For achieving Energy-Efficiency in wireless sensor networks(WSNs),different schemes have been proposed which focuses only on reducing the energy consumption.A shortest path determines for the Base Station(BS),but faul...For achieving Energy-Efficiency in wireless sensor networks(WSNs),different schemes have been proposed which focuses only on reducing the energy consumption.A shortest path determines for the Base Station(BS),but fault tolerance and energy balancing gives equal importance for improving the network lifetime.For saving energy in WSNs,clustering is considered as one of the effective methods for Wireless Sensor Networks.Because of the excessive overload,more energy consumed by cluster heads(CHs)in a cluster based WSN to receive and aggregate the information from member sensor nodes and it leads to failure.For increasing the WSNs’lifetime,the CHs selection has played a key role in energy consumption for sensor nodes.An Energy Efficient Unequal Fault Tolerant Clustering Approach(EEUFTC)is proposed for reducing the energy utilization through the intelligent methods like Particle Swarm Optimization(PSO).In this approach,an optimal Master Cluster Head(MCH)-Master data Aggregator(MDA),selection method is proposed which uses the fitness values and they evaluate based on the PSO for two optimal nodes in each cluster to act as Master Data Aggregator(MDA),and Master Cluster Head.The data from the cluster members collected by the chosen MCH exclusively and the MDA is used for collected data reception from MCH transmits to the BS.Thus,the MCH overhead reduces.During the heavy communication of data,overhead controls using the scheduling of Energy-Efficient Time Division Multiple Access(EE-TDMA).To describe the proposed method superiority based on various performance metrics,simulation and results are compared to the existing methods.展开更多
This paper proposes the existence of a human right to access clean energy in view of trends favoring greater resortto renewable energy sources within several parallel policy contexts. The existing international framew...This paper proposes the existence of a human right to access clean energy in view of trends favoring greater resortto renewable energy sources within several parallel policy contexts. The existing international framework for theprotection and promotion of human rights may be applied to support an entitlement to access energy for individualbenefi t. However, the application of human rights norms to an appropriate energy source must also be compatiblewith the contemporary sustainable development agenda. This includes balancing economic development, sustainablyusing natural resources, environmental protection and poverty alleviation. A human rights approach must also besuffi ciently receptive to similarities and differences in the energy strategies of developed and developing States. It isargued that a human right to access clean energy more accurately refl ects intergovernmental concerns for both humandevelopment and environmental sustainability. While such a right can be employed to satisfy basic human needs, enhanceliving standards, maintain good human health and alleviate poverty, it can also contribute to the effi cient useof existing natural resources, the prevention of climate change and environmental protection.展开更多
While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drasti...While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)展开更多
This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to u...This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.展开更多
Energy access is vital to a nation’s economic growth and its populace’s social well-being. Still, there is a lack of adequate energy in Nigeria, negatively affecting the country’s socio-economic development. Due to...Energy access is vital to a nation’s economic growth and its populace’s social well-being. Still, there is a lack of adequate energy in Nigeria, negatively affecting the country’s socio-economic development. Due to the inadequate energy supply, some manufacturing companies shut their operations, and most Nigerians now use backup generators (BUGs) with their attendant health hazards, environmental pollution, and global warming. The need for energy access and a sustainable energy supply through renewable energy (RE) resources necessitates adopting solar photovoltaics (PV) in Nigeria. Studies on Nigeria’s energy accessibility and sustainability are generally on RE development and a few on solar PV applications. This research covers the need for an in-depth analysis of the growth of solar PV in Nigeria, and the research question is: What factors promote or limit the adoption of solar photovoltaics in Nigeria? A method of Systematic Literature Review (SLR) and Thematic Analysis (TA) is employed for the analysis. The research findings are divided into drivers, barriers, and policies. Some identified factors promoting the adoption of solar PV are energy poverty and the urgency to improve electricity supply, the ease of its operation and maintenance, and the Nigerian government’s commitment to clean electricity supply with policy initiatives and increased awareness of solar PV applications. Conversely, some noticed factors mitigating the growth of solar PV are poor tariff systems, dual subsidies of electricity and petroleum, and lack of finance and economic incentives.展开更多
Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute envir...Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks.Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable elec-tricity access to underserved rural communities while achieving waste management.Therefore,this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities.A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study.The findings show that the daily household energy consumption was 6.6 kWh,equivalent to 206.40 kWh/month.A 1.2-kWp and 1.2-m^(3)hybrid solar-biogas system was found to adequately power the house.Financially,the total initial investment cost of the system was$5777.20 with a net present value of$6566.78,net profit of$4443.6,a payback period of 14 years and 8 months,and a levelized cost of energy of$0.21/kWh;these include a 60%initial investment and maintenance costs subsidy.Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system.The study successfully revealed the design,specifications and upscaling mechanism of the proposed hybrid solar-biogas system.More research is required to unveil the efficacy of the system,the performance gap and the perception of the technology by the beneficiaries.展开更多
Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispe...Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispensable means, which could protect the system from major shocks of out-of-step oscillation. After years of development, it has achieved certain amount of research results. Have the existing methods been able to meet the requirements of out-of-step splitting? What improvements are needed? Under this background, this review is written. It combs the development of out-of-step splitting control technologies and analyzes the technical routes and characteristics of different methods. It points out the contradiction between rapidity and optimality is the biggest technical problem, existing in both the traditional local measurement based out-of-step splitting protection and the wide-area information based out-of-step splitting protection. It further points out that the advantages of the two types of protections can be combined with the unique physical characteristics of the out-of-step center to form a more advantageous splitting strategy. Besides, facing the fact of large-scale renewable energy access to power grid in recent years, this review also analyzes the challenges brought by it and provides some corresponding suggestions. It is hoped to provide some guidance for the subsequent research work.展开更多
Guided by President Xi Jinping's key speech about energy revolution— "Four Revolutions and One Cooperation"-the Chinese oil and gas industry continued to accelerate its pace of reform in 2016.China has ...Guided by President Xi Jinping's key speech about energy revolution— "Four Revolutions and One Cooperation"-the Chinese oil and gas industry continued to accelerate its pace of reform in 2016.China has deepened its supply-side structural reforms,prevented and resolved the problem of excess production capacity,increased the effective supply of clean energy such as natural gas,and formed an energy innovation system.It has pushed forward the reform of pricing mechanisms with significant adjustments in the pricing mechanisms of oil products,pipeline transportation,gas storage and gas used for fertilizer production.It has also accelerated market access reform and encouraged various investors to enter into the fields of exploration & production,pipeline transportation and crude oil imports.China has sped up the legislative process of environmental protection to promote green and low-carbon development.It has accelerated oil & gas industry institutional reform,with some provinces initiating the pilot reform of oil and gas.展开更多
基金The authors would like to thank for the support from Taif University Researchers Supporting Project number(TURSP-2020/239),Taif University,Taif,Saudi Arabia.
文摘For achieving Energy-Efficiency in wireless sensor networks(WSNs),different schemes have been proposed which focuses only on reducing the energy consumption.A shortest path determines for the Base Station(BS),but fault tolerance and energy balancing gives equal importance for improving the network lifetime.For saving energy in WSNs,clustering is considered as one of the effective methods for Wireless Sensor Networks.Because of the excessive overload,more energy consumed by cluster heads(CHs)in a cluster based WSN to receive and aggregate the information from member sensor nodes and it leads to failure.For increasing the WSNs’lifetime,the CHs selection has played a key role in energy consumption for sensor nodes.An Energy Efficient Unequal Fault Tolerant Clustering Approach(EEUFTC)is proposed for reducing the energy utilization through the intelligent methods like Particle Swarm Optimization(PSO).In this approach,an optimal Master Cluster Head(MCH)-Master data Aggregator(MDA),selection method is proposed which uses the fitness values and they evaluate based on the PSO for two optimal nodes in each cluster to act as Master Data Aggregator(MDA),and Master Cluster Head.The data from the cluster members collected by the chosen MCH exclusively and the MDA is used for collected data reception from MCH transmits to the BS.Thus,the MCH overhead reduces.During the heavy communication of data,overhead controls using the scheduling of Energy-Efficient Time Division Multiple Access(EE-TDMA).To describe the proposed method superiority based on various performance metrics,simulation and results are compared to the existing methods.
文摘This paper proposes the existence of a human right to access clean energy in view of trends favoring greater resortto renewable energy sources within several parallel policy contexts. The existing international framework for theprotection and promotion of human rights may be applied to support an entitlement to access energy for individualbenefi t. However, the application of human rights norms to an appropriate energy source must also be compatiblewith the contemporary sustainable development agenda. This includes balancing economic development, sustainablyusing natural resources, environmental protection and poverty alleviation. A human rights approach must also besuffi ciently receptive to similarities and differences in the energy strategies of developed and developing States. It isargued that a human right to access clean energy more accurately refl ects intergovernmental concerns for both humandevelopment and environmental sustainability. While such a right can be employed to satisfy basic human needs, enhanceliving standards, maintain good human health and alleviate poverty, it can also contribute to the effi cient useof existing natural resources, the prevention of climate change and environmental protection.
基金supported by the key project of the National Natural Science Foundation of China(No.61431001)the 863 project No.2014AA01A701+4 种基金Program for New Century Excellent Talents in University(NECT12-0774)the open research fund of National Mobile Communications Research Laboratory Southeast University(No.2013D12)Fundamental Research Funds for the Central Universities(FRF-BD-15-012A)the Research Foundation of China Mobilethe Foundation of Beijing Engineering and Technology Center for Convergence Networks and Ubiquitous Services
文摘While operators have started deploying fourth generation(4G) wireless communication systems,which could provide up to1 Gbps downlink peak data rate,the improved system capacity is still insufficient to meet the drastically increasing demand of mobile users over the next decade.The main causes of the above-mentioned phenomenon include the following two aspects:1) the growth rate of the network capacity is far below that of user's demand,and 2) the relatively deterministic wireless access network(WAN) architecture in the existing systems cannot accommodate the prominent increase of mobile traffic with space-time domain dynamics.In order to address the above-mentioned challenges,we investigate the time-spatial consistency architecture for the future WAN,whilst emphasizing the critical roles of some spectral-efficient techniques such as Massive multiple-input multiple-output(MIMO),full-duplex(FD)operation and heterogeneous networks(HetNets).Furthermore,the energy efficiency(EE)of the HetNets under the proposed architecture is also evaluated,showing that the proposed user-selected uplink power control algorithm outperforms the traditional stochastic-scheduling strategy in terms of both capacity and EE in a two-tier HetNet.The other critical issues,including the tidal effect,the temporal failure owing to the instantaneously increased traffic,and the network wide load-balancing problem,etc.,are also anticipated to be addressed in the proposed architecture.(Abstract)
基金This research is funded by the African Centre of Excellence,Energy for Sustainable Development,University of Rwanda,through the World Bank ACE II Program.
文摘This paper posits that a low-speed wind turbine design is suitable for harnessing wind energy in Africa.Conventional wind turbines consisting of propeller designs are commonly used across the world.A major hurdle to utilizing wind energy in Africa is that conventional commercial wind turbines are designed to operate at wind speeds greater than those prevalent in most of the continent,especially in sub-Sahara Africa(SSA).They are heavy and expensive to purchase,install,and maintain.As a result,only a few countries in Africa have been able to include wind energy in their energy mix.In this paper,the feasibility of a novel low-speed wind turbine based on a Ferris wheel is demonstrated for low wind speed applications in Africa.The performance of Ferris wheel wind turbines(FWT)with 61m(200 ft),73m(240 ft)and 104m(341 ft)diameter rims and an 800kW generator are evaluated for selected African cities.The research also compares the Weibull wind distribution of the African cities of interest.A comparison between the FWT and the conventional commercial wind turbines in terms of efficiency,rated wind speed,cost,performance,and power to weight is included.Results show that the FWT has the potential for economic power generation at rated wind speeds of 6.74m/s,which are lower than the average of 12 m/s for conventional wind turbines and have lower power to weight ratios of 5.2 kW/tonne as compared to 6.0-9.2 kW/tonne for conventional wind turbines.
文摘Energy access is vital to a nation’s economic growth and its populace’s social well-being. Still, there is a lack of adequate energy in Nigeria, negatively affecting the country’s socio-economic development. Due to the inadequate energy supply, some manufacturing companies shut their operations, and most Nigerians now use backup generators (BUGs) with their attendant health hazards, environmental pollution, and global warming. The need for energy access and a sustainable energy supply through renewable energy (RE) resources necessitates adopting solar photovoltaics (PV) in Nigeria. Studies on Nigeria’s energy accessibility and sustainability are generally on RE development and a few on solar PV applications. This research covers the need for an in-depth analysis of the growth of solar PV in Nigeria, and the research question is: What factors promote or limit the adoption of solar photovoltaics in Nigeria? A method of Systematic Literature Review (SLR) and Thematic Analysis (TA) is employed for the analysis. The research findings are divided into drivers, barriers, and policies. Some identified factors promoting the adoption of solar PV are energy poverty and the urgency to improve electricity supply, the ease of its operation and maintenance, and the Nigerian government’s commitment to clean electricity supply with policy initiatives and increased awareness of solar PV applications. Conversely, some noticed factors mitigating the growth of solar PV are poor tariff systems, dual subsidies of electricity and petroleum, and lack of finance and economic incentives.
文摘Solar home systems for rural electrification are often designed with a limited energy supply,which presents a drawback for the technology.Furthermore,uncontrolled livestock faeces in rural communities constitute environmental sanitation and health risks.Livestock excrement can be used through a biogas digester to supplement solar energy to provide adequate and sustainable elec-tricity access to underserved rural communities while achieving waste management.Therefore,this study presents a hybrid solar-biogas system for a more dynamic energy supply and waste management for post-Covid recovery plans in rural communities.A parametric research approach that involves the use of the Integrated Environment Solution Virtual Environment software application and mathematical models to design the desired household load and the hybrid system sizing is used in the study.The findings show that the daily household energy consumption was 6.6 kWh,equivalent to 206.40 kWh/month.A 1.2-kWp and 1.2-m^(3)hybrid solar-biogas system was found to adequately power the house.Financially,the total initial investment cost of the system was$5777.20 with a net present value of$6566.78,net profit of$4443.6,a payback period of 14 years and 8 months,and a levelized cost of energy of$0.21/kWh;these include a 60%initial investment and maintenance costs subsidy.Energy performance contracting and energy-as-a-service were recommended to effectively run and operate the system.The study successfully revealed the design,specifications and upscaling mechanism of the proposed hybrid solar-biogas system.More research is required to unveil the efficacy of the system,the performance gap and the perception of the technology by the beneficiaries.
基金supported by the National Natural Science Foundation of China(Grant No.62273207,61821004,62350083,62192755)the Future Young Scholars Program of Shandong University,China.
文摘Out-of-step oscillation is a very destructive physical phenomenon in power system, which could directly cause big blackout accompanied by serious sociology-economic impacts. Out-of-step splitting control is an indispensable means, which could protect the system from major shocks of out-of-step oscillation. After years of development, it has achieved certain amount of research results. Have the existing methods been able to meet the requirements of out-of-step splitting? What improvements are needed? Under this background, this review is written. It combs the development of out-of-step splitting control technologies and analyzes the technical routes and characteristics of different methods. It points out the contradiction between rapidity and optimality is the biggest technical problem, existing in both the traditional local measurement based out-of-step splitting protection and the wide-area information based out-of-step splitting protection. It further points out that the advantages of the two types of protections can be combined with the unique physical characteristics of the out-of-step center to form a more advantageous splitting strategy. Besides, facing the fact of large-scale renewable energy access to power grid in recent years, this review also analyzes the challenges brought by it and provides some corresponding suggestions. It is hoped to provide some guidance for the subsequent research work.
文摘Guided by President Xi Jinping's key speech about energy revolution— "Four Revolutions and One Cooperation"-the Chinese oil and gas industry continued to accelerate its pace of reform in 2016.China has deepened its supply-side structural reforms,prevented and resolved the problem of excess production capacity,increased the effective supply of clean energy such as natural gas,and formed an energy innovation system.It has pushed forward the reform of pricing mechanisms with significant adjustments in the pricing mechanisms of oil products,pipeline transportation,gas storage and gas used for fertilizer production.It has also accelerated market access reform and encouraged various investors to enter into the fields of exploration & production,pipeline transportation and crude oil imports.China has sped up the legislative process of environmental protection to promote green and low-carbon development.It has accelerated oil & gas industry institutional reform,with some provinces initiating the pilot reform of oil and gas.