Photovoltaic Collector Research Articles

Integration of Solar Chimney Power Plant with Photovoltaic for Co-Cooling, Power Production, and Water Desalination

This work explores the technical possibilities of increasing the efficiency of a standard solar chimney power plant (SCPP) by integrating it with photovoltaic (PV) panels. The integration is possible by using the collector circumference to install the PV collectors, which provide a heat sink, allow for the better harvesting of the solar radiation, and increase energy production. The new design led to an increase in the annual electricity production from 380 to 494 MWh and water production from 278 to 326 k tons/year compared with the standard SCPP, marking an increase of 30% and 17%, respectively. The results also show that the integration reduced the greenhouse gas emissions (GHG), the localized cost of energy, and the capital cost of investment by 30%, 36%, and 20%, respectively. The proposed design supports the sustainable replacement of the existing desalination plants with zero operational costs and an excellent reduction in greenhouse gas emissions.

Ground view factor computation model for bifacial photovoltaic collector field: uniform and non-uniform surfaces

The photovoltaic collectors in a field are subject to three types of solar radiation: direct, diffuse, and reflected irradiance. The reflected irradiance received by solar photovoltaic (PV) depends on the view factor from solar PV to the ground. This view factor component is dominant for bifacial PV due to additional reflected irradiance gain, which can be achieved from the module’s rear side.This paper proposes and verifies a finite element method based view factor computation model, which can handle both uniform and non-uniform ground surfaces. The unique contribution of this work is that it introduces a geometric progression based finite element mesh generation process that forms the quasi-uniform grid. The generated grid values are fitted into the computation model to calculate the view factor from bifacial photovoltaics to the ground, known as the ground view factor (GVF). The proposed computation model can achieve an accuracy of 99%. To keep accuracy at this level, the smallest element size of the coarse mesh should be within 0.1%–0.4% of surface width or length. Moreover, the geometric progression ratio of the fine and coarse mesh should be in the range of 1.001–1.002 and 1.01–1.04, respectively. The model is analysed under six different PV field variables: multiple reflective ground surfaces, the height of PV, tilted ground surface, PV position in the ground, length and width of the ground, and PV string length. For the different string sizes considered here, the view factor model’s computation time varies from 180 s to 257 min for the iteration size of 7.67 billion to 765 billion. The view factor computation model will contribute to analyse reflected irradiance at the rear side of bifacial PV, which is essential to predict the energy generation accurately. The proposed model is also beneficial for urban planning and addressing heat gain of the building-integrated PV system and energy usage.

System-Scale Modeling of a Building-Integrated, Transparent Concentrating Photovoltaic and Thermal Collector

The buildings sector is a principal contributor to global greenhouse gas emissions, but consistently falls short of targets for harnessing on-site energy resources towards sustainable operation. Emerging integrated solar technologies could transform buildings and urban settings into resilient, self-sufficient, and healthy environments. But if effects of these technologies are not understood in the multiple contexts in which they operate (human-scale, building-scale, district-scale), their potential is difficult to project. To explore building-scale metabolization of solar energy, a previously-developed analytical model of a Building Envelope-Integrated, Transparent, Concentrating Photovoltaic and Thermal collector (BITCoPT) was run to project electrical and thermal energy and exergy production (cogeneration) in a range of orientations and operating temperatures. Simulated annual cogeneration efficiency was noted at 27% (exergy) at an operating temperature of 55°C, and up to 55% (energy) at 25°C. Exergetic efficiency remained nearly constant as operating temperatures increased through 75°C, indicating the thermal energy collected would be some heat-engine-based applications. Although the scope of this study excludes broader architectural benefits of daylighting (lighting load reduction), and reduction of solar gains (cooling loads), these results suggest BITCoPT merits further investigation for on-site net-zero and energy-positive commercial building design, and might contribute to expanding net-zero and energy-positive architecture opportunities.

An innovative hybrid structure of solar PV-driven air separation unit, molten carbonate fuel cell, and absorption–compression refrigeration system (Process development and exergy analysis)

The regasification of liquefied natural gas provides considerable cold energy that would have practical potential in different industrial fields and makes a suitable option for integrating with cryogenic air separation systems that requires a significant amount of energy. In this research, two-column cryogenic air separation units are driven with solar photovoltaic panels to produce oxygen and nitrogen. The gaseous natural gas feeds a molten carbonate fuel cell (MCFC), producing electricity and heat. The heat is recovered by an absorption–compression refrigeration cycle (ACRC) to supply a high-intensity cooling load at −67 °C. The proposed scheme is designed to provide 1781 kmol/h oxygen, 8574 kmol/h nitrogen, 136 MW electrical power, and 13.09 MW cooling load. The thermal efficiency of the whole combined structure and the electrical efficiency of the fuel cell are 51.07% and 51.93%, respectively. The exergy analysis illustrates that the solar photovoltaic collectors and heat exchanges are the two most exergy destructive components compared to others. The exergy efficiency and irreversibility of the developed hybrid process are 52.77% and 160.5 MW, respectively. The effect of working temperatures has been studied on the performance of the molten carbonate fuel cell, including voltage, power density, and efficiency. The exergy and thermal efficiencies of the proposed system increase up to 56.18% and 55.05%, respectively with an increase of LNG molar flow rate from 892 to 992 kmol/h.

Performance analysis ofNidentical PVT-CPC collectors with an active single slope solar distiller and helically coiled heat exchanger using CuO nanoparticles

AbstractThis paper presents performance analyses based on temperatures, thermal energy (overall), thermal exergy (overall), electrical exergy, and yield of the systems that have been investigated. In the present study, an analytical expression of N identical partly covered photovoltaic compound parabolic concentrator collectors connected in series (N-PVT-CPC-SS-HE) with an active single slope solar distiller unit and helically coiled heat exchanger has been found. The performance analyses of the proposed system have been executed for 0.25% concentration of CuO nanoparticles for collectors (N = 4), and fluid-flow rate 0.02 kg/s in 280 kg mass of basin fluid. The system's performance is compared with a previous system of N identical partly covered photovoltaic flat plate collectors connected in series (N-PVT-FPC-DS-HE) with an active double slope solar distiller unit and helically coiled heat exchanger. The thermal energy is 112,109.1 kWh, thermal exergy 312.07 kWh, and yield 3,615.05 kg annually. It is found that daily enhancement in thermal energy of the proposed system with CuO nanoparticles compared with the previous system with various nanofluids CuO, Al2O3, TiO2, and water is found to be 16.75%, 51.13%, 61.82%, and 80.67% more significant correspondingly. The enhancement in yield of the proposed system is obtained for CuO nanoparticles greater than the previous system with CuO by 11.19%, Al2O3 17.2%, TiO2 26.25%, and water 32.17%. The electrical exergy is almost the same as the previous system.

Multi-objective optimization with thermodynamic analysis of an integrated energy system based on biomass and solar energies

The integrated energy system (IES) can effectively utilize the distributed renewable energies, but its performance improvement requires advanced design and optimization methods. This study proposes a new IES based on biomass gasification integrated with an internal combustion engine, photovoltaic and solar collectors, an absorption chiller/heater, a heat pump and a thermal storage unit to utilize renewable energies effectively. Based on the thermodynamic models of components considering off-design conditions, a multi-objective optimization model of biomass IES is established to improve the comprehensive performances of energy, economy, and environment. A decision method is proposed to select the optimal configuration considering the Euclidean distance between the Pareto solution and the ideal solution. The results demonstrate that in the specific case, the capacity of the internal combustion engine with biomass gasification is preferred to be low, and 71.4% of Pareto solutions is less than 200 kW during the set range from 20 to 1,000 kW. The larger capacity of solar photovoltaic panels achieves more benefits than solar heat collectors. Moreover, the optimal IES determined by the minimum Euclidean distance has primary energy utilization efficiency of 43.4% and exergy efficiency of 18.0%, which saves primary energy of 7.1%, the annual total cost of 7.2%, and reduces carbon dioxide emission by 41.5%.

Holographic Optical Elements: Advantages and Disadvantages for Efficient Lighting, Sun Protection, and Photovoltaic Power Supply of Buildings

The research of holographic optical elements (HOE) was carried out very intensively in the 1980s and 1990s. They provided great advantages in high-efficiency natural light, while at the same time providing effective sun protection and did not disturb the free view from the windows. The light-directing qualities of these devices made it possible to concentrate direct and scattered solar energy on photovoltaic batteries and solar collectors for hot water supply and solar heating. However, in recent years, research in this area has become less and less frequent without any explanation. The analysis of the research carried out in the framework of one of the latest projects carried out on behalf of the European Commission under the program “Energy, Environment, and Sustainable Development” (EU Contract Number: ENK6-CT‑2000–00327) with the participation of nine research organizations, higher schools, and universities is presented. The role of each of the participants in this interdisciplinary project was to attract experienced researchers in various fields of science and use their knowledge to obtain an objective result.

Energetic performance analysis on a membrane distillation integrated with low concentrating PV/T hybrid system

Membrane distillation seawater desalination technology has received widespread attention. However, this technology has problems such as high energy consumption and high initial temperature requirements. A membrane distillation seawater desalination system integrated with low-concentrating photovoltaic/thermal (LCPV/T-MD) modules was designed. With the help of concentrating photovoltaic panels and solar collectors, the working fluid required for membrane distillation is cascaded heating to obtain distilled fresh water. The integrated LCPV/T-MD mathematical model the hybrid experimental system were established, and the thermal, electrical performance, and water yield were analyzed. The results show that the greater ΔP, the lower of the salinity c, and the higher the inlet water temperature Tin, the greater the water yield. The LCPV/T-STC heating subsystem can heat the water temperature above 60 °C, and then auxiliary heating by heating rod can meet the requirements of MD system for inlet water temperature. In the experiment, the thermal efficiency and the electrical efficiency of the system can reach 56.2% and 15.9%, respectively. The GOR of the total LCPV/T-MD system can reach 0.69, and the MD subsystem water yield can reach 0.579 L/(h·m2). The findings can provide guidance for the further study of membrane distillation.

Developing a techno-economic model to evaluate the cost performance of a zeolite 13X-based space heating system

Residential space heating contributes to greenhouse gas emissions because of natural gas combustion. One way to lower these emissions is to replace the natural gas space heating system with a zeolite 13X-based system. However, the economic feasibility of such a system is critical. There is limited information on the application and economic feasibility of a zeolite 13X-based heating system. In this study, we developed a data-intensive, bottom-up model to evaluate the life cycle cost of a zeolite 13X-based space heating system. We considered a traditional 16 kW space heating capacity for the zeolite-13X adsorbent and photovoltaic solar collector. The life cycle cost of the zeolite 13X-based system is 6 cents/kWh, a value comparable to traditional space heating systems like an electric boiler and natural gas-fired boilers. The uncertainty analysis shows that the system cost ranges from 5.4 cents to 6.1 cents/kWh. The overall cost is sensitive to the length-to-diameter ratio of the adsorbent vessel, zeolite pellet diameter, and solar collector potential. Improving these parameters would reduce the cost of the studied system. The scale factor for the capital cost of the zeolite 13X system was developed and it was estimated to be 0.76, which indicates that as the capacity of the system increases, the capital cost per unit output goes down. Overall, adsorbent storage connected to solar collectors for a space heating system is an economically competitive alternative technology to decarbonize the residential sector in cold climate regions.

Assessment of Electrical and Thermal Performance of Photovoltaic Thermal Air Collector in the Climate of Pantnagar, Uttarakhand

The photovoltaic thermal collector (PVT) produces electricity and extracts heat from a common area exposed to solar radiation. The present work provides a methodology to assess the potential of PVT at any location. The climate of Pantnagar (a town situated in the Terai belt of Uttarakhand) is selected for the study. An unglazed PVT air heating collector is modelled, taking account of both electrical and thermal aspects of design. The performance of the collector is then simulated on four days, representing average weather of four seasons observed in North Indian Plains, in correspondence with the typical meteorological year (TMY) data of 2006-2015 for the location. The diode parameters and characteristic curves of PV module selected for PVT are obtained for reference and operating conditions. The operating temperature of solar cell and heated air are plotted after convergence of numerical solution at available data points. Finally, electrical and thermal power output of the PVT with associated optical and thermal losses are obtained. The highest electrical power output of 223 W (136 W/m2) is observed at 12:20 hours (IST) on equinox of September while highest thermal power output of 411 W (251 W/m2) is obtained at 12:20 hours (IST) on summer solstice.

PV/T solar collector performance evaluation: generation of fuzzy rules by using weighted subsethood-based algorithm

A photovoltaic/thermal solar collector operates efficiently if the surrounding conditions are in a favorable state; where the factors or parameters such as solar radiation, ambient temperature, photovoltaic collector temperature and air mass flow rates are taken into consideration to ensure the performance of the collector achieves optimum level. Dependency on surrounding conditions limited the width of analysis that could be done on the factors affecting the performance of the solar collector. This study aims to generate fuzzy rules for solar collector performance evaluation. Experiments on the performance of a single passage air photovoltaic/thermal solar collector have been carried out, and a set of membership functions representing all significant factors has been generated. Then fuzzy rules of forecasting were developed using a weighted subsethood-based algorithm to predict the efficiency of the photovoltaic/thermal solar collector. In this fuzzy time series application, the concept of fuzzy rule-based systems was embedded to generate fuzzy if-then rules. The results showed that the PV/T solar collector performance with changes in parameters could be predicted based on the fuzzy rules that have been generated, and thus further could be used to determine the optimum factors conditions required to achieve optimum collector performance without having to carry out experiments.

Modification of circumsolar radiation for anisotropic diffuse radiation models: Photovoltaic collectors on sloped planes

Photovoltaic fields are deployed in multiple collector rows on horizontal and on sloped planes, therefore the second (and subsequent rows) sees the sky dome with a smaller angle than the first (front) row

Experimental investigation of a building-integrated, transparent, concentrating photovoltaic and thermal collector

As buildings consume roughly one-third of global primary energy, more effective strategies are required to convert on-site solar energy. Here, a multifunctional building façade system, using less than 1% of the semiconductor materials of conventional systems, was tested and developed to expand opportunities for net-zero commercial architecture by synergistically reducing cooling loads, lighting loads, and contributions to urban heat island effects, while converting ambient solar energy resources for internal demands. The Building Integrated, Transparent, Concentrating, Photovoltaic and Thermal collector (BITCoPT) optically separates diffuse and direct irradiance, transmitting diffuse light for illumination and views. Here, direct irradiance (which is often rejected in commercial buildings to control glare and cooling loads) is intercepted by BITCoPT and converted into electricity and thermal energy. A prototype was tested, demonstrating 43.6% cogeneration efficiency (at a 58 °C operating temperature) relative to direct normal irradiance transmitted through the building's exterior glazing, and 39.0% at 70 °C (which could supply active thermal processes at nominal coefficients of performance). An analytical model was calibrated with observed data, showing good correlation. By substituting parameter values for projected upgrades (to optics, cell type and exterior glazing) into the BITCoPT model, simulated cogeneration efficiency increased to 71.2% at 70 °C (31.2% electrical, 40.0% thermal).

A novel energy management method based on Deep Q Network algorithm for low operating cost of an integrated hybrid system

For minimizing the operational cost of an integrated hybrid system, which provides electricity, heating, cooling and water of a residential complex, a new energy management method presented here. The proposed energy management method uses the principles of Reinforcement Learning (RL) based on Deep Q Network (DQN) algorithm to find the operational strategy for the hybrid system. Unlike the stochastic presentation of RL with Markov Decision Process (MDP) in literature, a deterministic approach proposed in this study for energy management of a hybrid system. This presented approach does not require online trial and error or historical data of system performance to determine the operational strategy. This developed RL-DQN method used for energy management of a hybrid system with photovoltaic collectors, ET collectors, wind turbines, CHP units, a water heater, a hot water storage tank and batteries. Thus for a residential complex with variable electrical and thermal loads during a year (8760 h), RL-DQN energy management method estimated two unknown variables in operational strategy, i.e., the partial load of the CHP unit and the amount of heat generation by LPG-fueled water heater. The results of RL-DQN energy management also compared with results of two rule-based methods. The results show a reduction of the operating cost to 10983 $/year by RL-DQN which is lower 6.5% and 30.4% than that for two above mentioned rule-based methods. Lower CO2 production (2.8% and 62.8%) also observed in comparison with that for two above mentioned rule based methods. With the proposed EM method, 80.1% of the required electricity supplied with renewable energies and 82.2% of the thermal load supplied without direct consumption of fossil fuels. The benefit of using predicted load and renewable energies of future hours also investigated for EM. Results show that employing the predicted information decrease the operational cost by about 3.5 percent

Study of the Dependence of Solar Radiation Regarding Design Variables in Photovoltaic Solar Installations with Optimal Dual-Axis Tracking

Solar tracking is an efficient strategy to increase the radiative capture of photovoltaic collectors. Within the multiple efforts made in recent decades to improve the production of these facilities, various works have studied solutions to optimize the number of rotation axes (single or dual rotation axes), the degree of collector coverage, the distances between trackers, the geometric arrangement of trackers or the minimization of shading between collectors. However, although in this type of installation it is common to find collectors with geometric shapes other than rectangles, no studies on the influence of the shape of the collectors on the radiative incidence are found in the literature. In this connection, the present work systematically addresses the study of incident solar radiation in photovoltaic installations with dual-axis trackers with collectors of different geometric shapes. By means of the exhaustive study, the conclusion is drawn that, for dual-axis photovoltaic installations with an optimal tracking strategy, the main variables that influence the annual radiative incidence are the spacing between collectors, the coverage ratio (GCR), and the collector surface, while the type of arrangement of collectors and the shape of these do not show predictive values.

Experimental evaluation of a hybrid photovoltaic and thermal solar energy collector with integrated phase change material (PVT-PCM) in comparison with a traditional photovoltaic (PV) module

A novel thermal energy storage and recovery system is proposed as a modification to existing photovoltaic modules with the objective to improve the solar energy collector overall efficiency. Integrating a phase change material in the hybrid module (PVT-PCM), a lower and stable operating temperature is achieved. The baseline for the experimental comparison is established by an experimental campaign that includes simultaneous operation of a hybrid PVT-PCM module and a traditional photovoltaic (PV) module. Both photovoltaic modules used are from the same manufacturer, model, and technical specifications. Before the modification to a hybrid PVT-PCM module, a difference in electrical performance between the photovoltaic modules is quantified to determine the factual effect of the modification. After the modification, the daily electrical efficiency of the hybrid PVT-PCM increased a 7.43% with respect to the traditional PV module. In addition, the daily hybrid efficiency of the PVT-PCM module reaches 31.35%, while the daily electrical efficiency of the PV module is 13.12%, which translates to a total increase of 20.45% in the capability to extract useful energy from the sun for the PVT-PCM module.

A METHOD TO PREDICT FOULING ON MULTI-STOREY BUILDING MOUNTED SOLAR PHOTOVOLTAIC PANELS: A COMPUTATIONAL FLUID DYNAMICS APPROACH

The influence of installation and environmental parameters on dust particle deposition behavior on solar photovoltaic collectors were investigated using Computational Fluid Dynamics (CFD) simulation. Parameters including tilt, height of installation, dust particle size and wind speed were investigated. Modeling of wind flow on the building and the photovoltaic array was achieved using the Shear Stress Transport k-ω turbulence model. The discrete phase model was adopted for dust motion prediction and a model was developed to assess the impact of dust accumulation on the performance of the photovoltaic array. The study revealed that rooftop installations have less dust deposition unlike the ground-mounted installations. The wind flow characteristics on rooftop installations are greatly affected by the building while on ground mounted installations wind flow is only influenced by the tilt of the solar photovoltaic collector. Different tilt angles, wind speeds and particle sizes had different deposition characteristics. The lower impact velocities experienced on ground mounted Photovoltaic (PV) arrays resulted in more deposition for smaller sized (10µm) dust particles compared to the larger sized (50µm and 150µm) particles. On rooftop installations, dust particle size of 150µm had the most deposition at a velocity of 5m/s and hence it resulted in a 22.61% reduction in solar photovoltaic efficiency while the least reduction in efficiency of 1.32% was recorded at 15m/s and 10µm size dust particles. The tilt angles of 0o and 22.5o had large sized turbulent eddies compared to the tilt of 45o. The study revealed that ground mounted photovoltaic arrays had more dust deposition compared to rooftop mounted photovoltaics.

Results of CFD-simulation of a solar photovoltaic-thermal module

Currently, in the energy supply of agroindustrial complex facilities there is an increasing interest in the development of structures and engineering systems using renewable energy sources, including combined photovoltaic-thermal modules (PVT-modules), combining photovoltaic modules (PV-modules) and solar collectors in one design. The use of PVT-modules technology makes it possible to increase the electrical performance of solar cells due to their cooling during operation, while the use of PVT-modules integrated into the roofs and facades of buildings can significantly reduce the need for centralized electricity and heat supply. The purpose of this work is to develop a CFD model of a solar PVT module for producing an estimate of the thermal performance of a PVT module. Using the ANSYS Fluent software package, a CFD model of the PVT module was developed. The contours of the temperature distribution, the coolant pressure in the PVT module channel at different values of the coolant flow at the entrance to the PVT module were obtained. The paper presents the daily variation of thermal power and total insolation calculated using the solar calculator built into ANSYS. The verification of the developed CFD-model of the PVT-module showed the comparability of the calculated values with the data obtained analytically and experimentally - the relative error of the results was no more than ± 1%. ANSYS is an effective software package that allows simulating thermal processes in PVT-modules.

Optical Design of a Novel Polygonal Trough Collector for Solar Concentrating Photovoltaic Applications

This paper presents a methodology for the optical design of a novel solar concentrating photovoltaic trough collector, consisting of several flat reflecting segments, joined together in an open polygonal shape. The concentrator reflects the incident solar radiation to a flat receiver, thus forming a photovoltaic module. The system of analytical design equations modeled in this work accounts for the number of segments and their tilt angles, focal length, optical concentration ratio, concentration fraction, height, width and the rim-angle of the collector. The effects of angular deviation between the incoming radiation and tilt angles of the segments, as well as the incidence angle at the receiver, are also accounted for in this work. In order to generalize the results, the parameters are normalized with respect to the receiver’s length. The model is validated by comparing a developed design with measurements taken in a 2D drafting program. The effects on various design parameters of changing the focal length are presented and discussed in detail. A visual and tabular tool comprising eight different designs is illustrated, which can be used to quickly select a design according to the desired application.

Study and Proposal for a Hyperfluorinated Brackish Water Treatment System in the Fatick Region, Case of Diouroup (Senegal)

Groundwater is the main resource for human consumption in many countries, especially in developing countries. This groundwater is often brackish and hyperfluorinated, which leads to diseases such as dental and bone fluorosis, etc. The water from the Diouroup water drainage facilities, like those from many other water drainage facilities in the regions of Fatick, Kaolack, Diourbel and the area of Touba, is facing this problem. To solve these problems, several physicochemical and membrane methods have been implemented. In this work we have briefly outlined some of these methods and we have chosen one of them, low pressure reverse osmosis. In addition, this technique is very simple to operate and maintain. Reverse osmosis provides good quality water in a single step, without the need for additional sterilization or remineralization treatments. We then carried out simulations with the Reverse Osmosis System Analysis (ROSA) software. For reasonable operating parameters, we have noticed a low feed pressure of 11.58 bars, a good average flow of raw water of 27.79 L/m2/h and a recovery rate of the first pass of 75.01%. The results obtained also showed a good quality of the permeate which respects the recommendations of the World Health Organization (WHO) on drinking water. The fluorides of 0.59 mg/L have a recovery rate of 90.8% while the chlorides of 59.09 mg/L have a recovery rate of 92.12% as for the Total Dissolved Solids of 184.90 mg/L for an abatement of 92%. Finally, the low energy consumption of the process makes it possible to consider it in coupling with an electric supply by photovoltaic solar collectors for isolated sites.