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Harald Ries - One of the best experts on this subject based on the ideXlab platform.
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New high-flux two-stage optical designs for parabolic solar Concentrators
Solar Energy, 2004Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:Abstract We present a new two-stage optical design for parabolic dish Concentrators that can realistically attain close to 90% of the thermodynamic limit to concentration with practical, compact designs (e.g., at parabola rim half-angles of around 45°). For comparison, the parabolic dish-plus-compound parabolic Concentrator secondary design, at this rim angle, achieves no more than 50% of the thermodynamic limit. Our new secondary Concentrator is tailored to accept edge rays from the parabolic primary, and incurs less than one reflection on average. It necessitates displacing the absorber from the parabola's focal plane, along the Concentrator's optic axis, toward the primary reflector, and constructing the secondary between the absorber and the primary. The secondary tailored edge-ray Concentrators described here create new possibilities for building compact, extremely high flux solar furnaces and/or commercial parabolic dish systems.
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optical assessment of nonimaging Concentrators
Applied Optics, 2000Co-Authors: Andreas Timinger, Harald Ries, Abraham Kribus, Toni Smith, Markus WaltherAbstract:An optical measurement method for nonimaging radiation Concentrators is proposed. A Lambertian light source is placed in the exit aperture of the Concentrator. Looking into the Concentrator's entrance aperture from a remote position, one can photograph the transmission patterns. The patterns show the transmission of radiation through the Concentrator with the full resolution of the four-dimensional phase space of geometric optics. By matching ray-tracing simulations to the measurement, one can achieve detailed and accurate information about the geometry of the Concentrator. This is a remote, noncontact measurement and can be performed in situ for installed Concentrators. Additional information regarding small-scale reflector waviness and surface reflectivity can also be obtained from the same measurement with additional analysis.
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optical in situ analysis of secondary reflectors in solar tower plants
Journal De Physique Iv, 1999Co-Authors: Andreas Timinger, Harald Ries, Abraham Kribus, Toni Smith, Markus Walther, W Spirkl, P DoronAbstract:An optical measurement for radiation Concentrators is proposed. A Lambertian light source is placed in the exit aperture of the Concentrator. By taking pictures of the Concentrator as seen from a remote location one gets the transmission patterns which carry the information of transmission with the four-dimensional resolution of the phase space of geometric optics. By matching ray tracing simulations to the measurement, one can achieve detailed and accurate information about the geometry of the Concentrator. The reflectivity can he inferred by very simple means with 2% accuracy. This method has the potential to provide a handy tool to get automatically all optical information about a real size Concentrator in situ.
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compact high flux two stage solar collectors based on tailored edge ray Concentrators
Solar Energy, 1996Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:The recently-invented tailored edge-ray Concentrator (TERC) approach permits the design of compact two-stage high-flux solar collectors, with a focusing primary reflector and a non-imaging TERC secondary reflector. We present a new primary reflector shape based on the TERC approach and a secondary TERC tailored to its particular flux map, such that more compact Concentrators emerge at flux concentration levels in excess of 90% of the thermodynamic limit. Calculations and raytrace simulation results are also offered which demonstrate that V-cone approximations to a wide variety of TERCs attain the concentration of the TERC to within a few percent. These V-cones represent practical secondary Concentrators that may be superior to corresponding compound parabolic Concentrator or trumpet secondaries.
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compact high flux two stage solar collectors based on tailored edge ray Concentrators
SPIE's 1995 International Symposium on Optical Science Engineering and Instrumentation, 1995Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:Using the recently-invented tailored edge-ray Concentrator (TERC) approach for the design of compact two-stage high-flux solar collectors--a focusing primary reflector and a nonimaging TERC secondary reflector--we present: 1) a new primary reflector shape based on the TERC approach and a secondary TERC tailored to its particular flux map, such that more compact Concentrators emerge at flux concentration levels in excess of 90% of the thermodynamic limit; and 2) calculations and raytrace simulations result which demonstrate the V-cone approximations to a wide variety of TERCs attain the concentration of the TERC to within a few percent, and hence represent practical secondary Concentrators that may be superior to corresponding compound parabolic Concentrator or trumpet secondaries.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Jeffrey M. Gordon - One of the best experts on this subject based on the ideXlab platform.
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aplanatic optics for solar concentration
Optics Express, 2010Co-Authors: Jeffrey M. GordonAbstract:Aplanats are imaging optics that completely eliminate both spherical aberration and coma. They can fulfill the practical virtues of permitting sizable gaps between the absorber and the optic, as well as compactness. However, the ability of aplanats to efficiently approach the thermodynamic limit to flux concentration and optical tolerance had remained unrecognized. Both fundamental and applied aspects of dual-mirror aplanats are reviewed and elaborated, motivated by the exigencies of tenable, maximum-performance solar Concentrators, including examples from commercial Concentrator photovoltaics (CPV). Promising designs for future photovoltaic Concentrators are also identified, illustrating how pragmatic constraints translate into devising fundamentally new optics.
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New high-flux two-stage optical designs for parabolic solar Concentrators
Solar Energy, 2004Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:Abstract We present a new two-stage optical design for parabolic dish Concentrators that can realistically attain close to 90% of the thermodynamic limit to concentration with practical, compact designs (e.g., at parabola rim half-angles of around 45°). For comparison, the parabolic dish-plus-compound parabolic Concentrator secondary design, at this rim angle, achieves no more than 50% of the thermodynamic limit. Our new secondary Concentrator is tailored to accept edge rays from the parabolic primary, and incurs less than one reflection on average. It necessitates displacing the absorber from the parabola's focal plane, along the Concentrator's optic axis, toward the primary reflector, and constructing the secondary between the absorber and the primary. The secondary tailored edge-ray Concentrators described here create new possibilities for building compact, extremely high flux solar furnaces and/or commercial parabolic dish systems.
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optical designs for ultrahigh flux infrared and solar energy collection monolithic dielectric tailored edge ray Concentrators
Applied Optics, 1996Co-Authors: Robert P. Friedman, Jeffrey M. GordonAbstract:A new class of optical designs is developed for attaining ultrahigh flux in infrared and solar energy Concentrators. These Concentrators are required to satisfy simultaneously three criteria: (1) being monolithic, i.e., comprising a single piece of dielectric such that no mirrored surfaces or air spaces between Concentrator elements are introduced; (2) attaining at least 90% of the thermodynamic limit to concentration; and (3) being relatively compact, e.g., aspect ratios of the order of unity or less. Our inventions are rooted in the recently developed formalism of tailored edge-ray Concentrators.
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complementary construction of ideal nonimaging Concentrators and its applications
Applied Optics, 1996Co-Authors: Jeffrey M. GordonAbstract:A construction principle for ideal nonimaging Concentrators based on the complementary edge rays outside the nominal field of view is presented, with illustrations for the trumpet, compound parabolic Concentrator, and compound hyperbolic Concentrator. A simple string construction for the trumpet Concentrator is shown to follow from this observation—the trumpet having been the one ideal Concentrator for which no string-construction method had previously been noted. An application of these observations for solar Concentrator design when nonisothermal receivers are advantageous is also presented.
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compact high flux two stage solar collectors based on tailored edge ray Concentrators
Solar Energy, 1996Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:The recently-invented tailored edge-ray Concentrator (TERC) approach permits the design of compact two-stage high-flux solar collectors, with a focusing primary reflector and a non-imaging TERC secondary reflector. We present a new primary reflector shape based on the TERC approach and a secondary TERC tailored to its particular flux map, such that more compact Concentrators emerge at flux concentration levels in excess of 90% of the thermodynamic limit. Calculations and raytrace simulation results are also offered which demonstrate that V-cone approximations to a wide variety of TERCs attain the concentration of the TERC to within a few percent. These V-cones represent practical secondary Concentrators that may be superior to corresponding compound parabolic Concentrator or trumpet secondaries.
Robert P. Friedman - One of the best experts on this subject based on the ideXlab platform.
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New high-flux two-stage optical designs for parabolic solar Concentrators
Solar Energy, 2004Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:Abstract We present a new two-stage optical design for parabolic dish Concentrators that can realistically attain close to 90% of the thermodynamic limit to concentration with practical, compact designs (e.g., at parabola rim half-angles of around 45°). For comparison, the parabolic dish-plus-compound parabolic Concentrator secondary design, at this rim angle, achieves no more than 50% of the thermodynamic limit. Our new secondary Concentrator is tailored to accept edge rays from the parabolic primary, and incurs less than one reflection on average. It necessitates displacing the absorber from the parabola's focal plane, along the Concentrator's optic axis, toward the primary reflector, and constructing the secondary between the absorber and the primary. The secondary tailored edge-ray Concentrators described here create new possibilities for building compact, extremely high flux solar furnaces and/or commercial parabolic dish systems.
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optical designs for ultrahigh flux infrared and solar energy collection monolithic dielectric tailored edge ray Concentrators
Applied Optics, 1996Co-Authors: Robert P. Friedman, Jeffrey M. GordonAbstract:A new class of optical designs is developed for attaining ultrahigh flux in infrared and solar energy Concentrators. These Concentrators are required to satisfy simultaneously three criteria: (1) being monolithic, i.e., comprising a single piece of dielectric such that no mirrored surfaces or air spaces between Concentrator elements are introduced; (2) attaining at least 90% of the thermodynamic limit to concentration; and (3) being relatively compact, e.g., aspect ratios of the order of unity or less. Our inventions are rooted in the recently developed formalism of tailored edge-ray Concentrators.
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compact high flux two stage solar collectors based on tailored edge ray Concentrators
Solar Energy, 1996Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:The recently-invented tailored edge-ray Concentrator (TERC) approach permits the design of compact two-stage high-flux solar collectors, with a focusing primary reflector and a non-imaging TERC secondary reflector. We present a new primary reflector shape based on the TERC approach and a secondary TERC tailored to its particular flux map, such that more compact Concentrators emerge at flux concentration levels in excess of 90% of the thermodynamic limit. Calculations and raytrace simulation results are also offered which demonstrate that V-cone approximations to a wide variety of TERCs attain the concentration of the TERC to within a few percent. These V-cones represent practical secondary Concentrators that may be superior to corresponding compound parabolic Concentrator or trumpet secondaries.
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compact high flux two stage solar collectors based on tailored edge ray Concentrators
SPIE's 1995 International Symposium on Optical Science Engineering and Instrumentation, 1995Co-Authors: Robert P. Friedman, Jeffrey M. Gordon, Harald RiesAbstract:Using the recently-invented tailored edge-ray Concentrator (TERC) approach for the design of compact two-stage high-flux solar collectors--a focusing primary reflector and a nonimaging TERC secondary reflector--we present: 1) a new primary reflector shape based on the TERC approach and a secondary TERC tailored to its particular flux map, such that more compact Concentrators emerge at flux concentration levels in excess of 90% of the thermodynamic limit; and 2) calculations and raytrace simulations result which demonstrate the V-cone approximations to a wide variety of TERCs attain the concentration of the TERC to within a few percent, and hence represent practical secondary Concentrators that may be superior to corresponding compound parabolic Concentrator or trumpet secondaries.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Manuel Collarespereira - One of the best experts on this subject based on the ideXlab platform.
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a novel compound elliptical type Concentrator for parabolic primaries with tubular receiver
Solar Energy, 2016Co-Authors: Diogo Canavarro, Julio Chaves, Manuel CollarespereiraAbstract:Abstract The Parabolic Trough (PT) is the most used Concentrator in CSP (Concentrated Solar Power). However, this Concentrator technology is facing a significant challenge to increase its overall efficiency and cost-effectiveness. Meanwhile, other low-cost solutions such as Fresnel Concentrators are also being perceived as potentially attractive. In order to achieve the lower cost goal, new optical solutions can be considered, in parallel with improvements coming, for instance, through the use of new materials or manufacturing solutions. But conventional PTs can still be improved to yield, for instance, higher concentration values, a possible starting point for higher conversion efficiency. These new solutions, in turn, can also be useful for other technologies and applications (Fresnel Concentrators, Central Tower Receivers, etc.). However it is easier to develop and test these solutions in conjunction with parabolic primaries (continuum primary). And that is the topic of this paper: to present a new Compound Elliptical-type Concentrator for a parabolic primary with a tubular receiver. A comparison is made between this new Concentrator and two other Concentrators (a conventional PT Concentrator and a XX SMS (Simultaneous Multiple Surface) Concentrator), as well as a calculation of the total amount of collected energy (kW h) for a particular location, Faro (Portugal). The paper ends with a discussion of the results obtained, their impact and possible applications in the future.
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simultaneous multiple surface method for linear fresnel Concentrators with tubular receiver
Solar Energy, 2014Co-Authors: Diogo Canavarro, Julio Chaves, Manuel CollarespereiraAbstract:Abstract Linear Fresnel Concentrators (LFR) are known for their potential cost-effectiveness, reliability and wide range of possible solar applications. However, this technology is still facing the challenge of increasing its overall performance, especially in the Concentrated Solar Power (CSP) field where Parabolic Trough and Central Tower Receiver Concentrators are the predominant solutions. In order to increase the performance of conventional LFR Concentrators it is necessary to increase their optical performance as these Concentrators are still far from the theoretical limits of concentration. This paper presents a new Fresnel Concentrator designed with the Simultaneous Multiple Surface (SMS) method for two reflective (X) surfaces (Fresnel XX SMS) and with a tubular receiver. This design also promotes a good light uniformity on the receiver. A comparison is made between this new Fresnel XX SMS and two present day available Concentrators (a Fresnel with CPC (Compound Parabolic Concentrator) and a PT (Parabolic Trough) Concentrator), as well as a calculation of the total amount of collected energy (kW h), before thermal losses, for a particular location, Faro (Portugal). Furthermore, a new definition of CAP (Concentration Acceptance Product) is proposed, as the standard definition does not fully take into account the optical nature of LFR Concentrators. The paper ends with a discussion of the results obtained, their impact and possible applications in the future.
Pablo Benítez - One of the best experts on this subject based on the ideXlab platform.
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high performance fresnel based photovoltaic Concentrator
Optics Express, 2010Co-Authors: Pablo Benítez, Juan C. Miñano, Julio Chaves, Pablo Zamora, Ruben Mohedano, Aleksandra Cvetkovic, Marina Buljan, Maikel HernandezAbstract:In order to achieve competitive system costs in mass-production, it is essential that CPV Concentrators incorporate sufficient manufacturing tolerances. This paper presents an advanced Concentrator optic comprising a Fresnel lens and a refractive secondary element, both with broken rotational symmetry, an optic producing both the desired light concentration with high tolerance (high acceptance angle) as well as an excellent light homogenization by Kohler integration. This Concentrator compares well with conventional Fresnel-based CPV Concentrators.
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manufacturing tolerances for nonimaging Concentrators
Nonimaging Optics: Maximum Efficiency Light Transfer IV, 1997Co-Authors: Pablo Benítez, Ruben Mohedano Arroyo, Juan C. MiñanoAbstract:A 2D-error model for nonimaging Concentrators composed by multiple optical surfaces is presented. The Concentrator surfaces can be either dioptrics, sequential mirrors (as a conventional parabola) or non-sequential mirrors (i.e. CPC- like mirrors). Under the hypothesis of the model, the slope errors of all the surfaces can be transferred to entry aperture and combined there, and the effect of errors can be studied with a single probability density function as in the case of one-mirror Concentrators. A single number, the Concentrator error multiplier, is defined to characterize the Concentrator tolerance to errors. This number and the Concentrator acceptance angle are the key to analyze the error sensitivity of Concentrators. Finally the model is used to quantify the maximum tolerance on the Concentrators surfaces to guarantee a specified quality.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
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application of lorentz geometry to nonimaging optics new three dimensional ideal Concentrators
Journal of The Optical Society of America A-optics Image Science and Vision, 1996Co-Authors: Manuel Gutierrez, Juan C. Miñano, Carlos Vega, Pablo BenítezAbstract:A new family of three-dimensional ideal nonimaging Concentrators with rotational symmetry is presented. The flow-line Concentrator and the cone Concentrator are particular cases of this family. First, we looked for elliptic bundles of rays, i.e., bundles such that the subset of rays passing through any point of the space forms a cone with an elliptic base (this search was done with the Lorentz geometry formalism.) Second, the Concentrators, defined by their reflectors and receiver shapes, were derived from these elliptic bundles with the flow-line design method.
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application of lorentz geometry to nonimaging optics new 3d ideal Concentrators
SPIE's 1995 International Symposium on Optical Science Engineering and Instrumentation, 1995Co-Authors: Manuel Gutierrez, Juan C. Miñano, Carlos Vega, Pablo BenítezAbstract:A new family of 3D ideal nonimaging Concentrators with rotational symmetry is presented. The formulation has been done using Lorentz geometry. The flow line Concentrator and cone Concentrator appear as particular cases with this approach.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
