Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation...Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation on PV panels has been ongoing since the 1940s, but proposed solutions have tended to increase the cost of PV systems either from oversizing or from cleaning the system. The objective of this work, therefore, is to design and implement a low-cost affordable automated PV panel dust cleaning system for use in rural communities of Sub-Saharan Africa (SSA);where financial resources are limited and significantly strained in meeting livelihood activities. Complete design and implementation details of a prototype system are provided for easy replication and capitalization on PV systems for sustainable energy needs. The system detects dust based on the innovative use of light-dependent resistors. Testing and observation of the system in operational mode reveal satisfactory performance;measured parameters quantify a power output increase of 33.76% as a result of cleaning dust off the PV panel used in the study.展开更多
This paper presents a real time hotspot detection system using scan-method about PV （photo voltaic） solar panel I-V characteristic based on the periodic inspection of the I-V curve of the PV panel in real time. The ...This paper presents a real time hotspot detection system using scan-method about PV （photo voltaic） solar panel I-V characteristic based on the periodic inspection of the I-V curve of the PV panel in real time. The I-V tracking is performed by the means of periodic current sweeps during the normal operation of the panel. The current variation in a specific voltage range allows to distinguish hotspot cells from normal cells. In case if partial shadowing occurs to the PV panel, the PCS （power conditioning system） gives an immediate judgment whether hot-spot arises from one of the cells or not by applying the scan-method. The PCS is programed to calculate the current rate depending on the difference in the current divided by the short circuit current. From the experimental results, it is clarified that the hot-spot cells can be determined regardless of the solar intensity radiation.展开更多
Photovoltaic(PV)panels are essential to the global transition towards sustainable energy,offering a clean,renewable source that reduces reliance on fossil fuels and mitigates climate change.High temperatures can signi...Photovoltaic(PV)panels are essential to the global transition towards sustainable energy,offering a clean,renewable source that reduces reliance on fossil fuels and mitigates climate change.High temperatures can significantly affect the performance of photovoltaic(PV)panels by reducing their efficiency and power output.This paper explores the consequential effect of various rooftop coverings on the thermal performance of photovoltaic(PV)panels.It investigates the relationship between the type of rooftop covering materials and the efficiency of PV panels,considering the thermal performance and its implications for enhancing their overall performance and sustainability.The study compares four rooftop covering materials:wooden flakes packs(both dry and wet),polystyrene,and woolen insulation.The measurements were implemented under Iraqi weather conditions.The comparison was based on the PV panels’thermal behavior and its impact on conversion efficiency.The results revealed that covering the roof beneath the installed PV panels reduces their temperature and increases efficiency.The best performance was observedwhen placingwetwooden flakes beneath the panels,with an efficiency increase of 5%.Moreover,thewoolen insulation offered an efficiency rise of 12%near sunset.Themain outcome of thiswork is that the wet–wooden–flakes showed the best performance improvement of the PV panels.展开更多
The demand for water pumping in urban water supply and irrigation in Bangladesh is significantly influenced by electricity deficits and high diesel costs. To address these challenges, the adoption of solar power for w...The demand for water pumping in urban water supply and irrigation in Bangladesh is significantly influenced by electricity deficits and high diesel costs. To address these challenges, the adoption of solar power for water pumping emerges as a viable alternative to traditional systems reliant on grid power and diesel. In recent years, there has been a growing emphasis on clean and renewable energies, aligning with the environmental and economic priorities of Bangladesh. The agricultural sector, serving as the backbone of the country’s economy, witnesses an escalating demand for water as the population increases. The extraction and transfer of water for agricultural and drinking purposes translate to high-energy consumption. Leveraging the abundant and essentially free solar energy, particularly during the crop growth periods when irrigation is crucial, presents an optimal solution. This study underscores the underutilization of this vital resource in Bangladesh and advocates for the widespread implementation of solar energy conversion programs, specifically in photovoltaic pumping systems. By comparing these systems with conventional diesel pumps, this paper aims to inspire policymakers, statesmen, and industry professionals to integrate green energy into the water sector. The envisioned outcome is a strategic shift towards sustainable development, with a focus on harnessing solar power to pump water for villages and agriculture, thus contributing to economic and environmental sustainability.展开更多
Dust and impurity accumulation has a significant effect on the efficiency and performance of PV panel output power. It influences the transmittance of solar radiation from the PV panels surface. Scheduling weekly or m...Dust and impurity accumulation has a significant effect on the efficiency and performance of PV panel output power. It influences the transmittance of solar radiation from the PV panels surface. Scheduling weekly or monthly cleaning periods requires complete knowledge of area’s weather and environmental condition. In this study, an experimental-based investigation is conducted aiming for a proper scheduling cleaning periods by comparing the output power efficiency of two identical PV panels, the first being cleaned daily and the other cleaned monthly. Both are exposed to unstable weather condition with Sarayat season in April and May, winter and summer Shamal of Kuwait for one year. The results indicated a significant degradation of PV panel output power in April, May, October and December. A need for frequent weekly water washing is a necessity to maintain the power efficiency loss of 15.07%, 13.74%, 10.685% and 8.742% respectively, and frequent monthly water washing for the remaining months of the year.展开更多
The rapid and sustained advancement of photovoltaic(PV)power generation technology has intro-duced significant challenges to the power grid operation,including reduced grid strength and poor damping,there-by causing o...The rapid and sustained advancement of photovoltaic(PV)power generation technology has intro-duced significant challenges to the power grid operation,including reduced grid strength and poor damping,there-by causing occurrence of harmonic resonance and potential instability.Conventional stability assessments of PV in-verters often overlook critical factors-such as DC-side voltage control and operating mode variations-which arise from the characteristics of the connected PV array.Consequently,these assessments yield inaccurate stability assessments,particularly under weak grid conditions.This study addresses this issue by integrating the characteristics of PV output and DC-side power control into small-signal models while accounting for different control modes,such as constant current(CC),constant voltage(CV),and maximum power point tracking(MPPT).Initially,the study integrates the inverter’s output control,LCL filter,and characteristics of the grid to develop a comprehensive framework for the entire PV system.Subsequently,the study uses amplitude and phase stability margins to evalu-ate how DC-side operating modes,the short-circuit ratio(SCR)of the power grid,and inverter controller parame-ters influence the system stability.Finally,the accuracy and stability of the model are validated through simulations and a 20-kW three-level prototype PV inverter.展开更多
Bifacial rooftop photovoltaic panels appear to be an excellent means of power generation in this era of urbanization,especially for land-limited countries like Bangladesh.This paper presents a software-based approach ...Bifacial rooftop photovoltaic panels appear to be an excellent means of power generation in this era of urbanization,especially for land-limited countries like Bangladesh.This paper presents a software-based approach to design and simulate a bifacial solar-panel-based energy model on the rooftop of the North Hall of Residence of the Islamic University of Technology,Gazipur.This vertically mounted model investigates the feasibility and applicability of such an energy model in a university residence,situated in a load-shedding-prone area.Hence,three prominent software platforms,namely PVSOL,PVsyst and System Advisor Model(SAM),are brought into action and rigorous simulations are performed for three different orientations;promising outcomes are observed in terms of annual energy yield,bifacial gain(BG)and consumption coverage of the grid and PV model.The annual energy demand of the North Hall is~444733.5 kWh.The three orientations can generate annually 92508.62,94643.48 and 86758.94 kWh,respectively.Hence,it is evident that the proposed orientations can supply almost 19-21%of the site’s annual demand.Monthly BG analysis shows an overall increase in energy gain of 13%,15.6%and 6%for Orientation-1,Orientation-2 and Orientation-3,respectively.A rigorous comparative analysis and deviation analysis among the software results has been accomplished to gain more insight into the feasibility of the proposed system.Thus,we have focused on a detailed software-based estimation of energy production for different orientations of the PV panels,considering several factors,which will provide prior knowledge and assessment before going for hardware implementation in the future.展开更多
Experiments of soiling effects on the performances of a PV panel have been performed using dust collected from two sites in the region of Agadir-Morocco.The optical transmittance of the front glass was found to depend...Experiments of soiling effects on the performances of a PV panel have been performed using dust collected from two sites in the region of Agadir-Morocco.The optical transmittance of the front glass was found to depend on the nature and density of dust.The nature of dust was studied by means of scanning electron microscopy and energy dispersive x-ray spectroscopy.It was found that the granulometry of dust particles depends on the study area.For a dust density of around 20 g/m^(2),the maximum power Pmax of the solar panel decreases drastically from 30 to 20 W for the(HP)site,and no more than 14 W for the(AD)site.The diversity of the behavior of the soiled panel was explained in terms of the size of the particles collected from each area.The transmission of light across the front glass of the PV panel is more affected when the sizes of particles are small.展开更多
In the United States, university buildings use 17% of total non-residential building energy per year. According to the NREL （National Renewable Energy Laboratory）, the average lifecycle of a building in a university...In the United States, university buildings use 17% of total non-residential building energy per year. According to the NREL （National Renewable Energy Laboratory）, the average lifecycle of a building in a university is 42 years with an EUI （energy use intensity） of 23 kWh/m^2/y. Current building and energy codes limit the EUI to 16 kWh/m^2/y for new school buildings; this benchmark can vary depending on climate, occupancy, and other contextual factors. Although the LEED （leadership in energy and environmental design） system provides a set of guidelines to rate sustainable buildings, studies have shown that 28%-35% of the educational LEED-rated buildings use more energy than their conventional counterparts. This paper examines the issues specific to a LEED-rated design addition to an existing university building. The forum, a lecture hall expansion of to an existing building at the University of Kansas, has been proposed as environmentally friendly and energy-efficient building addition. Comfort and health aspects have been considered in the design in order to obtain LEED platinum certificate. The forum＇s energy performance strategies include a double-skin facade to reduce energy consumption and PV （photovoltaic） panels to generate onsite energy. This study considers various scenarios to meet NZEB （net-zero energy building） criteria and maximize energy savings. The feasibility of NZE criteria is evaluated for： （a） seasonal comparison; （b） facility occupancy; （c） PV panels＇ addition in relation to double skin facade. The results of NZEB approach are compared to LEED platinum requirements, based on Rol （return on investment） and PV panel＇s efficiency for this specific educational building.展开更多
In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been...In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been shown. The evaluation of the efficiency of the proposed chains compared to the classical one was performed. It is shown that LVDC use instead of standard AC plugs, in numerous applications, is promising in future. The registered annual saved energy can exceed 25% of the PV generated energy. This important rate, the need of better services at lower economic cost and environmental burden will incite to make reflection about industry and supplies’ future standards.展开更多
文摘Dust accumulation on photovoltaic (PV) panels degrades PV panels’ performance;leading to decreased power output and consequently high cost per generated kilowatt. Research addressing the severity of dust accumulation on PV panels has been ongoing since the 1940s, but proposed solutions have tended to increase the cost of PV systems either from oversizing or from cleaning the system. The objective of this work, therefore, is to design and implement a low-cost affordable automated PV panel dust cleaning system for use in rural communities of Sub-Saharan Africa (SSA);where financial resources are limited and significantly strained in meeting livelihood activities. Complete design and implementation details of a prototype system are provided for easy replication and capitalization on PV systems for sustainable energy needs. The system detects dust based on the innovative use of light-dependent resistors. Testing and observation of the system in operational mode reveal satisfactory performance;measured parameters quantify a power output increase of 33.76% as a result of cleaning dust off the PV panel used in the study.
文摘This paper presents a real time hotspot detection system using scan-method about PV （photo voltaic） solar panel I-V characteristic based on the periodic inspection of the I-V curve of the PV panel in real time. The I-V tracking is performed by the means of periodic current sweeps during the normal operation of the panel. The current variation in a specific voltage range allows to distinguish hotspot cells from normal cells. In case if partial shadowing occurs to the PV panel, the PCS （power conditioning system） gives an immediate judgment whether hot-spot arises from one of the cells or not by applying the scan-method. The PCS is programed to calculate the current rate depending on the difference in the current divided by the short circuit current. From the experimental results, it is clarified that the hot-spot cells can be determined regardless of the solar intensity radiation.
文摘Photovoltaic(PV)panels are essential to the global transition towards sustainable energy,offering a clean,renewable source that reduces reliance on fossil fuels and mitigates climate change.High temperatures can significantly affect the performance of photovoltaic(PV)panels by reducing their efficiency and power output.This paper explores the consequential effect of various rooftop coverings on the thermal performance of photovoltaic(PV)panels.It investigates the relationship between the type of rooftop covering materials and the efficiency of PV panels,considering the thermal performance and its implications for enhancing their overall performance and sustainability.The study compares four rooftop covering materials:wooden flakes packs(both dry and wet),polystyrene,and woolen insulation.The measurements were implemented under Iraqi weather conditions.The comparison was based on the PV panels’thermal behavior and its impact on conversion efficiency.The results revealed that covering the roof beneath the installed PV panels reduces their temperature and increases efficiency.The best performance was observedwhen placingwetwooden flakes beneath the panels,with an efficiency increase of 5%.Moreover,thewoolen insulation offered an efficiency rise of 12%near sunset.Themain outcome of thiswork is that the wet–wooden–flakes showed the best performance improvement of the PV panels.
文摘The demand for water pumping in urban water supply and irrigation in Bangladesh is significantly influenced by electricity deficits and high diesel costs. To address these challenges, the adoption of solar power for water pumping emerges as a viable alternative to traditional systems reliant on grid power and diesel. In recent years, there has been a growing emphasis on clean and renewable energies, aligning with the environmental and economic priorities of Bangladesh. The agricultural sector, serving as the backbone of the country’s economy, witnesses an escalating demand for water as the population increases. The extraction and transfer of water for agricultural and drinking purposes translate to high-energy consumption. Leveraging the abundant and essentially free solar energy, particularly during the crop growth periods when irrigation is crucial, presents an optimal solution. This study underscores the underutilization of this vital resource in Bangladesh and advocates for the widespread implementation of solar energy conversion programs, specifically in photovoltaic pumping systems. By comparing these systems with conventional diesel pumps, this paper aims to inspire policymakers, statesmen, and industry professionals to integrate green energy into the water sector. The envisioned outcome is a strategic shift towards sustainable development, with a focus on harnessing solar power to pump water for villages and agriculture, thus contributing to economic and environmental sustainability.
文摘Dust and impurity accumulation has a significant effect on the efficiency and performance of PV panel output power. It influences the transmittance of solar radiation from the PV panels surface. Scheduling weekly or monthly cleaning periods requires complete knowledge of area’s weather and environmental condition. In this study, an experimental-based investigation is conducted aiming for a proper scheduling cleaning periods by comparing the output power efficiency of two identical PV panels, the first being cleaned daily and the other cleaned monthly. Both are exposed to unstable weather condition with Sarayat season in April and May, winter and summer Shamal of Kuwait for one year. The results indicated a significant degradation of PV panel output power in April, May, October and December. A need for frequent weekly water washing is a necessity to maintain the power efficiency loss of 15.07%, 13.74%, 10.685% and 8.742% respectively, and frequent monthly water washing for the remaining months of the year.
基金supported in part by the Youth Project of National Natural Science Foundation of China(No.51907046)the University Natural Sciences Research Project of Anhui Province Project(No.2022AH030154)the University Synergy Innova-tion Program of Anhui Province(No.GXXT-2022-021).
文摘The rapid and sustained advancement of photovoltaic(PV)power generation technology has intro-duced significant challenges to the power grid operation,including reduced grid strength and poor damping,there-by causing occurrence of harmonic resonance and potential instability.Conventional stability assessments of PV in-verters often overlook critical factors-such as DC-side voltage control and operating mode variations-which arise from the characteristics of the connected PV array.Consequently,these assessments yield inaccurate stability assessments,particularly under weak grid conditions.This study addresses this issue by integrating the characteristics of PV output and DC-side power control into small-signal models while accounting for different control modes,such as constant current(CC),constant voltage(CV),and maximum power point tracking(MPPT).Initially,the study integrates the inverter’s output control,LCL filter,and characteristics of the grid to develop a comprehensive framework for the entire PV system.Subsequently,the study uses amplitude and phase stability margins to evalu-ate how DC-side operating modes,the short-circuit ratio(SCR)of the power grid,and inverter controller parame-ters influence the system stability.Finally,the accuracy and stability of the model are validated through simulations and a 20-kW three-level prototype PV inverter.
文摘Bifacial rooftop photovoltaic panels appear to be an excellent means of power generation in this era of urbanization,especially for land-limited countries like Bangladesh.This paper presents a software-based approach to design and simulate a bifacial solar-panel-based energy model on the rooftop of the North Hall of Residence of the Islamic University of Technology,Gazipur.This vertically mounted model investigates the feasibility and applicability of such an energy model in a university residence,situated in a load-shedding-prone area.Hence,three prominent software platforms,namely PVSOL,PVsyst and System Advisor Model(SAM),are brought into action and rigorous simulations are performed for three different orientations;promising outcomes are observed in terms of annual energy yield,bifacial gain(BG)and consumption coverage of the grid and PV model.The annual energy demand of the North Hall is~444733.5 kWh.The three orientations can generate annually 92508.62,94643.48 and 86758.94 kWh,respectively.Hence,it is evident that the proposed orientations can supply almost 19-21%of the site’s annual demand.Monthly BG analysis shows an overall increase in energy gain of 13%,15.6%and 6%for Orientation-1,Orientation-2 and Orientation-3,respectively.A rigorous comparative analysis and deviation analysis among the software results has been accomplished to gain more insight into the feasibility of the proposed system.Thus,we have focused on a detailed software-based estimation of energy production for different orientations of the PV panels,considering several factors,which will provide prior knowledge and assessment before going for hardware implementation in the future.
文摘Experiments of soiling effects on the performances of a PV panel have been performed using dust collected from two sites in the region of Agadir-Morocco.The optical transmittance of the front glass was found to depend on the nature and density of dust.The nature of dust was studied by means of scanning electron microscopy and energy dispersive x-ray spectroscopy.It was found that the granulometry of dust particles depends on the study area.For a dust density of around 20 g/m^(2),the maximum power Pmax of the solar panel decreases drastically from 30 to 20 W for the(HP)site,and no more than 14 W for the(AD)site.The diversity of the behavior of the soiled panel was explained in terms of the size of the particles collected from each area.The transmission of light across the front glass of the PV panel is more affected when the sizes of particles are small.
文摘In the United States, university buildings use 17% of total non-residential building energy per year. According to the NREL （National Renewable Energy Laboratory）, the average lifecycle of a building in a university is 42 years with an EUI （energy use intensity） of 23 kWh/m^2/y. Current building and energy codes limit the EUI to 16 kWh/m^2/y for new school buildings; this benchmark can vary depending on climate, occupancy, and other contextual factors. Although the LEED （leadership in energy and environmental design） system provides a set of guidelines to rate sustainable buildings, studies have shown that 28%-35% of the educational LEED-rated buildings use more energy than their conventional counterparts. This paper examines the issues specific to a LEED-rated design addition to an existing university building. The forum, a lecture hall expansion of to an existing building at the University of Kansas, has been proposed as environmentally friendly and energy-efficient building addition. Comfort and health aspects have been considered in the design in order to obtain LEED platinum certificate. The forum＇s energy performance strategies include a double-skin facade to reduce energy consumption and PV （photovoltaic） panels to generate onsite energy. This study considers various scenarios to meet NZEB （net-zero energy building） criteria and maximize energy savings. The feasibility of NZE criteria is evaluated for： （a） seasonal comparison; （b） facility occupancy; （c） PV panels＇ addition in relation to double skin facade. The results of NZEB approach are compared to LEED platinum requirements, based on Rol （return on investment） and PV panel＇s efficiency for this specific educational building.
文摘In this paper some photovoltaic, PV, conversion chains architectures for on-grid applications have been proposed and the advantage of the direct use of a Low Voltage Direct Current (LVDC) bus for the DC loads has been shown. The evaluation of the efficiency of the proposed chains compared to the classical one was performed. It is shown that LVDC use instead of standard AC plugs, in numerous applications, is promising in future. The registered annual saved energy can exceed 25% of the PV generated energy. This important rate, the need of better services at lower economic cost and environmental burden will incite to make reflection about industry and supplies’ future standards.
