Query: Challenges in the design of concentrator photovoltaic (CPV) modules to achieve highest efficiencies

Candidate papers:

abstract: Concentrator photovoltaics (CPV) is a special high efficiency system technology in the world of PV technologies. The idea of CPV is to use optical light concentrators to increase the incident power on solar cells. The solar cell area is comparatively tiny, thus saving expensive semiconductor materials and allowing the use of more sophisticated and more costly multi junction solar cells. The highest CPV module efficiency achieved is 38.9% This CPV module uses four junction III V based solar cells. Moreover, mini modules have already achieved an efficiency of 43.4% The interaction between optics, cells, and layout of the module and tracker determines the overall field performance. Today, some utility scale CPV plants are installed. The CPV technology allows for many technical solutions for system designs and for optimizing performance while maintaining the economics. This paper will review the achievements and discuss the challenges for the CPV module technology and its components. We discuss the different components and the most important effects regarding the module design. Furthermore, we present the module designs that have shown the highest efficiencies.Concentrator photovoltaics (CPV) is a special high efficiency system technology in the world of PV technologies. The idea of CPV is to use optical light concentrators to increase the incident power on solar cells. The solar cell area is comparatively tiny, thus saving expensive semiconductor materials and allowing the use of more sophisticated and more costly multi junction solar cells. The highest CPV module efficiency achieved is 38.9% This CPV module uses four junction III V based solar cells. Moreover, mini modules have already achieved an efficiency of 43.4% The interaction between optics, cells, and layout of the module and tracker determines the overall field performance. Today, some utility scale CPV plants are installed. The CPV technology allows for many technical solutions for system designs and for optimizing performance while maintaining the economics. This paper will review the achievements and discuss the challenges for the CPV module technology and its components. We discuss the differen.
author_names: Maike Wiesenfarth

Ignacio Anton

Andreas W Bett
title: Challenges in the design of concentrator photovoltaic (CPV) modules to achieve highest efficiencies
year: 2018

abstract: The world's oldest, and still functional, Concentrator Photovoltaic (CPV) power plant originally rated at 350 kW, and is situated 50 km from Riyadh, Saudi Arabia. There are ongoing efforts to retrofit the modules with new secondary optics and triple junction cell devices. The paper characterizes the initial optical train, whose design is non conventional in its use of a two area primary Fresnel lens. The first generation of a retrofit receiver package is described. Challenges beyond the optical design are encountered, including tracking and structural mechanics.The world's oldest, and still functional, Concentrator Photovoltaic (CPV) power plant originally rated at 350 kW, and is situated 50 km from Riyadh, Saudi Arabia. There are ongoing efforts to retrofit the modules with new secondary optics and triple junction cell devices. The paper characterizes the initial optical train, whose design is non conventional in its use of a two area primary Fresnel lens. The first generation of a retrofit receiver package is described. Challenges beyond the optical design are encountered, including tracking and structural mechanics.
author_names: Hussameldin I Khonkar

Fahad Radhi Alharbi

Abdulaziz Alyahyah

David C Miller

R K Leutz
title: Optical element design for the retrofit of the world's first concentrator photovoltaic (CPV) power plant
year: 2019

abstract: Abstract A new configuration of a photovoltaic module and a solar thermoelectric generator in a hybrid system integrated with a microchannel heat sink has been developed. The photovoltaic module and the solar thermoelectric generator sandwich the microchannel heat sink, as they are exposed to concentrated solar radiation. This newly developed hybrid system is compared to that with a conventional configuration in which an ordinary thermoelectric generator is attached directly to the rear surface of the concentrator photovoltaic module. To evaluate the performance of the new system in comparison to the conventional one, an all inclusive three dimensional thermo fluid thermoelectric model has been developed. This model is numerically simulated and is validated with both experimental and numerical results. The findings of this study show that the new system generates more output power and can be operated at higher concentration ratios with even lower average solar cell temperatures than the conventional system. In the new configuration, the average solar cell temperature is approximately 77 degC and the total electrical output power is approximately 3.2 kW/m2 at a solar concentration ratio of 20 suns. However, the maximum possible working concentration ratio for the conventional design is 10 suns, where the solar cell temperature approaches the highest tolerable temperature of approximately 90 degC. Moreover, the total electrical output power is approximately 1.2 kW/m2. Furthermore, it is found that at CR_PV 20, the rate of the produced thermal energy is approximately 12 kW/m2, for the conventional design while the new design achieves 15, 22, and 30 kW/m2 for CR_STEG of 1, 10, and 20, respectively. These findings have greatly aided in identifying a new design that achieves the highest performance under concentrated solar irradiance.
author_names: Ahmed Abdo

Shinichi Ookawara
title: Performance evaluation of a new design of concentrator photovoltaic and solar thermoelectric generator hybrid system
venue: Energy Conversion and Management
year: 2019

abstract: Abstract Dense array concentrator photovoltaic (DA CPV) system is facing large mismatch losses due to the highly concentrated non uniform radiation. In this paper, a novel rotational symmetry (RS) connection approach with two examples is proposed to reduce mismatch losses. The output performances of the two RS connections are compared with that of four conventional connections by using a two stage simulation method. The results indicate that under different illumination distributions and CPV cell's series resistances, the RS connection approach can dramatically reduce power losses. The proposed dichotomic rotational symmetry (DRS) and quartered rotational symmetry (QRS) connections can significantly improve the output characteristics of DA CPV modules. Compared with the conventional series parallel (SP) connections, the DRS and QRS connections can improve the conversion efficiency by at most 48% and 64.3% respectively. Meanwhile, the QRS connection exhibits smoother I V and P V curves, reducing the difficulty of system's maximum power point tracking (MPPT) and improving the stability of output performance with varying Gaussian illuminations. When considering the Joule heat losses generated from the series resistance of CPV cells, the RS connections can also achieve much higher conversion efficiencies than other conventional configurations.
author_names: Xinyu Pan

Xing Ju

Chao Chen Xu

Xiaoze Du

Yongping Yang
title: A novel rotational symmetry (RS) connection approach for dense array concentrator photovoltaic (DA CPV) modules
venue: Energy Conversion and Management
year: 2019

abstract: In this paper, we present a design and optical simulation of a novel linear Fresnel lens. The lens can be applied to a concentrator photovoltaic (CPV) system as a primary optical element (POE) to increase the concentration ratio and improve the uniformity of irradiance distribution over the receiver. In addition, the CPV system can use the proposed lens as a concentrator without involving a secondary optical element (SOE) The designed lens, which is a combination of two linear Fresnel lenses placed perpendicular to each other, can collect and distribute the direct sunlight on two dimensions. The lens is first designed in the MATLAB program, based on the edge ray theorem, Snell's law, and the conservation of the optical path length, and then drawn in three dimensions (3D) by using LightToolsTM. Furthermore, in order to optimize the structure and investigate the performance of the lens, the ray tracing and the simulation are also performed in LightToolsTM. The results show that the newly designed lens can achieve a high concentration ratio of 576 times, a high optical efficiency of 82.4% an acceptable tolerance of 0.84deg, and high uniform irradiance of around 77% for both horizontal and vertical investigation lines over the receiver.
author_names: Thanh Tuan Pham

Ngoc Hai Vu

Seoyong Shin
title: Novel Design of Primary Optical Elements Based on a Linear Fresnel Lens for Concentrator Photovoltaic Technology
venue: Energies
year: 2019

abstract: Concentration photovoltaic (CPV) modules promise a more efficient, higher power output than traditional photovoltaic modules. This is achieved by concentrating sunlight onto a small 1 cm2 concentrator triple junction (CTJ) InGaP/InGaAs/Ge cell by using high quality precision optics. In order to achieve high energy performance and reliability, well thought out design decisions must be made in the development of a CPV module. This paper investigates the design of two CPV modules (Module I and II) which are based on the Sandia III Baseline Fresnel module. The investigation concentrated on the effect of the optimization of the optical design on the electrical performance characteristics of CTJ cells with good thermal dissipation. The best performance achieved by Module I was at 336 times operational concentration (Xo) which produced a Pmax of 10.29 W per cell, with cell and module efficiencies of 39% and 24% respectively. In the development of the second module (Module II) pre deployment criteria such as the CTJ cell and system components characteristics was used to eliminate faulty components from the system what was observed in Module I. Cell units that were optimized in Module II showed no form of degradation in their Current Voltage (I V) characteristics. The cell unit operating under optical misalignment showed a progressive degradation with long term operation in the field.
author_names: R D Schultz

E Ernest van Dyk

F J Vorster
title: The optical design and performance of a concentrator photovoltaic module
year: 2017

abstract: Despite its highest efficiency, concentrated photovoltaic (CPV) technology is still finding its way into the current photovoltaic market which is saturated with conventional flat plate photovoltaic systems. CPV systems have a great performance potential as they utilize third generation multi junction solar cells. In the CPV system, the main aspect is its concentrating assembly design which affects not only its overall performance but also its operation and fabrication. Conventional CPV design targets to use individual solar concentrator for each solar cell. The main motivation of this chapter is to propose a novel concentrating assembly design for CPV that is able to handle multiple solar cells, without affecting their size, using single solar concentrator. Such proposed design, named as multicell concentrating assembly (MCA) will not only reduce the assembly efforts during CPV module fabrication, but it will also lower the overall system cost with simplified design. In this chapter, a detailed design methodology of multicell concentrating assembly (MCA) for CPV module is presented and developed with complete verification through ray tracing simulation and field experimentation.
author_names: Muhammad Burhan

Muhammad Wakil Shahzad

Kim ChoonNg
title: Multicell Design for Concentrated Photovoltaic (CPV) Module
year: 2018

abstract: This paper presents the project Concentrating Photovoltaic modules using advanced technologies and cells for highest efficiencies (CPVMatch) which is funded from the European Union's Horizon 2020 research and innovation programme. V multi junction solar cells and CPV modules. Concerning cells, novel wafer bonded four junction solar cells made of GaInP/GaAs//GaInAs/Ge are optimized with the target of reaching 48% efficiency under concentration at the end of the project. Moreover, multi junction solar cell technologies with advanced materials like ternary IV element mixtures (i.e. SiGeSn) and nanostructured anti reflective coatings are investigated. Concerning CPV modules the project focuses on both Fresnel based and mirror based technologies with a target efficiency of 40% under high concentrations beyond 800x. Achromatic Fresnel lenses for improved light management without secondary optics are investigated. In addition, smart, mirror based HCPV modules are developed, which include a new mirror based design, the integration of high efficiency, low cost DC/DC converters and an intelligent tracking sensor (PSD sensor) at module level. A profound life cycle and environmental assessment and the development of adapted characterization methods of new multi junction cells and HCPV modules complete the work plan of CPVMatch.This paper presents the project Concentrating Photovoltaic modules using advanced technologies and cells for highest efficiencies (CPVMatch) which is funded from the European Union's Horizon 2020 research and innovation programme. V multi junction solar cells and CPV modules. Concerning cells, novel wafer bonded four junction solar cells made of GaInP/GaAs//GaInAs/Ge are optimized with the target of reaching 48% efficiency under concentration at the end of the project. Moreover, multi junction solar cell technologies with advanced materials like ternary IV element mixtures (i.e. SiGeSn) and nanostructured anti reflective coatings are investigated. Concerning CPV modules the project focuses on both Fresnel based and mirror based technologies with a target efficiency of 40% under high concentrations beyond 800x. Achromatic Fresnel lenses for improved light management without secondary optics are investigated. In addition, smart, mirror based HCPV modules are developed, which include a new mirror based
author_names: Simon P Philipps

Mathieu Baudrit

Karla Hillerich

Valentine Moreau

Rolando Parmesani

Eduardo Roman

Gabriel Sala

Bernd Schineller

Gianluca Timo

Andreas W Bett
title: CPVMatch Concentrating photovoltaic modules using advanced technologies and cells for highest efficiencies
year: 2016

abstract: Concentrator Photovoltaic Thermoelectric (CPV TE) hybrid devices have the potential to address areas of limitation within concentrator photovoltaic devices, using the inherent flexibility and controllability of thermoelectrics. In this work, a full CPV TE module was designed and fabricated using commercial Primary and Secondary Optical Elements (POEs and SOEs respectively) The SOE CPV TE hybrid receivers were characterized prior to integration within the module, and connected into a string of three receivers. The acceptance angle of the POE SOE CPV TE hybrid module was experimentally characterized, and outdoor on tracker data was obtained at the University of Jaen. For the first time, the performance of CPV TE hybrid devices was evaluated within a 3 receiver string, and the efficiency of on sun TE cooling was investigated.A preliminary break even point was found at 0.3A, for active cooling verses non cooling for the CPV TE hybrid receivers. This highlights the future on sun performance increases possible with further optimised CPV TE module designs, including a low power regime for optimised TE operation.
author_names: Matthew Rolley

Tracy K N Sweet

Luka Eerens

Juan P Ferrer-Rodriguez

Eduardo F Fernandez
title: Experimental comparison of a III:V triple junction concentrator photovoltaic thermoelectric (CPV TE) hybrid module with commercial CPV and flat plate silicon modules
year: 2018

abstract: The current photovoltaic market is completely dominated by the conventional single junction PV panels, despite the fact that the highest energy efficiency of multi junction solar cells is in the form of concentrated photovoltaic (CPV) system. CPV technology has faced many challenges of reliability and performance since its conception. However, despite much improvement in design and reliability, CPV technology is still unable to gain the attention of customers and energy planners with its high performance potential. Due to its response to only solar beam radiations, CPV systems are believed to be only suitable to operate in clear sky weather conditions. That's why the current gigantic CPV systems are only designed to be installed in open desert regions. It is still lacking the same application scope which the conventional PV is experiencing. With the aim to boost its market potential, in this chapter, a compact CPV design is discussed with low cost but highly accurate performance, to be targeted to install at the rooftop of commercial and residential building in the urban region. In addition, the performance of CPV system is also evaluated and compared with the different conventional PV system in the tropical weather condition with low beam radiation availability.
author_names: Muhammad Burhan

Muhammad Wakil Shahzad

Kim Choon Ng
title: Concentrated Photovoltaic (CPV) From Deserts to Rooftops
year: 2019