Classifications

• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
  • G02B19/0004—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed
  • G02B19/0019—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors)
  • G02B19/0023—Condensers, e.g. light collectors or similar non-imaging optics characterised by the optical means employed having reflective surfaces only (e.g. louvre systems, systems with multiple planar reflectors) at least one surface having optical power
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F24—HEATING; RANGES; VENTILATING
  • F24S—SOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
  • F24S23/00—Arrangements for concentrating solar-rays for solar heat collectors
• • G—PHYSICS
  • G02—OPTICS
  • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
  • G02B19/00—Condensers, e.g. light collectors or similar non-imaging optics
  • G02B19/0033—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use
  • G02B19/0038—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with ambient light
  • G02B19/0042—Condensers, e.g. light collectors or similar non-imaging optics characterised by the use for use with ambient light for use with direct solar radiation
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10F—INORGANIC SEMICONDUCTOR DEVICES SENSITIVE TO INFRARED RADIATION, LIGHT, ELECTROMAGNETIC RADIATION OF SHORTER WAVELENGTH OR CORPUSCULAR RADIATION
  • H10F77/00—Constructional details of devices covered by this subclass
  • H10F77/40—Optical elements or arrangements
  • H10F77/42—Optical elements or arrangements directly associated or integrated with photovoltaic cells, e.g. light-reflecting means or light-concentrating means
  • H10F77/488—Reflecting light-concentrating means, e.g. parabolic mirrors or concentrators using total internal reflection
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/40—Solar thermal energy, e.g. solar towers
  • Y02E10/44—Heat exchange systems
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E10/00—Energy generation through renewable energy sources
  • Y02E10/50—Photovoltaic [PV] energy
  • Y02E10/52—PV systems with concentrators

Definitions

• the invention relates to a concentrator arrangement with a multiplicity of solar cells and with a plate made of a transparent material with a refractive index of more than 1.45, which has a flat upper side and a lower side, with a concentrator structure made of trough-shaped non-imaging concentrator elements with parabolically curved side walls connected is.
• the object of the invention is to create a concentrator arrangement of the type mentioned at the outset, which is distinguished by a higher concentration factor.
• the concentrator elements have parabolic curved mirror surfaces pointing in all four directions.
• FIG. 2 shows a concentrator arrangement according to the invention with a two-stage concentration in a perspective view
• FIG. 6 shows a concentrator arrangement with several concentrator elements according to FIG. 5, which are connected to one another by a plate,
• a static concentrator 1 of known type is shown, which has the shape of a trough and allows a one-dimensional concentration.
• the static concentrator 1 has a parabolic curved left side wall 2 and a likewise parabolic curved right side wall 3.
• the side walls 2, 3 have a distance d ⁇ at their upper edges and approach at their lower edges a distance d 2 .
• the side walls 2, 3 are mirrored.
• the static concentrator shown in FIG. 1 is oriented in the east-west direction, so that the end faces 4, 5 face east or west and the side walls 2, 3 face north or south.
• the concentrator 1 is rotated about its longitudinal axis running parallel to the side walls 2, 3 in order to achieve an orientation of the concentrator to the south with an optimal inclination. This inclination corresponds to the latitude of the installation site.
• the bottom of the static concentrator 1 shown in FIG. 1 is covered with a plurality of solar cells 6, which utilize the direct and diffuse solar light captured by the static concentrator 1 by means of photovoltaic energy conversion.
• n the refractive index of the medium in front of the concentrator
• n 2 the refractive index of the medium inside the concentrator
• ⁇ - is the opening angle of the rays at the entrance aperture and ⁇ «the opening angle of the radiation at the exit aperture.
• a static concentrator In order to receive as much direct solar radiation as possible, a static concentrator must have a large opening angle, which may be smaller in the north-south direction than in the east-west direction. In the north-south direction, the reception area must extend on the one hand to the upper culmination point of the sun, and on the other hand close to the southern horizon. In the case of staggered collectors or concentrators, the limitation can be at the lower culmination point of the sun. In the east-west direction, however, the opening angle must be 180 °.
• d- and d- mean the above-mentioned distances between the side walls 2, 3 and the widths of the concentrator 1 at the entrance aperture and the exit aperture surface.
• FIG. 2 shows a two-stage concentrator arrangement 1.0 according to the invention, which makes it possible to achieve a substantially higher static concentration while maintaining the aperture angle distribution.
• a two-stage concentration is carried out in a refractive medium.
• the two-stage concentrator arrangement 10 has a plate 11 made of transparent material with a Refractive index n that is greater than 1.45.
• the plate 11 is flat on the top 12 facing the incident radiation and optically and mechanically connected to a structure 13 for the non-imaging concentration of light on the side opposite the top 12.
• the structure 13 brings about a two-stage concentration of the light in linear-one-dimensional first stages 14 and two-dimensional second stages 15.
• the first stages 14 have the shape shown in FIG. 1 of a trough formed from glass or plastic.
• a plurality of second stages 15 are optically and mechanically coupled to the exit aperture surface of the first stages, which also have parabolic curved side walls 16 and 17 shown in FIG. 3 and parabolic front walls 18 and rear walls 19 which can be seen in FIG.
• the lower edges of the side walls 16, 17 and the front walls 18 and the rear walls 19 each end on a floor surface 20 which is optically coupled to a solar cell 21.
• the first steps 14 have rectangular entry apertures and rectangular exit apertures, while the touching second steps 15 have square entry and exit apertures.
• the second stages 15 are therefore not exactly radially symmetrical, which leads to a slight loss of concentration.
• this is expedient since on the one hand the aperture area can only be filled with square or rectangular structures, and on the other hand the solar cells 21 are square.
• This divergence can be increased to 90 ° by a two-dimensional concentration.
• this is achieved in that in the linear first stages 14 the north-south rays are brought to the same divergence as the east-west rays (by decomposition into vertical components) this consideration also for all obliquely incident rays).
• A. and A 2 are the entrance and exit aperture surfaces assigned to the second stages 15.
• the second stages 15 can consist of a transparent material with a refractive index n 2 that is greater than the refractive index n- of the transparent material of the first stages 14. This is important because little material is used and materials with a higher refractive index are usually expensive. In this case, the condition for the second stages is 15
• the opening angle ⁇ - of the first stages 14 is selected such that when the concentrator arrangement 10 is oriented to the south with an optimal inclination, the position of the sun at the highest point of the sun still falls within the acceptance range and the other limitation of the opening angle contains at least the minimum culmination point of the sun.
• the concentration factor C the second, two-dimensional stage 15 is selected such that C 2 - n 2 applies.
• first stages 14 are made of a material with a refractive index n and the second stages 15 are made of another material with a
• Refractive index n 2 are produced, which is larger than that
• the plate 11 is rectangular and has a flat front side. On the back there are many linear structures of the first stage 14 arranged next to one another, at the outlet openings of which there are contacting elements of the second stages 15.
• the plate 11, the first steps 14 and the second steps 15 can, in particular if they are made of a material with the same refractive index, can be made in one piece. If different materials are used, the individual stages 14, 15 are connected to one another in such a way that the best possible optical coupling is produced. A gradual change in the refractive index can also be provided in a transition region in order to avoid reflections.
• FIG. 5 shows a single concentrator for a one-stage version, the end faces 4 and 5 of which are like that Front walls 18 and 19 of the second stages 15 are curved parabolically.
• these structures can be connected to a continuous plate 11, which is illustrated in FIG. 6 and does not change the optical conditions.
• Steps 15 rectangular concentrators 22 can, as in
• Fig. 7 illustrates, can be realized with two materials 23, 24, whose refractive indices n 1 and ⁇ x ? are.
• FIG. 8a, 8b and 8c show contact geometries for the solar cells 21 in connection with the outlet apertures of the concentrator arrangement 10. Since the metal contacts of the solar cells 21 shield the radiation, they cause losses. For this reason, the contact grid areas are kept as small as possible. Static concentrators of the type described above offer the possibility of minimizing the shielding by the discharge grid 25 of the solar cells 21 by arranging the current contacts 26 (busbars) outside the illuminated areas of the solar cells 21, as illustrated in FIG. 8.
• 8a shows the course of the current busbar 26 outside the circumference of the lower end of a second stage 15.
• FIG. 8b shows a plan view of the solar cell 21 before being attached to the second stage 15.
• FIG. 8c shows a design option for one rectangular solar cell 21, which is used together with a concentrator 22.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Sustainable Development (AREA)
• Sustainable Energy (AREA)
• Toxicology (AREA)
• Health & Medical Sciences (AREA)
• Thermal Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Photovoltaic Devices (AREA)
• Optical Elements Other Than Lenses (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 1987
  • 1987-12-08 DE DE19873741477 patent/DE3741477A1/de active Granted
• 1988
  • 1988-11-07 US US07/392,976 patent/US4964713A/en not_active Expired - Fee Related
  • 1988-11-07 JP JP63508725A patent/JPH02502500A/ja active Pending
  • 1988-11-07 WO PCT/DE1988/000688 patent/WO1989005463A1/de not_active Application Discontinuation
  • 1988-11-07 EP EP88909974A patent/EP0347444A1/de not_active Ceased

Non-Patent Citations (1)

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