, T. International Lighting Plant growth and human life support for space travel. Wheeler4, and John C. Sager4 1 Physical Sciences Inc. In this system, solar light, or light from an electric lamp, is collected by reflector optics and focused on the end of an optical waveguide cable. The lighting capability of the system was evaluated for solar and electric light sources.

Based on the results we conclude that the solar plant lighting system with a supplemental electric light source is a viable and effective concept for space based crop production. Plants would also be useful tem using traditional electrical lighting approaches for transit missions, where a relatively small crop 3, 4.

Reference Mission for Mars Exploration calls for Larger plant production systems e. To date, eration and water processing 2. Lighting is one electrical lighting has been used for most of the Corresponding author: Takashi Nakamura, Physical Sciences Inc. For plant growth to troduction of heat into the plant growth chamber. This paper describes the development The rejected non-PAR solar spectra can be con- of a plant lighting system which collects, transmits verted to electric power by low band-gap PV cells.

The sources for biomass production in exploration mis- system concept discussed here is the outgrowth of sions. In the work conducted three decades ago, the authors showed that fused-silica-core optical fibers SYSTEM CONCEPT can effectively be employed in the transmission of solar radiation for photovoltaic, thermal and light- A schematic representation of the system is given ing applications.

After the above mentioned work, in Fig. In this system, solar light, or light from there have been a number of studies during s in Figure 1. The Optical Waveguide OW system which optical fibers have been used to transmit solar OW solar energy system for materials process- radiation for thermal processing 7, 8 , plant light- ing The prototype system which PSI de- ing and illumination The system consists of two solar tracking units, each of which is equipped with two in.

At the focal point of each concentrator is an optical fiber cable 10 m long , To evaluate the effectiveness of the system con- consisting of 37 optical fibers 1. We utilized this tor; 2 the electric light source; 3 the optical wave- prototype system for the Phase I work reviewed in guide cable; and 4 the lighting panel. A brief dis- this paper. Xenon Xe short-arc lamp rated for 1. Jacket Material Tefzel 1. Selective Optical Filters Used for the Program Optical Waveguide Cable Lighting Panel The optical waveguide cables are composed of Several lighting panel configurations were de- step-index, multimode fused silica-core optical fibers.

Figure 3 depicts Table 1 summarizes the properties of the optical fi- the mechanism of integrating optical fibers into ber for the cable. The transmission efficiency of the the lighting panel for indirect light delivery. The lighting panel for this space qualified optical waveguide cable An alternative approach allowed Selective spectral rejection can be readily achieved direct lighting by connecting 36 optical fibers to by using filters.

Several commercially available fil- the trough vertically as shown in Fig. The inner ters meet the spectral cut-off requirements of this reflective surface of the trough for both approach- system.

The chamber was 32 inches 81 centrator, optical fiber cable and the lighting cham- cm tall, 16 inches 41 cm wide and 16 inches 41 ber is shown in Fig. One concentrator of the PSI cm deep. It was made of acrylic plate with alumi- system was connected to the lighting chamber via nized Mylar surface inside of the chamber.

A height- an optical fiber cable consisting of 37 fibers 36 fi- adjustable shelf inside of the chamber was used for bers connected to the illuminator panel with one lighting uniformity measurements at several dis- tances from the lighting panel. Figure 3. Optical fibers emitting light horizontally into the Figure 4. The laboratory model consisting of the solar concentrator, the optical fiber cable and the lighting chamber fiber for diagnostic measurement.

In addi- lighting, were conducted. The lighting measure- tion to the solar lighting source, we also utilized ments were made using the instruments summarized the Xe arc lamp light source for performance char- in Table 4. Table 3 summarizes the char- A photograph of the trough lighting panel inside acteristics of the laboratory model.

For the solar of the lighting chamber is shown in Fig. With an area inside lighting box of 0. At were made at 10 cm, 20 cm and 40 cm from the light- each distance from the lighting panel, the average ing panel. At each height, the sensor was placed at PPF, standard deviation and coefficient of variance 49 locations on the target plane to map the intensity were calculated from the 49 locations on the base distribution. Figure 7 shows the PPF distribution plate.

The lighting chamber efficiency is defined as plot over the base plate at a distance of 10 cm from the ratio of the PAR photons reaching the measure- the illuminator plate. The trough direction Fig. The total power optical fibers into the chamber.

Note that the PPF is slightly lower on chamber; 2 the distance between the lighting panel the right due to the fiber-trough configuration. This and the sensor plane increases the uniformity of the phenomenon can be explained as follows.

As shown PAR flux; and 3 the wall absorption loss becomes in Fig. The PPF distribution in the horizontal plane 10 cm from the lighting panel for indirect light delivery Figure 8. Figure 9. The PPF distribution in the horizontal plane 40 cm from the lighting panel for indirect light delivery A second set of tests was conducted in which op- involved; and 2 non-uniformity of the PPF was sig- tical fibers were inserted at the lighting panel verti- nificant because each fiber in the cable tends to carry cally see Fig.

In this case 36 fibers from coefficient of variance of the data were also high one concentrator were inserted horizontally into the as shown in Fig. Results summarized in Table trough lighting panel Fig. A summary of the data is given in Table were the same for both cases. One technical differ- 7. This was caused by the fact that the light output from the Xe arc light source was Xe Arc Lamp Lighting Data close to parallel beams. Because of this, the reflected light was primarily directed to the left without going PPF distribution and internal chamber lighting effi- through multiple reflections.

Figure The Hot Mirror placed between the light source and the lighting chamber efficiency for this configuration us- fiber optic cable to characterize the ability to remove ing the Xe arc lamp is The hot mirror attenuated wave- light sources were taken between and nm lengths between and nm, thereby reducing at 2 nm intervals.

Measurements were made with the overall irradiant heat load to the chamber. The difference between the PAR wavelengths 20, As the non-PAR photons do not contribute without the hot mirror filter.

Spectral characteristics of solar light in the lighting chamber with and without a hot mirror placed between the light source and the optical fiber cable regime is a thermal burden to the system.

The tegration and evaluation of a laboratory model of difference between the PAR with and without the the solar plant lighting system for controlled envi- hot mirror is due to the Fresnel reflections on the ronment crop production.

The PAR Ph. Nakamura is were compatible with plant lighting requirements. The lighting efficiency, i. The system is based on the use of optical fi- difference from solar light with regard to PPF dis- bers for transmission of solar radiation, the concept tribution and the filter screened spectral character- Dr.

Nakamura pioneered in while he was at istics. Following Placing a hot mirror filter between the light source his graduate work, Mr. Van Pelt joined New Focus, and the inlet of the optical fiber cable significantly Inc. This clearly shows the lasers and related optoelectronics. At Physical Sci- feasibility of reducing the thermal input to a plant ences Inc. Incorporation of direct solar lighting schemes for plant growth should significantly re- Neil C.

Yorio earned a B.