Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV...Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV array’s power-voltage characteristics,thereby trapping conventional maximum power point tracking(MPPT)methods in local peaks.Swarm optimization approaches can be used to address this issue.However,these strategies have an unreasonably long convergence time.The Grey Wolf Optimizer(GWO)is a fast and more dependable optimization algorithm.This renders it a good option for MPPT of PV systems operating in varying partial shading.The conventional GWO method involves a long conversion time,large steady-state oscillations,and a high failure rate.This work attempts to address these issues by combining Cuckoo Search(CS)with the GWO algorithm to improve the MPPT performance.The results of this approach are compared with those of conventional MPPT according to GWO and MPPT methods based on perturb and observe(P&O).A comparative analysis reveals that under non-uniform operating conditions,the hybrid GWO CS(GWOCS)approach presented in this article outperforms the GWO and P&O approaches.展开更多
Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold a...Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold advantages:reduction in CO_(2)emission and production of artificial natural gas(methane)at the same time.In this paper,comparative energy,economic and environmental assessment of such photocatalytic methane production has been carried out between Japan and Malaysian conditions.Assumptions on the photocatalytic methane production plant and estimation of energy production,CO_(2)emission reduction,and economic indicators are made based on previous research and existing technologies.Energy analysis shows that Malaysia has a higher potential for energy production and CO_(2)emission reduction than Japan.Economic analysis reveals that the feasible reaction efficiencies of the plant in Japan and Malaysia are 8%.The slightly higher conversion efficiency in Malaysia is due to the energy price and CO_(2)tax.For the implementation of the photocatalytic methane production plant,the high energy price and CO_(2)tax will work as a driving force.展开更多
Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electri...Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electrical parameters at varying tilt angles in Malaysian conditions.There were two experimental modus:1)varying module tilt under constant irradiation level,2)varying irradiation intensity at the optimum tilt set up.For the former scheme,the irradiation level was maintained at 750 W/m^(2),and for the later arrangement,the module tilt angle was varied from 0 o to 80 o by means of a single-axis tracker.Results show that under constant irradiation of 750 W/m^(2),every 5 o increase in tilt angle causes a power drop of 2.09 W at indoor and 3.45 W at outdoor.In contrast,for the same condition,efficiency decreases by 0.54%for indoor case and by 0.76%at outdoor.On the other hand,for every 100 W/m^(2)increase in irradiation,solar cell temperature rises by 7.52℃at indoor and by 5.67℃at outdoor.As of module electrical parameters,open-circuit voltage,short-circuit current,maximum power point voltage and maximum power point current drops substantially with increasing tilt angle,whereas fill factor drops rather gradually.Outdoor experimental investigation confirms that the optimum tilt angle at Malaysian conditions is 15 o and orienting a PV module this angle will maximize the sun’s energy captured and thereby enhance its performance.展开更多
文摘Photovoltaic(PV)systems are adversely affected by partial shading and non-uniform conditions.Meanwhile,the addition of a bypass shunt diode to each PV module prevents hotspots.It also produces numerous peaks in the PV array’s power-voltage characteristics,thereby trapping conventional maximum power point tracking(MPPT)methods in local peaks.Swarm optimization approaches can be used to address this issue.However,these strategies have an unreasonably long convergence time.The Grey Wolf Optimizer(GWO)is a fast and more dependable optimization algorithm.This renders it a good option for MPPT of PV systems operating in varying partial shading.The conventional GWO method involves a long conversion time,large steady-state oscillations,and a high failure rate.This work attempts to address these issues by combining Cuckoo Search(CS)with the GWO algorithm to improve the MPPT performance.The results of this approach are compared with those of conventional MPPT according to GWO and MPPT methods based on perturb and observe(P&O).A comparative analysis reveals that under non-uniform operating conditions,the hybrid GWO CS(GWOCS)approach presented in this article outperforms the GWO and P&O approaches.
基金the support from the Kyoto University and University of Malaya double degree programme to carry out this research
文摘Photocatalytic methane(CH_(4))production wherein CO_(2)is reduced to CH_(4) by utilizing solar radiation energy is gaining research and industrial focus because of its environmental-friendly notion.It offers twofold advantages:reduction in CO_(2)emission and production of artificial natural gas(methane)at the same time.In this paper,comparative energy,economic and environmental assessment of such photocatalytic methane production has been carried out between Japan and Malaysian conditions.Assumptions on the photocatalytic methane production plant and estimation of energy production,CO_(2)emission reduction,and economic indicators are made based on previous research and existing technologies.Energy analysis shows that Malaysia has a higher potential for energy production and CO_(2)emission reduction than Japan.Economic analysis reveals that the feasible reaction efficiencies of the plant in Japan and Malaysia are 8%.The slightly higher conversion efficiency in Malaysia is due to the energy price and CO_(2)tax.For the implementation of the photocatalytic methane production plant,the high energy price and CO_(2)tax will work as a driving force.
基金The authors would like to acknowledge the financial support from University of Malaya,Impact Oriented Interdisciplinary Research Grant(Project:IIRG015B-2019)to carry out this research.
文摘Photovoltaic(PV)system’s performance is significantly affected by its orientation and tilt angle.Experimental investigation(indoor and outdoor)has been carried out to trace the variation in PV performance and electrical parameters at varying tilt angles in Malaysian conditions.There were two experimental modus:1)varying module tilt under constant irradiation level,2)varying irradiation intensity at the optimum tilt set up.For the former scheme,the irradiation level was maintained at 750 W/m^(2),and for the later arrangement,the module tilt angle was varied from 0 o to 80 o by means of a single-axis tracker.Results show that under constant irradiation of 750 W/m^(2),every 5 o increase in tilt angle causes a power drop of 2.09 W at indoor and 3.45 W at outdoor.In contrast,for the same condition,efficiency decreases by 0.54%for indoor case and by 0.76%at outdoor.On the other hand,for every 100 W/m^(2)increase in irradiation,solar cell temperature rises by 7.52℃at indoor and by 5.67℃at outdoor.As of module electrical parameters,open-circuit voltage,short-circuit current,maximum power point voltage and maximum power point current drops substantially with increasing tilt angle,whereas fill factor drops rather gradually.Outdoor experimental investigation confirms that the optimum tilt angle at Malaysian conditions is 15 o and orienting a PV module this angle will maximize the sun’s energy captured and thereby enhance its performance.
