Design Concepts for a Spectral Splitting CPVT Receiver

2021

Self Cite

Concentrating photovoltaic-thermal (CPVT) collectors have to face the challenge of contrary temperature requirements in the single receiver parts. The PV cells require low temperatures to achieve high efficiency, whereas the thermal part should generate high temperatures for providing industrial heat. The approach of “Spectral Splitting” can offer a solution for compact CPVT receivers; however, a clear quantification of the expected conversion efficiency is difficult. Therefore, this paper describes a modelling methodology for obtaining electrical and thermal performance parameters for a Spectral Splitting configuration using semiconductor-doped glass combined with appropriate heat transfer fluid. The PV technologies c-Si, CIGS and CdTe are considered. The presented model yields distinct results for maximising the electrical efficiency, calculates the reduction in waste heat dissipation within the cells and assesses the impacts of concentration factor and cell temperature. An optimised configuration could be found with CIGS cells, impinged by a selected wavelength spectrum between 868 nm and 1100 nm, where the theoretical efficiency reaches 42.9%. The waste heat dissipation within the cells is reduced by 84.9%, compared to a full-spectrum operation. The depicted CPVT receiver design using bendable thin-film PV cells will be realised as a prototype in a subsequent project phase.

Section: Development Of a Novel Cpvt Receiver Designmentioning

confidence: 99%

Section: Modelling the Potential Gain Of Conversion Performancementioning

confidence: 99%

Electrical Efficiency Increase in CPVT Collectors by Spectral Splitting

2021

Self Cite

“…The authors of this paper are presently working on the development and experimental implementation of a compact CPVT receiver for a linear Fresnel concentrator, including spectral splitting via absorptive filtering. A detailed description of the completed receiver design process can be found in [15]. One of the novelties of their construction is the utilisation of bendable CIGS PV modules representing the electrical receiver part [16].…”

Section: Introductionmentioning

confidence: 99%

“…The receiver input plane is supposed to be planar for the current version of the optical model. However, as the currently available design concepts of the authors include a circular cross section of the CPVT receiver [15,16], this simplification needs to be revised in an ensuing version, in case the proposed receiver designs are implemented into a prototype.…”

mentioning

confidence: 99%

Optical Modelling of a Linear Fresnel Concentrator for the Development of a Spectral Splitting Concentrating Photovoltaic Thermal Receiver

2023

Concentrating photovoltaic thermal (CPVT) solar collectors can be regarded as a promising technology, as they are capable of providing renewable electricity and industrial heat simultaneously. The development of a novel CPVT receiver for a linear Fresnel concentrator requires detailed knowledge about the optical performance of the utilised mirror field. Therefore, this paper presents a generic optical model for such concentrating solar systems. The model was developed in MATLAB™ and calculates the sun’s position depending on the location, date and time. The subsequent geometrical computation of each mirror stripe angle is the basis for the detailed consideration of internal shading mechanisms that are typical for Fresnel mirror concentrators. Furthermore, the cosine losses are determined separately for each mirror. The outcomes of the developed model comprise the optical performance parameters of the considered Fresnel mirror field, such as the geometric efficiency, resulting irradiance in the receiver input plane, expected width of the focus image, concentration factor and total radiant flux impinging the receiver. Due to the chosen design of the model, its application is not limited to a particular kind of Fresnel concentrator. By contrast, all geometric parameters, such as the number of mirrors, the dimensions of the mirrors and the receiver, among others, can be freely adjusted.

“…According to the opinion of the authors, the constructive design of a spectral splitting CPVT receiver should not be too complex, because if this technology shall overcome its niche status on the long-term perspective, it must also be economically viable in the future. Therefore, the research work of the authors focusses on spectral splitting by selective absorption, because this approach appears to be promising for developing compact CPVT receivers with a high probability of being experimentally feasible [12,[16][17][18][19][20][21].…”

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confidence: 99%

State-of-the-Art of Concentrating Photovoltaic Thermal Technology

2023

Concentrating photovoltaic thermal (CPVT) technology has the potential to support the industrial sector with renewable electricity and heat simultaneously. The implementation of spectral splitting emerges as a possible approach to significantly increase the conversion efficiency, and furthermore, to hurdle the fundamental discrepancy of CPVT systems, that the electrical and the thermal receiver part have opposing temperature requirements. This paper provides an introductive description of beam splitting methodology and presents an updated review of the latest developments in the specific sector of spectral splitting by selective absorption. Furthermore, a novel CPVT receiver design utilizing bendable PV cells and an innovative heat transfer fluid are explained in detail. Simulation results illustrate the possibilities of spectral splitting to raise the electrical conversion efficiency in CPVT receivers by up to 42.9%. Potential improvements in receiver designs are discussed for further enhancement of the technical capabilities and possible cost reduction of the implemented material.