Enhanced Efficiency in a Coupled Photovoltaic/Thermal Concentrating Solar Collector

Author(s):  
Ihtesham Chowdhury ◽  
Todd Otanicar ◽  
Ravi Prasher ◽  
Jonathan Sherbeck ◽  
Patrick Phelan ◽  
...  

We present an analysis of combined efficiencies in a coupled photovoltaic/thermal concentrating solar collector. The calculations take into account the drop in efficiency that accompanies the operation of photovoltaic cells at elevated temperatures along with a detailed analysis of the thermal system including all losses. An iterative numerical scheme is described that involves a coupled electro-thermal simulation of the solar energy conversion process. In the proposed configuration losses in the photovoltaic cell due to reduced efficiencies at elevated temperatures and the incident solar energy below the PV bandgap are both harnessed as heat. This thermal energy is then used to run a thermodynamic power cycle. The simulations show that it is possible to optimize the overall efficiency of the system by variation of key factors such as the solar concentration factor, band gap of the photovoltaic material, and the system thermal design configuration.

2021 ◽  
Vol 11 (15) ◽  
pp. 6862
Author(s):  
Hongzhe Wen ◽  
Xuan Luo

Perovskites have recently attracted interest in the field of solar energy due to their excellent photovoltaic properties. We herein present a new approach to the composition of lead free perovskites via mixing of halide and oxide perovskites that share the cubic ABX3 structure. Using first-principles calculations through Density Functional Theory, we systematically investigated the atomic and electronic structures of mixed perovskite compounds composed of four cubic ABX3 perovskites. Our result shows that the B and X atoms play important roles in their band structure. On the other hand, their valence bands contributed by O-2p, Rh-4p, and Ti-3p orbitals, and their electronic properties were determined by Rh-O and Ti-O bonds. With new understandings of the electronic properties of cubic halide or oxide perovskites, we lastly combined the cubic perovskites in various configurations to improve stability and tune the bandgap to values desirable for photovoltaic cell applications. Our investigations suggest that the mixed perovskite compound Cs2Sn2Cl3I3Sr2TiRhO6 produced a bandgap of 1.2 eV, which falls into the ideal range of 1.0 to 1.7 eV, indicating high photo-conversion efficiency and showing promise towards solar energy applications.


2021 ◽  
Vol 11 (15) ◽  
pp. 6887
Author(s):  
Chung-Hong Lee ◽  
Hsin-Chang Yang ◽  
Guan-Bo Ye

In recent years, many countries have provided promotion policies related to renewable energy in order to take advantage of the environmental factors of sufficient sunlight. However, the application of solar energy in the power grid also has disadvantages. The most obvious is the variability of power output, which will put pressure on the system. As more grid reserves are needed to compensate for fluctuations in power output, the variable nature of solar power may hinder further deployment. Besides, one of the main issues surrounding solar energy is the variability and unpredictability of sunlight. If it is cloudy or covered by clouds during the day, the photovoltaic cell cannot produce satisfactory electricity. How to collect relevant factors (variables) and data to make predictions so that the solar system can increase the power generation of solar power plants is an important topic that every solar supplier is constantly thinking about. The view is taken, therefore, in this work, we utilized the historical monitoring data collected by the ground-connected solar power plants to predict the power generation, using daily characteristics (24 h) to replace the usual seasonal characteristics (365 days) as the experimental basis. Further, we implemented daily numerical prediction of the whole-point power generation. The preliminary experimental evaluations demonstrate that our developed method is sensible, allowing for exploring the performance of solar power prediction.


Author(s):  
Stephanie Drozek ◽  
Christopher Damm ◽  
Ryan Enot ◽  
Andrew Hjortland ◽  
Brandon Jackson ◽  
...  

The purpose of this paper is to describe the implementation of a laboratory-scale solar thermal system for the Renewable Energy Systems Laboratory at the Milwaukee School of Engineering (MSOE). The system development began as a student senior design project where students designed and fabricated a laboratory-scale solar thermal system to complement an existing commercial solar energy system on campus. The solar thermal system is designed specifically for educating engineers. This laboratory equipment, including a solar light simulator, allows for variation of operating parameters to investigate their impact on system performance. The equipment will be utilized in two courses: Applied Thermodynamics, and Renewable Energy Utilization. During the solar thermal laboratories performed in these courses, students conduct experiments based on the American Society of Heating, Refrigeration and Air-Conditioning Engineers (ASHRAE) 93-2010 standard for testing and performance characterization of solar thermal systems. Their measurements are then used to quantify energy output, efficiency and losses of the system and subsystem components.


Author(s):  
David M. Bierman ◽  
Andrej Lenert ◽  
Evelyn N. Wang

Solar thermophotovoltaic (STPV) devices provide conversion of solar energy to electrical energy through the use of an intermediate absorber/emitter module, which converts the broad solar spectrum to a tailored spectrum that is emitted towards a photovoltaic cell [1]. While the use of an absorber/emitter device could potentially overcome the Shockley-Queisser limit of photovoltaic conversion [2], it also increases the number of heat loss mechanisms. One of the most prohibitive aspects of STPV conversion is the thermal transfer efficiency, which is a measure of how well solar energy is delivered to the emitter. Although reported thermophotovoltaic efficiencies (thermal to electric) have exceeded 10% [3], [4], previously measured STPV conversion efficiencies are below 1% [5], [6], [7]. In this work, we present the design and characterization of a nanostructured absorber for use in a planar STPV device with a high emitter-to-absorber area ratio. We used a process for spatially-selective growth of vertically aligned multi-walled carbon nanotube (MWCNT) forests on highly reflective, smooth tungsten (W) surfaces. We implemented these MWCNT/W absorbers in a TPV system with a one-dimensional photonic crystal emitter, which was spectrally paired with a low bandgap PV cell. A high fidelity, system-level model of the radiative transfer in the device was experimentally validated and used to optimize the absorber surface geometry. For an operating temperature of approximately 1200 K, we experimentally demonstrated a 100% increase in overall STPV efficiency using a 4 to 1 emitter-to-absorber area ratio (relative to a 1 to 1 area ratio), due to improved thermal transfer efficiency. By further increasing the solar concentration incident on the absorber surface, increased emitter-to-absorber area ratios will improve both thermal transfer and overall efficiencies for these planar devices.


2014 ◽  
Vol 634 ◽  
pp. 72-82
Author(s):  
Rosa Ana Conte ◽  
Daltro Garcia Pinatti ◽  
Luiz Fernando M. Marton ◽  
Sebastião Ribeiro ◽  
Thaís Witt Acosta ◽  
...  

Production of active rice husk silica (ARHS) in bubbling fluidized bed boiler of a thermoelectric unit (TEU) and its addition to high performance concrete (HPC) with a compression resistance of 90 MPa was developed in the last 10 years. A first factory in Brazil was established at Alegrete town, RS, and other factories are under planning. Data of ARHS production, specification and HPC trace are presented. Design of parabolic solar collector coverage (PSCC) for air heating for biomass drying in a special silo of the TEU is presented as well. Cost of HPC/ARHS is 10 times less than steel (USD 200/ton vs. USD 2000/ton, specific mass 2.5 vs. 7.6 g/cm3, respectively). Those characteristics allow simultaneous solution of four ecological problems: large span coverage, rain water collection, daily solar energy collection and storage, and drying of biomass. The integration of those characteristics results in decrease of biomass consumption maintaining the same UTE efficiency. Tracking parabolic solar collector can be avoided between Cancer and Capricorn Tropics, and it is sufficient its eastern-western orientation with inclination to the Equator by the latitude angle. Coverage of the area occupied by TEU is sufficient to dry its biomass consumption. Preheating of boiler water with solar energy is possible decreasing biomass consumption in sunny days; biomass is partially consummed at night and cloudy days. Coupling the above technologies with high pressure steam TEU and fast-growing short-rotation forest gives to the biomass electrical energy generation a competitive economical position with hydraulic, coal, natural gas, and aeolic energy generation.


1981 ◽  
Vol 103 (2) ◽  
pp. 144-152
Author(s):  
T. F. Smith ◽  
S. Chaidar

The benefits of light weight, structural strength, and reduced costs without significant reduction of transmission of solar energy of a corrugated fiberglass composite cover promise wide utilization of this cover in solar collectors to suppress convective and radiative heat losses from the absorber panel. In order to evaluate the thermal performance of a collector with a corrugated cover, the directional transmittance of the cover must be available. A study was undertaken to develop a model for the directional transmittance of a corrugated cover as represented by a sinusoidal periodic function. As an application of this model, hourly and daily thermal efficiencies of a solar collector with a corrugated cover are presented.


Author(s):  
Satchidanand R. Satpute ◽  
Nilesh A. Mali ◽  
Sunil S. Bhagwat

2021 ◽  
Vol 7 (20) ◽  
pp. 202129
Author(s):  
Vivyane Alencar Marques Araújo do Nascimento ◽  
Taynara Bastos Trindade ◽  
Clarice Maia Carvalho

ANALYSIS OF PARAMETERS FOR PHOTOVOLTAIC SOLAR ENERGY GENERATION IN ACRE, BRAZILANÁLISIS DE PARÁMETROS PARA LA GENERACIÓN DE ENERGÍA SOLAR FOTOVOLTAICA EN ACRE, BRASILRESUMOEnergia solar é obtida através de placas solares fotovoltaicas com a função de captar a energia do sol e transformar em energia elétrica, aumentando a geração de energia solar nas regiões com maior captação de energia luminosa. Assim, neste artigo analisou-se os parâmetros para geração de energia solar fotovoltaica no Acre, Brasil. Coletou-se dados referentes a insolação, temperaturas máximas e mínimas, precipitação e umidade relativa no Instituto Nacional de Meteorologia, irradiação solar, no Centro de Referências para Energias Solar e Eólica Sérgio de S. Brito, regionais do Vale do Juruá e Vale do Acre, no período de 2015-2020. As análises foram quantitativas, utilizando o cálculo da média e cálculo do plano inclinado. Na comparação das regionais, o Vale do Acre apresentou melhores resultados para geração de energia solar e com um ângulo com a maior média diária anual de irradiação solar, considerando-se projetar-se células fotovoltaicas na regional. O trabalho apresenta que o Acre possui bastante insolação e irradiação solar, indicando alto potencial de geração de energia solar para as regionais do estado.Palavras-chave: Eficiência Fotovoltaica; Radiação Solar; Temperatura da Célula Fotovoltaica; Irradiação.ABSTRACTSolar energy is obtained through photovoltaic solar panels with the function of capturing the sun's energy and transforming it into electrical energy, increasing the generation of solar energy in regions with greater capture of light energy. Thus, the parameters for the generation of photovoltaic solar energy in Acre, Brazil were analyzed. Data on insolation, maximum and minimum temperatures, precipitation and relative humidity were collected at the National Institute of Meteorology, solar irradiation, at the Reference Center for Solar and Wind Energy Sérgio de S. Brito, regions of Vale do Juruá and Vale do Acre, in the period 2015-2020. Analyzes were quantitative, using mean calculation and inclined plane calculation. When comparing the regions, Vale do Acre presented better results for solar energy generation and with an angle with the highest annual daily average of solar irradiation, considering the project of photovoltaic cells in the region. The work shows that Acre has a lot of insolation and solar irradiation, indicating a high potential for generating solar energy for the regional regions of the state.Keywords: Photovoltaic Efficiency; Solar Radiation; Photovoltaic Cell Temperature; Irradiation.RESUMENLa energía solar se obtiene a través de paneles solares fotovoltaicos con la función de captar la energía del sol y transformarla en energía eléctrica, aumentando la generación de energía solar en las regiones con mayor captación de energía luminosa. Así, se analizaron los parámetros para la generación de energía solar fotovoltaica en Acre, Brasil. Los datos sobre insolación, temperaturas máximas y mínimas, precipitación y humedad relativa fueron recolectados en el Instituto Nacional de Meteorología, irradiación solar, en el Centro de Referencia de Energía Solar y Eólica Sérgio de S. Brito, regiones de Vale do Juruá y Vale do Acre, en el período 2015-2020. Los análisis fueron cuantitativos, utilizando cálculo de medias y cálculo de plano inclinado. Al comparar las regiones, Vale do Acre presentó mejores resultados para la generación de energía solar y con un ángulo con el promedio diario anual más alto de irradiación solar, considerando el diseño de células fotovoltaicas en la región. El trabajo muestra que Acre tiene mucha insolación e irradiación solar, lo que indica un alto potencial de generación de energía solar para las regiones regionales del estado.Palabras clave: Eficiencia Fotovoltaica; Radiación Solar; Temperatura de la Celda Fotovoltaica; Irradiación.


2020 ◽  
Vol 205 ◽  
pp. 07009
Author(s):  
Di Wu ◽  
Gangqiang Kong ◽  
Hanlong Liu ◽  
Xi Zhu ◽  
Hefu Pu

Solar energy can be stored in subsurface and extracted to melt snow and deice in winter. In summer, the bridge deck heat element in a bridge deicing system could serve as a solar energy collector without additional cost. Numerical models were developed in this study to investigate the performance of a bridge deck solar collector. The effects of radiation intensity and wind speed on the solar energy collection efficiency of a bridge deck solar energy collector were discussed and analyzed. The results show that the temperature of the slab was decreased during the solar collection process, and the solar energy collection efficiency of the bridge deck solar collector was about 26~47%. The collection efficiency of solar energy at a given wind speed was increased with the decreasing of the radiation energy, and this effect was more pronounced when the wind speed was higher. The solar energy collection was beneficial to the durability of the top asphalt layer as well as the structural response of the bridge because the magnitude and gradient of the slab temperature were much lower when the bridge deck served as a solar energy collector.


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