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
House-hold PV panels are widely used;however, their performance is significantly degraded under real operating conditions. Environmental factors such as ambient temperature, wind speed, and solar irradiance has a majo...House-hold PV panels are widely used;however, their performance is significantly degraded under real operating conditions. Environmental factors such as ambient temperature, wind speed, and solar irradiance has a major impact on the house-hold PV panel efficiency. In this paper an experimental study was conducted during the winter period in a single building in Minqin county, Gansu province, China. The experimental measurements were used to quantify the house-hold PV panel performance and operating characteristics. Based on the experimental results the house-hold PV panel performance is basically affected by the PV surface temperature, therefore, multilevel of energy is detected. Approximately 3% efficiency variation is detected due to the impact of the environmental factors.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
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 conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy avai...The conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy availability varies, this criterion may not be optimal. This study explores two alternative optimization criteria focused on maximizing baseload supply potential and minimizing required storage capacity to address seasonality in energy generation. The optimal tilt angles determined for these criteria differed significantly from the standard approach. This research highlights additional factors crucial for designing solar power systems beyond gross energy generation, essential for the global transition towards a fully renewable energy-based electric grid in the future.展开更多
间隙排列PV结构兼具遮阳、采光、发电等性能,宜用作建筑顶部采光设施.文中针对广州地区的气候条件,对4种不同参数的PV结构进行对比研究,综合考虑采光性能与发电能力,选出了PV面板安装的最优方案,即PV面板与水平面之间呈60°倾角,以...间隙排列PV结构兼具遮阳、采光、发电等性能,宜用作建筑顶部采光设施.文中针对广州地区的气候条件,对4种不同参数的PV结构进行对比研究,综合考虑采光性能与发电能力,选出了PV面板安装的最优方案,即PV面板与水平面之间呈60°倾角,以此在保证较高采光能力的同时提供良好的发电能力;通过在设计案例中的应用对间隙排列PV结构的采光及发电性能进行了分析,结果表明:该间隙型PV结构具有良好的遮阳效果,其下方10 m处地面的平均采光系数为4.9%,年度累计发电能力为61.8 k W·h/m2.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
Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar ra...Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar radiation, air pollution and cloud movements), load profile and the tilt and orientation angles. This paper describes an experimental analysis of maximizing output power of a photovoltaic panel, based on the use of existing equations of tilt angles derived from mathematical models and simulation packages. Power regulation is achieved by the use of a DC-DC converter, a fixed load resistance and a single photovoltaic panel. A data logger is used to make repeated measurements which ensure reliability of the results. The results of the paper were taken over a four month period from April through July. The photovoltaic panel was set to an orientation angle of 0? with tilt angles of 16?, 26? and 36?. Preliminary results indicate that tilt angles between 26? and 36? provide optimum photovoltaic output power for winter months in South Africa.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
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House-hold PV panels are widely used;however, their performance is significantly degraded under real operating conditions. Environmental factors such as ambient temperature, wind speed, and solar irradiance has a major impact on the house-hold PV panel efficiency. In this paper an experimental study was conducted during the winter period in a single building in Minqin county, Gansu province, China. The experimental measurements were used to quantify the house-hold PV panel performance and operating characteristics. Based on the experimental results the house-hold PV panel performance is basically affected by the PV surface temperature, therefore, multilevel of energy is detected. Approximately 3% efficiency variation is detected due to the impact of the environmental factors.
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 conventional approach to optimizing tilt angles for fixed solar panels aims to maximize energy generation over the entire year. However, in the context of a supply controlled electric grid, where solar energy availability varies, this criterion may not be optimal. This study explores two alternative optimization criteria focused on maximizing baseload supply potential and minimizing required storage capacity to address seasonality in energy generation. The optimal tilt angles determined for these criteria differed significantly from the standard approach. This research highlights additional factors crucial for designing solar power systems beyond gross energy generation, essential for the global transition towards a fully renewable energy-based electric grid in the future.
文摘间隙排列PV结构兼具遮阳、采光、发电等性能,宜用作建筑顶部采光设施.文中针对广州地区的气候条件,对4种不同参数的PV结构进行对比研究,综合考虑采光性能与发电能力,选出了PV面板安装的最优方案,即PV面板与水平面之间呈60°倾角,以此在保证较高采光能力的同时提供良好的发电能力;通过在设计案例中的应用对间隙排列PV结构的采光及发电性能进行了分析,结果表明:该间隙型PV结构具有良好的遮阳效果,其下方10 m处地面的平均采光系数为4.9%,年度累计发电能力为61.8 k W·h/m2.
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.
文摘Optimizing the output power of a photovoltaic panel improves the efficiency of a solar driven energy system. The maximum output power of a photovoltaic panel depends on atmospheric conditions, such as (direct solar radiation, air pollution and cloud movements), load profile and the tilt and orientation angles. This paper describes an experimental analysis of maximizing output power of a photovoltaic panel, based on the use of existing equations of tilt angles derived from mathematical models and simulation packages. Power regulation is achieved by the use of a DC-DC converter, a fixed load resistance and a single photovoltaic panel. A data logger is used to make repeated measurements which ensure reliability of the results. The results of the paper were taken over a four month period from April through July. The photovoltaic panel was set to an orientation angle of 0? with tilt angles of 16?, 26? and 36?. Preliminary results indicate that tilt angles between 26? and 36? provide optimum photovoltaic output power for winter months in South Africa.
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.
